Added InAppWebView keep alive feature, Added hasJavaScriptHandler, hasUserScript, hasWebMessageListener InAppWebViewController methods, HeadlessInAppWebView.webViewController could be null, Removed throwIfAlreadyOpened, throwIfNotOpened InAppBrowser methods, Removed throwIfAlreadyOpened, throwIfNotOpened ChromeSafariBrowser methods

CHANGELOG.md

@@ -1,5 +1,10 @@
 ## 6.0.0-beta.24
 
+- Added InAppWebView keep alive feature
+- Added `hasJavaScriptHandler`, `hasUserScript`, `hasWebMessageListener` InAppWebViewController methods
+- `HeadlessInAppWebView.webViewController` could be `null`
+- Removed `throwIfAlreadyOpened`, `throwIfNotOpened` InAppBrowser methods
+- Removed `throwIfAlreadyOpened`, `throwIfNotOpened` ChromeSafariBrowser methods
 - Merged "fix #1389 #1315 contextMenu ios 13" [#1575](https://github.com/pichillilorenzo/flutter_inappwebview/pull/1575) (thanks to [heralight](https://github.com/heralight))
 - Merged "fix: remove ignored flutter_export_environment.sh" [#1593](https://github.com/pichillilorenzo/flutter_inappwebview/pull/1593) (thanks to [Sunbreak](https://github.com/Sunbreak))
 - Merged "Fix AndroidX migration URL in README.md" [#1529](https://github.com/pichillilorenzo/flutter_inappwebview/pull/1529) (thanks to [cslee](https://github.com/cslee))

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/FlutterWebViewFactory.java

@@ -1,52 +0,0 @@
-package com.pichillilorenzo.flutter_inappwebview;
-
-import android.content.Context;
-
-import com.pichillilorenzo.flutter_inappwebview.headless_in_app_webview.HeadlessInAppWebView;
-import com.pichillilorenzo.flutter_inappwebview.headless_in_app_webview.HeadlessInAppWebViewManager;
-import com.pichillilorenzo.flutter_inappwebview.webview.in_app_webview.FlutterWebView;
-import com.pichillilorenzo.flutter_inappwebview.webview.PlatformWebView;
-import com.pichillilorenzo.flutter_inappwebview.types.WebViewImplementation;
-
-import java.util.HashMap;
-
-import io.flutter.plugin.common.StandardMessageCodec;
-import io.flutter.plugin.platform.PlatformView;
-import io.flutter.plugin.platform.PlatformViewFactory;
-
-public class FlutterWebViewFactory extends PlatformViewFactory {
-  public static final String VIEW_TYPE_ID = "com.pichillilorenzo/flutter_inappwebview";
-  private final InAppWebViewFlutterPlugin plugin;
-
-  public FlutterWebViewFactory(final InAppWebViewFlutterPlugin plugin) {
-    super(StandardMessageCodec.INSTANCE);
-    this.plugin = plugin;
-  }
-
-  @Override
-  public PlatformView create(Context context, int id, Object args) {
-    HashMap<String, Object> params = (HashMap<String, Object>) args;
-    PlatformWebView flutterWebView = null;
-
-    String headlessWebViewId = (String) params.get("headlessWebViewId");
-    if (headlessWebViewId != null) {
-      HeadlessInAppWebView headlessInAppWebView = HeadlessInAppWebViewManager.webViews.get(headlessWebViewId);
-      if (headlessInAppWebView != null) {
-        flutterWebView = headlessInAppWebView.disposeAndGetFlutterWebView();
-      }
-    }
-
-    if (flutterWebView == null) {
-      WebViewImplementation implementation = WebViewImplementation.fromValue((Integer) params.get("implementation"));
-      switch (implementation) {
-        case NATIVE:
-        default:
-          flutterWebView = new FlutterWebView(plugin, context, id, params);
-      }
-      flutterWebView.makeInitialLoad(params);
-    }
-    
-    return flutterWebView;
-  }
-}
-

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/InAppWebViewFlutterPlugin.java

@@ -17,6 +17,8 @@ import com.pichillilorenzo.flutter_inappwebview.print_job.PrintJobManager;
 import com.pichillilorenzo.flutter_inappwebview.proxy.ProxyManager;
 import com.pichillilorenzo.flutter_inappwebview.service_worker.ServiceWorkerManager;
 import com.pichillilorenzo.flutter_inappwebview.tracing.TracingControllerManager;
+import com.pichillilorenzo.flutter_inappwebview.webview.FlutterWebViewFactory;
+import com.pichillilorenzo.flutter_inappwebview.webview.InAppWebViewManager;
 
 import io.flutter.embedding.engine.plugins.activity.ActivityAware;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
@@ -39,7 +41,7 @@ public class InAppWebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
   @Nullable
   public ChromeSafariBrowserManager chromeSafariBrowserManager;
   @Nullable
-  public InAppWebViewStatic inAppWebViewStatic;
+  public InAppWebViewManager inAppWebViewManager;
   @Nullable
   public MyCookieManager myCookieManager;
   @Nullable
@@ -56,11 +58,6 @@ public class InAppWebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
   public PrintJobManager printJobManager;
   @Nullable
   public TracingControllerManager tracingControllerManager;
-  @Nullable
-  public static ValueCallback<Uri> filePathCallbackLegacy;
-  @Nullable
-  public static ValueCallback<Uri[]> filePathCallback;
-
   public FlutterWebViewFactory flutterWebViewFactory;
   public Context applicationContext;
   public PluginRegistry.Registrar registrar;
@@ -110,7 +107,7 @@ public class InAppWebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
             FlutterWebViewFactory.VIEW_TYPE_ID, flutterWebViewFactory);
 
     platformUtil = new PlatformUtil(this);
-    inAppWebViewStatic = new InAppWebViewStatic(this);
+    inAppWebViewManager = new InAppWebViewManager(this);
     myCookieManager = new MyCookieManager(this);
     myWebStorage = new MyWebStorage(this);
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
@@ -122,7 +119,7 @@ public class InAppWebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
     webViewFeatureManager = new WebViewFeatureManager(this);
     proxyManager = new ProxyManager(this);
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
-      printJobManager = new PrintJobManager();
+      printJobManager = new PrintJobManager(this);
     }
     tracingControllerManager = new TracingControllerManager(this);
   }
@@ -157,9 +154,9 @@ public class InAppWebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
       credentialDatabaseHandler.dispose();
       credentialDatabaseHandler = null;
     }
-    if (inAppWebViewStatic != null) {
+    if (inAppWebViewManager != null) {
-      inAppWebViewStatic.dispose();
+      inAppWebViewManager.dispose();
-      inAppWebViewStatic = null;
+      inAppWebViewManager = null;
     }
     if (serviceWorkerManager != null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
       serviceWorkerManager.dispose();
@@ -181,8 +178,6 @@ public class InAppWebViewFlutterPlugin implements FlutterPlugin, ActivityAware {
       tracingControllerManager.dispose();
       tracingControllerManager = null;
     }
-    filePathCallbackLegacy = null;
-    filePathCallback = null;
   }
 
   @Override

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/MyCookieManager.java

@@ -393,6 +393,5 @@ public class MyCookieManager extends ChannelDelegateImpl {
   public void dispose() {
     super.dispose();
     plugin = null;
-    cookieManager = null;
   }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/MyWebStorage.java

@@ -134,6 +134,5 @@ public class MyWebStorage extends ChannelDelegateImpl {
   public void dispose() {
     super.dispose();
     plugin = null;
-    webStorageManager = null;
   }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/chrome_custom_tabs/ActionBroadcastReceiver.java

@@ -12,6 +12,7 @@ public class ActionBroadcastReceiver extends BroadcastReceiver {
   protected static final String LOG_TAG = "ActionBroadcastReceiver";
   public static final String KEY_ACTION_ID = "com.pichillilorenzo.flutter_inappwebview.ChromeCustomTabs.ACTION_ID";
   public static final String KEY_ACTION_VIEW_ID = "com.pichillilorenzo.flutter_inappwebview.ChromeCustomTabs.ACTION_VIEW_ID";
+  public static final String KEY_ACTION_MANAGER_ID = "com.pichillilorenzo.flutter_inappwebview.ChromeCustomTabs.ACTION_MANAGER_ID";
   public static final String KEY_URL_TITLE = "android.intent.extra.SUBJECT";
 
   @Override
@@ -21,21 +22,27 @@ public class ActionBroadcastReceiver extends BroadcastReceiver {
     if (url != null) {
       Bundle b = intent.getExtras();
       String viewId = b.getString(KEY_ACTION_VIEW_ID);
+      String managerId = b.getString(KEY_ACTION_MANAGER_ID);
 
+      if (managerId != null) {
+        ChromeSafariBrowserManager chromeSafariBrowserManager = ChromeSafariBrowserManager.shared.get(managerId);
+        if (chromeSafariBrowserManager != null) {
           if (clickedId == -1) {
             int id = b.getInt(KEY_ACTION_ID);
             String title = b.getString(KEY_URL_TITLE);
 
-        ChromeCustomTabsActivity browser = ChromeSafariBrowserManager.browsers.get(viewId);
+            ChromeCustomTabsActivity browser = chromeSafariBrowserManager.browsers.get(viewId);
             if (browser != null && browser.channelDelegate != null) {
               browser.channelDelegate.onItemActionPerform(id, url, title);
             }
           } else {
-        ChromeCustomTabsActivity browser = ChromeSafariBrowserManager.browsers.get(viewId);
+            ChromeCustomTabsActivity browser = chromeSafariBrowserManager.browsers.get(viewId);
             if (browser != null && browser.channelDelegate != null) {
               browser.channelDelegate.onSecondaryItemActionPerform(browser.getResources().getResourceName(clickedId), url);
             }
           }
         }
       }
+    }
+  }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/chrome_custom_tabs/ChromeCustomTabsActivity.java

@@ -82,7 +82,7 @@ public class ChromeCustomTabsActivity extends Activity implements Disposable {
     manager = ChromeSafariBrowserManager.shared.get(managerId);
     if (manager == null || manager.plugin == null || manager.plugin.messenger == null) return;
 
-    ChromeSafariBrowserManager.browsers.put(id, this);
+    manager.browsers.put(id, this);
 
     MethodChannel channel = new MethodChannel(manager.plugin.messenger, METHOD_CHANNEL_NAME_PREFIX + id);
     channelDelegate = new ChromeCustomTabsChannelDelegate(this, channel);
@@ -271,6 +271,7 @@ public class ChromeCustomTabsActivity extends Activity implements Disposable {
 
     Bundle extras = new Bundle();
     extras.putString(ActionBroadcastReceiver.KEY_ACTION_VIEW_ID, id);
+    extras.putString(ActionBroadcastReceiver.KEY_ACTION_MANAGER_ID, manager != null ? manager.id : null);
     broadcastIntent.putExtras(extras);
 
     if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
@@ -355,6 +356,7 @@ public class ChromeCustomTabsActivity extends Activity implements Disposable {
     Bundle extras = new Bundle();
     extras.putInt(ActionBroadcastReceiver.KEY_ACTION_ID, actionSourceId);
     extras.putString(ActionBroadcastReceiver.KEY_ACTION_VIEW_ID, id);
+    extras.putString(ActionBroadcastReceiver.KEY_ACTION_MANAGER_ID, manager != null ? manager.id : null);
     actionIntent.putExtras(extras);
 
     if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
@@ -374,8 +376,10 @@ public class ChromeCustomTabsActivity extends Activity implements Disposable {
       channelDelegate.dispose();
       channelDelegate = null;
     }
-    if (ChromeSafariBrowserManager.browsers.containsKey(id)) {
+    if (manager != null) {
-      ChromeSafariBrowserManager.browsers.put(id, null);
+      if (manager.browsers.containsKey(id)) {
+        manager.browsers.put(id, null);
+      }
     }
     manager = null;
   }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/chrome_custom_tabs/ChromeSafariBrowserManager.java

@@ -31,7 +31,7 @@ public class ChromeSafariBrowserManager extends ChannelDelegateImpl {
   public InAppWebViewFlutterPlugin plugin;
   public String id;
   public static final Map<String, ChromeSafariBrowserManager> shared = new HashMap<>();
-  public static final Map<String, ChromeCustomTabsActivity> browsers = new HashMap<>();
+  public final Map<String, ChromeCustomTabsActivity> browsers = new HashMap<>();
 
   public ChromeSafariBrowserManager(final InAppWebViewFlutterPlugin plugin) {
     super(new MethodChannel(plugin.messenger, METHOD_CHANNEL_NAME));

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/headless_in_app_webview/HeadlessInAppWebView.java

@@ -1,5 +1,6 @@
 package com.pichillilorenzo.flutter_inappwebview.headless_in_app_webview;
 
+import android.app.Activity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
@@ -130,10 +131,13 @@ public class HeadlessInAppWebView implements Disposable {
       channelDelegate.dispose();
       channelDelegate = null;
     }
-    if (HeadlessInAppWebViewManager.webViews.containsKey(id)) {
+    if (plugin != null) {
-      HeadlessInAppWebViewManager.webViews.put(id, null);
+      HeadlessInAppWebViewManager headlessInAppWebViewManager = plugin.headlessInAppWebViewManager;
+      if (headlessInAppWebViewManager != null && headlessInAppWebViewManager.webViews.containsKey(id)) {
+        headlessInAppWebViewManager.webViews.put(id, null);
       }
-    if (plugin != null && plugin.activity != null) {
+      Activity activity =  plugin.activity;
+      if (activity != null) {
         ViewGroup contentView = plugin.activity.findViewById(android.R.id.content);
         if (contentView != null) {
           ViewGroup mainView = (ViewGroup) (contentView).getChildAt(0);
@@ -145,6 +149,7 @@ public class HeadlessInAppWebView implements Disposable {
           }
         }
       }
+    }
     if (flutterWebView != null) {
       flutterWebView.dispose();
     }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/headless_in_app_webview/HeadlessInAppWebViewManager.java

@@ -42,7 +42,7 @@ public class HeadlessInAppWebViewManager extends ChannelDelegateImpl {
   protected static final String LOG_TAG = "HeadlessInAppWebViewManager";
   public static final String METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_headless_inappwebview";
   
-  public static final Map<String, HeadlessInAppWebView> webViews = new HashMap<>();
+  public final Map<String, HeadlessInAppWebView> webViews = new HashMap<>();
   @Nullable
   public InAppWebViewFlutterPlugin plugin;
 
@@ -76,7 +76,7 @@ public class HeadlessInAppWebViewManager extends ChannelDelegateImpl {
     }
     FlutterWebView flutterWebView = new FlutterWebView(plugin, context, id, params);
     HeadlessInAppWebView headlessInAppWebView = new HeadlessInAppWebView(plugin, id, flutterWebView);
-    HeadlessInAppWebViewManager.webViews.put(id, headlessInAppWebView);
+    webViews.put(id, headlessInAppWebView);
     
     headlessInAppWebView.prepare(params);
     headlessInAppWebView.onWebViewCreated();
@@ -93,5 +93,6 @@ public class HeadlessInAppWebViewManager extends ChannelDelegateImpl {
       }
     }
     webViews.clear();
+    plugin = null;
   }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/in_app_browser/InAppBrowserActivity.java

@@ -141,11 +141,13 @@ public class InAppBrowserActivity extends AppCompatActivity implements InAppBrow
     prepareView();
 
     if (windowId != -1) {
-      Message resultMsg = InAppWebViewChromeClient.windowWebViewMessages.get(windowId);
+      if (webView.plugin != null && webView.plugin.inAppWebViewManager != null) {
+        Message resultMsg = webView.plugin.inAppWebViewManager.windowWebViewMessages.get(windowId);
         if (resultMsg != null) {
           ((WebView.WebViewTransport) resultMsg.obj).setWebView(webView);
           resultMsg.sendToTarget();
         }
+      }
     } else {
       String initialFile = b.getString("initialFile");
       Map<String, Object> initialUrlRequest = (Map<String, Object>) b.getSerializable("initialUrlRequest");

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/print_job/PrintJobController.java

@@ -21,6 +21,8 @@ public class PrintJobController implements Disposable  {
   @NonNull
   public String id;
   @Nullable
+  public InAppWebViewFlutterPlugin plugin;
+  @Nullable
   public PrintJobChannelDelegate channelDelegate;
   @Nullable
   public android.print.PrintJob job;
@@ -30,6 +32,7 @@ public class PrintJobController implements Disposable  {
   public PrintJobController(@NonNull String id, @NonNull android.print.PrintJob job,
                             @Nullable PrintJobSettings settings, @NonNull InAppWebViewFlutterPlugin plugin) {
     this.id = id;
+    this.plugin = plugin;
     this.job = job;
     this.settings = settings;
     final MethodChannel channel = new MethodChannel(plugin.messenger, METHOD_CHANNEL_NAME_PREFIX + id);
@@ -61,12 +64,16 @@ public class PrintJobController implements Disposable  {
       channelDelegate.dispose();
       channelDelegate  = null;
     }
-    if (PrintJobManager.jobs.containsKey(id)) {
+    if (plugin != null) {
-      PrintJobManager.jobs.put(id, null);
+      PrintJobManager printJobManager = plugin.printJobManager;
+      if (printJobManager != null && printJobManager.jobs.containsKey(id)) {
+        printJobManager.jobs.put(id, null);
+      }
     }
     if (job != null) {
       job = null;
     }
+    plugin = null;
   }
   
   @Override
@@ -75,12 +82,16 @@ public class PrintJobController implements Disposable  {
       channelDelegate.dispose();
       channelDelegate  = null;
     }
-    if (PrintJobManager.jobs.containsKey(id)) {
+    if (plugin != null) {
-      PrintJobManager.jobs.put(id, null);
+      PrintJobManager printJobManager = plugin.printJobManager;
+      if (printJobManager != null && printJobManager.jobs.containsKey(id)) {
+        printJobManager.jobs.put(id, null);
+      }
     }
     if (job != null) {
       job.cancel();
       job = null;
     }
+    plugin = null;
   }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/print_job/PrintJobManager.java

@@ -23,8 +23,11 @@ package com.pichillilorenzo.flutter_inappwebview.print_job;
 
 import android.os.Build;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 
+import com.pichillilorenzo.flutter_inappwebview.InAppWebViewFlutterPlugin;
 import com.pichillilorenzo.flutter_inappwebview.types.Disposable;
 
 import java.util.Collection;
@@ -34,11 +37,13 @@ import java.util.Map;
 @RequiresApi(api = Build.VERSION_CODES.KITKAT)
 public class PrintJobManager implements Disposable {
   protected static final String LOG_TAG = "PrintJobManager";
+  @Nullable
+  public InAppWebViewFlutterPlugin plugin;
+  public final Map<String, PrintJobController> jobs = new HashMap<>();
 
-  public static final Map<String, PrintJobController> jobs = new HashMap<>();
+  public PrintJobManager(@NonNull final InAppWebViewFlutterPlugin plugin) {
-
-  public PrintJobManager() {
     super();
+    this.plugin = plugin;
   }
 
   public void dispose() {
@@ -49,5 +54,6 @@ public class PrintJobManager implements Disposable {
       }
     }
     jobs.clear();
+    plugin = null;
   }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/proxy/ProxyManager.java

@@ -124,21 +124,6 @@ public class ProxyManager extends ChannelDelegateImpl {
   @Override
   public void dispose() {
     super.dispose();
-    if (proxyController != null) {
-      // Clears the proxy settings
-      proxyController.clearProxyOverride(new Executor() {
-        @Override
-        public void execute(Runnable command) {
-
-        }
-      }, new Runnable() {
-        @Override
-        public void run() {
-
-        }
-      });
-      proxyController = null;
-    }
     plugin = null;
   }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/service_worker/ServiceWorkerManager.java

@@ -99,10 +99,6 @@ public class ServiceWorkerManager implements Disposable {
       channelDelegate.dispose();
       channelDelegate = null;
     }
-    if (serviceWorkerController != null) {
-      serviceWorkerController.setServiceWorkerClient(dummyServiceWorkerClientCompat());
-      serviceWorkerController = null; 
-    }
     plugin = null;
   }
 

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/tracing/TracingControllerManager.java

@@ -57,7 +57,6 @@ public class TracingControllerManager implements Disposable {
       channelDelegate.dispose();
       channelDelegate = null;
     }
-    tracingController = null;
     plugin = null;
   }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/types/WebViewImplementation.java

@@ -1,32 +0,0 @@
-package com.pichillilorenzo.flutter_inappwebview.types;
-
-public enum WebViewImplementation {
-  NATIVE(0);
-
-  private final int value;
-
-  private WebViewImplementation(int value) {
-    this.value = value;
-  }
-
-  public boolean equalsValue(int otherValue) {
-    return value == otherValue;
-  }
-
-  public static WebViewImplementation fromValue(int value) {
-    for( WebViewImplementation type : WebViewImplementation.values()) {
-      if(value == type.value)
-        return type;
-    }
-    throw new IllegalArgumentException("No enum constant: " + value);
-  }
-
-  public int rawValue() {
-    return this.value;
-  }
-
-  @Override
-  public String toString() {
-    return String.valueOf(this.value);
-  }
-}

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/webview/FlutterWebViewFactory.java

@@ -0,0 +1,81 @@
+package com.pichillilorenzo.flutter_inappwebview.webview;
+
+import android.content.Context;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.pichillilorenzo.flutter_inappwebview.InAppWebViewFlutterPlugin;
+import com.pichillilorenzo.flutter_inappwebview.headless_in_app_webview.HeadlessInAppWebView;
+import com.pichillilorenzo.flutter_inappwebview.headless_in_app_webview.HeadlessInAppWebViewManager;
+import com.pichillilorenzo.flutter_inappwebview.webview.in_app_webview.FlutterWebView;
+
+import java.util.HashMap;
+
+import io.flutter.plugin.common.StandardMessageCodec;
+import io.flutter.plugin.platform.PlatformView;
+import io.flutter.plugin.platform.PlatformViewFactory;
+
+public class FlutterWebViewFactory extends PlatformViewFactory {
+  public static final String VIEW_TYPE_ID = "com.pichillilorenzo/flutter_inappwebview";
+  private final InAppWebViewFlutterPlugin plugin;
+
+  public FlutterWebViewFactory(final InAppWebViewFlutterPlugin plugin) {
+    super(StandardMessageCodec.INSTANCE);
+    this.plugin = plugin;
+  }
+
+  @Override
+  public PlatformView create(Context context, int id, Object args) {
+    HashMap<String, Object> params = (HashMap<String, Object>) args;
+    FlutterWebView flutterWebView = null;
+    Object viewId = id;
+
+    String keepAliveId = (String) params.get("keepAliveId");
+    String headlessWebViewId = (String) params.get("headlessWebViewId");
+
+    HeadlessInAppWebViewManager headlessInAppWebViewManager = plugin.headlessInAppWebViewManager;
+    if (headlessWebViewId != null && headlessInAppWebViewManager != null) {
+      HeadlessInAppWebView headlessInAppWebView = headlessInAppWebViewManager.webViews.get(headlessWebViewId);
+      if (headlessInAppWebView != null) {
+        flutterWebView = headlessInAppWebView.disposeAndGetFlutterWebView();
+        if (flutterWebView != null) {
+          flutterWebView.keepAliveId = keepAliveId;
+        }
+      }
+    }
+
+    InAppWebViewManager inAppWebViewManager = plugin.inAppWebViewManager;
+    if (keepAliveId != null && flutterWebView == null && inAppWebViewManager != null) {
+      flutterWebView = inAppWebViewManager.keepAliveWebViews.get(keepAliveId);
+      if (flutterWebView != null) {
+        // be sure to remove the view from the previous parent.
+        View view = flutterWebView.getView();
+        if (view != null) {
+          ViewGroup parent = (ViewGroup) view.getParent();
+          if (parent != null) {
+            parent.removeView(view);
+          }
+        }
+      }
+    }
+
+    boolean shouldMakeInitialLoad = flutterWebView == null;
+    if (flutterWebView == null) {
+      if (keepAliveId != null) {
+        viewId = keepAliveId;
+      }
+      flutterWebView = new FlutterWebView(plugin, context, viewId, params);
+    }
+
+    if (keepAliveId != null && inAppWebViewManager != null) {
+      inAppWebViewManager.keepAliveWebViews.put(keepAliveId, flutterWebView);
+    }
+
+    if (shouldMakeInitialLoad) {
+      flutterWebView.makeInitialLoad(params);
+    }
+    
+    return flutterWebView;
+  }
+}
+

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/webview/InAppWebViewManager.java

@@ -1,9 +1,12 @@
-package com.pichillilorenzo.flutter_inappwebview;
+package com.pichillilorenzo.flutter_inappwebview.webview;
 
-import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.pm.PackageInfo;
+import android.net.Uri;
 import android.os.Build;
+import android.os.Message;
+import android.view.View;
+import android.view.ViewGroup;
 import android.webkit.ValueCallback;
 import android.webkit.WebSettings;
 import android.webkit.WebView;
@@ -13,9 +16,12 @@ import androidx.annotation.Nullable;
 import androidx.webkit.WebViewCompat;
 import androidx.webkit.WebViewFeature;
 
+import com.pichillilorenzo.flutter_inappwebview.InAppWebViewFlutterPlugin;
+import com.pichillilorenzo.flutter_inappwebview.headless_in_app_webview.HeadlessInAppWebView;
 import com.pichillilorenzo.flutter_inappwebview.types.ChannelDelegateImpl;
+import com.pichillilorenzo.flutter_inappwebview.webview.in_app_webview.FlutterWebView;
 
-import java.lang.reflect.Method;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -25,14 +31,19 @@ import java.util.Set;
 import io.flutter.plugin.common.MethodCall;
 import io.flutter.plugin.common.MethodChannel;
 
-public class InAppWebViewStatic extends ChannelDelegateImpl {
+public class InAppWebViewManager extends ChannelDelegateImpl {
-  protected static final String LOG_TAG = "InAppWebViewStatic";
+  protected static final String LOG_TAG = "InAppWebViewManager";
-  public static final String METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_inappwebview_static";
+  public static final String METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_inappwebview_manager";
   
   @Nullable
   public InAppWebViewFlutterPlugin plugin;
 
-  public InAppWebViewStatic(final InAppWebViewFlutterPlugin plugin) {
+  public final Map<String, FlutterWebView> keepAliveWebViews = new HashMap<>();
+
+  public final Map<Integer, Message> windowWebViewMessages = new HashMap<>();
+  public int windowAutoincrementId = 0;
+
+  public InAppWebViewManager(final InAppWebViewFlutterPlugin plugin) {
     super(new MethodChannel(plugin.messenger, METHOD_CHANNEL_NAME));
     this.plugin = plugin;
   }
@@ -41,7 +52,11 @@ public class InAppWebViewStatic extends ChannelDelegateImpl {
   public void onMethodCall(@NonNull MethodCall call, @NonNull final MethodChannel.Result result) {
     switch (call.method) {
       case "getDefaultUserAgent":
+        if (plugin != null) {
           result.success(WebSettings.getDefaultUserAgent(plugin.applicationContext));
+        } else {
+          result.success(null);
+        }
         break;
       case "clearClientCertPreferences":
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
@@ -118,6 +133,13 @@ public class InAppWebViewStatic extends ChannelDelegateImpl {
           result.success(false);
         }
         break;
+      case "disposeKeepAlive":
+        final String keepAliveId = (String) call.argument("keepAliveId");
+        if (keepAliveId != null) {
+          disposeKeepAlive(keepAliveId);
+        }
+        result.success(true);
+        break;
       default:
         result.notImplemented();
     }
@@ -133,9 +155,37 @@ public class InAppWebViewStatic extends ChannelDelegateImpl {
     return webViewPackageInfoMap;
   }
 
+  public void disposeKeepAlive(@NonNull String keepAliveId) {
+    FlutterWebView flutterWebView = keepAliveWebViews.get(keepAliveId);
+    if (flutterWebView != null) {
+      flutterWebView.keepAliveId = null;
+      // be sure to remove the view from the previous parent.
+      View view = flutterWebView.getView();
+      if (view != null) {
+        ViewGroup parent = (ViewGroup) view.getParent();
+        if (parent != null) {
+          parent.removeView(view);
+        }
+      }
+      flutterWebView.dispose();
+    }
+    if (keepAliveWebViews.containsKey(keepAliveId)) {
+      keepAliveWebViews.put(keepAliveId, null);
+    }
+  }
+
   @Override
   public void dispose() {
     super.dispose();
+    Collection<FlutterWebView> flutterWebViews = keepAliveWebViews.values();
+    for (FlutterWebView flutterWebView : flutterWebViews) {
+      String keepAliveId = flutterWebView.keepAliveId;
+      if (keepAliveId != null) {
+        disposeKeepAlive(flutterWebView.keepAliveId);
+      }
+    }
+    keepAliveWebViews.clear();
+    windowWebViewMessages.clear();
     plugin = null;
   }
 }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/webview/JavaScriptBridgeInterface.java

@@ -76,11 +76,13 @@ public class JavaScriptBridgeInterface {
 
               @Override
               public void defaultBehaviour(@Nullable Boolean handledByClient) {
-                PrintJobController printJobController = PrintJobManager.jobs.get(printJobId);
+                if (inAppWebView != null && inAppWebView.plugin != null && inAppWebView.plugin.printJobManager != null) {
+                  PrintJobController printJobController = inAppWebView.plugin.printJobManager.jobs.get(printJobId);
                   if (printJobController != null) {
                     printJobController.disposeNoCancel();
                   }
                 }
+              }
 
               @Override
               public void error(String errorCode, @Nullable String errorMessage, @Nullable Object errorDetails) {

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/webview/in_app_webview/FlutterWebView.java

@@ -42,6 +42,8 @@ public class FlutterWebView implements PlatformWebView {
   public InAppWebView webView;
   @Nullable
   public PullToRefreshLayout pullToRefreshLayout;
+  @Nullable
+  public String keepAliveId;
 
   public FlutterWebView(final InAppWebViewFlutterPlugin plugin, final Context context, Object id,
                         HashMap<String, Object> params) {
@@ -49,6 +51,8 @@ public class FlutterWebView implements PlatformWebView {
     DisplayManager displayManager = (DisplayManager) context.getSystemService(Context.DISPLAY_SERVICE);
     displayListenerProxy.onPreWebViewInitialization(displayManager);
 
+    keepAliveId = (String) params.get("keepAliveId");
+    
     Map<String, Object> initialSettings = (Map<String, Object>) params.get("initialSettings");
     Map<String, Object> contextMenu = (Map<String, Object>) params.get("contextMenu");
     Integer windowId = (Integer) params.get("windowId");
@@ -101,7 +105,8 @@ public class FlutterWebView implements PlatformWebView {
     final Map<String, String> initialData = (Map<String, String>) params.get("initialData");
 
     if (windowId != null) {
-      Message resultMsg = InAppWebViewChromeClient.windowWebViewMessages.get(windowId);
+      if (webView.plugin != null && webView.plugin.inAppWebViewManager != null) {
+        Message resultMsg = webView.plugin.inAppWebViewManager.windowWebViewMessages.get(windowId);
         if (resultMsg != null) {
           ((WebView.WebViewTransport) resultMsg.obj).setWebView(webView);
           resultMsg.sendToTarget();
@@ -123,6 +128,7 @@ public class FlutterWebView implements PlatformWebView {
             });
           }
         }
+      }
     } else {
       if (initialFile != null) {
         try {
@@ -151,7 +157,7 @@ public class FlutterWebView implements PlatformWebView {
 
   @Override
   public void dispose() {
-    if (webView != null) {
+    if (keepAliveId == null && webView != null) {
       if (webView.channelDelegate != null) {
         webView.channelDelegate.dispose();
       }

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/webview/in_app_webview/InAppWebView.java

@@ -1439,10 +1439,10 @@ final public class InAppWebView extends InputAwareWebView implements InAppWebVie
         // Create a printCurrentPage job with name and adapter instance
         android.print.PrintJob job = printManager.print(jobName, printAdapter, builder.build());
 
-        if (settings != null && settings.handledByClient) {
+        if (settings != null && settings.handledByClient && plugin.printJobManager != null) {
           String id = UUID.randomUUID().toString();
           PrintJobController printJobController = new PrintJobController(id, job, settings, plugin);
-          PrintJobManager.jobs.put(printJobController.id, printJobController);
+          plugin.printJobManager.jobs.put(printJobController.id, printJobController);
           return id; 
         }
       } else {
@@ -2011,8 +2011,8 @@ final public class InAppWebView extends InputAwareWebView implements InAppWebVie
       webViewAssetLoaderExt.dispose();
       webViewAssetLoaderExt = null;
     }
-    if (windowId != null) {
+    if (windowId != null && plugin != null && plugin.inAppWebViewManager != null) {
-      InAppWebViewChromeClient.windowWebViewMessages.remove(windowId);
+      plugin.inAppWebViewManager.windowWebViewMessages.remove(windowId);
     }
     mainLooperHandler.removeCallbacksAndMessages(null);
     mHandler.removeCallbacksAndMessages(null);

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/webview/in_app_webview/InAppWebViewChromeClient.java

@@ -77,14 +77,10 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
 
   protected static final String LOG_TAG = "IABWebChromeClient";
   private InAppBrowserDelegate inAppBrowserDelegate;
-  public static Map<Integer, Message> windowWebViewMessages = new HashMap<>();
-  private static int windowAutoincrementId = 0;
 
   private static final int PICKER = 1;
   private static final int PICKER_LEGACY = 3;
   final String DEFAULT_MIME_TYPES = "*/*";
-  private static Uri videoOutputFileUri;
-  private static Uri imageOutputFileUri;
 
   protected static final FrameLayout.LayoutParams FULLSCREEN_LAYOUT_PARAMS = new FrameLayout.LayoutParams(
           ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT, Gravity.CENTER);
@@ -115,6 +111,15 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
   @Nullable
   public InAppWebView inAppWebView;
 
+  @Nullable
+  private ValueCallback<Uri> filePathCallbackLegacy;
+  @Nullable
+  private ValueCallback<Uri[]> filePathCallback;
+  @Nullable
+  private Uri videoOutputFileUri;
+  @Nullable
+  private Uri imageOutputFileUri;
+
   public InAppWebViewChromeClient(@NonNull final InAppWebViewFlutterPlugin plugin,
                                   @NonNull InAppWebView inAppWebView, InAppBrowserDelegate inAppBrowserDelegate) {
     super();
@@ -610,8 +615,11 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
 
   @Override
   public boolean onCreateWindow(WebView view, boolean isDialog, boolean isUserGesture, final Message resultMsg) {
-    windowAutoincrementId++;
+    int windowId = 0;
-    final int windowId = windowAutoincrementId;
+    if (plugin != null && plugin.inAppWebViewManager != null) {
+      plugin.inAppWebViewManager.windowAutoincrementId++;
+      windowId = plugin.inAppWebViewManager.windowAutoincrementId;
+    }
 
     WebView.HitTestResult result = view.getHitTestResult();
     String url = result.getExtra();
@@ -639,9 +647,12 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
             isDialog
     );
 
-    windowWebViewMessages.put(windowId, resultMsg);
+    if (plugin != null && plugin.inAppWebViewManager != null) {
+      plugin.inAppWebViewManager.windowWebViewMessages.put(windowId, resultMsg);
+    }
 
     if (inAppWebView != null && inAppWebView.channelDelegate != null) {
+      int finalWindowId = windowId;
       inAppWebView.channelDelegate.onCreateWindow(createWindowAction, new WebViewChannelDelegate.CreateWindowCallback() {
         @Override
         public boolean nonNullSuccess(@NonNull Boolean handledByClient) {
@@ -650,7 +661,9 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
 
         @Override
         public void defaultBehaviour(@Nullable Boolean handledByClient) {
-          InAppWebViewChromeClient.windowWebViewMessages.remove(windowId);
+          if (plugin != null && plugin.inAppWebViewManager != null) {
+            plugin.inAppWebViewManager.windowWebViewMessages.remove(finalWindowId);
+          }
         }
 
         @Override
@@ -824,7 +837,7 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
 
   @Override
   public boolean onActivityResult(int requestCode, int resultCode, Intent data) {
-    if (InAppWebViewFlutterPlugin.filePathCallback == null && InAppWebViewFlutterPlugin.filePathCallbackLegacy == null) {
+    if (filePathCallback == null && filePathCallbackLegacy == null) {
       return true;
     }
 
@@ -838,8 +851,8 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
           results = getSelectedFiles(data, resultCode);
         }
 
-        if (InAppWebViewFlutterPlugin.filePathCallback != null) {
+        if (filePathCallback != null) {
-          InAppWebViewFlutterPlugin.filePathCallback.onReceiveValue(results);
+          filePathCallback.onReceiveValue(results);
         }
         break;
 
@@ -848,13 +861,14 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
         if (resultCode == RESULT_OK) {
           result = data != null ? data.getData() : getCapturedMediaFile();
         }
-
+        if (filePathCallbackLegacy != null) {
-        InAppWebViewFlutterPlugin.filePathCallbackLegacy.onReceiveValue(result);
+          filePathCallbackLegacy.onReceiveValue(result);
+        }
         break;
     }
 
-    InAppWebViewFlutterPlugin.filePathCallback = null;
+    filePathCallback = null;
-    InAppWebViewFlutterPlugin.filePathCallbackLegacy = null;
+    filePathCallbackLegacy = null;
     imageOutputFileUri = null;
     videoOutputFileUri = null;
 
@@ -921,7 +935,7 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
   }
 
   public void startPickerIntent(ValueCallback<Uri> filePathCallback, String acceptType, @Nullable String capture) {
-    InAppWebViewFlutterPlugin.filePathCallbackLegacy = filePathCallback;
+    filePathCallbackLegacy = filePathCallback;
 
     boolean images = acceptsImages(acceptType);
     boolean video = acceptsVideo(acceptType);
@@ -965,7 +979,7 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
   @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
   public boolean startPickerIntent(final ValueCallback<Uri[]> callback, final String[] acceptTypes,
                                    final boolean allowMultiple, final boolean captureEnabled) {
-    InAppWebViewFlutterPlugin.filePathCallback = callback;
+    filePathCallback = callback;
 
     boolean images = acceptsImages(acceptTypes);
     boolean video = acceptsVideo(acceptTypes);
@@ -1289,7 +1303,11 @@ public class InAppWebViewChromeClient extends WebChromeClient implements PluginR
       inAppBrowserDelegate.getActivityResultListeners().clear();
       inAppBrowserDelegate = null;
     }
-    plugin = null;
+    filePathCallbackLegacy = null;
+    filePathCallback = null;
+    videoOutputFileUri = null;
+    imageOutputFileUri = null;
     inAppWebView = null;
+    plugin = null;
   }
 }

example/integration_test/chrome_safari_browser/custom_menu_item.dart

@@ -25,7 +25,7 @@ void customMenuItem() {
     expect(chromeSafariBrowser.isOpened(), true);
     expect(() async {
       await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
-    }, throwsA(isInstanceOf<ChromeSafariBrowserAlreadyOpenedException>()));
+    }, throwsException);
 
     await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
     await chromeSafariBrowser.close();

example/integration_test/chrome_safari_browser/custom_tabs.dart

@@ -26,7 +26,7 @@ void customTabs() {
       expect(chromeSafariBrowser.isOpened(), true);
       expect(() async {
         await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
-      }, throwsA(isInstanceOf<ChromeSafariBrowserAlreadyOpenedException>()));
+      }, throwsException);
 
       await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
       await chromeSafariBrowser.close();
@@ -45,7 +45,7 @@ void customTabs() {
       expect(chromeSafariBrowser.isOpened(), true);
       expect(() async {
         await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
-      }, throwsA(isInstanceOf<ChromeSafariBrowserAlreadyOpenedException>()));
+      }, throwsException);
 
       await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
       await chromeSafariBrowser.close();
@@ -71,7 +71,7 @@ void customTabs() {
       expect(chromeSafariBrowser.isOpened(), true);
       expect(() async {
         await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
-      }, throwsA(isInstanceOf<ChromeSafariBrowserAlreadyOpenedException>()));
+      }, throwsException);
 
       await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
       await chromeSafariBrowser.updateActionButton(

example/integration_test/chrome_safari_browser/open_and_close.dart

@@ -50,7 +50,7 @@ void openAndClose() {
     expect(chromeSafariBrowser.isOpened(), true);
     expect(() async {
       await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
-    }, throwsA(isInstanceOf<ChromeSafariBrowserAlreadyOpenedException>()));
+    }, throwsException);
 
     await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
     await chromeSafariBrowser.close();

example/integration_test/chrome_safari_browser/sf_safari_view_controller.dart

@@ -22,7 +22,7 @@ void sfSafariViewController() {
       expect(chromeSafariBrowser.isOpened(), true);
       expect(() async {
         await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
-      }, throwsA(isInstanceOf<ChromeSafariBrowserAlreadyOpenedException>()));
+      }, throwsException);
 
       expect(await chromeSafariBrowser.firstPageLoaded.future, true);
       await chromeSafariBrowser.close();

example/integration_test/chrome_safari_browser/trusted_web_activity.dart

@@ -24,7 +24,7 @@ void trustedWebActivity() {
       expect(chromeSafariBrowser.isOpened(), true);
       expect(() async {
         await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
-      }, throwsA(isInstanceOf<ChromeSafariBrowserAlreadyOpenedException>()));
+      }, throwsException);
 
       await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
       await chromeSafariBrowser.close();
@@ -44,7 +44,7 @@ void trustedWebActivity() {
       expect(chromeSafariBrowser.isOpened(), true);
       expect(() async {
         await chromeSafariBrowser.open(url: TEST_CROSS_PLATFORM_URL_1);
-      }, throwsA(isInstanceOf<ChromeSafariBrowserAlreadyOpenedException>()));
+      }, throwsException);
 
       await expectLater(chromeSafariBrowser.firstPageLoaded.future, completes);
       await chromeSafariBrowser.close();

example/integration_test/in_app_browser/open_data_and_close.dart

@@ -19,7 +19,7 @@ void openDataAndClose() {
     expect(inAppBrowser.isOpened(), false);
     expect(() async {
       await inAppBrowser.show();
-    }, throwsA(isInstanceOf<InAppBrowserNotOpenedException>()));
+    }, throwsException);
 
     await inAppBrowser.openData(
         data: """
@@ -46,7 +46,7 @@ void openDataAndClose() {
     expect(() async {
       await inAppBrowser.openUrlRequest(
           urlRequest: URLRequest(url: TEST_URL_1));
-    }, throwsA(isInstanceOf<InAppBrowserAlreadyOpenedException>()));
+    }, throwsException);
 
     await inAppBrowser.firstPageLoaded.future;
     var controller = inAppBrowser.webViewController;

example/integration_test/in_app_browser/open_file_and_close.dart

@@ -19,7 +19,7 @@ void openFileAndClose() {
     expect(inAppBrowser.isOpened(), false);
     expect(() async {
       await inAppBrowser.show();
-    }, throwsA(isInstanceOf<InAppBrowserNotOpenedException>()));
+    }, throwsException);
 
     await inAppBrowser.openFile(
         assetFilePath: "test_assets/in_app_webview_initial_file_test.html");
@@ -28,7 +28,7 @@ void openFileAndClose() {
     expect(() async {
       await inAppBrowser.openUrlRequest(
           urlRequest: URLRequest(url: TEST_URL_1));
-    }, throwsA(isInstanceOf<InAppBrowserAlreadyOpenedException>()));
+    }, throwsException);
 
     await inAppBrowser.firstPageLoaded.future;
     var controller = inAppBrowser.webViewController;

example/integration_test/in_app_browser/open_url_and_close.dart

@@ -19,7 +19,7 @@ void openUrlAndClose() {
     expect(inAppBrowser.isOpened(), false);
     expect(() async {
       await inAppBrowser.show();
-    }, throwsA(isInstanceOf<InAppBrowserNotOpenedException>()));
+    }, throwsException);
 
     await inAppBrowser.openUrlRequest(urlRequest: URLRequest(url: TEST_URL_1));
     await inAppBrowser.browserCreated.future;
@@ -27,7 +27,7 @@ void openUrlAndClose() {
     expect(() async {
       await inAppBrowser.openUrlRequest(
           urlRequest: URLRequest(url: TEST_CROSS_PLATFORM_URL_1));
-    }, throwsA(isInstanceOf<InAppBrowserAlreadyOpenedException>()));
+    }, throwsException);
 
     await inAppBrowser.firstPageLoaded.future;
     var controller = inAppBrowser.webViewController;

example/lib/headless_in_app_webview.screen.dart

@@ -86,7 +86,7 @@ class _HeadlessInAppWebViewExampleScreenState
             child: ElevatedButton(
                 onPressed: () async {
                   if (headlessWebView?.isRunning() ?? false) {
-                    await headlessWebView?.webViewController.evaluateJavascript(
+                    await headlessWebView?.webViewController?.evaluateJavascript(
                         source: """console.log('Here is the message!');""");
                   } else {
                     ScaffoldMessenger.of(context).showSnackBar(SnackBar(

example/lib/in_app_webiew_example.screen.dart

@@ -126,7 +126,6 @@ class _InAppWebViewExampleScreenState extends State<InAppWebViewExampleScreen> {
                   pullToRefreshController: pullToRefreshController,
                   onWebViewCreated: (controller) async {
                     webViewController = controller;
-                    print(await controller.getUrl());
                   },
                   onLoadStart: (controller, url) async {
                     setState(() {

ios/Classes/FindInteraction/FindInteractionController.swift

@@ -11,6 +11,7 @@ import Flutter
 public class FindInteractionController : NSObject, Disposable {
     
     static var METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_find_interaction_";
+    var plugin: SwiftFlutterPlugin?
     var webView: InAppWebView?
     var channelDelegate: FindInteractionChannelDelegate?
     var settings: FindInteractionSettings?
@@ -48,14 +49,17 @@ public class FindInteractionController : NSObject, Disposable {
         }
     }
     
-    public init(registrar: FlutterPluginRegistrar, id: Any, webView: InAppWebView, settings: FindInteractionSettings?) {
+    public init(plugin: SwiftFlutterPlugin, id: Any, webView: InAppWebView, settings: FindInteractionSettings?) {
         super.init()
+        self.plugin = plugin
         self.webView = webView
         self.settings = settings
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: FindInteractionController.METHOD_CHANNEL_NAME_PREFIX + String(describing: id),
                                                binaryMessenger: registrar.messenger())
             self.channelDelegate = FindInteractionChannelDelegate(findInteractionController: self, channel: channel)
         }
+    }
     
     public func prepare() {
 //        if let settings = settings {
@@ -148,6 +152,7 @@ public class FindInteractionController : NSObject, Disposable {
         channelDelegate = nil
         webView = nil
         activeFindSession = nil
+        plugin = nil
     }
     
     deinit {

ios/Classes/HeadlessInAppWebView/HeadlessInAppWebView.swift

@@ -79,7 +79,7 @@ public class HeadlessInAppWebView : Disposable {
     public func dispose() {
         channelDelegate?.dispose()
         channelDelegate = nil
-        HeadlessInAppWebViewManager.webViews[id] = nil
+        plugin?.headlessInAppWebViewManager?.webViews[id] = nil
         flutterWebView = nil
         plugin = nil
     }

ios/Classes/HeadlessInAppWebView/HeadlessInAppWebViewManager.swift

@@ -16,7 +16,7 @@ import AVFoundation
 public class HeadlessInAppWebViewManager: ChannelDelegate {
     static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_headless_inappwebview"
     var plugin: SwiftFlutterPlugin?
-    static var webViews: [String: HeadlessInAppWebView?] = [:]
+    var webViews: [String: HeadlessInAppWebView?] = [:]
     
     init(plugin: SwiftFlutterPlugin) {
         super.init(channel: FlutterMethodChannel(name: HeadlessInAppWebViewManager.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger()))
@@ -40,15 +40,15 @@ public class HeadlessInAppWebViewManager: ChannelDelegate {
     }
     
     public func run(id: String, params: [String: Any?]) {
-        guard let plugin = plugin, let registrar = plugin.registrar else {
+        guard let plugin = plugin else {
             return
         }
-        let flutterWebView = FlutterWebViewController(registrar: registrar,
+        let flutterWebView = FlutterWebViewController(plugin: plugin,
             withFrame: CGRect.zero,
             viewIdentifier: id,
             params: params as NSDictionary)
         let headlessInAppWebView = HeadlessInAppWebView(plugin: plugin, id: id, flutterWebView: flutterWebView)
-        HeadlessInAppWebViewManager.webViews[id] = headlessInAppWebView
+        webViews[id] = headlessInAppWebView
         
         headlessInAppWebView.prepare(params: params as NSDictionary)
         headlessInAppWebView.onWebViewCreated()
@@ -57,11 +57,11 @@ public class HeadlessInAppWebViewManager: ChannelDelegate {
     
     public override func dispose() {
         super.dispose()
-        let headlessWebViews = HeadlessInAppWebViewManager.webViews.values
+        let headlessWebViews = webViews.values
         headlessWebViews.forEach { (headlessWebView: HeadlessInAppWebView?) in
             headlessWebView?.dispose()
         }
-        HeadlessInAppWebViewManager.webViews.removeAll()
+        webViews.removeAll()
         plugin = nil
     }
     

ios/Classes/InAppBrowser/InAppBrowserWebViewController.swift

@@ -42,7 +42,7 @@ public class InAppBrowserWebViewController: UIViewController, InAppBrowserDelega
     var isHidden = false
 
     public override func loadView() {
-        guard let registrar = plugin?.registrar else {
+        guard let plugin = plugin, let registrar = plugin.registrar else {
             return
         }
         
@@ -55,13 +55,13 @@ public class InAppBrowserWebViewController: UIViewController, InAppBrowserDelega
         }
         
         let preWebviewConfiguration = InAppWebView.preWKWebViewConfiguration(settings: webViewSettings)
-        if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+        if let wId = windowId, let webViewTransport = plugin.inAppWebViewManager?.windowWebViews[wId] {
             webView = webViewTransport.webView
             webView!.contextMenu = contextMenu
             webView!.initialUserScripts = userScripts
         } else {
             webView = InAppWebView(id: nil,
-                                   registrar: nil,
+                                   plugin: nil,
                                    frame: .zero,
                                    configuration: preWebviewConfiguration,
                                    contextMenu: contextMenu,
@@ -74,17 +74,18 @@ public class InAppBrowserWebViewController: UIViewController, InAppBrowserDelega
         
         webView.inAppBrowserDelegate = self
         webView.id = id
+        webView.plugin = plugin
         webView.channelDelegate = WebViewChannelDelegate(webView: webView, channel: channel)
         
         let pullToRefreshSettings = PullToRefreshSettings()
         let _ = pullToRefreshSettings.parse(settings: pullToRefreshInitialSettings)
-        let pullToRefreshControl = PullToRefreshControl(registrar: registrar, id: id, settings: pullToRefreshSettings)
+        let pullToRefreshControl = PullToRefreshControl(plugin: plugin, id: id, settings: pullToRefreshSettings)
         webView.pullToRefreshControl = pullToRefreshControl
         pullToRefreshControl.delegate = webView
         pullToRefreshControl.prepare()
         
         let findInteractionController = FindInteractionController(
-            registrar: registrar,
+            plugin: plugin,
             id: id, webView: webView, settings: nil)
         webView.findInteractionController = findInteractionController
         findInteractionController.prepare()
@@ -132,7 +133,7 @@ public class InAppBrowserWebViewController: UIViewController, InAppBrowserDelega
             }
         }
         
-        if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+        if let wId = windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
             webView?.load(webViewTransport.request)
             channelDelegate?.onBrowserCreated()
         } else {

ios/Classes/InAppWebView/FlutterWebViewController.swift

@@ -11,13 +11,16 @@ import WebKit
 public class FlutterWebViewController: NSObject, FlutterPlatformView, Disposable {
     
     var myView: UIView?
+    var keepAliveId: String?
 
-    init(registrar: FlutterPluginRegistrar, withFrame frame: CGRect, viewIdentifier viewId: Any, params: NSDictionary) {
+    init(plugin: SwiftFlutterPlugin, withFrame frame: CGRect, viewIdentifier viewId: Any, params: NSDictionary) {
         super.init()
         
         myView = UIView(frame: frame)
         myView!.clipsToBounds = true
         
+        keepAliveId = params["keepAliveId"] as? String
+        
         let initialSettings = params["initialSettings"] as! [String: Any?]
         let contextMenu = params["contextMenu"] as? [String: Any]
         let windowId = params["windowId"] as? Int64
@@ -37,18 +40,21 @@ public class FlutterWebViewController: NSObject, FlutterPlatformView, Disposable
         
         var webView: InAppWebView?
         
-        if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+        if let wId = windowId, let webViewTransport = plugin.inAppWebViewManager?.windowWebViews[wId] {
             webView = webViewTransport.webView
             webView!.id = viewId
+            webView!.plugin = plugin
+            if let registrar = plugin.registrar {
                 let channel = FlutterMethodChannel(name: InAppWebView.METHOD_CHANNEL_NAME_PREFIX + String(describing: viewId),
                                                    binaryMessenger: registrar.messenger())
                 webView!.channelDelegate = WebViewChannelDelegate(webView: webView!, channel: channel)
+            }
             webView!.frame = myView!.bounds
             webView!.contextMenu = contextMenu
             webView!.initialUserScripts = userScripts
         } else {
             webView = InAppWebView(id: viewId,
-                                   registrar: registrar,
+                                   plugin: plugin,
                                    frame: myView!.bounds,
                                    configuration: preWebviewConfiguration,
                                    contextMenu: contextMenu,
@@ -57,13 +63,13 @@ public class FlutterWebViewController: NSObject, FlutterPlatformView, Disposable
         
         let pullToRefreshSettings = PullToRefreshSettings()
         let _ = pullToRefreshSettings.parse(settings: pullToRefreshInitialSettings)
-        let pullToRefreshControl = PullToRefreshControl(registrar: registrar, id: viewId, settings: pullToRefreshSettings)
+        let pullToRefreshControl = PullToRefreshControl(plugin: plugin, id: viewId, settings: pullToRefreshSettings)
         webView!.pullToRefreshControl = pullToRefreshControl
         pullToRefreshControl.delegate = webView!
         pullToRefreshControl.prepare()
         
         let findInteractionController = FindInteractionController(
-            registrar: registrar,
+            plugin: plugin,
             id: viewId, webView: webView!, settings: nil)
         webView!.findInteractionController = findInteractionController
         findInteractionController.prepare()
@@ -132,7 +138,7 @@ public class FlutterWebViewController: NSObject, FlutterPlatformView, Disposable
             }
             load(initialUrlRequest: initialUrlRequest, initialFile: initialFile, initialData: initialData)
         }
-        else if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+        else if let wId = windowId, let webViewTransport = webView.plugin?.inAppWebViewManager?.windowWebViews[wId] {
             webView.load(webViewTransport.request)
         }
     }
@@ -180,11 +186,13 @@ public class FlutterWebViewController: NSObject, FlutterPlatformView, Disposable
     }
     
     public func dispose() {
+        if keepAliveId == nil {
             if let webView = webView() {
                 webView.dispose()
             }
             myView = nil
         }
+    }
     
     deinit {
         debugPrint("FlutterWebViewController - dealloc")

ios/Classes/InAppWebView/FlutterWebViewFactory.swift

@@ -10,11 +10,11 @@ import Foundation
 
 public class FlutterWebViewFactory: NSObject, FlutterPlatformViewFactory {
     static let VIEW_TYPE_ID = "com.pichillilorenzo/flutter_inappwebview"
-    private var registrar: FlutterPluginRegistrar?
+    private var plugin: SwiftFlutterPlugin
     
-    init(registrar: FlutterPluginRegistrar?) {
+    init(plugin: SwiftFlutterPlugin) {
+        self.plugin = plugin
         super.init()
-        self.registrar = registrar
     }
     
     public func createArgsCodec() -> FlutterMessageCodec & NSObjectProtocol {
@@ -23,18 +23,48 @@ public class FlutterWebViewFactory: NSObject, FlutterPlatformViewFactory {
     
     public func create(withFrame frame: CGRect, viewIdentifier viewId: Int64, arguments args: Any?) -> FlutterPlatformView {
         let arguments = args as? NSDictionary
+        var flutterWebView: FlutterWebViewController?
+        var id: Any = viewId
         
-        if let headlessWebViewId = arguments?["headlessWebViewId"] as? String,
+        let keepAliveId = arguments?["keepAliveId"] as? String
-           let headlessWebView = HeadlessInAppWebViewManager.webViews[headlessWebViewId],
+        let headlessWebViewId = arguments?["headlessWebViewId"] as? String
+        
+        if let headlessWebViewId = headlessWebViewId,
+           let headlessWebView = plugin.headlessInAppWebViewManager?.webViews[headlessWebViewId],
            let platformView = headlessWebView?.disposeAndGetFlutterWebView(withFrame: frame) {
-            return platformView
+            flutterWebView = platformView
+            flutterWebView?.keepAliveId = keepAliveId
         }
         
-        let webviewController = FlutterWebViewController(registrar: registrar!,
+        if let keepAliveId = keepAliveId,
+           flutterWebView == nil,
+           let keepAliveWebView = plugin.inAppWebViewManager?.keepAliveWebViews[keepAliveId] {
+            flutterWebView = keepAliveWebView
+            if let view = flutterWebView?.view() {
+                // remove from parent
+                view.removeFromSuperview()
+            }
+        }
+        
+        let shouldMakeInitialLoad = flutterWebView == nil
+        if flutterWebView == nil {
+            if let keepAliveId = keepAliveId {
+                id = keepAliveId
+            }
+            flutterWebView = FlutterWebViewController(plugin: plugin,
                                                       withFrame: frame,
-                                                         viewIdentifier: viewId,
+                                                      viewIdentifier: id,
                                                       params: arguments!)
-        webviewController.makeInitialLoad(params: arguments!)
+        }
-        return webviewController
+        
+        if let keepAliveId = keepAliveId {
+            plugin.inAppWebViewManager?.keepAliveWebViews[keepAliveId] = flutterWebView!
+        }
+        
+        if shouldMakeInitialLoad {
+            flutterWebView?.makeInitialLoad(params: arguments!)
+        }
+        
+        return flutterWebView!
     }
 }

ios/Classes/InAppWebView/InAppWebView.swift

@@ -17,7 +17,7 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
     static var METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_"
 
     var id: Any? // viewId
-    var registrar: FlutterPluginRegistrar?
+    var plugin: SwiftFlutterPlugin?
     var windowId: Int64?
     var windowCreated = false
     var inAppBrowserDelegate: InAppBrowserDelegate?
@@ -61,19 +61,16 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
     
     var customIMPs: [IMP] = []
     
-    static var windowWebViews: [Int64:WebViewTransport] = [:]
-    static var windowAutoincrementId: Int64 = 0;
-    
     var callAsyncJavaScriptBelowIOS14Results: [String:((Any?) -> Void)] = [:]
     
     var oldZoomScale = Float(1.0)
     
-    init(id: Any?, registrar: FlutterPluginRegistrar?, frame: CGRect, configuration: WKWebViewConfiguration,
+    init(id: Any?, plugin: SwiftFlutterPlugin?, frame: CGRect, configuration: WKWebViewConfiguration,
          contextMenu: [String: Any]?, userScripts: [UserScript] = []) {
         super.init(frame: frame, configuration: configuration)
         self.id = id
-        self.registrar = registrar
+        self.plugin = plugin
-        if let id = id, let registrar = registrar {
+        if let id = id, let registrar = plugin?.registrar {
             let channel = FlutterMethodChannel(name: InAppWebView.METHOD_CHANNEL_NAME_PREFIX + String(describing: id),
                                                binaryMessenger: registrar.messenger())
             self.channelDelegate = WebViewChannelDelegate(webView: self, channel: channel)
@@ -940,8 +937,8 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
     }
     
     public func loadFile(assetFilePath: String) throws {
-        if let registrar = registrar {
+        if let plugin = plugin {
-            let assetURL = try Util.getUrlAsset(registrar: registrar, assetFilePath: assetFilePath)
+            let assetURL = try Util.getUrlAsset(plugin: plugin, assetFilePath: assetFilePath)
             let urlRequest = URLRequest(url: assetURL)
             loadUrl(urlRequest: urlRequest, allowingReadAccessTo: nil)
         }
@@ -2090,8 +2087,8 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
                             
                             var path: String = certificatePath
                             do {
-                                if let registrar = self.registrar {
+                                if let plugin = self.plugin {
-                                    path = try Util.getAbsPathAsset(registrar: registrar, assetFilePath: certificatePath)
+                                    path = try Util.getAbsPathAsset(plugin: plugin, assetFilePath: certificatePath)
                                 }
                             } catch {}
                             
@@ -2464,10 +2461,14 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
                         createWebViewWith configuration: WKWebViewConfiguration,
                   for navigationAction: WKNavigationAction,
                   windowFeatures: WKWindowFeatures) -> WKWebView? {
-        InAppWebView.windowAutoincrementId += 1
+        var windowId: Int64 = 0
-        let windowId = InAppWebView.windowAutoincrementId
+        let inAppWebViewManager = plugin?.inAppWebViewManager
+        if let inAppWebViewManager = inAppWebViewManager {
+            inAppWebViewManager.windowAutoincrementId += 1
+            windowId = inAppWebViewManager.windowAutoincrementId
+        }
         
-        let windowWebView = InAppWebView(id: nil, registrar: nil, frame: CGRect.zero, configuration: configuration, contextMenu: nil)
+        let windowWebView = InAppWebView(id: nil, plugin: nil, frame: CGRect.zero, configuration: configuration, contextMenu: nil)
         windowWebView.windowId = windowId
         
         let webViewTransport = WebViewTransport(
@@ -2475,7 +2476,7 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
             request: navigationAction.request
         )
 
-        InAppWebView.windowWebViews[windowId] = webViewTransport
+        inAppWebViewManager?.windowWebViews[windowId] = webViewTransport
         windowWebView.stopLoading()
         
         let createWindowAction = CreateWindowAction(navigationAction: navigationAction, windowId: windowId, windowFeatures: windowFeatures, isDialog: nil)
@@ -2485,8 +2486,8 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
             return !handledByClient
         }
         callback.defaultBehaviour = { (handledByClient: Bool?) in
-            if InAppWebView.windowWebViews[windowId] != nil {
+            if inAppWebViewManager?.windowWebViews[windowId] != nil {
-                InAppWebView.windowWebViews.removeValue(forKey: windowId)
+                inAppWebViewManager?.windowWebViews.removeValue(forKey: windowId)
             }
             self.loadUrl(urlRequest: navigationAction.request, allowingReadAccessTo: nil)
         }
@@ -2752,7 +2753,7 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
             
             let _windowId = body["_windowId"] as? Int64
             var webView = self
-            if let wId = _windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+            if let wId = _windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
                 webView = webViewTransport.webView
             }
             webView.channelDelegate?.onConsoleMessage(message: consoleMessage, messageLevel: messageLevel)
@@ -2769,7 +2770,7 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
                         return !handledByClient
                     }
                     callback.defaultBehaviour = { (handledByClient: Bool?) in
-                        if let printJob = PrintJobManager.jobs[printJobId] {
+                        if let printJob = self.plugin?.printJobManager?.jobs[printJobId] {
                             printJob?.disposeNoDismiss()
                         }
                     }
@@ -2787,7 +2788,7 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate,
             
             let _windowId = body["_windowId"] as? Int64
             var webView = self
-            if let wId = _windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+            if let wId = _windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
                 webView = webViewTransport.webView
             }
             
@@ -2829,7 +2830,7 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
             
             let _windowId = body["_windowId"] as? Int64
             var webView = self
-            if let wId = _windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+            if let wId = _windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
                 webView = webViewTransport.webView
             }
             webView.findInteractionController?.channelDelegate?.onFindResultReceived(activeMatchOrdinal: activeMatchOrdinal, numberOfMatches: numberOfMatches, isDoneCounting: isDoneCounting)
@@ -2979,9 +2980,9 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
         }
         
         let animated = settings?.animated ?? true
-        if let id = printJobId, let registrar = registrar {
+        if let id = printJobId, let plugin = plugin {
-            let printJob = PrintJobController(registrar: registrar, id: id, job: printController, settings: settings)
+            let printJob = PrintJobController(plugin: plugin, id: id, job: printController, settings: settings)
-            PrintJobManager.jobs[id] = printJob
+            plugin.printJobManager?.jobs[id] = printJob
             printJob.present(animated: animated, completionHandler: completionHandler)
         } else {
             printController.present(animated: animated, completionHandler: completionHandler)
@@ -3123,12 +3124,12 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
     }
     
     public func createWebMessageChannel(completionHandler: ((WebMessageChannel?) -> Void)? = nil) -> WebMessageChannel? {
-        guard let registrar = registrar else {
+        guard let plugin = plugin else {
             completionHandler?(nil)
             return nil
         }
         let id = NSUUID().uuidString
-        let webMessageChannel = WebMessageChannel(registrar: registrar, id: id)
+        let webMessageChannel = WebMessageChannel(plugin: plugin, id: id)
         webMessageChannel.initJsInstance(webView: self, completionHandler: completionHandler)
         webMessageChannels[id] = webMessageChannel
         
@@ -3216,8 +3217,8 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
             if #available(iOS 11.0, *) {
                 configuration.userContentController.removeAllContentRuleLists()
             }
-        } else if let wId = windowId, InAppWebView.windowWebViews[wId] != nil {
+        } else if let wId = windowId, plugin?.inAppWebViewManager?.windowWebViews[wId] != nil {
-            InAppWebView.windowWebViews.removeValue(forKey: wId)
+            plugin?.inAppWebViewManager?.windowWebViews.removeValue(forKey: wId)
         }
         configuration.userContentController.dispose(windowId: windowId)
         NotificationCenter.default.removeObserver(self)
@@ -3245,7 +3246,7 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
         SharedLastTouchPointTimestamp.removeValue(forKey: self)
         callAsyncJavaScriptBelowIOS14Results.removeAll()
         super.removeFromSuperview()
-        registrar = nil
+        plugin = nil
     }
     
     deinit {

ios/Classes/InAppWebView/InAppWebViewManager.swift

@@ -1,5 +1,5 @@
 //
-//  InAppWebViewStatic.swift
+//  InAppWebViewManager.swift
 //  flutter_inappwebview
 //
 //  Created by Lorenzo Pichilli on 08/12/2019.
@@ -8,14 +8,18 @@
 import Foundation
 import WebKit
 
-public class InAppWebViewStatic: ChannelDelegate {
+public class InAppWebViewManager: ChannelDelegate {
-    static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_inappwebview_static"
+    static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_inappwebview_manager"
     var plugin: SwiftFlutterPlugin?
     var webViewForUserAgent: WKWebView?
     var defaultUserAgent: String?
     
+    var keepAliveWebViews: [String:FlutterWebViewController?] = [:]
+    var windowWebViews: [Int64:WebViewTransport] = [:]
+    var windowAutoincrementId: Int64 = 0
+    
     init(plugin: SwiftFlutterPlugin) {
-        super.init(channel: FlutterMethodChannel(name: InAppWebViewStatic.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger()))
+        super.init(channel: FlutterMethodChannel(name: InAppWebViewManager.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger()))
         self.plugin = plugin
     }
     
@@ -36,6 +40,11 @@ public class InAppWebViewStatic: ChannelDelegate {
                     result(false)
                 }
                 break
+            case "disposeKeepAlive":
+                let keepAliveId = arguments!["keepAliveId"] as! String
+                disposeKeepAlive(keepAliveId: keepAliveId)
+                result(true)
+                break
             default:
                 result(FlutterMethodNotImplemented)
                 break
@@ -67,11 +76,27 @@ public class InAppWebViewStatic: ChannelDelegate {
         }
     }
     
+    public func disposeKeepAlive(keepAliveId: String) {
+        if let flutterWebView = keepAliveWebViews[keepAliveId] as? FlutterWebViewController {
+            flutterWebView.keepAliveId = nil
+            flutterWebView.dispose()
+            keepAliveWebViews[keepAliveId] = nil
+        }
+    }
+    
     public override func dispose() {
         super.dispose()
-        plugin = nil
+        let keepAliveWebViewValues = keepAliveWebViews.values
+        keepAliveWebViewValues.forEach {(keepAliveWebView: FlutterWebViewController?) in
+            if let keepAliveId = keepAliveWebView?.keepAliveId {
+                disposeKeepAlive(keepAliveId: keepAliveId)
+            }
+        }
+        keepAliveWebViews.removeAll()
+        windowWebViews.removeAll()
         webViewForUserAgent = nil
         defaultUserAgent = nil
+        plugin = nil
     }
     
     deinit {

ios/Classes/InAppWebView/WebMessage/WebMessageChannel.swift

@@ -10,18 +10,20 @@ import Foundation
 public class WebMessageChannel : FlutterMethodCallDelegate {
     static var METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_web_message_channel_"
     var id: String
+    var plugin: SwiftFlutterPlugin?
     var channelDelegate: WebMessageChannelChannelDelegate?
     weak var webView: InAppWebView?
     var ports: [WebMessagePort] = []
-    var registrar: FlutterPluginRegistrar?
     
-    public init(registrar: FlutterPluginRegistrar, id: String) {
+    public init(plugin: SwiftFlutterPlugin, id: String) {
         self.id = id
-        self.registrar = registrar
+        self.plugin = plugin
         super.init()
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: WebMessageChannel.METHOD_CHANNEL_NAME_PREFIX + id,
                                                binaryMessenger: registrar.messenger())
             self.channelDelegate = WebMessageChannelChannelDelegate(webMessageChannel: self, channel: channel)
+        }
         self.ports = [
             WebMessagePort(name: "port1", webMessageChannel: self),
             WebMessagePort(name: "port2", webMessageChannel: self)
@@ -67,7 +69,7 @@ public class WebMessageChannel : FlutterMethodCallDelegate {
         })();
         """)
         webView = nil
-        registrar = nil
+        plugin = nil
     }
     
     deinit {

ios/Classes/InAppWebView/WebMessage/WebMessageListener.swift

@@ -15,18 +15,20 @@ public class WebMessageListener : FlutterMethodCallDelegate {
     var allowedOriginRules: Set<String>
     var channelDelegate: WebMessageListenerChannelDelegate?
     weak var webView: InAppWebView?
-    var registrar: FlutterPluginRegistrar?
+    var plugin: SwiftFlutterPlugin?
     
-    public init(registrar: FlutterPluginRegistrar, id: String, jsObjectName: String, allowedOriginRules: Set<String>) {
+    public init(plugin: SwiftFlutterPlugin, id: String, jsObjectName: String, allowedOriginRules: Set<String>) {
         self.id = id
-        self.registrar = registrar
+        self.plugin = plugin
         self.jsObjectName = jsObjectName
         self.allowedOriginRules = allowedOriginRules
         super.init()
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: WebMessageListener.METHOD_CHANNEL_NAME_PREFIX + self.id + "_" + self.jsObjectName,
                                                binaryMessenger: registrar.messenger())
             self.channelDelegate = WebMessageListenerChannelDelegate(webMessageListener: self, channel: channel)
         }
+    }
     
     public func assertOriginRulesValid() throws {
         for (index, originRule) in allowedOriginRules.enumerated() {
@@ -116,12 +118,12 @@ public class WebMessageListener : FlutterMethodCallDelegate {
         }
     }
     
-    public static func fromMap(registrar: FlutterPluginRegistrar, map: [String:Any?]?) -> WebMessageListener? {
+    public static func fromMap(plugin: SwiftFlutterPlugin, map: [String:Any?]?) -> WebMessageListener? {
         guard let map = map else {
             return nil
         }
         return WebMessageListener(
-            registrar: registrar,
+            plugin: plugin,
             id: map["id"] as! String,
             jsObjectName: map["jsObjectName"] as! String,
             allowedOriginRules: Set(map["allowedOriginRules"] as! [String])
@@ -180,7 +182,7 @@ public class WebMessageListener : FlutterMethodCallDelegate {
         channelDelegate?.dispose()
         channelDelegate = nil
         webView = nil
-        registrar = nil
+        plugin = nil
     }
     
     deinit {

ios/Classes/InAppWebView/WebViewChannelDelegate.swift

@@ -536,9 +536,9 @@ public class WebViewChannelDelegate : ChannelDelegate {
             }
             break
         case .addWebMessageListener:
-            if let webView = webView, let registrar = webView.registrar {
+            if let webView = webView, let plugin = webView.plugin {
                 let webMessageListenerMap = arguments!["webMessageListener"] as! [String: Any?]
-                let webMessageListener = WebMessageListener.fromMap(registrar: registrar, map: webMessageListenerMap)!
+                let webMessageListener = WebMessageListener.fromMap(plugin: plugin, map: webMessageListenerMap)!
                 do {
                     try webView.addWebMessageListener(webMessageListener: webMessageListener)
                     result(false)

ios/Classes/PrintJob/PrintJobController.swift

@@ -18,7 +18,7 @@ public enum PrintJobState: Int {
 public class PrintJobController : NSObject, Disposable, UIPrintInteractionControllerDelegate {
     static let METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_printjobcontroller_"
     var id: String
-    var registrar: FlutterPluginRegistrar?
+    var plugin: SwiftFlutterPlugin?
     var job: UIPrintInteractionController?
     var settings: PrintJobSettings?
     var printFormatter: UIPrintFormatter?
@@ -27,19 +27,21 @@ public class PrintJobController : NSObject, Disposable, UIPrintInteractionContro
     var state = PrintJobState.created
     var creationTime = Int64(Date().timeIntervalSince1970 * 1000)
     
-    public init(registrar: FlutterPluginRegistrar, id: String, job: UIPrintInteractionController? = nil, settings: PrintJobSettings? = nil) {
+    public init(plugin: SwiftFlutterPlugin, id: String, job: UIPrintInteractionController? = nil, settings: PrintJobSettings? = nil) {
         self.id = id
-        self.registrar = registrar
+        self.plugin = plugin
         super.init()
         self.job = job
         self.settings = settings
         self.printFormatter = job?.printFormatter
         self.printPageRenderer = job?.printPageRenderer
         self.job?.delegate = self
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: PrintJobController.METHOD_CHANNEL_NAME_PREFIX + id,
                                                binaryMessenger: registrar.messenger())
             self.channelDelegate = PrintJobChannelDelegate(printJobController: self, channel: channel)
         }
+    }
     
     public func printInteractionControllerWillStartJob(_ printInteractionController: UIPrintInteractionController) {
         state = .started
@@ -82,7 +84,8 @@ public class PrintJobController : NSObject, Disposable, UIPrintInteractionContro
         printPageRenderer = nil
         job?.delegate = nil
         job = nil
-        PrintJobManager.jobs[id] = nil
+        plugin?.printJobManager?.jobs[id] = nil
+        plugin = nil
     }
     
     public func dispose() {
@@ -93,7 +96,7 @@ public class PrintJobController : NSObject, Disposable, UIPrintInteractionContro
         job?.delegate = nil
         job?.dismiss(animated: false)
         job = nil
-        PrintJobManager.jobs[id] = nil
+        plugin?.printJobManager?.jobs[id] = nil
-        registrar = nil
+        plugin = nil
     }
 }

ios/Classes/PrintJob/PrintJobManager.swift

@@ -8,18 +8,21 @@
 import Foundation
 
 public class PrintJobManager: NSObject, Disposable {
-    static var jobs: [String: PrintJobController?] = [:]
+    var plugin: SwiftFlutterPlugin?
+    var jobs: [String: PrintJobController?] = [:]
     
-    public override init() {
+    public init(plugin: SwiftFlutterPlugin?) {
         super.init()
+        self.plugin = plugin
     }
     
     public func dispose() {
-        let jobs = PrintJobManager.jobs.values
+        let jobValues = jobs.values
-        jobs.forEach { (job: PrintJobController?) in
+        jobValues.forEach { (job: PrintJobController?) in
             job?.dispose()
         }
-        PrintJobManager.jobs.removeAll()
+        jobs.removeAll()
+        plugin = nil
     }
     
     deinit {

ios/Classes/PullToRefresh/PullToRefreshControl.swift

@@ -10,18 +10,22 @@ import Flutter
 
 public class PullToRefreshControl : UIRefreshControl, Disposable {
     static var METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_pull_to_refresh_";
+    var plugin: SwiftFlutterPlugin?
     var channelDelegate: PullToRefreshChannelDelegate?
     var settings: PullToRefreshSettings?
     var shouldCallOnRefresh = false
     var delegate: PullToRefreshDelegate?
     
-    public init(registrar: FlutterPluginRegistrar, id: Any, settings: PullToRefreshSettings?) {
+    public init(plugin: SwiftFlutterPlugin, id: Any, settings: PullToRefreshSettings?) {
         super.init()
+        self.plugin = plugin
         self.settings = settings
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: PullToRefreshControl.METHOD_CHANNEL_NAME_PREFIX + String(describing: id),
                                                binaryMessenger: registrar.messenger())
             self.channelDelegate = PullToRefreshChannelDelegate(pullToRefreshControl: self, channel: channel)
         }
+    }
     
     required init?(coder: NSCoder) {
         super.init(coder: coder)
@@ -59,6 +63,7 @@ public class PullToRefreshControl : UIRefreshControl, Disposable {
         channelDelegate = nil
         removeTarget(self, action: #selector(updateShouldCallOnRefresh), for: .valueChanged)
         delegate = nil
+        plugin = nil
     }
     
     deinit {

ios/Classes/SafariViewController/ChromeSafariBrowserManager.swift

@@ -15,9 +15,8 @@ import SafariServices
 public class ChromeSafariBrowserManager: ChannelDelegate {
     static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_chromesafaribrowser"
     var plugin: SwiftFlutterPlugin?
-    static var browsers: [String: SafariViewController?] = [:]
+    var browsers: [String: SafariViewController?] = [:]
-    @available(iOS 15.0, *)
+    var prewarmingTokens: [String: Any?] = [:]
-    static var prewarmingTokens: [String: SFSafariViewController.PrewarmingToken?] = [:]
     
     init(plugin: SwiftFlutterPlugin) {
         super.init(channel: FlutterMethodChannel(name: ChromeSafariBrowserManager.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger()))
@@ -61,7 +60,7 @@ public class ChromeSafariBrowserManager: ChannelDelegate {
                     }
                     let prewarmingToken = SFSafariViewController.prewarmConnections(to: URLs)
                     let prewarmingTokenId = NSUUID().uuidString
-                    ChromeSafariBrowserManager.prewarmingTokens[prewarmingTokenId] = prewarmingToken
+                    prewarmingTokens[prewarmingTokenId] = prewarmingToken
                     result([
                         "id": prewarmingTokenId
                     ])
@@ -72,9 +71,9 @@ public class ChromeSafariBrowserManager: ChannelDelegate {
                 if #available(iOS 15.0, *) {
                     let prewarmingToken = arguments!["prewarmingToken"] as! [String:Any?]
                     if let prewarmingTokenId = prewarmingToken["id"] as? String,
-                       let prewarmingToken = ChromeSafariBrowserManager.prewarmingTokens[prewarmingTokenId] {
+                       let prewarmingToken = prewarmingTokens[prewarmingTokenId] as? SFSafariViewController.PrewarmingToken? {
                         prewarmingToken?.invalidate()
-                        ChromeSafariBrowserManager.prewarmingTokens[prewarmingTokenId] = nil
+                        prewarmingTokens[prewarmingTokenId] = nil
                     }
                     result(true)
                 } else {
@@ -115,7 +114,7 @@ public class ChromeSafariBrowserManager: ChannelDelegate {
                     result(true)
                 }
                 
-                ChromeSafariBrowserManager.browsers[id] = safari
+                browsers[id] = safari
             }
             return
         }
@@ -125,17 +124,20 @@ public class ChromeSafariBrowserManager: ChannelDelegate {
     
     public override func dispose() {
         super.dispose()
-        let browsers = ChromeSafariBrowserManager.browsers.values
+        let browserValues = browsers.values
-        browsers.forEach { (browser: SafariViewController?) in
+        browserValues.forEach { (browser: SafariViewController?) in
             browser?.close(result: nil)
             browser?.dispose()
         }
-        ChromeSafariBrowserManager.browsers.removeAll()
+        browsers.removeAll()
         if #available(iOS 15.0, *) {
-            ChromeSafariBrowserManager.prewarmingTokens.values.forEach { (prewarmingToken: SFSafariViewController.PrewarmingToken?) in
+            let prewarmingTokensValues = prewarmingTokens.values
+            prewarmingTokensValues.forEach { (prewarmingToken: Any?) in
+                if let prewarmingToken = prewarmingToken as? SFSafariViewController.PrewarmingToken? {
                     prewarmingToken?.invalidate()
                 }
-            ChromeSafariBrowserManager.prewarmingTokens.removeAll()
+            }
+            prewarmingTokens.removeAll()
         }
         plugin = nil
     }

ios/Classes/SafariViewController/CustomUIActivity.swift

@@ -8,6 +8,7 @@
 import Foundation
 
 class CustomUIActivity : UIActivity {
+    var plugin: SwiftFlutterPlugin
     var viewId: String
     var id: Int64
     var url: URL
@@ -16,7 +17,8 @@ class CustomUIActivity : UIActivity {
     var label: String?
     var image: UIImage?
     
-    init(viewId: String, id: Int64, url: URL, title: String?, label: String?, type: UIActivity.ActivityType?, image: UIImage?) {
+    init(plugin: SwiftFlutterPlugin, viewId: String, id: Int64, url: URL, title: String?, label: String?, type: UIActivity.ActivityType?, image: UIImage?) {
+        self.plugin = plugin
         self.viewId = viewId
         self.id = id
         self.url = url
@@ -47,7 +49,7 @@ class CustomUIActivity : UIActivity {
     }
 
     override func perform() {
-        let browser = ChromeSafariBrowserManager.browsers[viewId]
+        let browser = plugin.chromeSafariBrowserManager?.browsers[viewId]
         browser??.channelDelegate?.onItemActionPerform(id: id, url: url, title: title)
     }
 }

ios/Classes/SafariViewController/SafariViewController.swift

@@ -105,9 +105,14 @@ public class SafariViewController: SFSafariViewController, SFSafariViewControlle
     }
     
     public func safariViewController(_ controller: SFSafariViewController, activityItemsFor URL: URL, title: String?) -> [UIActivity] {
+        guard let plugin = plugin else {
+            return []
+        }
         var uiActivities: [UIActivity] = []
         menuItemList.forEach { (menuItem) in
-            let activity = CustomUIActivity(viewId: id, id: menuItem["id"] as! Int64, url: URL, title: title, label: menuItem["label"] as? String, type: nil, image: .fromMap(map: menuItem["image"] as? [String:Any?]))
+            let activity = CustomUIActivity(plugin: plugin, viewId: id, id: menuItem["id"] as! Int64, url: URL,
+                                            title: title, label: menuItem["label"] as? String, type: nil,
+                                            image: .fromMap(map: menuItem["image"] as? [String:Any?]))
             uiActivities.append(activity)
         }
         return uiActivities
@@ -125,7 +130,7 @@ public class SafariViewController: SFSafariViewController, SFSafariViewControlle
         channelDelegate?.dispose()
         channelDelegate = nil
         delegate = nil
-        ChromeSafariBrowserManager.browsers[id] = nil
+        plugin?.chromeSafariBrowserManager?.browsers[id] = nil
         plugin = nil
     }
     

ios/Classes/SwiftFlutterPlugin.swift

@@ -26,7 +26,7 @@ public class SwiftFlutterPlugin: NSObject, FlutterPlugin {
     
     var registrar: FlutterPluginRegistrar?
     var platformUtil: PlatformUtil?
-    var inAppWebViewStatic: InAppWebViewStatic?
+    var inAppWebViewManager: InAppWebViewManager?
     var myCookieManager: Any?
     var myWebStorageManager: Any?
     var credentialDatabase: CredentialDatabase?
@@ -43,13 +43,13 @@ public class SwiftFlutterPlugin: NSObject, FlutterPlugin {
         super.init()
         
         self.registrar = registrar
-        registrar.register(FlutterWebViewFactory(registrar: registrar) as FlutterPlatformViewFactory, withId: FlutterWebViewFactory.VIEW_TYPE_ID)
+        registrar.register(FlutterWebViewFactory(plugin: self) as FlutterPlatformViewFactory, withId: FlutterWebViewFactory.VIEW_TYPE_ID)
         
         platformUtil = PlatformUtil(plugin: self)
         inAppBrowserManager = InAppBrowserManager(plugin: self)
         headlessInAppWebViewManager = HeadlessInAppWebViewManager(plugin: self)
         chromeSafariBrowserManager = ChromeSafariBrowserManager(plugin: self)
-        inAppWebViewStatic = InAppWebViewStatic(plugin: self)
+        inAppWebViewManager = InAppWebViewManager(plugin: self)
         credentialDatabase = CredentialDatabase(plugin: self)
         if #available(iOS 11.0, *) {
             myCookieManager = MyCookieManager(plugin: self)
@@ -58,7 +58,7 @@ public class SwiftFlutterPlugin: NSObject, FlutterPlugin {
             myWebStorageManager = MyWebStorageManager(plugin: self)
         }
         webAuthenticationSessionManager = WebAuthenticationSessionManager(plugin: self)
-        printJobManager = PrintJobManager()
+        printJobManager = PrintJobManager(plugin: self)
     }
     
     public static func register(with registrar: FlutterPluginRegistrar) {
@@ -74,8 +74,8 @@ public class SwiftFlutterPlugin: NSObject, FlutterPlugin {
         headlessInAppWebViewManager = nil
         chromeSafariBrowserManager?.dispose()
         chromeSafariBrowserManager = nil
-        inAppWebViewStatic?.dispose()
+        inAppWebViewManager?.dispose()
-        inAppWebViewStatic = nil
+        inAppWebViewManager = nil
         credentialDatabase?.dispose()
         credentialDatabase = nil
         if #available(iOS 11.0, *) {

ios/Classes/Util.swift

@@ -11,17 +11,17 @@ import WebKit
 var SharedLastTouchPointTimestamp: [InAppWebView: Int64] = [:]
 
 public class Util {
-    public static func getUrlAsset(registrar: FlutterPluginRegistrar, assetFilePath: String) throws -> URL {
+    public static func getUrlAsset(plugin: SwiftFlutterPlugin, assetFilePath: String) throws -> URL {
-        let key = registrar.lookupKey(forAsset: assetFilePath)
+        guard let key = plugin.registrar?.lookupKey(forAsset: assetFilePath),
-        guard let assetURL = Bundle.main.url(forResource: key, withExtension: nil) else {
+              let assetURL = Bundle.main.url(forResource: key, withExtension: nil) else {
             throw NSError(domain: assetFilePath + " asset file cannot be found!", code: 0)
         }
         return assetURL
     }
     
-    public static func getAbsPathAsset(registrar: FlutterPluginRegistrar, assetFilePath: String) throws -> String {
+    public static func getAbsPathAsset(plugin: SwiftFlutterPlugin, assetFilePath: String) throws -> String {
-        let key = registrar.lookupKey(forAsset: assetFilePath)
+        guard let key = plugin.registrar?.lookupKey(forAsset: assetFilePath),
-        guard let assetAbsPath = Bundle.main.path(forResource: key, ofType: nil) else {
+              let assetAbsPath = Bundle.main.path(forResource: key, ofType: nil) else {
             throw NSError(domain: assetFilePath + " asset file cannot be found!", code: 0)
         }
         return assetAbsPath

ios/Classes/WebAuthenticationSession/WebAuthenticationSession.swift

@@ -98,7 +98,7 @@ public class WebAuthenticationSession : NSObject, ASWebAuthenticationPresentatio
         channelDelegate?.dispose()
         channelDelegate = nil
         session = nil
-        WebAuthenticationSessionManager.sessions[id] = nil
+        plugin?.webAuthenticationSessionManager?.sessions[id] = nil
         plugin = nil
     }
     

ios/Classes/WebAuthenticationSession/WebAuthenticationSessionManager.swift

@@ -15,7 +15,7 @@ import SafariServices
 public class WebAuthenticationSessionManager: ChannelDelegate {
     static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_webauthenticationsession"
     var plugin: SwiftFlutterPlugin?
-    static var sessions: [String: WebAuthenticationSession?] = [:]
+    var sessions: [String: WebAuthenticationSession?] = [:]
     
     init(plugin: SwiftFlutterPlugin) {
         super.init(channel: FlutterMethodChannel(name: WebAuthenticationSessionManager.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger()))
@@ -53,7 +53,7 @@ public class WebAuthenticationSessionManager: ChannelDelegate {
             let _ = initialSettings.parse(settings: settings)
             let session = WebAuthenticationSession(plugin: plugin, id: id, url: sessionUrl, callbackURLScheme: callbackURLScheme, settings: initialSettings)
             session.prepare()
-            WebAuthenticationSessionManager.sessions[id] = session
+            sessions[id] = session
             result(true)
             return
         }
@@ -63,12 +63,12 @@ public class WebAuthenticationSessionManager: ChannelDelegate {
     
     public override func dispose() {
         super.dispose()
-        let sessions = WebAuthenticationSessionManager.sessions.values
+        let sessionValues = sessions.values
-        sessions.forEach { (session: WebAuthenticationSession?) in
+        sessionValues.forEach { (session: WebAuthenticationSession?) in
             session?.cancel()
             session?.dispose()
         }
-        WebAuthenticationSessionManager.sessions.removeAll()
+        sessions.removeAll()
         plugin = nil
     }
     

lib/src/android/main.dart

@@ -1,6 +1,6 @@
 export 'service_worker_controller.dart';
 export 'webview_feature.dart' show WebViewFeature, AndroidWebViewFeature;
-export 'proxy_controller.dart';
+export 'proxy_controller.dart' show ProxyController, ProxySettings;
 export 'webview_asset_loader.dart'
     show
         WebViewAssetLoader,

lib/src/android/proxy_controller.dart

@@ -1,9 +1,13 @@
 import 'dart:async';
 import 'package:flutter/services.dart';
+import 'package:flutter_inappwebview_internal_annotations/flutter_inappwebview_internal_annotations.dart';
+import '../types/proxy_rule.dart';
 import 'webview_feature.dart';
 import '../in_app_webview/webview.dart';
 import '../types/main.dart';
 
+part 'proxy_controller.g.dart';
+
 ///Manages setting and clearing a process-specific override for the Android system-wide proxy settings that govern network requests made by [WebView].
 ///
 ///[WebView] may make network requests in order to fetch content that is not otherwise read from the file system or provided directly by application code.
@@ -78,7 +82,8 @@ class ProxyController {
 ///
 ///**Supported Platforms/Implementations**:
 ///- Android native WebView ([Official API - ProxyConfig](https://developer.android.com/reference/androidx/webkit/ProxyConfig))
-class ProxySettings {
+@ExchangeableObject(copyMethod: true)
+class ProxySettings_ {
   ///List of bypass rules.
   ///
   ///A bypass rule describes URLs that should skip proxy override settings and make a direct connection instead. These can be URLs or IP addresses. Wildcards are accepted.
@@ -99,7 +104,7 @@ class ProxySettings {
   ///Port number is optional and defaults to `80` for `HTTP`, `443` for `HTTPS` and `1080` for `SOCKS`.
   ///
   ///The correct syntax for hosts is defined by [RFC 3986](https://tools.ietf.org/html/rfc3986#section-3.2.2).
-  List<ProxyRule> proxyRules;
+  List<ProxyRule_> proxyRules;
 
   ///Hostnames without a period in them (and that are not IP literals) will skip proxy settings and be connected to directly instead. Examples: `"abc"`, `"local"`, `"some-domain"`.
   ///
@@ -128,7 +133,7 @@ class ProxySettings {
   ///**NOTE**: available only if [WebViewFeature.PROXY_OVERRIDE_REVERSE_BYPASS] feature is supported.
   bool reverseBypassEnabled;
 
-  ProxySettings(
+  ProxySettings_(
       {this.bypassRules = const [],
       this.directs = const [],
       this.proxyRules = const [],
@@ -136,40 +141,40 @@ class ProxySettings {
       this.removeImplicitRules,
       this.reverseBypassEnabled = false});
 
-  Map<String, dynamic> toMap() {
+  // Map<String, dynamic> toMap() {
-    return {
+  //   return {
-      "bypassRules": bypassRules,
+  //     "bypassRules": bypassRules,
-      "directs": directs,
+  //     "directs": directs,
-      "proxyRules": proxyRules.map((e) => e.toMap()).toList(),
+  //     "proxyRules": proxyRules.map((e) => e.toMap()).toList(),
-      "bypassSimpleHostnames": bypassSimpleHostnames,
+  //     "bypassSimpleHostnames": bypassSimpleHostnames,
-      "removeImplicitRules": removeImplicitRules,
+  //     "removeImplicitRules": removeImplicitRules,
-      "reverseBypassEnabled": reverseBypassEnabled
+  //     "reverseBypassEnabled": reverseBypassEnabled
-    };
+  //   };
-  }
+  // }
-
+  //
-  static ProxySettings fromMap(Map<String, dynamic> map) {
+  // static ProxySettings fromMap(Map<String, dynamic> map) {
-    var settings = ProxySettings();
+  //   var settings = ProxySettings();
-    settings.bypassRules = map["bypassRules"];
+  //   settings.bypassRules = map["bypassRules"];
-    settings.directs = map["directs"];
+  //   settings.directs = map["directs"];
-    settings.proxyRules = (map["proxyRules"].cast<Map<String, dynamic>>()
+  //   settings.proxyRules = (map["proxyRules"].cast<Map<String, dynamic>>()
-            as List<Map<String, dynamic>>)
+  //           as List<Map<String, dynamic>>)
-        .map((e) => ProxyRule.fromMap(e)) as List<ProxyRule>;
+  //       .map((e) => ProxyRule.fromMap(e)) as List<ProxyRule>;
-    settings.bypassSimpleHostnames = map["bypassSimpleHostnames"];
+  //   settings.bypassSimpleHostnames = map["bypassSimpleHostnames"];
-    settings.removeImplicitRules = map["removeImplicitRules"];
+  //   settings.removeImplicitRules = map["removeImplicitRules"];
-    settings.reverseBypassEnabled = map["reverseBypassEnabled"];
+  //   settings.reverseBypassEnabled = map["reverseBypassEnabled"];
-    return settings;
+  //   return settings;
-  }
+  // }
-
+  //
-  Map<String, dynamic> toJson() {
+  // Map<String, dynamic> toJson() {
-    return this.toMap();
+  //   return this.toMap();
-  }
+  // }
-
+  //
-  @override
+  // @override
-  String toString() {
+  // String toString() {
-    return toMap().toString();
+  //   return 'ProxySettings{bypassRules: $bypassRules, directs: $directs, proxyRules: $proxyRules, bypassSimpleHostnames: $bypassSimpleHostnames, removeImplicitRules: $removeImplicitRules, reverseBypassEnabled: $reverseBypassEnabled}';
-  }
+  // }
-
+  //
-  ProxySettings copy() {
+  // ProxySettings copy() {
-    return ProxySettings.fromMap(this.toMap());
+  //   return ProxySettings.fromMap(this.toMap());
-  }
+  // }
 }

lib/src/android/proxy_controller.g.dart

@@ -0,0 +1,114 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'proxy_controller.dart';
+
+// **************************************************************************
+// ExchangeableObjectGenerator
+// **************************************************************************
+
+///Class that represents the settings used to configure the [ProxyController].
+///
+///**Supported Platforms/Implementations**:
+///- Android native WebView ([Official API - ProxyConfig](https://developer.android.com/reference/androidx/webkit/ProxyConfig))
+class ProxySettings {
+  ///List of bypass rules.
+  ///
+  ///A bypass rule describes URLs that should skip proxy override settings and make a direct connection instead. These can be URLs or IP addresses. Wildcards are accepted.
+  ///For instance, the rule "*example.com" would mean that requests to "http://example.com" and "www.example.com" would not be directed to any proxy,
+  ///instead, would be made directly to the origin specified by the URL.
+  List<String> bypassRules;
+
+  ///Hostnames without a period in them (and that are not IP literals) will skip proxy settings and be connected to directly instead. Examples: `"abc"`, `"local"`, `"some-domain"`.
+  ///
+  ///Hostnames with a trailing dot are not considered simple by this definition.
+  bool? bypassSimpleHostnames;
+
+  ///List of scheme filters.
+  ///
+  ///URLs that match these scheme filters are connected to directly instead of using a proxy server.
+  List<String> directs;
+
+  ///List of proxy rules to be used for all URLs. This method can be called multiple times to add multiple rules. Additional rules have decreasing precedence.
+  ///
+  ///Proxy is a string in the format `[scheme://]host[:port]`.
+  ///Scheme is optional, if present must be `HTTP`, `HTTPS` or [SOCKS](https://tools.ietf.org/html/rfc1928) and defaults to `HTTP`.
+  ///Host is one of an IPv6 literal with brackets, an IPv4 literal or one or more labels separated by a period.
+  ///Port number is optional and defaults to `80` for `HTTP`, `443` for `HTTPS` and `1080` for `SOCKS`.
+  ///
+  ///The correct syntax for hosts is defined by [RFC 3986](https://tools.ietf.org/html/rfc3986#section-3.2.2).
+  List<ProxyRule> proxyRules;
+
+  ///By default, certain hostnames implicitly bypass the proxy if they are link-local IPs, or localhost addresses.
+  ///For instance hostnames matching any of (non-exhaustive list):
+  ///- localhost
+  ///- *.localhost
+  ///- [::1]
+  ///- 127.0.0.1/8
+  ///- 169.254/16
+  ///- [FE80::]/10
+  ///Set this to `true` to override the default behavior and force localhost and link-local URLs to be sent through the proxy.
+  bool? removeImplicitRules;
+
+  ///Reverse the bypass list.
+  ///
+  ///The default value is `false`, in which case all URLs will use proxy settings except the ones in the bypass list, which will be connected to directly instead.
+  ///
+  ///If set to `true`, then only URLs in the bypass list will use these proxy settings, and all other URLs will be connected to directly.
+  ///
+  ///Use [bypassRules] to add bypass rules.
+  ///
+  ///**NOTE**: available only if [WebViewFeature.PROXY_OVERRIDE_REVERSE_BYPASS] feature is supported.
+  bool reverseBypassEnabled;
+  ProxySettings(
+      {this.bypassRules = const [],
+      this.bypassSimpleHostnames,
+      this.directs = const [],
+      this.proxyRules = const [],
+      this.removeImplicitRules,
+      this.reverseBypassEnabled = false});
+
+  ///Gets a possible [ProxySettings] instance from a [Map] value.
+  static ProxySettings? fromMap(Map<String, dynamic>? map) {
+    if (map == null) {
+      return null;
+    }
+    final instance = ProxySettings(
+      bypassSimpleHostnames: map['bypassSimpleHostnames'],
+      removeImplicitRules: map['removeImplicitRules'],
+    );
+    instance.bypassRules =
+        List<String>.from(map['bypassRules']!.cast<String>());
+    instance.directs = List<String>.from(map['directs']!.cast<String>());
+    instance.proxyRules = List<ProxyRule>.from(map['proxyRules']
+        .map((e) => ProxyRule.fromMap(e?.cast<String, dynamic>())!));
+    instance.reverseBypassEnabled = map['reverseBypassEnabled'];
+    return instance;
+  }
+
+  ///Converts instance to a map.
+  Map<String, dynamic> toMap() {
+    return {
+      "bypassRules": bypassRules,
+      "bypassSimpleHostnames": bypassSimpleHostnames,
+      "directs": directs,
+      "proxyRules": proxyRules.map((e) => e.toMap()).toList(),
+      "removeImplicitRules": removeImplicitRules,
+      "reverseBypassEnabled": reverseBypassEnabled,
+    };
+  }
+
+  ///Converts instance to a map.
+  Map<String, dynamic> toJson() {
+    return toMap();
+  }
+
+  ///Returns a copy of ProxySettings.
+  ProxySettings copy() {
+    return ProxySettings.fromMap(toMap()) ?? ProxySettings();
+  }
+
+  @override
+  String toString() {
+    return 'ProxySettings{bypassRules: $bypassRules, bypassSimpleHostnames: $bypassSimpleHostnames, directs: $directs, proxyRules: $proxyRules, removeImplicitRules: $removeImplicitRules, reverseBypassEnabled: $reverseBypassEnabled}';
+  }
+}

lib/src/chrome_safari_browser/chrome_safari_browser.dart

@@ -15,30 +15,6 @@ import '../debug_logging_settings.dart';
 import '../web_uri.dart';
 import 'chrome_safari_browser_settings.dart';
 
-class ChromeSafariBrowserAlreadyOpenedException implements Exception {
-  final dynamic message;
-
-  ChromeSafariBrowserAlreadyOpenedException([this.message]);
-
-  String toString() {
-    Object? message = this.message;
-    if (message == null) return "ChromeSafariBrowserAlreadyOpenedException";
-    return "ChromeSafariBrowserAlreadyOpenedException: $message";
-  }
-}
-
-class ChromeSafariBrowserNotOpenedException implements Exception {
-  final dynamic message;
-
-  ChromeSafariBrowserNotOpenedException([this.message]);
-
-  String toString() {
-    Object? message = this.message;
-    if (message == null) return "ChromeSafariBrowserNotOpenedException";
-    return "ChromeSafariBrowserNotOpenedException: $message";
-  }
-}
-
 ///This class uses native [Chrome Custom Tabs](https://developer.android.com/reference/android/support/customtabs/package-summary) on Android
 ///and [SFSafariViewController](https://developer.apple.com/documentation/safariservices/sfsafariviewcontroller) on iOS.
 ///
@@ -60,7 +36,7 @@ class ChromeSafariBrowser {
   Map<int, ChromeSafariBrowserMenuItem> _menuItems = new HashMap();
   ChromeSafariBrowserSecondaryToolbar? _secondaryToolbar;
   bool _isOpened = false;
-  late MethodChannel _channel;
+  MethodChannel? _channel;
   static const MethodChannel _sharedChannel =
       const MethodChannel('com.pichillilorenzo/flutter_chromesafaribrowser');
 
@@ -68,7 +44,7 @@ class ChromeSafariBrowser {
     id = IdGenerator.generate();
     this._channel =
         MethodChannel('com.pichillilorenzo/flutter_chromesafaribrowser_$id');
-    this._channel.setMethodCallHandler((call) async {
+    this._channel?.setMethodCallHandler((call) async {
       try {
         return await _handleMethod(call);
       } on Error catch (e) {
@@ -79,6 +55,19 @@ class ChromeSafariBrowser {
     _isOpened = false;
   }
 
+  _init() {
+    this._channel =
+        MethodChannel('com.pichillilorenzo/flutter_chromesafaribrowser_$id');
+    this._channel?.setMethodCallHandler((call) async {
+      try {
+        return await _handleMethod(call);
+      } on Error catch (e) {
+        print(e);
+        print(e.stackTrace);
+      }
+    });
+  }
+
   _debugLog(String method, dynamic args) {
     debugLog(
         className: this.runtimeType.toString(),
@@ -125,8 +114,9 @@ class ChromeSafariBrowser {
         onWillOpenInBrowser();
         break;
       case "onClosed":
+        _isOpened = false;
+        _dispose();
         onClosed();
-        this._isOpened = false;
         break;
       case "onItemActionPerform":
         String url = call.arguments["url"];
@@ -208,6 +198,9 @@ class ChromeSafariBrowser {
           // ignore: deprecated_member_use_from_same_package
           ChromeSafariBrowserClassOptions? options,
       ChromeSafariBrowserSettings? settings}) async {
+    assert(!_isOpened, 'The browser is already opened.');
+    _isOpened = true;
+
     if (Util.isIOS) {
       assert(url != null, 'The specified URL must not be null on iOS.');
       assert(['http', 'https'].contains(url!.scheme),
@@ -216,9 +209,8 @@ class ChromeSafariBrowser {
     if (url != null) {
       assert(url.toString().isNotEmpty, 'The specified URL must not be empty.');
     }
-    this.throwIsAlreadyOpened(message: url != null ? 'Cannot open $url!' : '');
 
-    this._isOpened = true;
+    _init();
 
     List<Map<String, dynamic>> menuItemList = [];
     _menuItems.forEach((key, value) {
@@ -269,7 +261,7 @@ class ChromeSafariBrowser {
     args.putIfAbsent('otherLikelyURLs',
         () => otherLikelyURLs?.map((e) => e.toString()).toList());
     args.putIfAbsent('referrer', () => referrer?.toString());
-    await _channel.invokeMethod("launchUrl", args);
+    await _channel?.invokeMethod("launchUrl", args);
   }
 
   ///Tells the browser of a likely future navigation to a URL.
@@ -290,7 +282,7 @@ class ChromeSafariBrowser {
     args.putIfAbsent('url', () => url?.toString());
     args.putIfAbsent('otherLikelyURLs',
         () => otherLikelyURLs?.map((e) => e.toString()).toList());
-    return await _channel.invokeMethod("mayLaunchUrl", args);
+    return await _channel?.invokeMethod("mayLaunchUrl", args);
   }
 
   ///Requests to validate a relationship between the application and an origin.
@@ -315,7 +307,7 @@ class ChromeSafariBrowser {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('relation', () => relation.toNativeValue());
     args.putIfAbsent('origin', () => origin.toString());
-    return await _channel.invokeMethod("validateRelationship", args);
+    return await _channel?.invokeMethod("validateRelationship", args);
   }
 
   ///Closes the [ChromeSafariBrowser] instance.
@@ -325,7 +317,7 @@ class ChromeSafariBrowser {
   ///- iOS
   Future<void> close() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod("close", args);
+    await _channel?.invokeMethod("close", args);
   }
 
   ///Set a custom action button.
@@ -349,7 +341,7 @@ class ChromeSafariBrowser {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('icon', () => icon);
     args.putIfAbsent('description', () => description);
-    await _channel.invokeMethod("updateActionButton", args);
+    await _channel?.invokeMethod("updateActionButton", args);
     _actionButton?.icon = icon;
     _actionButton?.description = description;
   }
@@ -375,7 +367,7 @@ class ChromeSafariBrowser {
       ChromeSafariBrowserSecondaryToolbar secondaryToolbar) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('secondaryToolbar', () => secondaryToolbar.toMap());
-    await _channel.invokeMethod("updateSecondaryToolbar", args);
+    await _channel?.invokeMethod("updateSecondaryToolbar", args);
     this._secondaryToolbar = secondaryToolbar;
   }
 
@@ -546,23 +538,13 @@ class ChromeSafariBrowser {
   ///- Android
   ///- iOS
   bool isOpened() {
-    return this._isOpened;
+    return _isOpened;
   }
 
-  void throwIsAlreadyOpened({String message = ''}) {
+  ///Disposes the channel.
-    if (this.isOpened()) {
+  void _dispose() {
-      throw ChromeSafariBrowserAlreadyOpenedException([
+    _channel?.setMethodCallHandler(null);
-        'Error: ${(message.isEmpty) ? '' : message + ' '}The browser is already opened.'
+    _channel = null;
-      ]);
-    }
-  }
-
-  void throwIsNotOpened({String message = ''}) {
-    if (!this.isOpened()) {
-      throw ChromeSafariBrowserNotOpenedException([
-        'Error: ${(message.isEmpty) ? '' : message + ' '}The browser is not opened.'
-      ]);
-    }
   }
 }
 

lib/src/cookie_manager.dart

@@ -275,7 +275,7 @@ class CookieManager {
     await pageLoaded.future;
 
     List<String> documentCookies = (await headlessWebView.webViewController
-            .evaluateJavascript(source: 'document.cookie') as String)
+            !.evaluateJavascript(source: 'document.cookie') as String)
         .split(';')
         .map((documentCookie) => documentCookie.trim())
         .toList();

lib/src/find_interaction/find_interaction_controller.dart

@@ -37,20 +37,6 @@ class FindInteractionController {
 
   FindInteractionController({this.onFindResultReceived}) {}
 
-  void initMethodChannel(dynamic id) {
-    this._channel = MethodChannel(
-        'com.pichillilorenzo/flutter_inappwebview_find_interaction_$id');
-
-    this._channel?.setMethodCallHandler((call) async {
-      try {
-        return await _handleMethod(call);
-      } on Error catch (e) {
-        print(e);
-        print(e.stackTrace);
-      }
-    });
-  }
-
   _debugLog(String method, dynamic args) {
     debugLog(
         className: this.runtimeType.toString(),
@@ -217,4 +203,29 @@ class FindInteractionController {
             ?.cast<String, dynamic>();
     return FindSession.fromMap(result);
   }
+
+  ///Disposes the controller.
+  void dispose({bool isKeepAlive = false}) {
+    if (!isKeepAlive) {
+      _channel?.setMethodCallHandler(null);
+    }
+    _channel = null;
+  }
+}
+
+extension InternalFindInteractionController on FindInteractionController {
+  void init(dynamic id) {
+    this._channel = MethodChannel(
+        'com.pichillilorenzo/flutter_inappwebview_find_interaction_$id');
+
+    this._channel?.setMethodCallHandler((call) async {
+      if (_channel == null) return null;
+      try {
+        return await _handleMethod(call);
+      } on Error catch (e) {
+        print(e);
+        print(e.stackTrace);
+      }
+    });
+  }
 }

lib/src/find_interaction/main.dart

@@ -1 +1 @@
-export 'find_interaction_controller.dart';
+export 'find_interaction_controller.dart' show FindInteractionController;

lib/src/in_app_browser/in_app_browser.dart

@@ -18,30 +18,7 @@ import '../print_job/main.dart';
 import '../web_uri.dart';
 import 'in_app_browser_settings.dart';
 import '../debug_logging_settings.dart';
-
+import '../pull_to_refresh/pull_to_refresh_controller.dart';
-class InAppBrowserAlreadyOpenedException implements Exception {
-  final dynamic message;
-
-  InAppBrowserAlreadyOpenedException([this.message]);
-
-  String toString() {
-    Object? message = this.message;
-    if (message == null) return "InAppBrowserAlreadyOpenedException";
-    return "InAppBrowserAlreadyOpenedException: $message";
-  }
-}
-
-class InAppBrowserNotOpenedException implements Exception {
-  final dynamic message;
-
-  InAppBrowserNotOpenedException([this.message]);
-
-  String toString() {
-    Object? message = this.message;
-    if (message == null) return "InAppBrowserNotOpenedException";
-    return "InAppBrowserNotOpenedException: $message";
-  }
-}
 
 ///This class uses the native WebView of the platform.
 ///The [webViewController] field can be used to access the [InAppWebViewController] API.
@@ -70,11 +47,11 @@ class InAppBrowser {
   final UnmodifiableListView<UserScript>? initialUserScripts;
 
   bool _isOpened = false;
-  late MethodChannel _channel;
+  MethodChannel? _channel;
   static const MethodChannel _sharedChannel =
       const MethodChannel('com.pichillilorenzo/flutter_inappbrowser');
 
-  late final InAppWebViewController _webViewController;
+  InAppWebViewController? _webViewController;
 
   ///WebView Controller that can be used to access the [InAppWebViewController] API.
   ///When [onExit] is fired, this will be `null` and cannot be used anymore.
@@ -85,18 +62,16 @@ class InAppBrowser {
   ///The window id of a [CreateWindowAction.windowId].
   final int? windowId;
 
-  ///Represents the WebView native implementation to be used.
-  ///The default value is [WebViewImplementation.NATIVE].
-  final WebViewImplementation implementation;
-
   InAppBrowser(
       {this.windowId,
-      this.initialUserScripts,
+      this.initialUserScripts}) {
-      this.implementation = WebViewImplementation.NATIVE}) {
     id = IdGenerator.generate();
+  }
+
+  _init() {
     this._channel =
         MethodChannel('com.pichillilorenzo/flutter_inappbrowser_$id');
-    this._channel.setMethodCallHandler((call) async {
+    this._channel?.setMethodCallHandler((call) async {
       try {
         return await _handleMethod(call);
       } on Error catch (e) {
@@ -104,9 +79,10 @@ class InAppBrowser {
         print(e.stackTrace);
       }
     });
-    _isOpened = false;
     _webViewController = new InAppWebViewController.fromInAppBrowser(
-        this._channel, this, this.initialUserScripts);
+        this._channel!, this, this.initialUserScripts);
+    pullToRefreshController?.init(id);
+    findInteractionController?.init(id);
   }
 
   _debugLog(String method, dynamic args) {
@@ -122,18 +98,16 @@ class InAppBrowser {
     switch (call.method) {
       case "onBrowserCreated":
         _debugLog(call.method, call.arguments);
-        this._isOpened = true;
-        this.pullToRefreshController?.initMethodChannel(id);
-        this.findInteractionController?.initMethodChannel(id);
         onBrowserCreated();
         break;
       case "onExit":
         _debugLog(call.method, call.arguments);
-        this._isOpened = false;
+        _isOpened = false;
+        _dispose();
         onExit();
         break;
       default:
-        return _webViewController.handleMethod(call);
+        return _webViewController?.handleMethod(call);
     }
   }
 
@@ -154,8 +128,10 @@ class InAppBrowser {
       // ignore: deprecated_member_use_from_same_package
       @Deprecated('Use settings instead') InAppBrowserClassOptions? options,
       InAppBrowserClassSettings? settings}) async {
-    this.throwIfAlreadyOpened(message: 'Cannot open $urlRequest!');
+    assert(!_isOpened, 'The browser is already opened.');
+    _isOpened = true;
     assert(urlRequest.url != null && urlRequest.url.toString().isNotEmpty);
+    _init();
 
     var initialSettings = settings?.toMap() ??
         options?.toMap() ??
@@ -173,7 +149,6 @@ class InAppBrowser {
     args.putIfAbsent('settings', () => initialSettings);
     args.putIfAbsent('contextMenu', () => contextMenu?.toMap() ?? {});
     args.putIfAbsent('windowId', () => windowId);
-    args.putIfAbsent('implementation', () => implementation.toNativeValue());
     args.putIfAbsent('initialUserScripts',
         () => initialUserScripts?.map((e) => e.toMap()).toList() ?? []);
     args.putIfAbsent('pullToRefreshSettings', () => pullToRefreshSettings);
@@ -227,8 +202,10 @@ class InAppBrowser {
       // ignore: deprecated_member_use_from_same_package
       @Deprecated('Use settings instead') InAppBrowserClassOptions? options,
       InAppBrowserClassSettings? settings}) async {
-    this.throwIfAlreadyOpened(message: 'Cannot open $assetFilePath!');
+    assert(!_isOpened, 'The browser is already opened.');
+    _isOpened = true;
     assert(assetFilePath.isNotEmpty);
+    _init();
 
     var initialSettings = settings?.toMap() ??
         options?.toMap() ??
@@ -246,7 +223,6 @@ class InAppBrowser {
     args.putIfAbsent('settings', () => initialSettings);
     args.putIfAbsent('contextMenu', () => contextMenu?.toMap() ?? {});
     args.putIfAbsent('windowId', () => windowId);
-    args.putIfAbsent('implementation', () => implementation.toNativeValue());
     args.putIfAbsent('initialUserScripts',
         () => initialUserScripts?.map((e) => e.toMap()).toList() ?? []);
     args.putIfAbsent('pullToRefreshSettings', () => pullToRefreshSettings);
@@ -279,7 +255,9 @@ class InAppBrowser {
       // ignore: deprecated_member_use_from_same_package
       @Deprecated('Use settings instead') InAppBrowserClassOptions? options,
       InAppBrowserClassSettings? settings}) async {
-    this.throwIfAlreadyOpened(message: 'Cannot open data!');
+    assert(!_isOpened, 'The browser is already opened.');
+    _isOpened = true;
+    _init();
 
     var initialSettings = settings?.toMap() ??
         options?.toMap() ??
@@ -302,7 +280,6 @@ class InAppBrowser {
         () => (historyUrl ?? androidHistoryUrl)?.toString() ?? "about:blank");
     args.putIfAbsent('contextMenu', () => contextMenu?.toMap() ?? {});
     args.putIfAbsent('windowId', () => windowId);
-    args.putIfAbsent('implementation', () => implementation.toNativeValue());
     args.putIfAbsent('initialUserScripts',
         () => initialUserScripts?.map((e) => e.toMap()).toList() ?? []);
     args.putIfAbsent('pullToRefreshSettings', () => pullToRefreshSettings);
@@ -317,6 +294,7 @@ class InAppBrowser {
   ///- MacOS
   static Future<void> openWithSystemBrowser({required WebUri url}) async {
     assert(url.toString().isNotEmpty);
+
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('url', () => url.toString());
     return await _sharedChannel.invokeMethod('openWithSystemBrowser', args);
@@ -329,9 +307,10 @@ class InAppBrowser {
   ///- iOS
   ///- MacOS
   Future<void> show() async {
-    this.throwIfNotOpened();
+    assert(_isOpened, 'The browser is not opened.');
+
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('show', args);
+    await _channel?.invokeMethod('show', args);
   }
 
   ///Hides the [InAppBrowser] window. Calling this has no effect if the [InAppBrowser] was already hidden.
@@ -341,9 +320,10 @@ class InAppBrowser {
   ///- iOS
   ///- MacOS
   Future<void> hide() async {
-    this.throwIfNotOpened();
+    assert(_isOpened, 'The browser is not opened.');
+
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('hide', args);
+    await _channel?.invokeMethod('hide', args);
   }
 
   ///Closes the [InAppBrowser] window.
@@ -353,9 +333,10 @@ class InAppBrowser {
   ///- iOS
   ///- MacOS
   Future<void> close() async {
-    this.throwIfNotOpened();
+    assert(_isOpened, 'The browser is not opened.');
+
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('close', args);
+    await _channel?.invokeMethod('close', args);
   }
 
   ///Check if the Web View of the [InAppBrowser] instance is hidden.
@@ -365,29 +346,30 @@ class InAppBrowser {
   ///- iOS
   ///- MacOS
   Future<bool> isHidden() async {
-    this.throwIfNotOpened();
+    assert(_isOpened, 'The browser is not opened.');
+
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('isHidden', args);
+    return await _channel?.invokeMethod('isHidden', args);
   }
 
   ///Use [setSettings] instead.
   @Deprecated('Use setSettings instead')
   Future<void> setOptions({required InAppBrowserClassOptions options}) async {
-    this.throwIfNotOpened();
+    assert(_isOpened, 'The browser is not opened.');
 
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('settings', () => options.toMap());
-    await _channel.invokeMethod('setSettings', args);
+    await _channel?.invokeMethod('setSettings', args);
   }
 
   ///Use [getSettings] instead.
   @Deprecated('Use getSettings instead')
   Future<InAppBrowserClassOptions?> getOptions() async {
-    this.throwIfNotOpened();
+    assert(_isOpened, 'The browser is not opened.');
     Map<String, dynamic> args = <String, dynamic>{};
 
     Map<dynamic, dynamic>? options =
-        await _channel.invokeMethod('getSettings', args);
+        await _channel?.invokeMethod('getSettings', args);
     if (options != null) {
       options = options.cast<String, dynamic>();
       return InAppBrowserClassOptions.fromMap(options as Map<String, dynamic>);
@@ -404,11 +386,11 @@ class InAppBrowser {
   ///- MacOS
   Future<void> setSettings(
       {required InAppBrowserClassSettings settings}) async {
-    this.throwIfNotOpened();
+    assert(_isOpened, 'The browser is not opened.');
 
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('settings', () => settings.toMap());
-    await _channel.invokeMethod('setSettings', args);
+    await _channel?.invokeMethod('setSettings', args);
   }
 
   ///Gets the current [InAppBrowser] settings. Returns `null` if it wasn't able to get them.
@@ -418,11 +400,12 @@ class InAppBrowser {
   ///- iOS
   ///- MacOS
   Future<InAppBrowserClassSettings?> getSettings() async {
-    this.throwIfNotOpened();
+    assert(_isOpened, 'The browser is not opened.');
+
     Map<String, dynamic> args = <String, dynamic>{};
 
     Map<dynamic, dynamic>? settings =
-        await _channel.invokeMethod('getSettings', args);
+        await _channel?.invokeMethod('getSettings', args);
     if (settings != null) {
       settings = settings.cast<String, dynamic>();
       return InAppBrowserClassSettings.fromMap(
@@ -1321,19 +1304,15 @@ class InAppBrowser {
   ///- iOS
   void onContentSizeChanged(Size oldContentSize, Size newContentSize) {}
 
-  void throwIfAlreadyOpened({String message = ''}) {
+  ///Disposes the channel and controllers.
-    if (this.isOpened()) {
+  void _dispose() {
-      throw InAppBrowserAlreadyOpenedException([
+    _channel?.setMethodCallHandler(null);
-        'Error: ${(message.isEmpty) ? '' : message + ' '}The browser is already opened.'
+    _channel = null;
-      ]);
+    _webViewController?.dispose();
-    }
+    _webViewController = null;
-  }
+    pullToRefreshController?.dispose();
-
+    pullToRefreshController = null;
-  void throwIfNotOpened({String message = ''}) {
+    findInteractionController?.dispose();
-    if (!this.isOpened()) {
+    findInteractionController = null;
-      throw InAppBrowserNotOpenedException([
-        'Error: ${(message.isEmpty) ? '' : message + ' '}The browser is not opened.'
-      ]);
-    }
   }
 }

lib/src/in_app_webview/_static_channel.dart

@@ -1,4 +1,4 @@
 import 'package:flutter/services.dart';
 
 const IN_APP_WEBVIEW_STATIC_CHANNEL =
-    const MethodChannel('com.pichillilorenzo/flutter_inappwebview_static');
+    const MethodChannel('com.pichillilorenzo/flutter_inappwebview_manager');

lib/src/in_app_webview/android/in_app_webview_controller.dart

@@ -8,7 +8,7 @@ import '../in_app_webview_controller.dart';
 ///Use [InAppWebViewController] instead.
 @Deprecated("Use InAppWebViewController instead")
 class AndroidInAppWebViewController {
-  late MethodChannel _channel;
+  MethodChannel? _channel;
 
   AndroidInAppWebViewController({required MethodChannel channel}) {
     this._channel = channel;
@@ -18,28 +18,28 @@ class AndroidInAppWebViewController {
   @Deprecated("Use InAppWebViewController.startSafeBrowsing instead")
   Future<bool> startSafeBrowsing() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('startSafeBrowsing', args);
+    return await _channel?.invokeMethod('startSafeBrowsing', args);
   }
 
   ///Use [InAppWebViewController.clearSslPreferences] instead.
   @Deprecated("Use InAppWebViewController.clearSslPreferences instead")
   Future<void> clearSslPreferences() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('clearSslPreferences', args);
+    await _channel?.invokeMethod('clearSslPreferences', args);
   }
 
   ///Use [InAppWebViewController.pause] instead.
   @Deprecated("Use InAppWebViewController.pause instead")
   Future<void> pause() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('pause', args);
+    await _channel?.invokeMethod('pause', args);
   }
 
   ///Use [InAppWebViewController.resume] instead.
   @Deprecated("Use InAppWebViewController.resume instead")
   Future<void> resume() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('resume', args);
+    await _channel?.invokeMethod('resume', args);
   }
 
   ///Use [InAppWebViewController.pageDown] instead.
@@ -47,7 +47,7 @@ class AndroidInAppWebViewController {
   Future<bool> pageDown({required bool bottom}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("bottom", () => bottom);
-    return await _channel.invokeMethod('pageDown', args);
+    return await _channel?.invokeMethod('pageDown', args);
   }
 
   ///Use [InAppWebViewController.pageUp] instead.
@@ -55,28 +55,28 @@ class AndroidInAppWebViewController {
   Future<bool> pageUp({required bool top}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("top", () => top);
-    return await _channel.invokeMethod('pageUp', args);
+    return await _channel?.invokeMethod('pageUp', args);
   }
 
   ///Use [InAppWebViewController.zoomIn] instead.
   @Deprecated("Use InAppWebViewController.zoomIn instead")
   Future<bool> zoomIn() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('zoomIn', args);
+    return await _channel?.invokeMethod('zoomIn', args);
   }
 
   ///Use [InAppWebViewController.zoomOut] instead.
   @Deprecated("Use InAppWebViewController.zoomOut instead")
   Future<bool> zoomOut() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('zoomOut', args);
+    return await _channel?.invokeMethod('zoomOut', args);
   }
 
   ///Use [InAppWebViewController.clearHistory] instead.
   @Deprecated("Use InAppWebViewController.clearHistory instead")
   Future<void> clearHistory() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('clearHistory', args);
+    return await _channel?.invokeMethod('clearHistory', args);
   }
 
   ///Use [InAppWebViewController.clearClientCertPreferences] instead.
@@ -120,7 +120,11 @@ class AndroidInAppWebViewController {
   @Deprecated('Use InAppWebViewController.getOriginalUrl instead')
   Future<Uri?> getOriginalUrl() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    String? url = await _channel.invokeMethod('getOriginalUrl', args);
+    String? url = await _channel?.invokeMethod('getOriginalUrl', args);
     return url != null ? Uri.tryParse(url) : null;
   }
+
+  void dispose() {
+    _channel = null;
+  }
 }

lib/src/in_app_webview/apple/in_app_webview_controller.dart

@@ -9,7 +9,8 @@ import '../in_app_webview_controller.dart';
 ///Use [InAppWebViewController] instead.
 @Deprecated("Use InAppWebViewController instead")
 class IOSInAppWebViewController {
-  late MethodChannel _channel;
+  MethodChannel? _channel;
+
   IOSInAppWebViewController({required MethodChannel channel}) {
     this._channel = channel;
   }
@@ -18,7 +19,7 @@ class IOSInAppWebViewController {
   @Deprecated("Use InAppWebViewController.reloadFromOrigin instead")
   Future<void> reloadFromOrigin() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('reloadFromOrigin', args);
+    await _channel?.invokeMethod('reloadFromOrigin', args);
   }
 
   ///Use [InAppWebViewController.createPdf] instead.
@@ -31,21 +32,21 @@ class IOSInAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('pdfConfiguration',
         () => pdfConfiguration?.toMap() ?? iosWKPdfConfiguration?.toMap());
-    return await _channel.invokeMethod('createPdf', args);
+    return await _channel?.invokeMethod('createPdf', args);
   }
 
   ///Use [InAppWebViewController.createWebArchiveData] instead.
   @Deprecated("Use InAppWebViewController.createWebArchiveData instead")
   Future<Uint8List?> createWebArchiveData() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('createWebArchiveData', args);
+    return await _channel?.invokeMethod('createWebArchiveData', args);
   }
 
   ///Use [InAppWebViewController.hasOnlySecureContent] instead.
   @Deprecated("Use InAppWebViewController.hasOnlySecureContent instead")
   Future<bool> hasOnlySecureContent() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('hasOnlySecureContent', args);
+    return await _channel?.invokeMethod('hasOnlySecureContent', args);
   }
 
   ///Use [InAppWebViewController.handlesURLScheme] instead.
@@ -53,4 +54,8 @@ class IOSInAppWebViewController {
   static Future<bool> handlesURLScheme(String urlScheme) async {
     return await InAppWebViewController.handlesURLScheme(urlScheme);
   }
+
+  void dispose() {
+    _channel = null;
+  }
 }

lib/src/in_app_webview/headless_in_app_webview.dart

@@ -3,7 +3,7 @@ import 'dart:typed_data';
 import 'dart:ui';
 
 import 'package:flutter/services.dart';
-import 'package:flutter_inappwebview/src/util.dart';
+import '../util.dart';
 
 import '../context_menu.dart';
 import '../find_interaction/find_interaction_controller.dart';
@@ -38,10 +38,12 @@ class HeadlessInAppWebView implements WebView, Disposable {
 
   static const MethodChannel _sharedChannel =
       const MethodChannel('com.pichillilorenzo/flutter_headless_inappwebview');
-  late MethodChannel _channel;
+  MethodChannel? _channel;
+
+  InAppWebViewController? _webViewController;
 
   ///WebView Controller that can be used to access the [InAppWebViewController] API.
-  late final InAppWebViewController webViewController;
+  InAppWebViewController? get webViewController => _webViewController;
 
   ///{@macro flutter_inappwebview.WebView.windowId}
   final int? windowId;
@@ -74,7 +76,6 @@ class HeadlessInAppWebView implements WebView, Disposable {
       this.initialUserScripts,
       this.pullToRefreshController,
       this.findInteractionController,
-      this.implementation = WebViewImplementation.NATIVE,
       this.onWebViewCreated,
       this.onLoadStart,
       this.onLoadStop,
@@ -180,10 +181,15 @@ class HeadlessInAppWebView implements WebView, Disposable {
       this.onMicrophoneCaptureStateChanged,
       this.onContentSizeChanged}) {
     id = IdGenerator.generate();
-    webViewController = new InAppWebViewController(id, this);
+  }
+
+  _init() {
+    _webViewController = InAppWebViewController(id, this);
+    pullToRefreshController?.init(id);
+    findInteractionController?.init(id);
     this._channel =
         MethodChannel('com.pichillilorenzo/flutter_headless_inappwebview_$id');
-    this._channel.setMethodCallHandler((call) async {
+    this._channel?.setMethodCallHandler((call) async {
       try {
         return await handleMethod(call);
       } on Error catch (e) {
@@ -196,10 +202,8 @@ class HeadlessInAppWebView implements WebView, Disposable {
   Future<dynamic> handleMethod(MethodCall call) async {
     switch (call.method) {
       case "onWebViewCreated":
-        pullToRefreshController?.initMethodChannel(id);
+        if (onWebViewCreated != null && _webViewController != null) {
-        findInteractionController?.initMethodChannel(id);
+          onWebViewCreated!(_webViewController!);
-        if (onWebViewCreated != null) {
-          onWebViewCreated!(webViewController);
         }
         break;
       default:
@@ -222,6 +226,7 @@ class HeadlessInAppWebView implements WebView, Disposable {
       return;
     }
     _started = true;
+    _init();
 
     final initialSettings = this.initialSettings ?? InAppWebViewSettings();
     _inferInitialSettings(initialSettings);
@@ -249,7 +254,6 @@ class HeadlessInAppWebView implements WebView, Disposable {
               'initialSettings': settingsMap,
               'contextMenu': this.contextMenu?.toMap() ?? {},
               'windowId': this.windowId,
-              'implementation': this.implementation.toNativeValue(),
               'initialUserScripts':
                   this.initialUserScripts?.map((e) => e.toMap()).toList() ?? [],
               'pullToRefreshSettings': pullToRefreshSettings,
@@ -306,9 +310,15 @@ class HeadlessInAppWebView implements WebView, Disposable {
       return;
     }
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('dispose', args);
+    await _channel?.invokeMethod('dispose', args);
+    _channel?.setMethodCallHandler(null);
+    _channel = null;
     _started = false;
     _running = false;
+    _webViewController?.dispose();
+    _webViewController = null;
+    pullToRefreshController?.dispose();
+    findInteractionController?.dispose();
   }
 
   ///Indicates if the headless WebView is running or not.
@@ -343,7 +353,7 @@ class HeadlessInAppWebView implements WebView, Disposable {
 
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('size', () => size.toMap());
-    await _channel.invokeMethod('setSize', args);
+    await _channel?.invokeMethod('setSize', args);
   }
 
   ///Gets the current size in pixels of the WebView.
@@ -362,7 +372,7 @@ class HeadlessInAppWebView implements WebView, Disposable {
 
     Map<String, dynamic> args = <String, dynamic>{};
     Map<String, dynamic> sizeMap =
-        (await _channel.invokeMethod('getSize', args))?.cast<String, dynamic>();
+        (await _channel?.invokeMethod('getSize', args))?.cast<String, dynamic>();
     return MapSize.fromMap(sizeMap);
   }
 
@@ -403,10 +413,6 @@ class HeadlessInAppWebView implements WebView, Disposable {
   @override
   final FindInteractionController? findInteractionController;
 
-  ///{@macro flutter_inappwebview.WebView.implementation}
-  @override
-  final WebViewImplementation implementation;
-
   ///Use [onGeolocationPermissionsHidePrompt] instead.
   @override
   @Deprecated('Use onGeolocationPermissionsHidePrompt instead')

lib/src/in_app_webview/in_app_webview.dart

@@ -8,8 +8,8 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter/gestures.dart';
-import 'package:flutter_inappwebview/src/in_app_webview/headless_in_app_webview.dart';
+import 'headless_in_app_webview.dart';
-import 'package:flutter_inappwebview/src/util.dart';
+import '../util.dart';
 
 import '../find_interaction/find_interaction_controller.dart';
 import '../web/web_platform_manager.dart';
@@ -23,6 +23,8 @@ import 'webview.dart';
 import 'in_app_webview_controller.dart';
 import 'in_app_webview_settings.dart';
 import '../pull_to_refresh/main.dart';
+import '../pull_to_refresh/pull_to_refresh_controller.dart';
+import 'in_app_webview_keep_alive.dart';
 
 ///{@template flutter_inappwebview.InAppWebView}
 ///Flutter Widget for adding an **inline native WebView** integrated in the flutter widget tree.
@@ -46,7 +48,7 @@ class InAppWebView extends StatefulWidget implements WebView {
   @override
   final int? windowId;
 
-  ///The [HeadlessInAppWebView] to use to initialize this widget
+  ///The [HeadlessInAppWebView] to use to initialize this widget.
   ///
   ///**Supported Platforms/Implementations**:
   ///- Android native WebView
@@ -54,33 +56,46 @@ class InAppWebView extends StatefulWidget implements WebView {
   ///- Web
   final HeadlessInAppWebView? headlessWebView;
 
+  ///Used to keep alive this WebView.
+  ///Remember to dispose the [InAppWebViewKeepAlive] instance
+  ///using [InAppWebViewController.disposeKeepAlive].
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  ///- iOS
+  final InAppWebViewKeepAlive? keepAlive;
+
   ///{@macro flutter_inappwebview.InAppWebView}
   const InAppWebView({
     Key? key,
     this.windowId,
+    this.keepAlive,
     this.initialUrlRequest,
     this.initialFile,
     this.initialData,
-    @Deprecated('Use initialSettings instead') this.initialOptions,
+    @Deprecated('Use initialSettings instead')
+        this.initialOptions,
     this.initialSettings,
     this.initialUserScripts,
     this.pullToRefreshController,
     this.findInteractionController,
-    this.implementation = WebViewImplementation.NATIVE,
     this.contextMenu,
     this.onWebViewCreated,
     this.onLoadStart,
     this.onLoadStop,
-    @Deprecated("Use onReceivedError instead") this.onLoadError,
+    @Deprecated("Use onReceivedError instead")
+        this.onLoadError,
     this.onReceivedError,
-    @Deprecated("Use onReceivedHttpError instead") this.onLoadHttpError,
+    @Deprecated("Use onReceivedHttpError instead")
+        this.onLoadHttpError,
     this.onReceivedHttpError,
     this.onConsoleMessage,
     this.onProgressChanged,
     this.shouldOverrideUrlLoading,
     this.onLoadResource,
     this.onScrollChanged,
-    @Deprecated('Use onDownloadStartRequest instead') this.onDownloadStart,
+    @Deprecated('Use onDownloadStartRequest instead')
+        this.onDownloadStart,
     this.onDownloadStartRequest,
     @Deprecated('Use onLoadResourceWithCustomScheme instead')
         this.onLoadResourceCustomScheme,
@@ -100,7 +115,8 @@ class InAppWebView extends StatefulWidget implements WebView {
     this.onAjaxProgress,
     this.shouldInterceptFetchRequest,
     this.onUpdateVisitedHistory,
-    @Deprecated("Use onPrintRequest instead") this.onPrint,
+    @Deprecated("Use onPrintRequest instead")
+        this.onPrint,
     this.onPrintRequest,
     this.onLongPressHitTestResult,
     this.onEnterFullscreen,
@@ -111,7 +127,8 @@ class InAppWebView extends StatefulWidget implements WebView {
     this.onWindowBlur,
     this.onOverScrolled,
     this.onZoomScaleChanged,
-    @Deprecated('Use onSafeBrowsingHit instead') this.androidOnSafeBrowsingHit,
+    @Deprecated('Use onSafeBrowsingHit instead')
+        this.androidOnSafeBrowsingHit,
     this.onSafeBrowsingHit,
     @Deprecated('Use onPermissionRequest instead')
         this.androidOnPermissionRequest,
@@ -137,13 +154,16 @@ class InAppWebView extends StatefulWidget implements WebView {
     @Deprecated('Use onFormResubmission instead')
         this.androidOnFormResubmission,
     this.onFormResubmission,
-    @Deprecated('Use onZoomScaleChanged instead') this.androidOnScaleChanged,
+    @Deprecated('Use onZoomScaleChanged instead')
-    @Deprecated('Use onReceivedIcon instead') this.androidOnReceivedIcon,
+        this.androidOnScaleChanged,
+    @Deprecated('Use onReceivedIcon instead')
+        this.androidOnReceivedIcon,
     this.onReceivedIcon,
     @Deprecated('Use onReceivedTouchIconUrl instead')
         this.androidOnReceivedTouchIconUrl,
     this.onReceivedTouchIconUrl,
-    @Deprecated('Use onJsBeforeUnload instead') this.androidOnJsBeforeUnload,
+    @Deprecated('Use onJsBeforeUnload instead')
+        this.androidOnJsBeforeUnload,
     this.onJsBeforeUnload,
     @Deprecated('Use onReceivedLoginRequest instead')
         this.androidOnReceivedLoginRequest,
@@ -222,10 +242,6 @@ class InAppWebView extends StatefulWidget implements WebView {
   @override
   final URLRequest? initialUrlRequest;
 
-  ///{@macro flutter_inappwebview.WebView.implementation}
-  @override
-  final WebViewImplementation implementation;
-
   ///{@macro flutter_inappwebview.WebView.initialUserScripts}
   @override
   final UnmodifiableListView<UserScript>? initialUserScripts;
@@ -704,6 +720,15 @@ class _InAppWebViewState extends State<InAppWebView> {
             widget.pullToRefreshController?.options.toMap() ??
             PullToRefreshSettings(enabled: false).toMap();
 
+    if ((widget.headlessWebView?.isRunning() ?? false) &&
+        widget.keepAlive != null) {
+      final headlessId = widget.headlessWebView?.id;
+      if (headlessId != null) {
+        // force keep alive id to match headless webview id
+        widget.keepAlive?.id = headlessId;
+      }
+    }
+
     if (Util.isWeb) {
       return HtmlElementView(
         viewType: 'com.pichillilorenzo/flutter_inappwebview',
@@ -727,9 +752,7 @@ class _InAppWebViewState extends State<InAppWebView> {
     } else if (Util.isAndroid) {
       var useHybridComposition = (widget.initialSettings != null
               ? initialSettings.useHybridComposition
-              :
+              : widget.initialOptions?.android.useHybridComposition) ??
-              // ignore: deprecated_member_use_from_same_package
-              widget.initialOptions?.android.useHybridComposition) ??
           true;
 
       return PlatformViewLink(
@@ -762,11 +785,11 @@ class _InAppWebViewState extends State<InAppWebView> {
               'headlessWebViewId': widget.headlessWebView?.isRunning() ?? false
                   ? widget.headlessWebView?.id
                   : null,
-              'implementation': widget.implementation.toNativeValue(),
               'initialUserScripts':
                   widget.initialUserScripts?.map((e) => e.toMap()).toList() ??
                       [],
-              'pullToRefreshSettings': pullToRefreshSettings
+              'pullToRefreshSettings': pullToRefreshSettings,
+              'keepAliveId': widget.keepAlive?.id
             },
           )
             ..addOnPlatformViewCreatedListener(params.onPlatformViewCreated)
@@ -790,10 +813,10 @@ class _InAppWebViewState extends State<InAppWebView> {
           'headlessWebViewId': widget.headlessWebView?.isRunning() ?? false
               ? widget.headlessWebView?.id
               : null,
-          'implementation': widget.implementation.toNativeValue(),
           'initialUserScripts':
               widget.initialUserScripts?.map((e) => e.toMap()).toList() ?? [],
-          'pullToRefreshSettings': pullToRefreshSettings
+          'pullToRefreshSettings': pullToRefreshSettings,
+          'keepAliveId': widget.keepAlive?.id
         },
         creationParamsCodec: const StandardMessageCodec(),
       );
@@ -810,13 +833,24 @@ class _InAppWebViewState extends State<InAppWebView> {
   @override
   void dispose() {
     dynamic viewId = _controller?.getViewId();
+    debugLog(
+        className: "InAppWebView",
+        name: "WebView",
+        id: viewId?.toString(),
+        debugLoggingSettings: WebView.debugLoggingSettings,
+        method: "dispose",
+        args: []);
     if (viewId != null &&
         kIsWeb &&
         WebPlatformManager.webViews.containsKey(viewId)) {
       WebPlatformManager.webViews.remove(viewId);
     }
-    super.dispose();
+    final isKeepAlive = widget.keepAlive != null;
+    _controller?.dispose(isKeepAlive: isKeepAlive);
     _controller = null;
+    widget.pullToRefreshController?.dispose(isKeepAlive: isKeepAlive);
+    widget.findInteractionController?.dispose(isKeepAlive: isKeepAlive);
+    super.dispose();
   }
 
   AndroidViewController _createAndroidViewController({
@@ -845,14 +879,17 @@ class _InAppWebViewState extends State<InAppWebView> {
   }
 
   void _onPlatformViewCreated(int id) {
-    final viewId = (!kIsWeb && (widget.headlessWebView?.isRunning() ?? false))
+    dynamic viewId = id;
-        ? widget.headlessWebView?.id
+    if (!kIsWeb) {
-        : id;
+      if (widget.headlessWebView?.isRunning() ?? false) {
+        viewId = widget.headlessWebView?.id;
+      }
+      viewId = widget.keepAlive?.id ?? viewId ?? id;
+    }
     widget.headlessWebView?.internalDispose();
     _controller = InAppWebViewController(viewId, widget);
-    widget.pullToRefreshController?.initMethodChannel(viewId);
+    widget.pullToRefreshController?.init(viewId);
-    widget.findInteractionController?.initMethodChannel(viewId);
+    widget.findInteractionController?.init(viewId);
-    if (widget.onWebViewCreated != null) {
     debugLog(
         className: "InAppWebView",
         name: "WebView",
@@ -860,6 +897,7 @@ class _InAppWebViewState extends State<InAppWebView> {
         debugLoggingSettings: WebView.debugLoggingSettings,
         method: "onWebViewCreated",
         args: []);
+    if (widget.onWebViewCreated != null) {
       widget.onWebViewCreated!(_controller!);
     }
   }

lib/src/in_app_webview/in_app_webview_controller.dart

@@ -27,6 +27,7 @@ import 'in_app_webview.dart';
 import 'in_app_webview_settings.dart';
 import 'webview.dart';
 import '_static_channel.dart';
+import 'in_app_webview_keep_alive.dart';
 
 import '../print_job/main.dart';
 import '../find_interaction/main.dart';
@@ -52,17 +53,23 @@ final _JAVASCRIPT_HANDLER_FORBIDDEN_NAMES = UnmodifiableListView<String>([
 ///callback. Instead, if you are using an [InAppBrowser] instance, you can get it through the [InAppBrowser.webViewController] attribute.
 class InAppWebViewController {
   WebView? _webview;
-  late MethodChannel _channel;
+  MethodChannel? _channel;
-  static MethodChannel _staticChannel = IN_APP_WEBVIEW_STATIC_CHANNEL;
+  static final MethodChannel _staticChannel = IN_APP_WEBVIEW_STATIC_CHANNEL;
-  Map<String, JavaScriptHandlerCallback> javaScriptHandlersMap =
+
+  // properties to be saved and restored for keep alive feature
+  Map<String, JavaScriptHandlerCallback> _javaScriptHandlersMap =
       HashMap<String, JavaScriptHandlerCallback>();
-  final Map<UserScriptInjectionTime, List<UserScript>> _userScripts = {
+  Map<UserScriptInjectionTime, List<UserScript>> _userScripts = {
     UserScriptInjectionTime.AT_DOCUMENT_START: <UserScript>[],
     UserScriptInjectionTime.AT_DOCUMENT_END: <UserScript>[]
   };
   Set<String> _webMessageListenerObjNames = Set();
   Map<String, ScriptHtmlTagAttributes> _injectedScriptsFromURL = {};
 
+  // static map that contains the properties to be saved and restored for keep alive feature
+  static final Map<InAppWebViewKeepAlive, InAppWebViewControllerKeepAliveProps?>
+      _keepAliveMap = {};
+
   dynamic _id;
 
   InAppBrowser? _inAppBrowser;
@@ -82,7 +89,8 @@ class InAppWebViewController {
     this._id = id;
     this._channel =
         MethodChannel('com.pichillilorenzo/flutter_inappwebview_$id');
-    this._channel.setMethodCallHandler((call) async {
+    this._channel?.setMethodCallHandler((call) async {
+      if (_channel == null) return null;
       try {
         return await handleMethod(call);
       } on Error catch (e) {
@@ -136,12 +144,31 @@ class InAppWebViewController {
   }
 
   void _init() {
-    // ignore: deprecated_member_use_from_same_package
+    android = AndroidInAppWebViewController(channel: _channel!);
-    this.android = AndroidInAppWebViewController(channel: _channel);
+    ios = IOSInAppWebViewController(channel: _channel!);
-    // ignore: deprecated_member_use_from_same_package
+    webStorage = WebStorage(
-    this.ios = IOSInAppWebViewController(channel: _channel);
-    this.webStorage = WebStorage(
         localStorage: LocalStorage(this), sessionStorage: SessionStorage(this));
+
+    if (_webview is InAppWebView) {
+      final keepAlive = (_webview as InAppWebView).keepAlive;
+      if (keepAlive != null) {
+        InAppWebViewControllerKeepAliveProps? props = _keepAliveMap[keepAlive];
+        if (props == null) {
+          // save controller properties to restore it later
+          _keepAliveMap[keepAlive] = InAppWebViewControllerKeepAliveProps(
+              injectedScriptsFromURL: _injectedScriptsFromURL,
+              javaScriptHandlersMap: _javaScriptHandlersMap,
+              userScripts: _userScripts,
+              webMessageListenerObjNames: _webMessageListenerObjNames);
+        } else {
+          // restore controller properties
+          _injectedScriptsFromURL = props.injectedScriptsFromURL;
+          _javaScriptHandlersMap = props.javaScriptHandlersMap;
+          _userScripts = props.userScripts;
+          _webMessageListenerObjNames = props.webMessageListenerObjNames;
+        }
+      }
+    }
   }
 
   _debugLog(String method, dynamic args) {
@@ -1374,10 +1401,10 @@ class InAppWebViewController {
             return null;
         }
 
-        if (javaScriptHandlersMap.containsKey(handlerName)) {
+        if (_javaScriptHandlersMap.containsKey(handlerName)) {
           // convert result to json
           try {
-            return jsonEncode(await javaScriptHandlersMap[handlerName]!(args));
+            return jsonEncode(await _javaScriptHandlersMap[handlerName]!(args));
           } catch (error, stacktrace) {
             developer.log(error.toString() + '\n' + stacktrace.toString(),
                 name: 'JavaScript Handler "$handlerName"');
@@ -1404,7 +1431,7 @@ class InAppWebViewController {
   ///- Web
   Future<WebUri?> getUrl() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    String? url = await _channel.invokeMethod('getUrl', args);
+    String? url = await _channel?.invokeMethod('getUrl', args);
     return url != null ? WebUri(url) : null;
   }
 
@@ -1419,7 +1446,7 @@ class InAppWebViewController {
   ///- Web
   Future<String?> getTitle() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('getTitle', args);
+    return await _channel?.invokeMethod('getTitle', args);
   }
 
   ///Gets the progress for the current page. The progress value is between 0 and 100.
@@ -1430,7 +1457,7 @@ class InAppWebViewController {
   ///- MacOS ([Official API - WKWebView.estimatedProgress](https://developer.apple.com/documentation/webkit/wkwebview/1415007-estimatedprogress))
   Future<int?> getProgress() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('getProgress', args);
+    return await _channel?.invokeMethod('getProgress', args);
   }
 
   ///Gets the content html of the page. It first tries to get the content through javascript.
@@ -1693,7 +1720,7 @@ class InAppWebViewController {
         () =>
             allowingReadAccessTo?.toString() ??
             iosAllowingReadAccessTo?.toString());
-    await _channel.invokeMethod('loadUrl', args);
+    await _channel?.invokeMethod('loadUrl', args);
   }
 
   ///Loads the given [url] with [postData] (x-www-form-urlencoded) using `POST` method into this WebView.
@@ -1717,7 +1744,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('url', () => url.toString());
     args.putIfAbsent('postData', () => postData);
-    await _channel.invokeMethod('postUrl', args);
+    await _channel?.invokeMethod('postUrl', args);
   }
 
   ///Loads the given [data] into this WebView, using [baseUrl] as the base URL for the content.
@@ -1771,7 +1798,7 @@ class InAppWebViewController {
         () =>
             allowingReadAccessTo?.toString() ??
             iosAllowingReadAccessTo?.toString());
-    await _channel.invokeMethod('loadData', args);
+    await _channel?.invokeMethod('loadData', args);
   }
 
   ///Loads the given [assetFilePath].
@@ -1813,7 +1840,7 @@ class InAppWebViewController {
     assert(assetFilePath.isNotEmpty);
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('assetFilePath', () => assetFilePath);
-    await _channel.invokeMethod('loadFile', args);
+    await _channel?.invokeMethod('loadFile', args);
   }
 
   ///Reloads the WebView.
@@ -1827,7 +1854,7 @@ class InAppWebViewController {
   ///- Web ([Official API - Location.reload](https://developer.mozilla.org/en-US/docs/Web/API/Location/reload))
   Future<void> reload() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('reload', args);
+    await _channel?.invokeMethod('reload', args);
   }
 
   ///Goes back in the history of the WebView.
@@ -1841,7 +1868,7 @@ class InAppWebViewController {
   ///- Web ([Official API - History.back](https://developer.mozilla.org/en-US/docs/Web/API/History/back))
   Future<void> goBack() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('goBack', args);
+    await _channel?.invokeMethod('goBack', args);
   }
 
   ///Returns a boolean value indicating whether the WebView can move backward.
@@ -1852,7 +1879,7 @@ class InAppWebViewController {
   ///- MacOS ([Official API - WKWebView.canGoBack](https://developer.apple.com/documentation/webkit/wkwebview/1414966-cangoback))
   Future<bool> canGoBack() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('canGoBack', args);
+    return await _channel?.invokeMethod('canGoBack', args);
   }
 
   ///Goes forward in the history of the WebView.
@@ -1866,7 +1893,7 @@ class InAppWebViewController {
   ///- Web ([Official API - History.forward](https://developer.mozilla.org/en-US/docs/Web/API/History/forward))
   Future<void> goForward() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('goForward', args);
+    await _channel?.invokeMethod('goForward', args);
   }
 
   ///Returns a boolean value indicating whether the WebView can move forward.
@@ -1877,7 +1904,7 @@ class InAppWebViewController {
   ///- MacOS ([Official API - WKWebView.canGoForward](https://developer.apple.com/documentation/webkit/wkwebview/1414962-cangoforward))
   Future<bool> canGoForward() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('canGoForward', args);
+    return await _channel?.invokeMethod('canGoForward', args);
   }
 
   ///Goes to the history item that is the number of steps away from the current item. Steps is negative if backward and positive if forward.
@@ -1892,7 +1919,7 @@ class InAppWebViewController {
   Future<void> goBackOrForward({required int steps}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('steps', () => steps);
-    await _channel.invokeMethod('goBackOrForward', args);
+    await _channel?.invokeMethod('goBackOrForward', args);
   }
 
   ///Returns a boolean value indicating whether the WebView can go back or forward the given number of steps. Steps is negative if backward and positive if forward.
@@ -1904,7 +1931,7 @@ class InAppWebViewController {
   Future<bool> canGoBackOrForward({required int steps}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('steps', () => steps);
-    return await _channel.invokeMethod('canGoBackOrForward', args);
+    return await _channel?.invokeMethod('canGoBackOrForward', args);
   }
 
   ///Navigates to a [WebHistoryItem] from the back-forward [WebHistory.list] and sets it as the current item.
@@ -1932,7 +1959,7 @@ class InAppWebViewController {
   ///- Web
   Future<bool> isLoading() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('isLoading', args);
+    return await _channel?.invokeMethod('isLoading', args);
   }
 
   ///Stops the WebView from loading.
@@ -1946,7 +1973,7 @@ class InAppWebViewController {
   ///- Web ([Official API - Window.stop](https://developer.mozilla.org/en-US/docs/Web/API/Window/stop))
   Future<void> stopLoading() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('stopLoading', args);
+    await _channel?.invokeMethod('stopLoading', args);
   }
 
   ///Evaluates JavaScript [source] code into the WebView and returns the result of the evaluation.
@@ -1976,7 +2003,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('source', () => source);
     args.putIfAbsent('contentWorld', () => contentWorld?.toMap());
-    var data = await _channel.invokeMethod('evaluateJavascript', args);
+    var data = await _channel?.invokeMethod('evaluateJavascript', args);
     if (data != null && (Util.isAndroid || Util.isWeb)) {
       try {
         // try to json decode the data coming from JavaScript
@@ -2015,7 +2042,7 @@ class InAppWebViewController {
     args.putIfAbsent('urlFile', () => urlFile.toString());
     args.putIfAbsent(
         'scriptHtmlTagAttributes', () => scriptHtmlTagAttributes?.toMap());
-    await _channel.invokeMethod('injectJavascriptFileFromUrl', args);
+    await _channel?.invokeMethod('injectJavascriptFileFromUrl', args);
   }
 
   ///Evaluates the content of a JavaScript file into the WebView from the flutter assets directory.
@@ -2055,7 +2082,7 @@ class InAppWebViewController {
   Future<void> injectCSSCode({required String source}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('source', () => source);
-    await _channel.invokeMethod('injectCSSCode', args);
+    await _channel?.invokeMethod('injectCSSCode', args);
   }
 
   ///Injects an external CSS file into the WebView from a defined url.
@@ -2082,7 +2109,7 @@ class InAppWebViewController {
     args.putIfAbsent('urlFile', () => urlFile.toString());
     args.putIfAbsent(
         'cssLinkHtmlTagAttributes', () => cssLinkHtmlTagAttributes?.toMap());
-    await _channel.invokeMethod('injectCSSFileFromUrl', args);
+    await _channel?.invokeMethod('injectCSSFileFromUrl', args);
   }
 
   ///Injects a CSS file into the WebView from the flutter assets directory.
@@ -2164,7 +2191,7 @@ class InAppWebViewController {
       required JavaScriptHandlerCallback callback}) {
     assert(!_JAVASCRIPT_HANDLER_FORBIDDEN_NAMES.contains(handlerName),
         '"$handlerName" is a forbidden name!');
-    this.javaScriptHandlersMap[handlerName] = (callback);
+    this._javaScriptHandlersMap[handlerName] = (callback);
   }
 
   ///Removes a JavaScript message handler previously added with the [addJavaScriptHandler] associated to [handlerName] key.
@@ -2177,7 +2204,17 @@ class InAppWebViewController {
   ///- MacOS
   JavaScriptHandlerCallback? removeJavaScriptHandler(
       {required String handlerName}) {
-    return this.javaScriptHandlersMap.remove(handlerName);
+    return this._javaScriptHandlersMap.remove(handlerName);
+  }
+
+  ///Returns `true` if a JavaScript handler with [handlerName] already exists, otherwise `false`.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  ///- iOS
+  ///- MacOS
+  bool hasJavaScriptHandler({required String handlerName}) {
+    return this._javaScriptHandlersMap.containsKey(handlerName);
   }
 
   ///Takes a screenshot of the WebView's visible viewport and returns a [Uint8List]. Returns `null` if it wasn't be able to take it.
@@ -2197,7 +2234,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent(
         'screenshotConfiguration', () => screenshotConfiguration?.toMap());
-    return await _channel.invokeMethod('takeScreenshot', args);
+    return await _channel?.invokeMethod('takeScreenshot', args);
   }
 
   ///Use [setSettings] instead.
@@ -2233,7 +2270,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
 
     args.putIfAbsent('settings', () => settings.toMap());
-    await _channel.invokeMethod('setSettings', args);
+    await _channel?.invokeMethod('setSettings', args);
   }
 
   ///Gets the current WebView settings. Returns `null` if it wasn't able to get them.
@@ -2247,7 +2284,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
 
     Map<dynamic, dynamic>? settings =
-        await _channel.invokeMethod('getSettings', args);
+        await _channel?.invokeMethod('getSettings', args);
     if (settings != null) {
       settings = settings.cast<String, dynamic>();
       return InAppWebViewSettings.fromMap(settings as Map<String, dynamic>);
@@ -2268,7 +2305,7 @@ class InAppWebViewController {
   Future<WebHistory?> getCopyBackForwardList() async {
     Map<String, dynamic> args = <String, dynamic>{};
     Map<String, dynamic>? result =
-        (await _channel.invokeMethod('getCopyBackForwardList', args))
+        (await _channel?.invokeMethod('getCopyBackForwardList', args))
             ?.cast<String, dynamic>();
     return WebHistory.fromMap(result);
   }
@@ -2281,7 +2318,7 @@ class InAppWebViewController {
   ///- MacOS
   Future<void> clearCache() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('clearCache', args);
+    await _channel?.invokeMethod('clearCache', args);
   }
 
   ///Use [FindInteractionController.findAll] instead.
@@ -2289,7 +2326,7 @@ class InAppWebViewController {
   Future<void> findAllAsync({required String find}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('find', () => find);
-    await _channel.invokeMethod('findAll', args);
+    await _channel?.invokeMethod('findAll', args);
   }
 
   ///Use [FindInteractionController.findNext] instead.
@@ -2297,14 +2334,14 @@ class InAppWebViewController {
   Future<void> findNext({required bool forward}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('forward', () => forward);
-    await _channel.invokeMethod('findNext', args);
+    await _channel?.invokeMethod('findNext', args);
   }
 
   ///Use [FindInteractionController.clearMatches] instead.
   @Deprecated("Use FindInteractionController.clearMatches instead")
   Future<void> clearMatches() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('clearMatches', args);
+    await _channel?.invokeMethod('clearMatches', args);
   }
 
   ///Use [tRexRunnerHtml] instead.
@@ -2342,7 +2379,7 @@ class InAppWebViewController {
     args.putIfAbsent('x', () => x);
     args.putIfAbsent('y', () => y);
     args.putIfAbsent('animated', () => animated);
-    await _channel.invokeMethod('scrollTo', args);
+    await _channel?.invokeMethod('scrollTo', args);
   }
 
   ///Moves the scrolled position of the WebView.
@@ -2368,7 +2405,7 @@ class InAppWebViewController {
     args.putIfAbsent('x', () => x);
     args.putIfAbsent('y', () => y);
     args.putIfAbsent('animated', () => animated);
-    await _channel.invokeMethod('scrollBy', args);
+    await _channel?.invokeMethod('scrollBy', args);
   }
 
   ///On Android native WebView, it pauses all layout, parsing, and JavaScript timers for all WebViews.
@@ -2384,7 +2421,7 @@ class InAppWebViewController {
   ///- MacOS
   Future<void> pauseTimers() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('pauseTimers', args);
+    await _channel?.invokeMethod('pauseTimers', args);
   }
 
   ///On Android, it resumes all layout, parsing, and JavaScript timers for all WebViews. This will resume dispatching all timers.
@@ -2399,7 +2436,7 @@ class InAppWebViewController {
   ///- MacOS
   Future<void> resumeTimers() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('resumeTimers', args);
+    await _channel?.invokeMethod('resumeTimers', args);
   }
 
   ///Prints the current page.
@@ -2422,7 +2459,7 @@ class InAppWebViewController {
       {PrintJobSettings? settings}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("settings", () => settings?.toMap());
-    String? jobId = await _channel.invokeMethod('printCurrentPage', args);
+    String? jobId = await _channel?.invokeMethod('printCurrentPage', args);
     if (jobId != null) {
       return PrintJobController(id: jobId);
     }
@@ -2442,7 +2479,7 @@ class InAppWebViewController {
   ///- Web ([Official API - Document.documentElement.scrollHeight](https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollHeight))
   Future<int?> getContentHeight() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    var height = await _channel.invokeMethod('getContentHeight', args);
+    var height = await _channel?.invokeMethod('getContentHeight', args);
     if (height == null || height == 0) {
       // try to use javascript
       var scrollHeight = await evaluateJavascript(
@@ -2469,7 +2506,7 @@ class InAppWebViewController {
   ///- Web ([Official API - Document.documentElement.scrollWidth](https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollWidth))
   Future<int?> getContentWidth() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    var height = await _channel.invokeMethod('getContentWidth', args);
+    var height = await _channel?.invokeMethod('getContentWidth', args);
     if (height == null || height == 0) {
       // try to use javascript
       var scrollHeight = await evaluateJavascript(
@@ -2503,7 +2540,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('zoomFactor', () => zoomFactor);
     args.putIfAbsent('animated', () => iosAnimated ?? animated);
-    return await _channel.invokeMethod('zoomBy', args);
+    return await _channel?.invokeMethod('zoomBy', args);
   }
 
   ///Gets the URL that was originally requested for the current page.
@@ -2519,7 +2556,7 @@ class InAppWebViewController {
   ///- Web
   Future<WebUri?> getOriginalUrl() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    String? url = await _channel.invokeMethod('getOriginalUrl', args);
+    String? url = await _channel?.invokeMethod('getOriginalUrl', args);
     return url != null ? WebUri(url) : null;
   }
 
@@ -2530,7 +2567,7 @@ class InAppWebViewController {
   ///- iOS ([Official API - UIScrollView.zoomScale](https://developer.apple.com/documentation/uikit/uiscrollview/1619419-zoomscale))
   Future<double?> getZoomScale() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('getZoomScale', args);
+    return await _channel?.invokeMethod('getZoomScale', args);
   }
 
   ///Use [getZoomScale] instead.
@@ -2554,7 +2591,7 @@ class InAppWebViewController {
   ///- Web
   Future<String?> getSelectedText() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('getSelectedText', args);
+    return await _channel?.invokeMethod('getSelectedText', args);
   }
 
   ///Gets the hit result for hitting an HTML elements.
@@ -2567,7 +2604,7 @@ class InAppWebViewController {
   Future<InAppWebViewHitTestResult?> getHitTestResult() async {
     Map<String, dynamic> args = <String, dynamic>{};
     Map<dynamic, dynamic>? hitTestResultMap =
-        await _channel.invokeMethod('getHitTestResult', args);
+        await _channel?.invokeMethod('getHitTestResult', args);
 
     if (hitTestResultMap == null) {
       return null;
@@ -2589,7 +2626,7 @@ class InAppWebViewController {
   ///- iOS ([Official API - UIResponder.resignFirstResponder](https://developer.apple.com/documentation/uikit/uiresponder/1621097-resignfirstresponder))
   Future<void> clearFocus() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('clearFocus', args);
+    return await _channel?.invokeMethod('clearFocus', args);
   }
 
   ///Sets or updates the WebView context menu to be used next time it will appear.
@@ -2600,7 +2637,7 @@ class InAppWebViewController {
   Future<void> setContextMenu(ContextMenu? contextMenu) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("contextMenu", () => contextMenu?.toMap());
-    await _channel.invokeMethod('setContextMenu', args);
+    await _channel?.invokeMethod('setContextMenu', args);
     _inAppBrowser?.contextMenu = contextMenu;
   }
 
@@ -2614,7 +2651,7 @@ class InAppWebViewController {
   Future<RequestFocusNodeHrefResult?> requestFocusNodeHref() async {
     Map<String, dynamic> args = <String, dynamic>{};
     Map<dynamic, dynamic>? result =
-        await _channel.invokeMethod('requestFocusNodeHref', args);
+        await _channel?.invokeMethod('requestFocusNodeHref', args);
     return result != null
         ? RequestFocusNodeHrefResult(
             url: result['url'] != null ? WebUri(result['url']) : null,
@@ -2634,7 +2671,7 @@ class InAppWebViewController {
   Future<RequestImageRefResult?> requestImageRef() async {
     Map<String, dynamic> args = <String, dynamic>{};
     Map<dynamic, dynamic>? result =
-        await _channel.invokeMethod('requestImageRef', args);
+        await _channel?.invokeMethod('requestImageRef', args);
     return result != null
         ? RequestImageRefResult(
             url: result['url'] != null ? WebUri(result['url']) : null,
@@ -2730,7 +2767,7 @@ class InAppWebViewController {
     try {
       Map<String, dynamic> args = <String, dynamic>{};
       themeColor = UtilColor.fromStringRepresentation(
-          await _channel.invokeMethod('getMetaThemeColor', args));
+          await _channel?.invokeMethod('getMetaThemeColor', args));
       return themeColor;
     } catch (e) {
       // not implemented
@@ -2773,7 +2810,7 @@ class InAppWebViewController {
   ///- Web ([Official API - Window.scrollX](https://developer.mozilla.org/en-US/docs/Web/API/Window/scrollX))
   Future<int?> getScrollX() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('getScrollX', args);
+    return await _channel?.invokeMethod('getScrollX', args);
   }
 
   ///Returns the scrolled top position of the current WebView.
@@ -2789,7 +2826,7 @@ class InAppWebViewController {
   ///- Web ([Official API - Window.scrollY](https://developer.mozilla.org/en-US/docs/Web/API/Window/scrollY))
   Future<int?> getScrollY() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('getScrollY', args);
+    return await _channel?.invokeMethod('getScrollY', args);
   }
 
   ///Gets the SSL certificate for the main top-level page or null if there is no certificate (the site is not secure).
@@ -2801,7 +2838,7 @@ class InAppWebViewController {
   Future<SslCertificate?> getCertificate() async {
     Map<String, dynamic> args = <String, dynamic>{};
     Map<String, dynamic>? sslCertificateMap =
-        (await _channel.invokeMethod('getCertificate', args))
+        (await _channel?.invokeMethod('getCertificate', args))
             ?.cast<String, dynamic>();
     return SslCertificate.fromMap(sslCertificateMap);
   }
@@ -2824,7 +2861,7 @@ class InAppWebViewController {
     if (!(_userScripts[userScript.injectionTime]?.contains(userScript) ??
         false)) {
       _userScripts[userScript.injectionTime]?.add(userScript);
-      await _channel.invokeMethod('addUserScript', args);
+      await _channel?.invokeMethod('addUserScript', args);
     }
   }
 
@@ -2870,7 +2907,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('userScript', () => userScript.toMap());
     args.putIfAbsent('index', () => index);
-    await _channel.invokeMethod('removeUserScript', args);
+    await _channel?.invokeMethod('removeUserScript', args);
 
     return true;
   }
@@ -2907,7 +2944,7 @@ class InAppWebViewController {
 
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('groupName', () => groupName);
-    await _channel.invokeMethod('removeUserScriptsByGroupName', args);
+    await _channel?.invokeMethod('removeUserScriptsByGroupName', args);
   }
 
   ///Removes the [userScripts] from the webpage’s content.
@@ -2947,7 +2984,18 @@ class InAppWebViewController {
     _userScripts[UserScriptInjectionTime.AT_DOCUMENT_END]?.clear();
 
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('removeAllUserScripts', args);
+    await _channel?.invokeMethod('removeAllUserScripts', args);
+  }
+
+  ///Returns `true` if the [userScript] has been already added, otherwise `false`.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  ///- iOS
+  ///- MacOS
+  bool hasUserScript({required UserScript userScript}) {
+    return _userScripts[userScript.injectionTime]?.contains(userScript) ??
+        false;
   }
 
   ///Executes the specified string as an asynchronous JavaScript function.
@@ -2991,7 +3039,7 @@ class InAppWebViewController {
     args.putIfAbsent('functionBody', () => functionBody);
     args.putIfAbsent('arguments', () => arguments);
     args.putIfAbsent('contentWorld', () => contentWorld?.toMap());
-    var data = await _channel.invokeMethod('callAsyncJavaScript', args);
+    var data = await _channel?.invokeMethod('callAsyncJavaScript', args);
     if (data == null) {
       return null;
     }
@@ -3034,7 +3082,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("filePath", () => filePath);
     args.putIfAbsent("autoname", () => autoname);
-    return await _channel.invokeMethod('saveWebArchive', args);
+    return await _channel?.invokeMethod('saveWebArchive', args);
   }
 
   ///Indicates whether the webpage context is capable of using features that require [secure contexts](https://developer.mozilla.org/en-US/docs/Web/Security/Secure_Contexts).
@@ -3051,7 +3099,7 @@ class InAppWebViewController {
   ///- Web ([Official API - Window.isSecureContext](https://developer.mozilla.org/en-US/docs/Web/API/Window/isSecureContext))
   Future<bool> isSecureContext() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('isSecureContext', args);
+    return await _channel?.invokeMethod('isSecureContext', args);
   }
 
   ///Creates a message channel to communicate with JavaScript and returns the message channel with ports that represent the endpoints of this message channel.
@@ -3074,7 +3122,7 @@ class InAppWebViewController {
   Future<WebMessageChannel?> createWebMessageChannel() async {
     Map<String, dynamic> args = <String, dynamic>{};
     Map<String, dynamic>? result =
-        (await _channel.invokeMethod('createWebMessageChannel', args))
+        (await _channel?.invokeMethod('createWebMessageChannel', args))
             ?.cast<String, dynamic>();
     return WebMessageChannel.fromMap(result);
   }
@@ -3102,7 +3150,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('message', () => message.toMap());
     args.putIfAbsent('targetOrigin', () => targetOrigin.toString());
-    await _channel.invokeMethod('postWebMessage', args);
+    await _channel?.invokeMethod('postWebMessage', args);
   }
 
   ///Adds a [WebMessageListener] to the WebView and injects a JavaScript object into each frame that the [WebMessageListener] will listen on.
@@ -3278,7 +3326,18 @@ class InAppWebViewController {
 
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('webMessageListener', () => webMessageListener.toMap());
-    await _channel.invokeMethod('addWebMessageListener', args);
+    await _channel?.invokeMethod('addWebMessageListener', args);
+  }
+
+  ///Returns `true` if the [webMessageListener] has been already added, otherwise `false`.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  ///- iOS
+  ///- MacOS
+  bool hasWebMessageListener(WebMessageListener webMessageListener) {
+    return _webMessageListenerObjNames
+        .contains(webMessageListener.jsObjectName);
   }
 
   ///Returns `true` if the webpage can scroll vertically, otherwise `false`.
@@ -3294,7 +3353,7 @@ class InAppWebViewController {
   ///- Web
   Future<bool> canScrollVertically() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('canScrollVertically', args);
+    return await _channel?.invokeMethod('canScrollVertically', args);
   }
 
   ///Returns `true` if the webpage can scroll horizontally, otherwise `false`.
@@ -3310,7 +3369,7 @@ class InAppWebViewController {
   ///- Web
   Future<bool> canScrollHorizontally() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('canScrollHorizontally', args);
+    return await _channel?.invokeMethod('canScrollHorizontally', args);
   }
 
   ///Starts Safe Browsing initialization.
@@ -3327,7 +3386,7 @@ class InAppWebViewController {
   ///- Android native WebView ([Official API - WebView.startSafeBrowsing](https://developer.android.com/reference/android/webkit/WebView#startSafeBrowsing(android.content.Context,%20android.webkit.ValueCallback%3Cjava.lang.Boolean%3E)))
   Future<bool> startSafeBrowsing() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('startSafeBrowsing', args);
+    return await _channel?.invokeMethod('startSafeBrowsing', args);
   }
 
   ///Clears the SSL preferences table stored in response to proceeding with SSL certificate errors.
@@ -3336,7 +3395,7 @@ class InAppWebViewController {
   ///- Android native WebView ([Official API - WebView.clearSslPreferences](https://developer.android.com/reference/android/webkit/WebView#clearSslPreferences()))
   Future<void> clearSslPreferences() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('clearSslPreferences', args);
+    await _channel?.invokeMethod('clearSslPreferences', args);
   }
 
   ///Does a best-effort attempt to pause any processing that can be paused safely, such as animations and geolocation. Note that this call does not pause JavaScript.
@@ -3346,7 +3405,7 @@ class InAppWebViewController {
   ///- Android native WebView ([Official API - WebView.onPause](https://developer.android.com/reference/android/webkit/WebView#onPause()))
   Future<void> pause() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('pause', args);
+    await _channel?.invokeMethod('pause', args);
   }
 
   ///Resumes a WebView after a previous call to [pause].
@@ -3355,7 +3414,7 @@ class InAppWebViewController {
   ///- Android native WebView ([Official API - WebView.onResume](https://developer.android.com/reference/android/webkit/WebView#onResume()))
   Future<void> resume() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('resume', args);
+    await _channel?.invokeMethod('resume', args);
   }
 
   ///Scrolls the contents of this WebView down by half the page size.
@@ -3368,7 +3427,7 @@ class InAppWebViewController {
   Future<bool> pageDown({required bool bottom}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("bottom", () => bottom);
-    return await _channel.invokeMethod('pageDown', args);
+    return await _channel?.invokeMethod('pageDown', args);
   }
 
   ///Scrolls the contents of this WebView up by half the view size.
@@ -3381,7 +3440,7 @@ class InAppWebViewController {
   Future<bool> pageUp({required bool top}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("top", () => top);
-    return await _channel.invokeMethod('pageUp', args);
+    return await _channel?.invokeMethod('pageUp', args);
   }
 
   ///Performs zoom in in this WebView.
@@ -3391,7 +3450,7 @@ class InAppWebViewController {
   ///- Android native WebView ([Official API - WebView.zoomIn](https://developer.android.com/reference/android/webkit/WebView#zoomIn()))
   Future<bool> zoomIn() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('zoomIn', args);
+    return await _channel?.invokeMethod('zoomIn', args);
   }
 
   ///Performs zoom out in this WebView.
@@ -3401,7 +3460,7 @@ class InAppWebViewController {
   ///- Android native WebView ([Official API - WebView.zoomOut](https://developer.android.com/reference/android/webkit/WebView#zoomOut()))
   Future<bool> zoomOut() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('zoomOut', args);
+    return await _channel?.invokeMethod('zoomOut', args);
   }
 
   ///Clears the internal back/forward list.
@@ -3410,7 +3469,7 @@ class InAppWebViewController {
   ///- Android native WebView ([Official API - WebView.clearHistory](https://developer.android.com/reference/android/webkit/WebView#clearHistory()))
   Future<void> clearHistory() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('clearHistory', args);
+    return await _channel?.invokeMethod('clearHistory', args);
   }
 
   ///Reloads the current page, performing end-to-end revalidation using cache-validating conditionals if possible.
@@ -3420,7 +3479,7 @@ class InAppWebViewController {
   ///- MacOS ([Official API - WKWebView.reloadFromOrigin](https://developer.apple.com/documentation/webkit/wkwebview/1414956-reloadfromorigin))
   Future<void> reloadFromOrigin() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('reloadFromOrigin', args);
+    await _channel?.invokeMethod('reloadFromOrigin', args);
   }
 
   ///Generates PDF data from the web view’s contents asynchronously.
@@ -3443,7 +3502,7 @@ class InAppWebViewController {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('pdfConfiguration',
         () => pdfConfiguration?.toMap() ?? iosWKPdfConfiguration?.toMap());
-    return await _channel.invokeMethod('createPdf', args);
+    return await _channel?.invokeMethod('createPdf', args);
   }
 
   ///Creates a web archive of the web view’s current contents asynchronously.
@@ -3458,7 +3517,7 @@ class InAppWebViewController {
   ///- MacOS ([Official API - WKWebView.createWebArchiveData](https://developer.apple.com/documentation/webkit/wkwebview/3650491-createwebarchivedata))
   Future<Uint8List?> createWebArchiveData() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('createWebArchiveData', args);
+    return await _channel?.invokeMethod('createWebArchiveData', args);
   }
 
   ///A Boolean value indicating whether all resources on the page have been loaded over securely encrypted connections.
@@ -3468,7 +3527,7 @@ class InAppWebViewController {
   ///- MacOS ([Official API - WKWebView.hasOnlySecureContent](https://developer.apple.com/documentation/webkit/wkwebview/1415002-hasonlysecurecontent))
   Future<bool> hasOnlySecureContent() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('hasOnlySecureContent', args);
+    return await _channel?.invokeMethod('hasOnlySecureContent', args);
   }
 
   ///Pauses playback of all media in the web view.
@@ -3482,7 +3541,7 @@ class InAppWebViewController {
   ///- MacOS ([Official API - WKWebView.pauseAllMediaPlayback](https://developer.apple.com/documentation/webkit/wkwebview/3752240-pauseallmediaplayback)).
   Future<void> pauseAllMediaPlayback() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('pauseAllMediaPlayback', args);
+    return await _channel?.invokeMethod('pauseAllMediaPlayback', args);
   }
 
   ///Changes whether the webpage is suspending playback of all media in the page.
@@ -3500,7 +3559,7 @@ class InAppWebViewController {
   Future<void> setAllMediaPlaybackSuspended({required bool suspended}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("suspended", () => suspended);
-    return await _channel.invokeMethod('setAllMediaPlaybackSuspended', args);
+    return await _channel?.invokeMethod('setAllMediaPlaybackSuspended', args);
   }
 
   ///Closes all media the web view is presenting, including picture-in-picture video and fullscreen video.
@@ -3514,7 +3573,7 @@ class InAppWebViewController {
   ///- MacOS ([Official API - WKWebView.closeAllMediaPresentations](https://developer.apple.com/documentation/webkit/wkwebview/3752235-closeallmediapresentations)).
   Future<void> closeAllMediaPresentations() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('closeAllMediaPresentations', args);
+    return await _channel?.invokeMethod('closeAllMediaPresentations', args);
   }
 
   ///Requests the playback status of media in the web view.
@@ -3531,7 +3590,7 @@ class InAppWebViewController {
   Future<MediaPlaybackState?> requestMediaPlaybackState() async {
     Map<String, dynamic> args = <String, dynamic>{};
     return MediaPlaybackState.fromNativeValue(
-        await _channel.invokeMethod('requestMediaPlaybackState', args));
+        await _channel?.invokeMethod('requestMediaPlaybackState', args));
   }
 
   ///Returns `true` if the [WebView] is in fullscreen mode, otherwise `false`.
@@ -3542,7 +3601,7 @@ class InAppWebViewController {
   ///- MacOS
   Future<bool> isInFullscreen() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('isInFullscreen', args);
+    return await _channel?.invokeMethod('isInFullscreen', args);
   }
 
   ///Returns a [MediaCaptureState] that indicates whether the webpage is using the camera to capture images or video.
@@ -3557,7 +3616,7 @@ class InAppWebViewController {
   Future<MediaCaptureState?> getCameraCaptureState() async {
     Map<String, dynamic> args = <String, dynamic>{};
     return MediaCaptureState.fromNativeValue(
-        await _channel.invokeMethod('getCameraCaptureState', args));
+        await _channel?.invokeMethod('getCameraCaptureState', args));
   }
 
   ///Changes whether the webpage is using the camera to capture images or video.
@@ -3572,7 +3631,7 @@ class InAppWebViewController {
   Future<void> setCameraCaptureState({required MediaCaptureState state}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('state', () => state.toNativeValue());
-    await _channel.invokeMethod('setCameraCaptureState', args);
+    await _channel?.invokeMethod('setCameraCaptureState', args);
   }
 
   ///Returns a [MediaCaptureState] that indicates whether the webpage is using the microphone to capture audio.
@@ -3587,7 +3646,7 @@ class InAppWebViewController {
   Future<MediaCaptureState?> getMicrophoneCaptureState() async {
     Map<String, dynamic> args = <String, dynamic>{};
     return MediaCaptureState.fromNativeValue(
-        await _channel.invokeMethod('getMicrophoneCaptureState', args));
+        await _channel?.invokeMethod('getMicrophoneCaptureState', args));
   }
 
   ///Changes whether the webpage is using the microphone to capture audio.
@@ -3603,7 +3662,7 @@ class InAppWebViewController {
       {required MediaCaptureState state}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('state', () => state.toNativeValue());
-    await _channel.invokeMethod('setMicrophoneCaptureState', args);
+    await _channel?.invokeMethod('setMicrophoneCaptureState', args);
   }
 
   ///Loads the web content from the data you provide as if the data were the response to the request.
@@ -3639,7 +3698,7 @@ class InAppWebViewController {
     args.putIfAbsent('urlRequest', () => urlRequest.toMap());
     args.putIfAbsent('data', () => data);
     args.putIfAbsent('urlResponse', () => urlResponse?.toMap());
-    await _channel.invokeMethod('loadSimulatedRequest', args);
+    await _channel?.invokeMethod('loadSimulatedRequest', args);
   }
 
   ///Returns the iframe `id` attribute used on the Web platform.
@@ -3648,7 +3707,7 @@ class InAppWebViewController {
   ///- Web
   Future<String?> getIFrameId() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('getIFrameId', args);
+    return await _channel?.invokeMethod('getIFrameId', args);
   }
 
   ///Gets the default user agent.
@@ -3812,6 +3871,19 @@ class InAppWebViewController {
     return await _staticChannel.invokeMethod('handlesURLScheme', args);
   }
 
+  ///Disposes the WebView that is using the [keepAlive] instance
+  ///for the keep alive feature.
+  ///
+  ///**Supported Platforms/Implementations**:
+  ///- Android native WebView
+  ///- iOS
+  static Future<void> disposeKeepAlive(InAppWebViewKeepAlive keepAlive) async {
+    Map<String, dynamic> args = <String, dynamic>{};
+    args.putIfAbsent('keepAliveId', () => keepAlive.id);
+    await _staticChannel.invokeMethod('disposeKeepAlive', args);
+    _keepAliveMap[keepAlive] = null;
+  }
+
   ///Gets the html (with javascript) of the Chromium's t-rex runner game. Used in combination with [tRexRunnerCss].
   ///
   ///**Supported Platforms/Implementations**:
@@ -3831,7 +3903,7 @@ class InAppWebViewController {
       'packages/flutter_inappwebview/assets/t_rex_runner/t-rex.css');
 
   ///Used internally.
-  MethodChannel getChannel() {
+  MethodChannel? getChannel() {
     return _channel;
   }
 
@@ -3839,4 +3911,23 @@ class InAppWebViewController {
   dynamic getViewId() {
     return _id;
   }
+
+  ///Disposes the controller.
+  void dispose({bool isKeepAlive = false}) {
+    if (!isKeepAlive) {
+      _channel?.setMethodCallHandler(null);
+    }
+    android.dispose();
+    ios.dispose();
+    _channel = null;
+    _webview = null;
+    _inAppBrowser = null;
+    webStorage.dispose();
+    if (!isKeepAlive) {
+      _javaScriptHandlersMap.clear();
+      _userScripts.clear();
+      _webMessageListenerObjNames.clear();
+      _injectedScriptsFromURL.clear();
+    }
+  }
 }

lib/src/in_app_webview/in_app_webview_keep_alive.dart

@@ -0,0 +1,33 @@
+import '../types/main.dart';
+import '../util.dart';
+import 'in_app_webview.dart';
+import 'in_app_webview_controller.dart';
+
+///Class used to keep alive a [InAppWebView].
+class InAppWebViewKeepAlive {
+  String _id = IdGenerator.generate();
+}
+
+///Used internally
+extension InternalInAppWebViewKeepAlive on InAppWebViewKeepAlive {
+  set id(String id) {
+    _id = id;
+  }
+
+  String get id => _id;
+}
+
+///Used internally to save and restore [InAppWebViewController] properties
+///for the keep alive feature.
+class InAppWebViewControllerKeepAliveProps {
+  Map<String, JavaScriptHandlerCallback> javaScriptHandlersMap;
+  Map<UserScriptInjectionTime, List<UserScript>> userScripts;
+  Set<String> webMessageListenerObjNames;
+  Map<String, ScriptHtmlTagAttributes> injectedScriptsFromURL;
+
+  InAppWebViewControllerKeepAliveProps(
+      {required this.javaScriptHandlersMap,
+        required this.userScripts,
+        required this.webMessageListenerObjNames,
+        required this.injectedScriptsFromURL});
+}

lib/src/in_app_webview/main.dart

@@ -11,3 +11,4 @@ export 'headless_in_app_webview.dart' hide InternalHeadlessInAppWebView;
 export 'android/main.dart';
 export 'apple/main.dart';
 export '../find_interaction/find_interaction_controller.dart';
+export 'in_app_webview_keep_alive.dart' show InAppWebViewKeepAlive;

lib/src/in_app_webview/webview.dart

@@ -1191,12 +1191,6 @@ abstract class WebView {
   ///{@endtemplate}
   final FindInteractionController? findInteractionController;
 
-  ///{@template flutter_inappwebview.WebView.implementation}
-  ///Represents the WebView native implementation to be used.
-  ///The default value is [WebViewImplementation.NATIVE].
-  ///{@endtemplate}
-  final WebViewImplementation implementation;
-
   ///{@macro flutter_inappwebview.WebView}
   WebView(
       {this.windowId,
@@ -1314,6 +1308,5 @@ abstract class WebView {
       this.contextMenu,
       this.initialUserScripts,
       this.pullToRefreshController,
-      this.findInteractionController,
+      this.findInteractionController});
-      this.implementation = WebViewImplementation.NATIVE});
 }

lib/src/print_job/print_job_controller.dart

@@ -17,7 +17,7 @@ class PrintJobController implements Disposable {
   ///Print job ID.
   final String id;
 
-  late MethodChannel _channel;
+  MethodChannel? _channel;
 
   ///A completion handler used to handle the conclusion of the print job (for instance, to reset state) and to handle any errors encountered in printing.
   ///
@@ -29,7 +29,7 @@ class PrintJobController implements Disposable {
   PrintJobController({required this.id}) {
     this._channel = MethodChannel(
         'com.pichillilorenzo/flutter_inappwebview_printjobcontroller_$id');
-    this._channel.setMethodCallHandler((call) async {
+    this._channel?.setMethodCallHandler((call) async {
       try {
         return await _handleMethod(call);
       } on Error catch (e) {
@@ -60,7 +60,7 @@ class PrintJobController implements Disposable {
   ///- Android native WebView ([Official API - PrintJob.cancel](https://developer.android.com/reference/android/print/PrintJob#cancel()))
   Future<void> cancel() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('cancel', args);
+    await _channel?.invokeMethod('cancel', args);
   }
 
   ///Restarts this print job.
@@ -70,7 +70,7 @@ class PrintJobController implements Disposable {
   ///- Android native WebView ([Official API - PrintJob.restart](https://developer.android.com/reference/android/print/PrintJob#restart()))
   Future<void> restart() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('restart', args);
+    await _channel?.invokeMethod('restart', args);
   }
 
   ///Dismisses the printing-options sheet or popover.
@@ -85,7 +85,7 @@ class PrintJobController implements Disposable {
   Future<void> dismiss({bool animated: true}) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent("animated", () => animated);
-    await _channel.invokeMethod('dismiss', args);
+    await _channel?.invokeMethod('dismiss', args);
   }
 
   ///Gets the [PrintJobInfo] that describes this job.
@@ -101,7 +101,7 @@ class PrintJobController implements Disposable {
   Future<PrintJobInfo?> getInfo() async {
     Map<String, dynamic> args = <String, dynamic>{};
     Map<String, dynamic>? infoMap =
-        (await _channel.invokeMethod('getInfo', args))?.cast<String, dynamic>();
+        (await _channel?.invokeMethod('getInfo', args))?.cast<String, dynamic>();
     return PrintJobInfo.fromMap(infoMap);
   }
 
@@ -114,6 +114,8 @@ class PrintJobController implements Disposable {
   @override
   Future<void> dispose() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod('dispose', args);
+    await _channel?.invokeMethod('dispose', args);
+    _channel?.setMethodCallHandler(null);
+    _channel = null;
   }
 }

lib/src/pull_to_refresh/main.dart

@@ -1,3 +1,4 @@
-export 'pull_to_refresh_controller.dart';
+export 'pull_to_refresh_controller.dart'
+  show PullToRefreshController;
 export 'pull_to_refresh_settings.dart'
     show PullToRefreshSettings, PullToRefreshOptions;

lib/src/pull_to_refresh/pull_to_refresh_controller.dart

@@ -44,19 +44,6 @@ class PullToRefreshController {
     this.settings = settings ?? PullToRefreshSettings();
   }
 
-  void initMethodChannel(dynamic id) {
-    this._channel = MethodChannel(
-        'com.pichillilorenzo/flutter_inappwebview_pull_to_refresh_$id');
-    this._channel?.setMethodCallHandler((call) async {
-      try {
-        return await _handleMethod(call);
-      } on Error catch (e) {
-        print(e);
-        print(e.stackTrace);
-      }
-    });
-  }
-
   _debugLog(String method, dynamic args) {
     debugLog(
         className: this.runtimeType.toString(),
@@ -228,4 +215,28 @@ class PullToRefreshController {
     args.putIfAbsent('attributedTitle', () => attributedTitle.toMap());
     await _channel?.invokeMethod('setStyledTitle', args);
   }
+
+  ///Disposes the controller.
+  void dispose({bool isKeepAlive = false}) {
+    if (!isKeepAlive) {
+      _channel?.setMethodCallHandler(null);
+    }
+    _channel = null;
+  }
+}
+
+extension InternalPullToRefreshController on PullToRefreshController {
+  void init(dynamic id) {
+    this._channel = MethodChannel(
+        'com.pichillilorenzo/flutter_inappwebview_pull_to_refresh_$id');
+    this._channel?.setMethodCallHandler((call) async {
+      if (_channel == null) return null;
+      try {
+        return await _handleMethod(call);
+      } on Error catch (e) {
+        print(e);
+        print(e.stackTrace);
+      }
+    });
+  }
 }

lib/src/types/main.dart

@@ -198,7 +198,6 @@ export 'web_storage_type.dart' show WebStorageType;
 export 'website_data_record.dart'
     show WebsiteDataRecord, IOSWKWebsiteDataRecord;
 export 'website_data_type.dart' show WebsiteDataType, IOSWKWebsiteDataType;
-export 'webview_implementation.dart' show WebViewImplementation;
 export 'webview_package_info.dart'
     show WebViewPackageInfo, AndroidWebViewPackageInfo;
 export 'webview_render_process_action.dart' show WebViewRenderProcessAction;

lib/src/types/webview_implementation.dart

@@ -1,16 +0,0 @@
-import 'package:flutter_inappwebview_internal_annotations/flutter_inappwebview_internal_annotations.dart';
-
-import '../in_app_webview/webview.dart';
-
-part 'webview_implementation.g.dart';
-
-///Class that represents the [WebView] native implementation to be used.
-@ExchangeableEnum()
-class WebViewImplementation_ {
-  // ignore: unused_field
-  final int _value;
-  const WebViewImplementation_._internal(this._value);
-
-  ///Default native implementation, such as `WKWebView` for iOS and `android.webkit.WebView` for Android.
-  static const NATIVE = const WebViewImplementation_._internal(0);
-}

lib/src/types/webview_implementation.g.dart

@@ -1,73 +0,0 @@
-// GENERATED CODE - DO NOT MODIFY BY HAND
-
-part of 'webview_implementation.dart';
-
-// **************************************************************************
-// ExchangeableEnumGenerator
-// **************************************************************************
-
-///Class that represents the [WebView] native implementation to be used.
-class WebViewImplementation {
-  final int _value;
-  final int _nativeValue;
-  const WebViewImplementation._internal(this._value, this._nativeValue);
-// ignore: unused_element
-  factory WebViewImplementation._internalMultiPlatform(
-          int value, Function nativeValue) =>
-      WebViewImplementation._internal(value, nativeValue());
-
-  ///Default native implementation, such as `WKWebView` for iOS and `android.webkit.WebView` for Android.
-  static const NATIVE = WebViewImplementation._internal(0, 0);
-
-  ///Set of all values of [WebViewImplementation].
-  static final Set<WebViewImplementation> values = [
-    WebViewImplementation.NATIVE,
-  ].toSet();
-
-  ///Gets a possible [WebViewImplementation] instance from [int] value.
-  static WebViewImplementation? fromValue(int? value) {
-    if (value != null) {
-      try {
-        return WebViewImplementation.values
-            .firstWhere((element) => element.toValue() == value);
-      } catch (e) {
-        return null;
-      }
-    }
-    return null;
-  }
-
-  ///Gets a possible [WebViewImplementation] instance from a native value.
-  static WebViewImplementation? fromNativeValue(int? value) {
-    if (value != null) {
-      try {
-        return WebViewImplementation.values
-            .firstWhere((element) => element.toNativeValue() == value);
-      } catch (e) {
-        return null;
-      }
-    }
-    return null;
-  }
-
-  ///Gets [int] value.
-  int toValue() => _value;
-
-  ///Gets [int] native value.
-  int toNativeValue() => _nativeValue;
-
-  @override
-  int get hashCode => _value.hashCode;
-
-  @override
-  bool operator ==(value) => value == _value;
-
-  @override
-  String toString() {
-    switch (_value) {
-      case 0:
-        return 'NATIVE';
-    }
-    return _value.toString();
-  }
-}

lib/src/web_authentication_session/web_authenticate_session.dart

@@ -56,7 +56,7 @@ class WebAuthenticationSession implements Disposable {
   ///A completion handler the session calls when it completes successfully, or when the user cancels the session.
   WebAuthenticationSessionCompletionHandler onComplete;
 
-  late MethodChannel _channel;
+  MethodChannel? _channel;
   static const MethodChannel _sharedChannel = const MethodChannel(
       'com.pichillilorenzo/flutter_webauthenticationsession');
 
@@ -104,7 +104,7 @@ class WebAuthenticationSession implements Disposable {
         initialSettings ?? WebAuthenticationSessionSettings();
     this._channel = MethodChannel(
         'com.pichillilorenzo/flutter_webauthenticationsession_$id');
-    this._channel.setMethodCallHandler((call) async {
+    this._channel?.setMethodCallHandler((call) async {
       try {
         return await _handleMethod(call);
       } on Error catch (e) {
@@ -147,10 +147,10 @@ class WebAuthenticationSession implements Disposable {
   ///- iOS ([Official API - ASWebAuthenticationSession.canStart](https://developer.apple.com/documentation/authenticationservices/aswebauthenticationsession/3516277-canstart))
   Future<bool> canStart() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('canStart', args);
+    return await _channel?.invokeMethod('canStart', args);
   }
 
-  ///Starts a web authentication session.
+  ///Starts the web authentication session.
   ///
   ///Returns a boolean value indicating whether the web authentication session started successfully.
   ///
@@ -161,10 +161,10 @@ class WebAuthenticationSession implements Disposable {
   ///- iOS ([Official API - ASWebAuthenticationSession.start](https://developer.apple.com/documentation/authenticationservices/aswebauthenticationsession/2990953-start))
   Future<bool> start() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    return await _channel.invokeMethod('start', args);
+    return await _channel?.invokeMethod('start', args);
   }
 
-  ///Cancels a web authentication session.
+  ///Cancels the web authentication session.
   ///
   ///If the session has already presented a view with the authentication webpage, calling this method dismisses that view.
   ///Calling [cancel] on an already canceled session has no effect.
@@ -173,17 +173,19 @@ class WebAuthenticationSession implements Disposable {
   ///- iOS ([Official API - ASWebAuthenticationSession.cancel](https://developer.apple.com/documentation/authenticationservices/aswebauthenticationsession/2990951-cancel))
   Future<void> cancel() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod("cancel", args);
+    await _channel?.invokeMethod("cancel", args);
   }
 
-  ///Disposes a web authentication session.
+  ///Disposes the web authentication session.
   ///
   ///**Supported Platforms/Implementations**:
   ///- iOS
   @override
   Future<void> dispose() async {
     Map<String, dynamic> args = <String, dynamic>{};
-    await _channel.invokeMethod("dispose", args);
+    await _channel?.invokeMethod("dispose", args);
+    _channel?.setMethodCallHandler(null);
+    _channel = null;
   }
 
   ///Returns `true` if [ASWebAuthenticationSession](https://developer.apple.com/documentation/authenticationservices/aswebauthenticationsession)

lib/src/web_message/web_message_channel.dart

@@ -18,13 +18,13 @@ class WebMessageChannel {
   ///The second [WebMessagePort] object of the channel.
   final WebMessagePort port2;
 
-  late MethodChannel _channel;
+  MethodChannel? _channel;
 
   WebMessageChannel(
       {required this.id, required this.port1, required this.port2}) {
     this._channel = MethodChannel(
         'com.pichillilorenzo/flutter_inappwebview_web_message_channel_$id');
-    this._channel.setMethodCallHandler((call) async {
+    this._channel?.setMethodCallHandler((call) async {
       try {
         return await _handleMethod(call);
       } on Error catch (e) {
@@ -97,7 +97,7 @@ class WebMessagePort {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('index', () => this._index);
     await _webMessageChannel._channel
-        .invokeMethod('setWebMessageCallback', args);
+        ?.invokeMethod('setWebMessageCallback', args);
     this._onMessage = onMessage;
   }
 
@@ -106,14 +106,14 @@ class WebMessagePort {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('index', () => this._index);
     args.putIfAbsent('message', () => message.toMap());
-    await _webMessageChannel._channel.invokeMethod('postMessage', args);
+    await _webMessageChannel._channel?.invokeMethod('postMessage', args);
   }
 
   ///Close the message port and free any resources associated with it.
   Future<void> close() async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('index', () => this._index);
-    await _webMessageChannel._channel.invokeMethod('close', args);
+    await _webMessageChannel._channel?.invokeMethod('close', args);
   }
 
   Map<String, dynamic> toMap() {

lib/src/web_message/web_message_listener.dart

@@ -34,7 +34,7 @@ class WebMessageListener {
   ///**Official Android API**: https://developer.android.com/reference/androidx/webkit/WebViewCompat.WebMessageListener#onPostMessage(android.webkit.WebView,%20androidx.webkit.WebMessageCompat,%20android.net.Uri,%20boolean,%20androidx.webkit.JavaScriptReplyProxy)
   OnPostMessageCallback? onPostMessage;
 
-  late MethodChannel _channel;
+  MethodChannel? _channel;
 
   WebMessageListener(
       {required this.jsObjectName,
@@ -47,7 +47,7 @@ class WebMessageListener {
         "allowedOriginRules cannot contain empty strings");
     this._channel = MethodChannel(
         'com.pichillilorenzo/flutter_inappwebview_web_message_listener_${id}_$jsObjectName');
-    this._channel.setMethodCallHandler((call) async {
+    this._channel?.setMethodCallHandler((call) async {
       try {
         return await _handleMethod(call);
       } on Error catch (e) {
@@ -114,6 +114,6 @@ class JavaScriptReplyProxy {
   Future<void> postMessage(String message) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('message', () => message);
-    await _webMessageListener._channel.invokeMethod('postMessage', args);
+    await _webMessageListener._channel?.invokeMethod('postMessage', args);
   }
 }

lib/src/web_storage/web_storage.dart

@@ -19,6 +19,12 @@ class WebStorage {
   SessionStorage sessionStorage;
 
   WebStorage({required this.localStorage, required this.sessionStorage});
+
+  ///Disposes the web storage.
+  void dispose() {
+    localStorage.dispose();
+    sessionStorage.dispose();
+  }
 }
 
 ///Class that represents a single web storage item of the JavaScript `window.sessionStorage` and `window.localStorage` objects.
@@ -51,7 +57,7 @@ class WebStorageItem {
 ///Class that provides methods to manage the JavaScript [Storage](https://developer.mozilla.org/en-US/docs/Web/API/Storage) object.
 ///It is used by [LocalStorage] and [SessionStorage].
 class Storage {
-  late InAppWebViewController _controller;
+  InAppWebViewController? _controller;
 
   ///The web storage type: `window.sessionStorage` or `window.localStorage`.
   WebStorageType webStorageType;
@@ -69,7 +75,7 @@ class Storage {
   ///- iOS
   ///- Web
   Future<int?> length() async {
-    var result = await _controller.evaluateJavascript(source: """
+    var result = await _controller?.evaluateJavascript(source: """
     window.$webStorageType.length;
     """);
     return result != null ? int.parse(json.decode(result)) : null;
@@ -85,7 +91,7 @@ class Storage {
   ///- Web
   Future<void> setItem({required String key, required dynamic value}) async {
     var encodedValue = json.encode(value);
-    await _controller.evaluateJavascript(source: """
+    await _controller?.evaluateJavascript(source: """
     window.$webStorageType.setItem("$key", ${value is String ? encodedValue : "JSON.stringify($encodedValue)"});
     """);
   }
@@ -99,7 +105,7 @@ class Storage {
   ///- iOS
   ///- Web
   Future<dynamic> getItem({required String key}) async {
-    var itemValue = await _controller.evaluateJavascript(source: """
+    var itemValue = await _controller?.evaluateJavascript(source: """
     window.$webStorageType.getItem("$key");
     """);
 
@@ -123,7 +129,7 @@ class Storage {
   ///- iOS
   ///- Web
   Future<void> removeItem({required String key}) async {
-    await _controller.evaluateJavascript(source: """
+    await _controller?.evaluateJavascript(source: """
     window.$webStorageType.removeItem("$key");
     """);
   }
@@ -140,7 +146,7 @@ class Storage {
     var webStorageItems = <WebStorageItem>[];
 
     List<Map<dynamic, dynamic>>? items =
-        (await _controller.evaluateJavascript(source: """
+        (await _controller?.evaluateJavascript(source: """
 (function() {
   var webStorageItems = [];
   for(var i = 0; i < window.$webStorageType.length; i++){
@@ -177,7 +183,7 @@ class Storage {
   ///- iOS
   ///- Web
   Future<void> clear() async {
-    await _controller.evaluateJavascript(source: """
+    await _controller?.evaluateJavascript(source: """
     window.$webStorageType.clear();
     """);
   }
@@ -192,11 +198,16 @@ class Storage {
   ///- iOS
   ///- Web
   Future<String> key({required int index}) async {
-    var result = await _controller.evaluateJavascript(source: """
+    var result = await _controller?.evaluateJavascript(source: """
     window.$webStorageType.key($index);
     """);
     return result != null ? json.decode(result) : null;
   }
+
+  ///Disposes the storage.
+  void dispose() {
+    _controller = null;
+  }
 }
 
 ///Class that provides methods to manage the JavaScript `window.localStorage` object.

macos/Classes/FindInteraction/FindInteractionController.swift

@@ -11,6 +11,7 @@ import FlutterMacOS
 public class FindInteractionController : NSObject, Disposable {
     
     static var METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_find_interaction_";
+    var plugin: InAppWebViewFlutterPlugin?
     var webView: InAppWebView?
     var channelDelegate: FindInteractionChannelDelegate?
     var settings: FindInteractionSettings?
@@ -18,14 +19,17 @@ public class FindInteractionController : NSObject, Disposable {
     var searchText: String?
     var activeFindSession: FindSession?
     
-    public init(registrar: FlutterPluginRegistrar, id: Any, webView: InAppWebView, settings: FindInteractionSettings?) {
+    public init(plugin: InAppWebViewFlutterPlugin, id: Any, webView: InAppWebView, settings: FindInteractionSettings?) {
         super.init()
+        self.plugin = plugin
         self.webView = webView
         self.settings = settings
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: FindInteractionController.METHOD_CHANNEL_NAME_PREFIX + String(describing: id),
                                                binaryMessenger: registrar.messenger)
             self.channelDelegate = FindInteractionChannelDelegate(findInteractionController: self, channel: channel)
         }
+    }
     
     public func prepare() {
 //        if let settings = settings {
@@ -87,6 +91,7 @@ public class FindInteractionController : NSObject, Disposable {
         channelDelegate = nil
         webView = nil
         activeFindSession = nil
+        plugin = nil
     }
     
     deinit {

macos/Classes/HeadlessInAppWebView/HeadlessInAppWebView.swift

@@ -81,7 +81,7 @@ public class HeadlessInAppWebView : Disposable {
     public func dispose() {
         channelDelegate?.dispose()
         channelDelegate = nil
-        HeadlessInAppWebViewManager.webViews[id] = nil
+        plugin?.headlessInAppWebViewManager?.webViews[id] = nil
         if let view = flutterWebView?.view() {
             view.superview?.removeFromSuperview()
         }

macos/Classes/HeadlessInAppWebView/HeadlessInAppWebViewManager.swift

@@ -16,7 +16,7 @@ import AVFoundation
 public class HeadlessInAppWebViewManager: ChannelDelegate {
     static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_headless_inappwebview"
     var plugin: InAppWebViewFlutterPlugin?
-    static var webViews: [String: HeadlessInAppWebView?] = [:]
+    var webViews: [String: HeadlessInAppWebView?] = [:]
     
     init(plugin: InAppWebViewFlutterPlugin) {
         super.init(channel: FlutterMethodChannel(name: HeadlessInAppWebViewManager.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger))
@@ -40,15 +40,15 @@ public class HeadlessInAppWebViewManager: ChannelDelegate {
     }
     
     public func run(id: String, params: [String: Any?]) {
-        guard let plugin = plugin, let registrar = plugin.registrar else {
+        guard let plugin = plugin else {
             return
         }
-        let flutterWebView = FlutterWebViewController(registrar: registrar,
+        let flutterWebView = FlutterWebViewController(plugin: plugin,
             withFrame: CGRect.zero,
             viewIdentifier: id,
             params: params as NSDictionary)
         let headlessInAppWebView = HeadlessInAppWebView(plugin: plugin, id: id, flutterWebView: flutterWebView)
-        HeadlessInAppWebViewManager.webViews[id] = headlessInAppWebView
+        webViews[id] = headlessInAppWebView
         
         headlessInAppWebView.prepare(params: params as NSDictionary)
         headlessInAppWebView.onWebViewCreated()
@@ -57,11 +57,11 @@ public class HeadlessInAppWebViewManager: ChannelDelegate {
     
     public override func dispose() {
         super.dispose()
-        let headlessWebViews = HeadlessInAppWebViewManager.webViews.values
+        let headlessWebViews = webViews.values
         headlessWebViews.forEach { (headlessWebView: HeadlessInAppWebView?) in
             headlessWebView?.dispose()
         }
-        HeadlessInAppWebViewManager.webViews.removeAll()
+        webViews.removeAll()
         plugin = nil
     }
     

macos/Classes/InAppBrowser/InAppBrowserWebViewController.swift

@@ -33,7 +33,7 @@ public class InAppBrowserWebViewController: NSViewController, InAppBrowserDelega
     var isHidden = false
 
     public override func loadView() {
-        guard let registrar = plugin?.registrar else {
+        guard let plugin = plugin, let registrar = plugin.registrar else {
             return
         }
         
@@ -46,12 +46,12 @@ public class InAppBrowserWebViewController: NSViewController, InAppBrowserDelega
         }
         
         let preWebviewConfiguration = InAppWebView.preWKWebViewConfiguration(settings: webViewSettings)
-        if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+        if let wId = windowId, let webViewTransport = plugin.inAppWebViewManager?.windowWebViews[wId] {
             webView = webViewTransport.webView
             webView!.initialUserScripts = userScripts
         } else {
             webView = InAppWebView(id: nil,
-                                   registrar: nil,
+                                   plugin: nil,
                                    frame: .zero,
                                    configuration: preWebviewConfiguration,
                                    userScripts: userScripts)
@@ -63,10 +63,11 @@ public class InAppBrowserWebViewController: NSViewController, InAppBrowserDelega
         
         webView.inAppBrowserDelegate = self
         webView.id = id
+        webView.plugin = plugin
         webView.channelDelegate = WebViewChannelDelegate(webView: webView, channel: channel)
         
         let findInteractionController = FindInteractionController(
-            registrar: registrar,
+            plugin: plugin,
             id: id, webView: webView, settings: nil)
         webView.findInteractionController = findInteractionController
         findInteractionController.prepare()
@@ -99,7 +100,7 @@ public class InAppBrowserWebViewController: NSViewController, InAppBrowserDelega
         progressBar.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 0.0).isActive = true
         progressBar.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: 0.0).isActive = true
         
-        if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+        if let wId = windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
             webView?.load(webViewTransport.request)
             channelDelegate?.onBrowserCreated()
         } else {

macos/Classes/InAppWebView/FlutterWebViewController.swift

@@ -12,12 +12,15 @@ import FlutterMacOS
 public class FlutterWebViewController: NSObject, /*FlutterPlatformView,*/ Disposable {
     
     var myView: NSView?
+    var keepAliveId: String?
 
-    init(registrar: FlutterPluginRegistrar, withFrame frame: CGRect, viewIdentifier viewId: Any, params: NSDictionary) {
+    init(plugin: InAppWebViewFlutterPlugin, withFrame frame: CGRect, viewIdentifier viewId: Any, params: NSDictionary) {
         super.init()
         
         myView = NSView(frame: frame)
         
+        keepAliveId = params["keepAliveId"] as? String
+        
         let initialSettings = params["initialSettings"] as! [String: Any?]
         let windowId = params["windowId"] as? Int64
         let initialUserScripts = params["initialUserScripts"] as? [[String: Any]]
@@ -35,24 +38,27 @@ public class FlutterWebViewController: NSObject, /*FlutterPlatformView,*/ Dispos
         
         var webView: InAppWebView?
         
-        if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+        if let wId = windowId, let webViewTransport = plugin.inAppWebViewManager?.windowWebViews[wId] {
             webView = webViewTransport.webView
             webView!.id = viewId
+            webView!.plugin = plugin
+            if let registrar = plugin.registrar {
                 let channel = FlutterMethodChannel(name: InAppWebView.METHOD_CHANNEL_NAME_PREFIX + String(describing: viewId),
                                                    binaryMessenger: registrar.messenger)
                 webView!.channelDelegate = WebViewChannelDelegate(webView: webView!, channel: channel)
+            }
             webView!.frame = myView!.bounds
             webView!.initialUserScripts = userScripts
         } else {
             webView = InAppWebView(id: viewId,
-                                   registrar: registrar,
+                                   plugin: plugin,
                                    frame: myView!.bounds,
                                    configuration: preWebviewConfiguration,
                                    userScripts: userScripts)
         }
 
         let findInteractionController = FindInteractionController(
-            registrar: registrar,
+            plugin: plugin,
             id: viewId, webView: webView!, settings: nil)
         webView!.findInteractionController = findInteractionController
         findInteractionController.prepare()
@@ -121,7 +127,7 @@ public class FlutterWebViewController: NSObject, /*FlutterPlatformView,*/ Dispos
             }
             load(initialUrlRequest: initialUrlRequest, initialFile: initialFile, initialData: initialData)
         }
-        else if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+        else if let wId = windowId, let webViewTransport = webView.plugin?.inAppWebViewManager?.windowWebViews[wId] {
             webView.load(webViewTransport.request)
         }
     }
@@ -169,11 +175,13 @@ public class FlutterWebViewController: NSObject, /*FlutterPlatformView,*/ Dispos
     }
     
     public func dispose() {
+        if keepAliveId == nil {
             if let webView = webView() {
                 webView.dispose()
             }
             myView = nil
         }
+    }
     
     deinit {
         debugPrint("FlutterWebViewController - dealloc")

macos/Classes/InAppWebView/FlutterWebViewFactory.swift

@@ -12,11 +12,11 @@ import Foundation
 
 public class FlutterWebViewFactory: NSObject, FlutterPlatformViewFactory {
     static let VIEW_TYPE_ID = "com.pichillilorenzo/flutter_inappwebview"
-    private var registrar: FlutterPluginRegistrar?
+    private var plugin: InAppWebViewFlutterPlugin
     
-    init(registrar: FlutterPluginRegistrar?) {
+    init(plugin: InAppWebViewFlutterPlugin) {
+        self.plugin = plugin
         super.init()
-        self.registrar = registrar
     }
     
     public func createArgsCodec() -> (FlutterMessageCodec & NSObjectProtocol)? {
@@ -25,18 +25,48 @@ public class FlutterWebViewFactory: NSObject, FlutterPlatformViewFactory {
     
     public func create(withViewIdentifier viewId: Int64, arguments args: Any?) -> NSView {
         let arguments = args as? NSDictionary
+        var flutterWebView: FlutterWebViewController?
+        var id: Any = viewId
         
-        if let headlessWebViewId = arguments?["headlessWebViewId"] as? String,
+        let keepAliveId = arguments?["keepAliveId"] as? String
-           let headlessWebView = HeadlessInAppWebViewManager.webViews[headlessWebViewId],
+        let headlessWebViewId = arguments?["headlessWebViewId"] as? String
+        
+        if let headlessWebViewId = headlessWebViewId,
+           let headlessWebView = plugin.headlessInAppWebViewManager?.webViews[headlessWebViewId],
            let platformView = headlessWebView?.disposeAndGetFlutterWebView(withFrame: .zero) {
-            return platformView.view()
+            flutterWebView = platformView
+            flutterWebView?.keepAliveId = keepAliveId
         }
         
-        let webviewController = FlutterWebViewController(registrar: registrar!,
+        if let keepAliveId = keepAliveId,
+           flutterWebView == nil,
+           let keepAliveWebView = plugin.inAppWebViewManager?.keepAliveWebViews[keepAliveId] {
+            flutterWebView = keepAliveWebView
+            if let view = flutterWebView?.view() {
+                // remove from parent
+                view.removeFromSuperview()
+            }
+        }
+        
+        let shouldMakeInitialLoad = flutterWebView == nil
+        if flutterWebView == nil {
+            if let keepAliveId = keepAliveId {
+                id = keepAliveId
+            }
+            flutterWebView = FlutterWebViewController(plugin: plugin,
                                                       withFrame: .zero,
-                                                         viewIdentifier: viewId,
+                                                      viewIdentifier: id,
                                                       params: arguments!)
-        webviewController.makeInitialLoad(params: arguments!)
+        }
-        return webviewController.view()
+        
+        if let keepAliveId = keepAliveId {
+            plugin.inAppWebViewManager?.keepAliveWebViews[keepAliveId] = flutterWebView!
+        }
+        
+        if shouldMakeInitialLoad {
+            flutterWebView?.makeInitialLoad(params: arguments!)
+        }
+        
+        return flutterWebView!.view()
     }
 }

macos/Classes/InAppWebView/InAppWebView.swift

@@ -16,7 +16,7 @@ public class InAppWebView: WKWebView, WKUIDelegate,
     static var METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_"
 
     var id: Any? // viewId
-    var registrar: FlutterPluginRegistrar?
+    var plugin: InAppWebViewFlutterPlugin?
     var windowId: Int64?
     var windowCreated = false
     var inAppBrowserDelegate: InAppBrowserDelegate?
@@ -43,19 +43,16 @@ public class InAppWebView: WKWebView, WKUIDelegate,
     
     var customIMPs: [IMP] = []
     
-    static var windowWebViews: [Int64:WebViewTransport] = [:]
-    static var windowAutoincrementId: Int64 = 0;
-    
     var callAsyncJavaScriptBelowIOS14Results: [String:((Any?) -> Void)] = [:]
     
     var currentOpenPanel: NSOpenPanel?
     
-    init(id: Any?, registrar: FlutterPluginRegistrar?, frame: CGRect, configuration: WKWebViewConfiguration,
+    init(id: Any?, plugin: InAppWebViewFlutterPlugin?, frame: CGRect, configuration: WKWebViewConfiguration,
          userScripts: [UserScript] = []) {
         super.init(frame: frame, configuration: configuration)
         self.id = id
-        self.registrar = registrar
+        self.plugin = plugin
-        if let id = id, let registrar = registrar {
+        if let id = id, let registrar = plugin?.registrar {
             let channel = FlutterMethodChannel(name: InAppWebView.METHOD_CHANNEL_NAME_PREFIX + String(describing: id),
                                            binaryMessenger: registrar.messenger)
             self.channelDelegate = WebViewChannelDelegate(webView: self, channel: channel)
@@ -1788,10 +1785,14 @@ public class InAppWebView: WKWebView, WKUIDelegate,
                         createWebViewWith configuration: WKWebViewConfiguration,
                   for navigationAction: WKNavigationAction,
                   windowFeatures: WKWindowFeatures) -> WKWebView? {
-        InAppWebView.windowAutoincrementId += 1
+        var windowId: Int64 = 0
-        let windowId = InAppWebView.windowAutoincrementId
+        let inAppWebViewManager = plugin?.inAppWebViewManager
+        if let inAppWebViewManager = inAppWebViewManager {
+            inAppWebViewManager.windowAutoincrementId += 1
+            windowId = inAppWebViewManager.windowAutoincrementId
+        }
         
-        let windowWebView = InAppWebView(id: nil, registrar: nil, frame: CGRect.zero, configuration: configuration)
+        let windowWebView = InAppWebView(id: nil, plugin: nil, frame: CGRect.zero, configuration: configuration)
         windowWebView.windowId = windowId
         
         let webViewTransport = WebViewTransport(
@@ -1799,7 +1800,7 @@ public class InAppWebView: WKWebView, WKUIDelegate,
             request: navigationAction.request
         )
 
-        InAppWebView.windowWebViews[windowId] = webViewTransport
+        inAppWebViewManager?.windowWebViews[windowId] = webViewTransport
         windowWebView.stopLoading()
         
         let createWindowAction = CreateWindowAction(navigationAction: navigationAction, windowId: windowId, windowFeatures: windowFeatures, isDialog: nil)
@@ -1809,8 +1810,8 @@ public class InAppWebView: WKWebView, WKUIDelegate,
             return !handledByClient
         }
         callback.defaultBehaviour = { (handledByClient: Bool?) in
-            if InAppWebView.windowWebViews[windowId] != nil {
+            if inAppWebViewManager?.windowWebViews[windowId] != nil {
-                InAppWebView.windowWebViews.removeValue(forKey: windowId)
+                inAppWebViewManager?.windowWebViews.removeValue(forKey: windowId)
             }
             self.loadUrl(urlRequest: navigationAction.request, allowingReadAccessTo: nil)
         }
@@ -2066,7 +2067,7 @@ public class InAppWebView: WKWebView, WKUIDelegate,
             
             let _windowId = body["_windowId"] as? Int64
             var webView = self
-            if let wId = _windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+            if let wId = _windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
                 webView = webViewTransport.webView
             }
             webView.channelDelegate?.onConsoleMessage(message: consoleMessage, messageLevel: messageLevel)
@@ -2083,7 +2084,7 @@ public class InAppWebView: WKWebView, WKUIDelegate,
                         return !handledByClient
                     }
                     callback.defaultBehaviour = { (handledByClient: Bool?) in
-                        if let printJob = PrintJobManager.jobs[printJobId] {
+                        if let printJob = self.plugin?.printJobManager?.jobs[printJobId] {
                             printJob?.disposeNoDismiss()
                         }
                     }
@@ -2101,7 +2102,7 @@ public class InAppWebView: WKWebView, WKUIDelegate,
             
             let _windowId = body["_windowId"] as? Int64
             var webView = self
-            if let wId = _windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+            if let wId = _windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
                 webView = webViewTransport.webView
             }
             
@@ -2143,7 +2144,7 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
             
             let _windowId = body["_windowId"] as? Int64
             var webView = self
-            if let wId = _windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+            if let wId = _windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
                 webView = webViewTransport.webView
             }
             webView.findInteractionController?.channelDelegate?.onFindResultReceived(activeMatchOrdinal: activeMatchOrdinal, numberOfMatches: numberOfMatches, isDoneCounting: isDoneCounting)
@@ -2155,7 +2156,7 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
             
             let _windowId = body["_windowId"] as? Int64
             var webView = self
-            if let wId = _windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
+            if let wId = _windowId, let webViewTransport = plugin?.inAppWebViewManager?.windowWebViews[wId] {
                 webView = webViewTransport.webView
             }
             webView.channelDelegate?.onScrollChanged(x: x, y: y)
@@ -2358,9 +2359,9 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
                 }
             }
             
-            if let id = printJobId, let registrar = registrar {
+            if let id = printJobId, let plugin = plugin {
-                let printJob = PrintJobController(registrar: registrar, id: id, job: printOperation, settings: settings)
+                let printJob = PrintJobController(plugin: plugin, id: id, job: printOperation, settings: settings)
-                PrintJobManager.jobs[id] = printJob
+                plugin.printJobManager?.jobs[id] = printJob
                 printJob.present(parentWindow: window, completionHandler: completionHandler)
             } else if let window = window {
                 printJobCompletionHandler = completionHandler
@@ -2458,12 +2459,12 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
     }
     
     public func createWebMessageChannel(completionHandler: ((WebMessageChannel?) -> Void)? = nil) -> WebMessageChannel? {
-        guard let registrar = registrar else {
+        guard let plugin = plugin else {
             completionHandler?(nil)
             return nil
         }
         let id = NSUUID().uuidString
-        let webMessageChannel = WebMessageChannel(registrar: registrar, id: id)
+        let webMessageChannel = WebMessageChannel(plugin: plugin, id: id)
         webMessageChannel.initJsInstance(webView: self, completionHandler: completionHandler)
         webMessageChannels[id] = webMessageChannel
         
@@ -2567,8 +2568,8 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
             if #available(macOS 10.13, *) {
                 configuration.userContentController.removeAllContentRuleLists()
             }
-        } else if let wId = windowId, InAppWebView.windowWebViews[wId] != nil {
+        } else if let wId = windowId, plugin?.inAppWebViewManager?.windowWebViews[wId] != nil {
-            InAppWebView.windowWebViews.removeValue(forKey: wId)
+            plugin?.inAppWebViewManager?.windowWebViews.removeValue(forKey: wId)
         }
         configuration.userContentController.dispose(windowId: windowId)
         NotificationCenter.default.removeObserver(self)
@@ -2582,7 +2583,7 @@ if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {
         isPausedTimersCompletionHandler = nil
         callAsyncJavaScriptBelowIOS14Results.removeAll()
         super.removeFromSuperview()
-        registrar = nil
+        plugin = nil
     }
     
     deinit {

macos/Classes/InAppWebView/InAppWebViewManager.swift

@@ -1,5 +1,5 @@
 //
-//  InAppWebViewStatic.swift
+//  InAppWebViewManager.swift
 //  flutter_inappwebview
 //
 //  Created by Lorenzo Pichilli on 08/12/2019.
@@ -9,14 +9,18 @@ import Foundation
 import WebKit
 import FlutterMacOS
 
-public class InAppWebViewStatic: ChannelDelegate {
+public class InAppWebViewManager: ChannelDelegate {
-    static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_inappwebview_static"
+    static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_inappwebview_manager"
     var plugin: InAppWebViewFlutterPlugin?
     var webViewForUserAgent: WKWebView?
     var defaultUserAgent: String?
     
+    var keepAliveWebViews: [String:FlutterWebViewController?] = [:]
+    var windowWebViews: [Int64:WebViewTransport] = [:]
+    var windowAutoincrementId: Int64 = 0
+    
     init(plugin: InAppWebViewFlutterPlugin) {
-        super.init(channel: FlutterMethodChannel(name: InAppWebViewStatic.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger))
+        super.init(channel: FlutterMethodChannel(name: InAppWebViewManager.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger))
         self.plugin = plugin
     }
     
@@ -37,6 +41,11 @@ public class InAppWebViewStatic: ChannelDelegate {
                     result(false)
                 }
                 break
+            case "disposeKeepAlive":
+                let keepAliveId = arguments!["keepAliveId"] as! String
+                disposeKeepAlive(keepAliveId: keepAliveId)
+                result(true)
+                break
             default:
                 result(FlutterMethodNotImplemented)
                 break
@@ -68,11 +77,27 @@ public class InAppWebViewStatic: ChannelDelegate {
         }
     }
     
+    public func disposeKeepAlive(keepAliveId: String) {
+        if let flutterWebView = keepAliveWebViews[keepAliveId] as? FlutterWebViewController {
+            flutterWebView.keepAliveId = nil
+            flutterWebView.dispose()
+            keepAliveWebViews[keepAliveId] = nil
+        }
+    }
+    
     public override func dispose() {
         super.dispose()
-        plugin = nil
+        let keepAliveWebViewValues = keepAliveWebViews.values
+        keepAliveWebViewValues.forEach {(keepAliveWebView: FlutterWebViewController?) in
+            if let keepAliveId = keepAliveWebView?.keepAliveId {
+                disposeKeepAlive(keepAliveId: keepAliveId)
+            }
+        }
+        keepAliveWebViews.removeAll()
+        windowWebViews.removeAll()
         webViewForUserAgent = nil
         defaultUserAgent = nil
+        plugin = nil
     }
     
     deinit {

macos/Classes/InAppWebView/WebMessage/WebMessageChannel.swift

@@ -11,18 +11,20 @@ import FlutterMacOS
 public class WebMessageChannel : FlutterMethodCallDelegate {
     static var METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_web_message_channel_"
     var id: String
+    var plugin: InAppWebViewFlutterPlugin?
     var channelDelegate: WebMessageChannelChannelDelegate?
     weak var webView: InAppWebView?
     var ports: [WebMessagePort] = []
-    var registrar: FlutterPluginRegistrar?
     
-    public init(registrar: FlutterPluginRegistrar, id: String) {
+    public init(plugin: InAppWebViewFlutterPlugin, id: String) {
         self.id = id
-        self.registrar = registrar
+        self.plugin = plugin
         super.init()
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: WebMessageChannel.METHOD_CHANNEL_NAME_PREFIX + id,
                                                binaryMessenger: registrar.messenger)
             self.channelDelegate = WebMessageChannelChannelDelegate(webMessageChannel: self, channel: channel)
+        }
         self.ports = [
             WebMessagePort(name: "port1", webMessageChannel: self),
             WebMessagePort(name: "port2", webMessageChannel: self)
@@ -68,7 +70,7 @@ public class WebMessageChannel : FlutterMethodCallDelegate {
         })();
         """)
         webView = nil
-        registrar = nil
+        plugin = nil
     }
     
     deinit {

macos/Classes/InAppWebView/WebMessage/WebMessageListener.swift

@@ -16,18 +16,20 @@ public class WebMessageListener : FlutterMethodCallDelegate {
     var allowedOriginRules: Set<String>
     var channelDelegate: WebMessageListenerChannelDelegate?
     weak var webView: InAppWebView?
-    var registrar: FlutterPluginRegistrar?
+    var plugin: InAppWebViewFlutterPlugin?
     
-    public init(registrar: FlutterPluginRegistrar, id: String, jsObjectName: String, allowedOriginRules: Set<String>) {
+    public init(plugin: InAppWebViewFlutterPlugin, id: String, jsObjectName: String, allowedOriginRules: Set<String>) {
         self.id = id
-        self.registrar = registrar
+        self.plugin = plugin
         self.jsObjectName = jsObjectName
         self.allowedOriginRules = allowedOriginRules
         super.init()
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: WebMessageListener.METHOD_CHANNEL_NAME_PREFIX + self.id + "_" + self.jsObjectName,
                                                binaryMessenger: registrar.messenger)
             self.channelDelegate = WebMessageListenerChannelDelegate(webMessageListener: self, channel: channel)
         }
+    }
     
     public func assertOriginRulesValid() throws {
         for (index, originRule) in allowedOriginRules.enumerated() {
@@ -117,12 +119,12 @@ public class WebMessageListener : FlutterMethodCallDelegate {
         }
     }
     
-    public static func fromMap(registrar: FlutterPluginRegistrar, map: [String:Any?]?) -> WebMessageListener? {
+    public static func fromMap(plugin: InAppWebViewFlutterPlugin, map: [String:Any?]?) -> WebMessageListener? {
         guard let map = map else {
             return nil
         }
         return WebMessageListener(
-            registrar: registrar,
+            plugin: plugin,
             id: map["id"] as! String,
             jsObjectName: map["jsObjectName"] as! String,
             allowedOriginRules: Set(map["allowedOriginRules"] as! [String])
@@ -181,7 +183,7 @@ public class WebMessageListener : FlutterMethodCallDelegate {
         channelDelegate?.dispose()
         channelDelegate = nil
         webView = nil
-        registrar = nil
+        plugin = nil
     }
     
     deinit {

macos/Classes/InAppWebView/WebViewChannelDelegate.swift

@@ -507,9 +507,9 @@ public class WebViewChannelDelegate : ChannelDelegate {
             }
             break
         case .addWebMessageListener:
-            if let webView = webView, let registrar = webView.registrar  {
+            if let webView = webView, let plugin = webView.plugin  {
                 let webMessageListenerMap = arguments!["webMessageListener"] as! [String: Any?]
-                let webMessageListener = WebMessageListener.fromMap(registrar: registrar, map: webMessageListenerMap)!
+                let webMessageListener = WebMessageListener.fromMap(plugin: plugin, map: webMessageListenerMap)!
                 do {
                     try webView.addWebMessageListener(webMessageListener: webMessageListener)
                     result(false)

macos/Classes/InAppWebViewFlutterPlugin.swift

@@ -27,14 +27,14 @@ public class InAppWebViewFlutterPlugin: NSObject, FlutterPlugin {
     
     var registrar: FlutterPluginRegistrar?
     var platformUtil: PlatformUtil?
-    var inAppWebViewStatic: InAppWebViewStatic?
+    var inAppWebViewManager: InAppWebViewManager?
     var myCookieManager: Any?
     var myWebStorageManager: MyWebStorageManager?
     var credentialDatabase: CredentialDatabase?
     var inAppBrowserManager: InAppBrowserManager?
     var headlessInAppWebViewManager: HeadlessInAppWebViewManager?
     var webAuthenticationSessionManager: WebAuthenticationSessionManager?
-//    var printJobManager: PrintJobManager?
+    var printJobManager: PrintJobManager?
     
     var webViewControllers: [String: InAppBrowserWebViewController?] = [:]
     var safariViewControllers: [String: Any?] = [:]
@@ -42,19 +42,19 @@ public class InAppWebViewFlutterPlugin: NSObject, FlutterPlugin {
     public init(with registrar: FlutterPluginRegistrar) {
         super.init()
         self.registrar = registrar
-        registrar.register(FlutterWebViewFactory(registrar: registrar) as FlutterPlatformViewFactory, withId: FlutterWebViewFactory.VIEW_TYPE_ID)
+        registrar.register(FlutterWebViewFactory(plugin: self) as FlutterPlatformViewFactory, withId: FlutterWebViewFactory.VIEW_TYPE_ID)
         
         platformUtil = PlatformUtil(plugin: self)
         inAppBrowserManager = InAppBrowserManager(plugin: self)
         headlessInAppWebViewManager = HeadlessInAppWebViewManager(plugin: self)
-        inAppWebViewStatic = InAppWebViewStatic(plugin: self)
+        inAppWebViewManager = InAppWebViewManager(plugin: self)
         credentialDatabase = CredentialDatabase(plugin: self)
         if #available(macOS 10.13, *) {
             myCookieManager = MyCookieManager(plugin: self)
         }
         myWebStorageManager = MyWebStorageManager(plugin: self)
         webAuthenticationSessionManager = WebAuthenticationSessionManager(plugin: self)
-//        printJobManager = PrintJobManager()
+        printJobManager = PrintJobManager(plugin: self)
     }
     
     public static func register(with registrar: FlutterPluginRegistrar) {
@@ -68,8 +68,8 @@ public class InAppWebViewFlutterPlugin: NSObject, FlutterPlugin {
         inAppBrowserManager = nil
         headlessInAppWebViewManager?.dispose()
         headlessInAppWebViewManager = nil
-        inAppWebViewStatic?.dispose()
+        inAppWebViewManager?.dispose()
-        inAppWebViewStatic = nil
+        inAppWebViewManager = nil
         credentialDatabase?.dispose()
         credentialDatabase = nil
         if #available(macOS 10.13, *) {
@@ -80,7 +80,7 @@ public class InAppWebViewFlutterPlugin: NSObject, FlutterPlugin {
         myWebStorageManager = nil
         webAuthenticationSessionManager?.dispose()
         webAuthenticationSessionManager = nil
-//        printJobManager?.dispose()
+        printJobManager?.dispose()
-//        printJobManager = nil
+        printJobManager = nil
     }
 }

macos/Classes/PrintJob/PrintJobController.swift

@@ -18,7 +18,7 @@ public enum PrintJobState: Int {
 public class PrintJobController : NSObject, Disposable {
     static let METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappwebview_printjobcontroller_"
     var id: String
-    var registrar: FlutterPluginRegistrar?
+    var plugin: InAppWebViewFlutterPlugin?
     var job: NSPrintOperation?
     var settings: PrintJobSettings?
     var channelDelegate: PrintJobChannelDelegate?
@@ -30,16 +30,18 @@ public class PrintJobController : NSObject, Disposable {
                                           _ success: Bool,
                                           _ contextInfo: UnsafeMutableRawPointer?) -> Void
     
-    public init(registrar: FlutterPluginRegistrar, id: String, job: NSPrintOperation? = nil, settings: PrintJobSettings? = nil) {
+    public init(plugin: InAppWebViewFlutterPlugin, id: String, job: NSPrintOperation? = nil, settings: PrintJobSettings? = nil) {
         self.id = id
-        self.registrar = registrar
+        self.plugin = plugin
         super.init()
         self.job = job
         self.settings = settings
+        if let registrar = plugin.registrar {
             let channel = FlutterMethodChannel(name: PrintJobController.METHOD_CHANNEL_NAME_PREFIX + id,
                                                binaryMessenger: registrar.messenger)
             self.channelDelegate = PrintJobChannelDelegate(printJobController: self, channel: channel)
         }
+    }
     
     public func present(parentWindow: NSWindow? = nil, completionHandler: PrintJobController.CompletionHandler? = nil) {
         guard let job = job else {
@@ -76,7 +78,8 @@ public class PrintJobController : NSObject, Disposable {
         channelDelegate = nil
         completionHandler = nil
         job = nil
-        PrintJobManager.jobs[id] = nil
+        plugin?.printJobManager?.jobs[id] = nil
+        plugin = nil
     }
     
     public func dispose() {
@@ -84,7 +87,7 @@ public class PrintJobController : NSObject, Disposable {
         channelDelegate = nil
         completionHandler = nil
         job = nil
-        PrintJobManager.jobs[id] = nil
+        plugin?.printJobManager?.jobs[id] = nil
-        registrar = nil
+        plugin = nil
     }
 }

macos/Classes/PrintJob/PrintJobManager.swift

@@ -8,18 +8,21 @@
 import Foundation
 
 public class PrintJobManager: NSObject, Disposable {
-    static var jobs: [String: PrintJobController?] = [:]
+    var plugin: InAppWebViewFlutterPlugin?
+    var jobs: [String: PrintJobController?] = [:]
     
-    public override init() {
+    public init(plugin: InAppWebViewFlutterPlugin?) {
         super.init()
+        self.plugin = plugin
     }
     
     public func dispose() {
-        let jobs = PrintJobManager.jobs.values
+        let jobValues = jobs.values
-        jobs.forEach { (job: PrintJobController?) in
+        jobValues.forEach { (job: PrintJobController?) in
             job?.dispose()
         }
-        PrintJobManager.jobs.removeAll()
+        jobs.removeAll()
+        plugin = nil
     }
     
     deinit {

macos/Classes/WebAuthenticationSession/WebAuthenticationSession.swift

@@ -91,7 +91,7 @@ public class WebAuthenticationSession : NSObject, ASWebAuthenticationPresentatio
         channelDelegate?.dispose()
         channelDelegate = nil
         session = nil
-        WebAuthenticationSessionManager.sessions[id] = nil
+        plugin?.webAuthenticationSessionManager?.sessions[id] = nil
         plugin = nil
     }
     

macos/Classes/WebAuthenticationSession/WebAuthenticationSessionManager.swift

@@ -15,7 +15,7 @@ import SafariServices
 public class WebAuthenticationSessionManager: ChannelDelegate {
     static let METHOD_CHANNEL_NAME = "com.pichillilorenzo/flutter_webauthenticationsession"
     var plugin: InAppWebViewFlutterPlugin?
-    static var sessions: [String: WebAuthenticationSession?] = [:]
+    var sessions: [String: WebAuthenticationSession?] = [:]
     
     init(plugin: InAppWebViewFlutterPlugin) {
         super.init(channel: FlutterMethodChannel(name: WebAuthenticationSessionManager.METHOD_CHANNEL_NAME, binaryMessenger: plugin.registrar!.messenger))
@@ -53,7 +53,7 @@ public class WebAuthenticationSessionManager: ChannelDelegate {
             let _ = initialSettings.parse(settings: settings)
             let session = WebAuthenticationSession(plugin: plugin, id: id, url: sessionUrl, callbackURLScheme: callbackURLScheme, settings: initialSettings)
             session.prepare()
-            WebAuthenticationSessionManager.sessions[id] = session
+            sessions[id] = session
             result(true)
             return
         }
@@ -63,12 +63,12 @@ public class WebAuthenticationSessionManager: ChannelDelegate {
     
     public override func dispose() {
         super.dispose()
-        let sessions = WebAuthenticationSessionManager.sessions.values
+        let sessionValues = sessions.values
-        sessions.forEach { (session: WebAuthenticationSession?) in
+        sessionValues.forEach { (session: WebAuthenticationSession?) in
             session?.cancel()
             session?.dispose()
         }
-        WebAuthenticationSessionManager.sessions.removeAll()
+        sessions.removeAll()
         plugin = nil
     }