[webview_flutter_android][webview_flutter_wkwebview] Adds platform implementations to set over-scroll mode (#9101)

Platform implementation for flutter/flutter#57090

## Pre-Review Checklist

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

Author: bparrishMines

packages/webview_flutter/webview_flutter_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 4.4.0
+
+* Adds support to set the over-scroll mode for the WebView. See `AndroidWebViewController.setOverScrollMode`.
+
 ## 4.3.5
 
 * Adds internal wrapper methods for native `WebViewClient`.

packages/webview_flutter/webview_flutter_android/android/src/main/java/io/flutter/plugins/webviewflutter/AndroidWebkitLibrary.g.kt

@@ -642,6 +642,7 @@ private class AndroidWebkitLibraryPigeonProxyApiBaseCodec(
         value is String ||
         value is FileChooserMode ||
         value is ConsoleMessageLevel ||
+        value is OverScrollMode ||
         value is SslErrorType ||
         value == null) {
       super.writeValue(stream, value)
@@ -814,6 +815,31 @@ enum class ConsoleMessageLevel(val raw: Int) {
   }
 }
 
+/**
+ * The over-scroll mode for a view.
+ *
+ * See https://developer.android.com/reference/android/view/View#OVER_SCROLL_ALWAYS.
+ */
+enum class OverScrollMode(val raw: Int) {
+  /** Always allow a user to over-scroll this view, provided it is a view that can scroll. */
+  ALWAYS(0),
+  /**
+   * Allow a user to over-scroll this view only if the content is large enough to meaningfully
+   * scroll, provided it is a view that can scroll.
+   */
+  IF_CONTENT_SCROLLS(1),
+  /** Never allow a user to over-scroll this view. */
+  NEVER(2),
+  /** The type is not recognized by this wrapper. */
+  UNKNOWN(3);
+
+  companion object {
+    fun ofRaw(raw: Int): OverScrollMode? {
+      return values().firstOrNull { it.raw == raw }
+    }
+  }
+}
+
 /**
  * Type of error for a SslCertificate.
  *
@@ -852,6 +878,9 @@ private open class AndroidWebkitLibraryPigeonCodec : StandardMessageCodec() {
         return (readValue(buffer) as Long?)?.let { ConsoleMessageLevel.ofRaw(it.toInt()) }
       }
       131.toByte() -> {
+        return (readValue(buffer) as Long?)?.let { OverScrollMode.ofRaw(it.toInt()) }
+      }
+      132.toByte() -> {
         return (readValue(buffer) as Long?)?.let { SslErrorType.ofRaw(it.toInt()) }
       }
       else -> super.readValueOfType(type, buffer)
@@ -868,10 +897,14 @@ private open class AndroidWebkitLibraryPigeonCodec : StandardMessageCodec() {
         stream.write(130)
         writeValue(stream, value.raw)
       }
-      is SslErrorType -> {
+      is OverScrollMode -> {
         stream.write(131)
         writeValue(stream, value.raw)
       }
+      is SslErrorType -> {
+        stream.write(132)
+        writeValue(stream, value.raw)
+      }
       else -> super.writeValue(stream, value)
     }
   }
@@ -4780,6 +4813,9 @@ abstract class PigeonApiView(
   /** Return the scrolled position of this view. */
   abstract fun getScrollPosition(pigeon_instance: android.view.View): WebViewPoint
 
+  /** Set the over-scroll mode for this view. */
+  abstract fun setOverScrollMode(pigeon_instance: android.view.View, mode: OverScrollMode)
+
   companion object {
     @Suppress("LocalVariableName")
     fun setUpMessageHandlers(binaryMessenger: BinaryMessenger, api: PigeonApiView?) {
@@ -4852,6 +4888,30 @@ abstract class PigeonApiView(
           channel.setMessageHandler(null)
         }
       }
+      run {
+        val channel =
+            BasicMessageChannel<Any?>(
+                binaryMessenger,
+                "dev.flutter.pigeon.webview_flutter_android.View.setOverScrollMode",
+                codec)
+        if (api != null) {
+          channel.setMessageHandler { message, reply ->
+            val args = message as List<Any?>
+            val pigeon_instanceArg = args[0] as android.view.View
+            val modeArg = args[1] as OverScrollMode
+            val wrapped: List<Any?> =
+                try {
+                  api.setOverScrollMode(pigeon_instanceArg, modeArg)
+                  listOf(null)
+                } catch (exception: Throwable) {
+                  wrapError(exception)
+                }
+            reply.reply(wrapped)
+          }
+        } else {
+          channel.setMessageHandler(null)
+        }
+      }
     }
   }
 

packages/webview_flutter/webview_flutter_android/android/src/main/java/io/flutter/plugins/webviewflutter/ViewProxyApi.java

@@ -19,6 +19,12 @@ public ViewProxyApi(@NonNull ProxyApiRegistrar pigeonRegistrar) {
     super(pigeonRegistrar);
   }
 
+  @NonNull
+  @Override
+  public ProxyApiRegistrar getPigeonRegistrar() {
+    return (ProxyApiRegistrar) super.getPigeonRegistrar();
+  }
+
   @Override
   public void scrollTo(@NonNull View pigeon_instance, long x, long y) {
     pigeon_instance.scrollTo((int) x, (int) y);
@@ -34,4 +40,21 @@ public void scrollBy(@NonNull View pigeon_instance, long x, long y) {
   public WebViewPoint getScrollPosition(@NonNull View pigeon_instance) {
     return new WebViewPoint(pigeon_instance.getScrollX(), pigeon_instance.getScrollY());
   }
+
+  @Override
+  public void setOverScrollMode(@NonNull View pigeon_instance, @NonNull OverScrollMode mode) {
+    switch (mode) {
+      case ALWAYS:
+        pigeon_instance.setOverScrollMode(View.OVER_SCROLL_ALWAYS);
+        break;
+      case IF_CONTENT_SCROLLS:
+        pigeon_instance.setOverScrollMode(View.OVER_SCROLL_IF_CONTENT_SCROLLS);
+        break;
+      case NEVER:
+        pigeon_instance.setOverScrollMode(View.OVER_SCROLL_NEVER);
+        break;
+      case UNKNOWN:
+        throw getPigeonRegistrar().createUnknownEnumException(OverScrollMode.UNKNOWN);
+    }
+  }
 }

packages/webview_flutter/webview_flutter_android/android/src/test/java/io/flutter/plugins/webviewflutter/ViewTest.java

@@ -49,4 +49,15 @@ public void getScrollPosition() {
     assertEquals(value.getX(), api.getScrollPosition(instance).getX());
     assertEquals(value.getY(), api.getScrollPosition(instance).getY());
   }
+
+  @Test
+  public void setOverScrollMode() {
+    final PigeonApiView api = new TestProxyApiRegistrar().getPigeonApiView();
+
+    final View instance = mock(View.class);
+    final OverScrollMode mode = io.flutter.plugins.webviewflutter.OverScrollMode.ALWAYS;
+    api.setOverScrollMode(instance, mode);
+
+    verify(instance).setOverScrollMode(View.OVER_SCROLL_ALWAYS);
+  }
 }

packages/webview_flutter/webview_flutter_android/example/pubspec.yaml

@@ -17,7 +17,7 @@ dependencies:
     # The example app is bundled with the plugin so we use a path dependency on
     # the parent directory to use the current plugin's version.
     path: ../
-  webview_flutter_platform_interface: ^2.10.0
+  webview_flutter_platform_interface: ^2.11.0
 
 dev_dependencies:
   espresso: ^0.4.0

packages/webview_flutter/webview_flutter_android/lib/src/android_webkit.g.dart

@@ -521,6 +521,25 @@ enum ConsoleMessageLevel {
   unknown,
 }
 
+/// The over-scroll mode for a view.
+///
+/// See https://developer.android.com/reference/android/view/View#OVER_SCROLL_ALWAYS.
+enum OverScrollMode {
+  /// Always allow a user to over-scroll this view, provided it is a view that
+  /// can scroll.
+  always,
+
+  /// Allow a user to over-scroll this view only if the content is large enough
+  /// to meaningfully scroll, provided it is a view that can scroll.
+  ifContentScrolls,
+
+  /// Never allow a user to over-scroll this view.
+  never,
+
+  /// The type is not recognized by this wrapper.
+  unknown,
+}
+
 /// Type of error for a SslCertificate.
 ///
 /// See https://developer.android.com/reference/android/net/http/SslError#SSL_DATE_INVALID.
@@ -560,9 +579,12 @@ class _PigeonCodec extends StandardMessageCodec {
     } else if (value is ConsoleMessageLevel) {
       buffer.putUint8(130);
       writeValue(buffer, value.index);
-    } else if (value is SslErrorType) {
+    } else if (value is OverScrollMode) {
       buffer.putUint8(131);
       writeValue(buffer, value.index);
+    } else if (value is SslErrorType) {
+      buffer.putUint8(132);
+      writeValue(buffer, value.index);
     } else {
       super.writeValue(buffer, value);
     }
@@ -578,6 +600,9 @@ class _PigeonCodec extends StandardMessageCodec {
         final int? value = readValue(buffer) as int?;
         return value == null ? null : ConsoleMessageLevel.values[value];
       case 131:
+        final int? value = readValue(buffer) as int?;
+        return value == null ? null : OverScrollMode.values[value];
+      case 132:
         final int? value = readValue(buffer) as int?;
         return value == null ? null : SslErrorType.values[value];
       default:
@@ -6586,6 +6611,36 @@ class View extends PigeonInternalProxyApiBaseClass {
     }
   }
 
+  /// Set the over-scroll mode for this view.
+  Future<void> setOverScrollMode(OverScrollMode mode) async {
+    final _PigeonInternalProxyApiBaseCodec pigeonChannelCodec =
+        _pigeonVar_codecView;
+    final BinaryMessenger? pigeonVar_binaryMessenger = pigeon_binaryMessenger;
+    const String pigeonVar_channelName =
+        'dev.flutter.pigeon.webview_flutter_android.View.setOverScrollMode';
+    final BasicMessageChannel<Object?> pigeonVar_channel =
+        BasicMessageChannel<Object?>(
+      pigeonVar_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: pigeonVar_binaryMessenger,
+    );
+    final Future<Object?> pigeonVar_sendFuture =
+        pigeonVar_channel.send(<Object?>[this, mode]);
+    final List<Object?>? pigeonVar_replyList =
+        await pigeonVar_sendFuture as List<Object?>?;
+    if (pigeonVar_replyList == null) {
+      throw _createConnectionError(pigeonVar_channelName);
+    } else if (pigeonVar_replyList.length > 1) {
+      throw PlatformException(
+        code: pigeonVar_replyList[0]! as String,
+        message: pigeonVar_replyList[1] as String?,
+        details: pigeonVar_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
   @override
   View pigeon_copy() {
     return View.pigeon_detached(

packages/webview_flutter/webview_flutter_android/lib/src/android_webview_controller.dart

@@ -731,6 +731,24 @@ class AndroidWebViewController extends PlatformWebViewController {
     _onJavaScriptPrompt = onJavaScriptTextInputDialog;
     return _webChromeClient.setSynchronousReturnValueForOnJsPrompt(true);
   }
+
+  @override
+  Future<void> setOverScrollMode(WebViewOverScrollMode mode) {
+    return switch (mode) {
+      WebViewOverScrollMode.always => _webView.setOverScrollMode(
+          android_webview.OverScrollMode.always,
+        ),
+      WebViewOverScrollMode.ifContentScrolls => _webView.setOverScrollMode(
+          android_webview.OverScrollMode.ifContentScrolls,
+        ),
+      WebViewOverScrollMode.never => _webView.setOverScrollMode(
+          android_webview.OverScrollMode.never,
+        ),
+      // This prevents future additions from causing a breaking change.
+      // ignore: unreachable_switch_case
+      _ => throw UnsupportedError('Android does not support $mode.'),
+    };
+  }
 }
 
 /// Android implementation of [PlatformWebViewPermissionRequest].

packages/webview_flutter/webview_flutter_android/pigeons/android_webkit.dart

@@ -80,6 +80,25 @@ enum ConsoleMessageLevel {
   unknown,
 }
 
+/// The over-scroll mode for a view.
+///
+/// See https://developer.android.com/reference/android/view/View#OVER_SCROLL_ALWAYS.
+enum OverScrollMode {
+  /// Always allow a user to over-scroll this view, provided it is a view that
+  /// can scroll.
+  always,
+
+  /// Allow a user to over-scroll this view only if the content is large enough
+  /// to meaningfully scroll, provided it is a view that can scroll.
+  ifContentScrolls,
+
+  /// Never allow a user to over-scroll this view.
+  never,
+
+  /// The type is not recognized by this wrapper.
+  unknown,
+}
+
 /// Type of error for a SslCertificate.
 ///
 /// See https://developer.android.com/reference/android/net/http/SslError#SSL_DATE_INVALID.
@@ -832,6 +851,9 @@ abstract class View {
 
   /// Return the scrolled position of this view.
   WebViewPoint getScrollPosition();
+
+  /// Set the over-scroll mode for this view.
+  void setOverScrollMode(OverScrollMode mode);
 }
 
 /// A callback interface used by the host application to set the Geolocation

packages/webview_flutter/webview_flutter_android/pubspec.yaml

@@ -2,7 +2,7 @@ name: webview_flutter_android
 description: A Flutter plugin that provides a WebView widget on Android.
 repository: https://github.com/flutter/packages/tree/main/packages/webview_flutter/webview_flutter_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+webview%22
-version: 4.3.5
+version: 4.4.0
 
 environment:
   sdk: ^3.6.0
@@ -20,14 +20,14 @@ flutter:
 dependencies:
   flutter:
     sdk: flutter
-  webview_flutter_platform_interface: ^2.10.0
+  webview_flutter_platform_interface: ^2.11.0
 
 dev_dependencies:
   build_runner: ^2.1.4
   flutter_test:
     sdk: flutter
   mockito: ^5.4.4
-  pigeon: ^25.2.0
+  pigeon: ^25.3.0
 
 topics:
   - html

packages/webview_flutter/webview_flutter_android/test/android_webview_controller_test.dart

@@ -1624,6 +1624,21 @@ void main() {
     verify(mockSettings.setTextZoom(100)).called(1);
   });
 
+  test('setOverScrollMode', () async {
+    final MockWebView mockWebView = MockWebView();
+    final AndroidWebViewController controller = createControllerWithMocks(
+      mockWebView: mockWebView,
+    );
+
+    await controller.setOverScrollMode(WebViewOverScrollMode.always);
+
+    verify(
+      mockWebView.setOverScrollMode(
+        android_webview.OverScrollMode.always,
+      ),
+    ).called(1);
+  });
+
   test('webViewIdentifier', () {
     final MockWebView mockWebView = MockWebView();