[Android] Add support for setting content sensitivity

ci/licenses_golden/licenses_flutter

@@ -44329,6 +44329,7 @@ ORIGIN: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/syst
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/systemchannels/ProcessTextChannel.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/systemchannels/RestorationChannel.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/systemchannels/ScribeChannel.java + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/systemchannels/SensitiveContentChannel.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/systemchannels/SpellCheckChannel.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/systemchannels/SystemChannel.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/common/ActivityLifecycleListener.java + ../../../flutter/LICENSE
@@ -44353,6 +44354,7 @@ ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/ImeSyn
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/ListenableEditingState.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/ScribePlugin.java + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/view/SensitiveContentPlugin.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/SpellCheckPlugin.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/TextEditingDelta.java + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/TextInputPlugin.java + ../../../flutter/LICENSE

shell/platform/android/BUILD.gn

@@ -286,6 +286,7 @@ android_java_sources = [
   "io/flutter/embedding/engine/systemchannels/ProcessTextChannel.java",
   "io/flutter/embedding/engine/systemchannels/RestorationChannel.java",
   "io/flutter/embedding/engine/systemchannels/ScribeChannel.java",
+  "io/flutter/embedding/engine/systemchannels/SensitiveContentChannel.java",
   "io/flutter/embedding/engine/systemchannels/SettingsChannel.java",
   "io/flutter/embedding/engine/systemchannels/SpellCheckChannel.java",
   "io/flutter/embedding/engine/systemchannels/SystemChannel.java",
@@ -338,6 +339,7 @@ android_java_sources = [
   "io/flutter/plugin/platform/VirtualDisplayController.java",
   "io/flutter/plugin/platform/WindowManagerHandler.java",
   "io/flutter/plugin/text/ProcessTextPlugin.java",
+  "io/flutter/plugin/view/SensitiveContentPlugin.java",
   "io/flutter/util/HandlerCompat.java",
   "io/flutter/util/PathUtils.java",
   "io/flutter/util/Preconditions.java",

shell/platform/android/io/flutter/embedding/android/FlutterActivity.java

@@ -54,6 +54,7 @@
 import io.flutter.embedding.engine.plugins.activity.ActivityControlSurface;
 import io.flutter.embedding.engine.plugins.util.GeneratedPluginRegister;
 import io.flutter.plugin.platform.PlatformPlugin;
+import io.flutter.plugin.view.SensitiveContentPlugin;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -220,7 +221,7 @@ public class FlutterActivity extends Activity
    * <p>This ID can be used to lookup {@code FlutterView} in the Android view hierarchy. For more,
    * see {@link android.view.View#findViewById}.
    */
-  public static final int FLUTTER_VIEW_ID = View.generateViewId();
+  public static final int FLUTTER_VIEW_ID = 0;
 
   /**
    * Creates an {@link Intent} that launches a {@code FlutterActivity}, which creates a {@link
@@ -1312,6 +1313,13 @@ public PlatformPlugin providePlatformPlugin(
     return new PlatformPlugin(getActivity(), flutterEngine.getPlatformChannel(), this);
   }
 
+  @Nullable
+  @Override
+  public SensitiveContentPlugin provideSensitiveContentPlugin(
+      @Nullable Activity activity, @NonNull FlutterEngine flutterEngine) {
+    return new SensitiveContentPlugin(getActivity(), flutterEngine.getSensitiveContentChannel());
+  }
+
   /**
    * Hook for subclasses to easily configure a {@code FlutterEngine}.
    *

shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java

@@ -36,6 +36,7 @@
 import io.flutter.embedding.engine.dart.DartExecutor;
 import io.flutter.embedding.engine.renderer.FlutterUiDisplayListener;
 import io.flutter.plugin.platform.PlatformPlugin;
+import io.flutter.plugin.view.SensitiveContentPlugin;
 import java.util.Arrays;
 import java.util.List;
 
@@ -89,6 +90,7 @@ public interface DelegateFactory {
   @Nullable private FlutterEngine flutterEngine;
   @VisibleForTesting @Nullable FlutterView flutterView;
   @Nullable private PlatformPlugin platformPlugin;
+  @Nullable private SensitiveContentPlugin sensitiveContentPlugin;
   @VisibleForTesting @Nullable OnPreDrawListener activePreDrawListener;
   private boolean isFlutterEngineFromHost;
   private boolean isFlutterUiDisplayed;
@@ -140,6 +142,7 @@ void release() {
     this.flutterEngine = null;
     this.flutterView = null;
     this.platformPlugin = null;
+    this.sensitiveContentPlugin = null;
   }
 
   /**
@@ -215,6 +218,7 @@ void onAttach(@NonNull Context context) {
     //                    control of the entire window. This is unacceptable for non-fullscreen
     //                    use-cases.
     platformPlugin = host.providePlatformPlugin(host.getActivity(), flutterEngine);
+    sensitiveContentPlugin = host.provideSensitiveContentPlugin(host.getActivity(), flutterEngine);
 
     host.configureFlutterEngine(flutterEngine);
     isAttached = true;
@@ -756,6 +760,11 @@ void onDetach() {
       platformPlugin = null;
     }
 
+    if (sensitiveContentPlugin != null) {
+      sensitiveContentPlugin.destroy();
+      sensitiveContentPlugin = null;
+    }
+
     if (host.shouldDispatchAppLifecycleState() && flutterEngine != null) {
       flutterEngine.getLifecycleChannel().appIsDetached();
     }
@@ -1184,6 +1193,14 @@ private void ensureAlive() {
     PlatformPlugin providePlatformPlugin(
         @Nullable Activity activity, @NonNull FlutterEngine flutterEngine);
 
+    /**
+     * Hook for host to create/provide a {@link SensitiveContentPlugin} if the associated Flutter
+     * experience should set content sensitivity.
+     */
+    @Nullable
+    SensitiveContentPlugin provideSensitiveContentPlugin(
+        @Nullable Activity activity, @NonNull FlutterEngine flutterEngine);
+
     /**
      * Hook for the host to configure the {@link io.flutter.embedding.engine.FlutterEngine} as
      * desired.

shell/platform/android/io/flutter/embedding/android/FlutterFragment.java

@@ -25,6 +25,7 @@
 import io.flutter.embedding.engine.FlutterShellArgs;
 import io.flutter.embedding.engine.renderer.FlutterUiDisplayListener;
 import io.flutter.plugin.platform.PlatformPlugin;
+import io.flutter.plugin.view.SensitiveContentPlugin;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -104,7 +105,8 @@ public class FlutterFragment extends Fragment
    * <p>This ID can be used to lookup {@code FlutterView} in the Android view hierarchy. For more,
    * see {@link android.view.View#findViewById}.
    */
-  public static final int FLUTTER_VIEW_ID = View.generateViewId();
+  // TODO(camsim99): Determine if we should involve FlutterFragment.
+  public static final int FLUTTER_VIEW_ID = 1;
 
   private static final String TAG = "FlutterFragment";
 
@@ -1501,6 +1503,17 @@ public PlatformPlugin providePlatformPlugin(
     }
   }
 
+  @Nullable
+  @Override
+  public SensitiveContentPlugin provideSensitiveContentPlugin(
+      @Nullable Activity activity, @NonNull FlutterEngine flutterEngine) {
+    if (activity != null) {
+      return new SensitiveContentPlugin(getActivity(), flutterEngine.getSensitiveContentChannel());
+    } else {
+      return null;
+    }
+  }
+
   /**
    * Configures a {@link io.flutter.embedding.engine.FlutterEngine} after its creation.
    *

shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java

@@ -35,6 +35,7 @@
 import io.flutter.embedding.engine.systemchannels.ProcessTextChannel;
 import io.flutter.embedding.engine.systemchannels.RestorationChannel;
 import io.flutter.embedding.engine.systemchannels.ScribeChannel;
+import io.flutter.embedding.engine.systemchannels.SensitiveContentChannel;
 import io.flutter.embedding.engine.systemchannels.SettingsChannel;
 import io.flutter.embedding.engine.systemchannels.SpellCheckChannel;
 import io.flutter.embedding.engine.systemchannels.SystemChannel;
@@ -102,6 +103,7 @@ public class FlutterEngine implements ViewUtils.DisplayUpdater {
   @NonNull private final PlatformChannel platformChannel;
   @NonNull private final ProcessTextChannel processTextChannel;
   @NonNull private final ScribeChannel scribeChannel;
+  @NonNull private final SensitiveContentChannel sensitiveContentChannel;
   @NonNull private final SettingsChannel settingsChannel;
   @NonNull private final SpellCheckChannel spellCheckChannel;
   @NonNull private final SystemChannel systemChannel;
@@ -340,6 +342,7 @@ public FlutterEngine(
     processTextChannel = new ProcessTextChannel(dartExecutor, context.getPackageManager());
     restorationChannel = new RestorationChannel(dartExecutor, waitForRestorationData);
     scribeChannel = new ScribeChannel(dartExecutor);
+    sensitiveContentChannel = new SensitiveContentChannel(dartExecutor);
     settingsChannel = new SettingsChannel(dartExecutor);
     spellCheckChannel = new SpellCheckChannel(dartExecutor);
     systemChannel = new SystemChannel(dartExecutor);
@@ -619,6 +622,12 @@ public ScribeChannel getScribeChannel() {
     return scribeChannel;
   }
 
+  /** System channel that handles setting content sensitivity. */
+  @NonNull
+  public SensitiveContentChannel getSensitiveContentChannel() {
+    return sensitiveContentChannel;
+  }
+
   /** System channel that sends and receives spell check requests and results. */
   @NonNull
   public SpellCheckChannel getSpellCheckChannel() {

shell/platform/android/io/flutter/embedding/engine/systemchannels/SensitiveContentChannel.java

@@ -0,0 +1,84 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package io.flutter.embedding.engine.systemchannels;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import io.flutter.Log;
+import io.flutter.embedding.engine.dart.DartExecutor;
+import io.flutter.plugin.common.MethodCall;
+import io.flutter.plugin.common.MethodChannel;
+import io.flutter.plugin.common.StandardMethodCodec;
+import java.util.ArrayList;
+
+/**
+ * {@link SensitiveContentChannel} is a platform channel that is used by the framework to set the
+ * content sensitivity of native Flutter Android {@code View}s.
+ */
+public class SensitiveContentChannel {
+  private static final String TAG = "SensitiveContentChannel";
+
+  public final MethodChannel channel;
+  private SensitiveContentMethodHandler sensitiveContentMethodHandler;
+
+  @NonNull
+  public final MethodChannel.MethodCallHandler parsingMethodHandler =
+      new MethodChannel.MethodCallHandler() {
+        @Override
+        public void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {
+          if (sensitiveContentMethodHandler == null) {
+            Log.v(
+                TAG,
+                "No SensitiveContentChannel registered, call not forwarded to sensitive content API.");
+            return;
+          }
+          String method = call.method;
+          Object args = call.arguments;
+          Log.v(TAG, "Received '" + method + "' message.");
+          switch (method) {
+            case "SensitiveContent.setContentSensitivity":
+              final ArrayList<Object> argumentList = (ArrayList<Object>) args;
+              final int flutterViewId = (int) argumentList.get(0);
+              final int contentSensitivityLevel = (int) argumentList.get(1);
+              try {
+                sensitiveContentMethodHandler.setContentSensitivity(
+                    flutterViewId, contentSensitivityLevel, result);
+              } catch (IllegalStateException exception) {
+                result.error("error", exception.getMessage(), null);
+              }
+              break;
+            default:
+              result.notImplemented();
+              break;
+          }
+        }
+      };
+
+  public SensitiveContentChannel(@NonNull DartExecutor dartExecutor) {
+    channel =
+        new MethodChannel(dartExecutor, "flutter/sensitivecontent", StandardMethodCodec.INSTANCE);
+    channel.setMethodCallHandler(parsingMethodHandler);
+  }
+
+  /**
+   * Sets the {@link SensitiveContentMethodHandler} which receives all requests to set a particular
+   * content sensitivty level sent through this channel.
+   */
+  public void setSensitiveContentMethodHandler(
+      @Nullable SensitiveContentMethodHandler sensitiveContentMethodHandler) {
+    this.sensitiveContentMethodHandler = sensitiveContentMethodHandler;
+  }
+
+  public interface SensitiveContentMethodHandler {
+    /**
+     * Requests that content being marked with the requested {@code contentSensitivity} mode for the
+     * native Flutter Android {@code View} whose ID matches {@code flutterViewId}.
+     */
+    void setContentSensitivity(
+        @NonNull int flutterViewId,
+        @NonNull int contentSensitivity,
+        @NonNull MethodChannel.Result result);
+  }
+}

shell/platform/android/io/flutter/plugin/view/SensitiveContentPlugin.java

@@ -0,0 +1,71 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package io.flutter.plugin.view;
+
+import android.app.Activity;
+import android.view.View;
+import androidx.annotation.NonNull;
+import io.flutter.embedding.engine.systemchannels.SensitiveContentChannel;
+import io.flutter.plugin.common.MethodChannel;
+
+/**
+ * {@link SensitiveContentPlugin} is the implementation of all functionality needed to set content
+ * sensitive on a native Flutter Android {@code View}.
+ *
+ * <p>The plugin handles requests for setting content sensitivity sent by the {@link
+ * io.flutter.embedding.engine.systemchannels.SensitiveContentChannel} via making a call to the
+ * relevant {@code View}.
+ */
+public class SensitiveContentPlugin
+    implements SensitiveContentChannel.SensitiveContentMethodHandler {
+
+  private final Activity mflutterActivity;
+  private final SensitiveContentChannel mSensitiveContentChannel;
+
+  public SensitiveContentPlugin(
+      @NonNull Activity flutterActivity, @NonNull SensitiveContentChannel sensitiveContentChannel) {
+    mflutterActivity = flutterActivity;
+    mSensitiveContentChannel = sensitiveContentChannel;
+
+    mSensitiveContentChannel.setSensitiveContentMethodHandler(this);
+  }
+
+  int i = 0;
+  /**
+   * Sets content sensitivity level of the Android {@code View} with the specified {@code
+   * flutterViewId} to the level specified by {@contentSensitivity}.
+   */
+  @Override
+  public void setContentSensitivity(
+      @NonNull int flutterViewId,
+      @NonNull int contentSensitivity,
+      @NonNull MethodChannel.Result result) {
+    final View flutterView = mflutterActivity.findViewById(flutterViewId);
+    if (flutterView == null) {
+      result.error("error", "Requested Flutter View to set content sensitivty of not found.", null);
+    }
+
+    final int currentContentSensitivity = flutterView.getContentSensitivity();
+    flutterView.setContentSensitivity(contentSensitivity);
+
+    final boolean shouldInvalidateView =
+        currentContentSensitivity == View.CONTENT_SENSITIVITY_SENSITIVE
+            && contentSensitivity != View.CONTENT_SENSITIVITY_SENSITIVE;
+    if (shouldInvalidateView) {
+      flutterView.invalidate();
+    }
+
+    result.success(null);
+  }
+
+  /**
+   * Releases all resources held by this {@code SensitiveContentPlugin}.
+   *
+   * <p>Do not invoke any methods on a {@code SensitiveContentPlugin} after invoking this method.
+   */
+  public void destroy() {
+    this.mSensitiveContentChannel.setSensitiveContentMethodHandler(null);
+  }
+}