[Android] Add support for the PlatformChannel "Share.invoke" command

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

@@ -187,6 +187,11 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result
                   result.success(response);
                   break;
                 }
+              case "Share.invoke":
+                String text = (String) arguments;
+                platformMessageHandler.share(text);
+                result.success(null);
+                break;
               default:
                 result.notImplemented();
                 break;
@@ -549,6 +554,13 @@ default void setFrameworkHandlesBack(boolean frameworkHandlesBack) {}
      * can be pasted.
      */
     boolean clipboardHasStrings();
+
+    /**
+     * The Flutter application would like to share the given {@code text} using the Android standard
+     * intent action named {@code Intent.ACTION_SEND}. See:
+     * https://developer.android.com/reference/android/content/Intent.html#ACTION_SEND
+     */
+    void share(@NonNull String text);
   }
 
   /** Types of sounds the Android OS can play on behalf of an application. */

shell/platform/android/io/flutter/plugin/platform/PlatformPlugin.java

@@ -11,6 +11,7 @@
 import android.content.ClipDescription;
 import android.content.ClipboardManager;
 import android.content.Context;
+import android.content.Intent;
 import android.content.res.AssetFileDescriptor;
 import android.os.Build;
 import android.view.HapticFeedbackConstants;
@@ -145,6 +146,11 @@ public void setClipboardData(@NonNull String text) {
         public boolean clipboardHasStrings() {
           return PlatformPlugin.this.clipboardHasStrings();
         }
+
+        @Override
+        public void share(@NonNull String text) {
+          PlatformPlugin.this.share(text);
+        }
       };
 
   public PlatformPlugin(@NonNull Activity activity, @NonNull PlatformChannel platformChannel) {
@@ -570,4 +576,13 @@ private boolean clipboardHasStrings() {
     }
     return description.hasMimeType("text/*");
   }
+
+  private void share(@NonNull String text) {
+    Intent intent = new Intent();
+    intent.setAction(Intent.ACTION_SEND);
+    intent.setType("text/plain");
+    intent.putExtra(Intent.EXTRA_TEXT, text);
+
+    activity.startActivity(Intent.createChooser(intent, null));
+  }
 }

shell/platform/android/test/io/flutter/embedding/engine/systemchannels/PlatformChannelTest.java

@@ -1,6 +1,8 @@
 package io.flutter.embedding.engine.systemchannels;
 
+import static org.junit.Assert.assertEquals;
 import static org.mockito.ArgumentMatchers.refEq;
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
@@ -15,6 +17,7 @@
 import org.json.JSONObject;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
 import org.robolectric.annotation.Config;
 
 @Config(manifest = Config.NONE)
@@ -42,4 +45,26 @@ public void platformChannel_hasStringsMessage() {
     }
     verify(mockResult).success(refEq(expected));
   }
+
+  @Test
+  public void platformChannel_shareInvokeMessage() {
+    MethodChannel rawChannel = mock(MethodChannel.class);
+    FlutterJNI mockFlutterJNI = mock(FlutterJNI.class);
+    DartExecutor dartExecutor = new DartExecutor(mockFlutterJNI, mock(AssetManager.class));
+    PlatformChannel fakePlatformChannel = new PlatformChannel(dartExecutor);
+    PlatformChannel.PlatformMessageHandler mockMessageHandler =
+        mock(PlatformChannel.PlatformMessageHandler.class);
+    fakePlatformChannel.setPlatformMessageHandler(mockMessageHandler);
+
+    ArgumentCaptor<String> valueCapture = ArgumentCaptor.forClass(String.class);
+    doNothing().when(mockMessageHandler).share(valueCapture.capture());
+
+    final String expectedContent = "Flutter";
+    MethodCall methodCall = new MethodCall("Share.invoke", expectedContent);
+    MethodChannel.Result mockResult = mock(MethodChannel.Result.class);
+    fakePlatformChannel.parsingMethodCallHandler.onMethodCall(methodCall, mockResult);
+
+    assertEquals(valueCapture.getValue(), expectedContent);
+    verify(mockResult).success(null);
+  }
 }

shell/platform/android/test/io/flutter/plugin/platform/PlatformPluginTest.java

@@ -6,16 +6,19 @@
 
 import static android.view.WindowInsetsController.APPEARANCE_LIGHT_NAVIGATION_BARS;
 import static android.view.WindowInsetsController.APPEARANCE_LIGHT_STATUS_BARS;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.anyBoolean;
 import static org.mockito.Mockito.anyString;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
@@ -28,6 +31,7 @@
 import android.content.ClipboardManager;
 import android.content.ContentResolver;
 import android.content.Context;
+import android.content.Intent;
 import android.content.res.AssetFileDescriptor;
 import android.net.Uri;
 import android.os.Build;
@@ -47,6 +51,8 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.MockedStatic;
 import org.robolectric.Robolectric;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.android.controller.ActivityController;
@@ -629,4 +635,35 @@ public void performsDefaultBehaviorWhenNoDelegateProvided() {
 
     verify(mockActivity, times(1)).finish();
   }
+
+  @Test
+  public void startChoosenActivityWhenSharingText() {
+    Activity mockActivity = mock(Activity.class);
+    PlatformChannel mockPlatformChannel = mock(PlatformChannel.class);
+    PlatformPluginDelegate mockPlatformPluginDelegate = mock(PlatformPluginDelegate.class);
+    PlatformPlugin platformPlugin =
+        new PlatformPlugin(mockActivity, mockPlatformChannel, mockPlatformPluginDelegate);
+
+    // Mock Intent.createChooser (in real application it opens a chooser where the user can
+    // select which application will be used to share the selected text).
+    Intent choosenIntent = new Intent();
+    MockedStatic<Intent> intentClass = mockStatic(Intent.class);
+    ArgumentCaptor<Intent> intentCaptor = ArgumentCaptor.forClass(Intent.class);
+    intentClass
+        .when(() -> Intent.createChooser(intentCaptor.capture(), any()))
+        .thenReturn(choosenIntent);
+
+    final String expectedContent = "Flutter";
+    platformPlugin.mPlatformMessageHandler.share(expectedContent);
+
+    // Activity.startActivity should have been called.
+    verify(mockActivity, times(1)).startActivity(choosenIntent);
+
+    // The intent action created by the plugin and passed to Intent.createChooser should be
+    // 'Intent.ACTION_SEND'.
+    Intent sendToIntent = intentCaptor.getValue();
+    assertEquals(sendToIntent.getAction(), Intent.ACTION_SEND);
+    assertEquals(sendToIntent.getType(), "text/plain");
+    assertEquals(sendToIntent.getStringExtra(Intent.EXTRA_TEXT), expectedContent);
+  }
 }