Changes from chat discussion

1. Move all classes into `dev`.
2. Clean up the MethodChannel based on the engine lifecycle handlers.

packages/android_intent/android/src/main/java/dev/flutter/plugins/androidintent/AndroidIntentPlugin.java

@@ -4,16 +4,15 @@
 import io.flutter.embedding.engine.plugins.FlutterPlugin;
 import io.flutter.embedding.engine.plugins.activity.ActivityAware;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
-import io.flutter.plugin.common.MethodChannel;
 
 /**
  * Plugin implementation that uses the new {@code io.flutter.embedding} package.
  *
- * <p>This can be included in an add to app scenario to gracefully handle activity and context
- * changes, unlike the previous {@link io.flutter.plugins.androidintent.AndroidIntentPlugin}.
+ * <p>Instantiate this in an add to app scenario to gracefully handle activity and context changes.
  */
 public final class AndroidIntentPlugin implements FlutterPlugin, ActivityAware {
   private final IntentSender sender;
+  private final MethodCallHandlerImpl impl;
 
   /**
    * Initialize this within the {@code #configureFlutterEngine} of a Flutter activity or fragment.
@@ -22,22 +21,21 @@ public final class AndroidIntentPlugin implements FlutterPlugin, ActivityAware {
    */
   public AndroidIntentPlugin() {
     sender = new IntentSender(/*activity=*/ null, /*context=*/ null);
+    impl = new MethodCallHandlerImpl(sender);
   }
 
   @Override
   public void onAttachedToEngine(@NonNull FlutterPluginBinding binding) {
     sender.setApplicationContext(binding.getApplicationContext());
     sender.setActivity(null);
-    MethodChannel channel =
-        new MethodChannel(
-            binding.getFlutterEngine().getDartExecutor(), "plugins.flutter.io/android_intent");
-    channel.setMethodCallHandler(new MethodCallHandlerImpl(sender));
+    impl.startListening(binding.getFlutterEngine().getDartExecutor());
   }
 
   @Override
   public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
     sender.setApplicationContext(null);
     sender.setActivity(null);
+    impl.stopListening();
   }
 
   @Override

packages/android_intent/android/src/main/java/dev/flutter/plugins/androidintent/AndroidIntentPluginRegistrar.java

@@ -0,0 +1,28 @@
+// Copyright 2017 The Chromium 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 dev.flutter.plugins.androidintent;
+
+import io.flutter.plugin.common.PluginRegistry.Registrar;
+
+/**
+ * Automatically registers a plugin implementation that relies on the stable {@code
+ * io.flutter.plugin.common} package.
+ */
+public final class AndroidIntentPluginRegistrar {
+  private AndroidIntentPluginRegistrar() {}
+
+  /**
+   * Registers a plugin implementation that uses the stable {@code io.flutter.plugin.common}
+   * package.
+   *
+   * <p>Calling this automatically initializes the plugin. However plugins initialized this way
+   * won't react to changes in activity or context, unlike {@link AndroidIntentPlugin}.
+   */
+  public static void registerWith(Registrar registrar) {
+    IntentSender sender = new IntentSender(registrar.activity(), registrar.context());
+    MethodCallHandlerImpl impl = new MethodCallHandlerImpl(sender);
+    impl.startListening(registrar.messenger());
+  }
+}

packages/android_intent/android/src/main/java/dev/flutter/plugins/androidintent/MethodCallHandlerImpl.java

@@ -6,27 +6,65 @@
 import android.os.Bundle;
 import android.provider.Settings;
 import android.text.TextUtils;
+import android.util.Log;
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.common.MethodCall;
+import io.flutter.plugin.common.MethodChannel;
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
 import io.flutter.plugin.common.MethodChannel.Result;
 import java.util.ArrayList;
 import java.util.Map;
 
 /** Forwards incoming {@link MethodCall}s to {@link IntentSender#send}. */
 public final class MethodCallHandlerImpl implements MethodCallHandler {
+  private static final String TAG = "MethodCallHandlerImpl";
   private final IntentSender sender;
+  private @Nullable MethodChannel methodChannel;
 
   /**
    * Uses the given {@code sender} for all incoming calls.
    *
    * <p>This assumes that the sender's context and activity state are managed elsewhere and
    * correctly initialized before being sent here.
    */
-  public MethodCallHandlerImpl(IntentSender sender) {
+  MethodCallHandlerImpl(IntentSender sender) {
     this.sender = sender;
   }
 
+  /**
+   * Registers this instance as a method call handler on the given {@code messenger}.
+   *
+   * <p>Stops any previously started and unstopped calls.
+   *
+   * <p>This should be cleaned with {@link #stopListening} once the messenger is disposed of.
+   */
+  void startListening(BinaryMessenger messenger) {
+    if (methodChannel != null) {
+      Log.wtf(TAG, "Setting a method call handler before the last was disposed.");
+      stopListening();
+    }
+
+    methodChannel = new MethodChannel(messenger, "plugins.flutter.io/android_intent");
+    methodChannel.setMethodCallHandler(this);
+  }
+
+  /**
+   * Clears this instance from listening to method calls.
+   *
+   * <p>Does nothing is {@link #startListening} hasn't been called, or if we're already stopped.
+   */
+  void stopListening() {
+    if (methodChannel == null) {
+      Log.d(TAG, "Tried to stop listening when no methodChannel had been initialized.");
+      return;
+    }
+
+    methodChannel.setMethodCallHandler(null);
+    methodChannel = null;
+  }
+
   /**
    * Parses the incoming call and forwards it to the cached {@link IntentSender}.
    *

packages/android_intent/android/src/test/java/dev/flutter/plugins/androidintent/MethodCallHandlerImplTest.java

@@ -4,7 +4,10 @@
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.robolectric.Shadows.shadowOf;
@@ -14,6 +17,8 @@
 import android.content.Intent;
 import android.net.Uri;
 import androidx.test.core.app.ApplicationProvider;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugin.common.BinaryMessenger.BinaryMessageHandler;
 import io.flutter.plugin.common.MethodCall;
 import io.flutter.plugin.common.MethodChannel.Result;
 import java.util.HashMap;
@@ -25,6 +30,7 @@
 
 @RunWith(RobolectricTestRunner.class)
 public class MethodCallHandlerImplTest {
+  private static final String CHANNEL_NAME = "plugins.flutter.io/android_intent";
   private Context context;
   private IntentSender sender;
   private MethodCallHandlerImpl methodCallHandler;
@@ -36,6 +42,49 @@ public void setUp() {
     methodCallHandler = new MethodCallHandlerImpl(sender);
   }
 
+  @Test
+  public void startListening_registersChannel() {
+    BinaryMessenger messenger = mock(BinaryMessenger.class);
+
+    methodCallHandler.startListening(messenger);
+
+    verify(messenger, times(1))
+        .setMessageHandler(eq(CHANNEL_NAME), any(BinaryMessageHandler.class));
+  }
+
+  @Test
+  public void startListening_unregistersExistingChannel() {
+    BinaryMessenger firstMessenger = mock(BinaryMessenger.class);
+    BinaryMessenger secondMessenger = mock(BinaryMessenger.class);
+    methodCallHandler.startListening(firstMessenger);
+
+    methodCallHandler.startListening(secondMessenger);
+
+    // Unregisters the first and then registers the second.
+    verify(firstMessenger, times(1)).setMessageHandler(CHANNEL_NAME, null);
+    verify(secondMessenger, times(1))
+        .setMessageHandler(eq(CHANNEL_NAME), any(BinaryMessageHandler.class));
+  }
+
+  @Test
+  public void stopListening_unregistersExistingChannel() {
+    BinaryMessenger messenger = mock(BinaryMessenger.class);
+    methodCallHandler.startListening(messenger);
+
+    methodCallHandler.stopListening();
+
+    verify(messenger, times(1)).setMessageHandler(CHANNEL_NAME, null);
+  }
+
+  @Test
+  public void stopListening_doesNothingWhenUnset() {
+    BinaryMessenger messenger = mock(BinaryMessenger.class);
+
+    methodCallHandler.stopListening();
+
+    verify(messenger, never()).setMessageHandler(CHANNEL_NAME, null);
+  }
+
   @Test
   public void onMethodCall_doesNothingWhenContextIsNull() {
     Result result = mock(Result.class);

packages/android_intent/pubspec.yaml

@@ -6,9 +6,9 @@ version: 0.3.3+3
 
 flutter:
   plugin:
-    androidPackage: io.flutter.plugins.androidintent
+    androidPackage: dev.flutter.plugins.androidintent
     iosPrefix: FLT
-    pluginClass: AndroidIntentPlugin
+    pluginClass: AndroidIntentPluginRegistrar
 
 dependencies:
   flutter: