Android plugin registry (#3641)

shell/platform/android/BUILD.gn

@@ -90,6 +90,7 @@ java_library("flutter_shell_java") {
     "io/flutter/plugin/common/MethodCall.java",
     "io/flutter/plugin/common/MethodChannel.java",
     "io/flutter/plugin/common/MethodCodec.java",
+    "io/flutter/plugin/common/PluginRegistry.java",
     "io/flutter/plugin/common/StandardMessageCodec.java",
     "io/flutter/plugin/common/StandardMethodCodec.java",
     "io/flutter/plugin/common/StringCodec.java",

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

@@ -10,16 +10,27 @@ import android.os.Build;
 import android.os.Bundle;
 import android.view.Window;
 import android.view.WindowManager;
+import io.flutter.plugin.common.BinaryMessenger;
+import io.flutter.plugin.common.PluginRegistry;
+import io.flutter.plugin.common.PluginRegistry.Registrar;
 import io.flutter.plugin.platform.PlatformPlugin;
 import io.flutter.view.FlutterMain;
 import io.flutter.view.FlutterView;
-import java.util.ArrayList;
 
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
 
 /**
  * Base class for activities that use Flutter.
  */
-public class FlutterActivity extends Activity {
+public class FlutterActivity extends Activity implements PluginRegistry {
+    private final Map<String, Object> pluginMap = new LinkedHashMap<>(0);
+    private final List<RequestPermissionResultListener> requestPermissionResultListeners = new ArrayList<>(0);
+    private final List<ActivityResultListener> activityResultListeners = new ArrayList<>(0);
+    private final List<NewIntentListener> newIntentListeners = new ArrayList<>(0);
+    private final List<UserLeaveHintListener> userLeaveHintListeners = new ArrayList<>(0);
     private FlutterView flutterView;
 
     private String[] getArgsFromIntent(Intent intent) {
@@ -68,6 +79,26 @@ public class FlutterActivity extends Activity {
         onFlutterReady();
     }
 
+    @Override
+    public boolean hasPlugin(String key) {
+        return pluginMap.containsKey(key);
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public <T> T valuePublishedByPlugin(String pluginKey) {
+        return (T) pluginMap.get(pluginKey);
+    }
+
+    @Override
+    public Registrar registrarFor(String pluginKey) {
+        if (pluginMap.containsKey(pluginKey)) {
+            throw new IllegalStateException("Plugin key " + pluginKey + " is already in use");
+        }
+        pluginMap.put(pluginKey, null);
+        return new FlutterRegistrar(pluginKey);
+    }
+
     /**
      * @see android.app.Activity#onDestroy()
      */
@@ -118,8 +149,39 @@ public class FlutterActivity extends Activity {
         }
     }
 
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+        for (RequestPermissionResultListener listener : requestPermissionResultListeners) {
+            if (listener.onRequestPermissionResult(requestCode, permissions, grantResults)) {
+                return;
+            }
+        }
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        for (ActivityResultListener listener : activityResultListeners) {
+            if (listener.onActivityResult(requestCode, resultCode, data)) {
+                return;
+            }
+        }
+    }
+
+    @Override
     protected void onNewIntent(Intent intent) {
-        loadIntent(intent);
+        if (!loadIntent(intent)) {
+            for (NewIntentListener listener : newIntentListeners) {
+                if (listener.onNewIntent(intent)) {
+                    return;
+                }
+            }
+        }
+    }
+
+    @Override
+    public void onUserLeaveHint() {
+        for (UserLeaveHintListener listener : userLeaveHintListeners) {
+            listener.onUserLeaveHint();
+        }
     }
 
     public boolean loadIntent(Intent intent) {
@@ -159,4 +221,58 @@ public class FlutterActivity extends Activity {
         if (level == TRIM_MEMORY_RUNNING_LOW)
             flutterView.onMemoryPressure();
     }
+
+    private class FlutterRegistrar implements Registrar  {
+        private final String pluginKey;
+
+        FlutterRegistrar(String pluginKey) {
+            this.pluginKey = pluginKey;
+        }
+
+        public Activity activity() {
+            return FlutterActivity.this;
+        }
+
+        public BinaryMessenger messenger() {
+            return getFlutterView();
+        }
+
+        /**
+         * Publishes a value associated with the plugin being registered.
+         *
+         * <p>The published value is available to interested clients via
+         * {@link PluginRegistry#valuePublishedByPlugin(String)}.</p>
+         *
+         * <p>Publication should be done only when there is an interesting value
+         * to be shared with other code. This would typically be an instance of
+         * the plugin's main class itself that must be wired up to receive
+         * notifications or events from an Android API.
+         *
+         * <p>Overwrites any previously published value.</p>
+         */
+        public Registrar publish(Object value) {
+            pluginMap.put(pluginKey, value);
+            return this;
+        }
+
+        public Registrar addRequestPermissionResultListener(RequestPermissionResultListener listener) {
+            requestPermissionResultListeners.add(listener);
+            return this;
+        }
+
+        public Registrar addActivityResultListener(ActivityResultListener listener) {
+            activityResultListeners.add(listener);
+            return this;
+        }
+
+        public Registrar addNewIntentListener(NewIntentListener listener) {
+            newIntentListeners.add(listener);
+            return this;
+        }
+
+        public Registrar addUserLeaveHintListener(UserLeaveHintListener listener) {
+            userLeaveHintListeners.add(listener);
+            return this;
+        }
+    };
 }

shell/platform/android/io/flutter/plugin/common/PluginRegistry.java

+// 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 io.flutter.plugin.common;
+
+import android.app.Activity;
+import android.content.Intent;
+
+/**
+ * Registry used by plugins to set up interaction with Android APIs.
+ *
+ * <p>Flutter applications by default include an auto-generated and auto-updated
+ * plugin registrant class (GeneratedPluginRegistrant) that makes use of a
+ * {@link PluginRegistry} to register contributions from each plugin mentioned
+ * in the application's pubspec file. The generated registrant class is, again
+ * by default, called from the application's main {@link Activity}, which
+ * defaults to an instance of {@link io.flutter.app.FlutterActivity}, itself a
+ * {@link PluginRegistry}.</p>
+ */
+public interface PluginRegistry {
+    /**
+     * Returns a {@link Registrar} for receiving the registrations pertaining
+     * to the specified plugin.
+     *
+     * @param pluginKey a unique String identifying the plugin; typically the
+     * fully qualified name of the plugin's main class.
+     */
+    Registrar registrarFor(String pluginKey);
+
+    /**
+     * Returns whether the specified plugin is known to this registry.
+     *
+     * @param pluginKey a unique String identifying the plugin; typically the
+     * fully qualified name of the plugin's main class.
+     * @return true if this registry has handed out a registrar for the
+     * specified plugin.
+     */
+    boolean hasPlugin(String pluginKey);
+
+    /**
+     * Returns the value published by the specified plugin, if any.
+     *
+     * <p>Plugins may publish a single value, such as an instance of the
+     * plugin's main class, for situations where external control or
+     * interaction is needed. Clients are expected to know the value's
+     * type.</p>
+     *
+     * @param pluginKey a unique String identifying the plugin; typically the
+     * fully qualified name of the plugin's main class.
+     * @return the published value, possibly null.
+     */
+    <T> T valuePublishedByPlugin(String pluginKey);
+
+    /**
+     * Receiver of registrations from a single plugin.
+     */
+    interface Registrar {
+        /**
+         * Returns the {@link Activity} that forms the plugin's operating context.
+         */
+        Activity activity();
+
+        /**
+         * Returns a {@link BinaryMessenger} which the plugin can use for
+         * creating channels for communicating with the Dart side.
+         */
+        BinaryMessenger messenger();
+
+        /**
+         * Publishes a value associated with the plugin being registered.
+         *
+         * <p>The published value is available to interested clients via
+         * {@link PluginRegistry#valuePublishedByPlugin(String)}.</p>
+         *
+         * <p>Publication should be done only when client code needs to interact
+         * with the plugin in a way that cannot be accomplished by the plugin
+         * registering callbacks with client APIs.</p>
+         *
+         * <p>Overwrites any previously published value.</p>
+         *
+         * @param value the value, possibly null.
+         * @return this {@link Registrar}.
+         */
+        Registrar publish(Object value);
+
+        /**
+         * Adds a callback allowing the plugin to take part in handling incoming
+         * calls to {@Activity#onRequestPermissionsResult(int, String[], int[])}
+         * or {android.support.v4.app.ActivityCompat.OnRequestPermissionsResultCallback#onRequestPermissionsResult(int, String[], int[])}.
+         *
+         * @param listener a {@link RequestPermissionResultListener} callback.
+         * @return this {@link Registrar}.
+         */
+        Registrar addRequestPermissionResultListener(RequestPermissionResultListener listener);
+
+        /**
+         * Adds a callback allowing the plugin to take part in handling incoming
+         * calls to {@Activity#onActivityResult(int, int, Intent)}.
+         *
+         * @param listener an {@link ActivityResultListener} callback.
+         * @return this {@link Registrar}.
+         */
+        Registrar addActivityResultListener(ActivityResultListener listener);
+
+        /**
+         * Adds a callback allowing the plugin to take part in handling incoming
+         * calls to {@Activity#onNewIntent(Intent)}.
+         *
+         * @param listener a {@link NewIntentListener} callback.
+         * @return this {@link Registrar}.
+         */
+        Registrar addNewIntentListener(NewIntentListener listener);
+
+        /**
+         * Adds a callback allowing the plugin to take part in handling incoming
+         * calls to {@Activity#onUserLeaveHint()}.
+         *
+         * @param listener a {@link UserLeaveHintListener} callback.
+         * @return this {@link Registrar}.
+         */
+        Registrar addUserLeaveHintListener(UserLeaveHintListener listener);
+    }
+
+    /**
+     * Delegate interface for handling results of permission requests on
+     * behalf of the main {@link Activity}.
+     */
+    interface RequestPermissionResultListener {
+        /**
+         * @return true if the result has been handled.
+         */
+        boolean onRequestPermissionResult(int requestCode, String[] permissions, int[] grantResults);
+    }
+
+    /**
+     * Delegate interface for handling activity results on behalf of the main
+     * {@link Activity}.
+     */
+    interface ActivityResultListener {
+        /**
+         * @return true if the result has been handled.
+         */
+        boolean onActivityResult(int requestCode, int resultCode, Intent data);
+    }
+
+    /**
+     * Delegate interface for handling new intents on behalf of the main
+     * {@link Activity}.
+     */
+    interface NewIntentListener {
+        /**
+         * @return true if the new intent has been handled.
+         */
+        boolean onNewIntent(Intent intent);
+    }
+
+    /**
+     * Delegate interface for handling user leave hints on behalf of the main
+     * {@link Activity}.
+     */
+    interface UserLeaveHintListener {
+        void onUserLeaveHint();
+    }
+}

travis/licenses_golden/licenses_flutter

@@ -1427,6 +1427,7 @@ FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/MessageCo
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/MethodCall.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/MethodChannel.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/MethodCodec.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/PluginRegistry.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/StandardMessageCodec.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/StandardMethodCodec.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/StringCodec.java