Add PlatformPlugin.java (#3121)

The PlatformPlugin is the first of the built-in plugins that will replace the
mojom platform services.

lib/ui/window.dart

@@ -215,14 +215,14 @@ class Window {
   /// semantics update cannot be used further.
   void updateSemantics(SemanticsUpdate update) native "Window_updateSemantics";
 
-  void sendPlatformMesssage(String name,
-                            ByteData data,
-                            PlatformMessageResponseCallback callback) {
-    _sendPlatformMesssage(name, callback, data);
+  void sendPlatformMessage(String name,
+                           ByteData data,
+                           PlatformMessageResponseCallback callback) {
+    _sendPlatformMessage(name, callback, data);
   }
-  void _sendPlatformMesssage(String name,
-                             PlatformMessageResponseCallback callback,
-                             ByteData data) native "Window_sendPlatformMesssage";
+  void _sendPlatformMessage(String name,
+                            PlatformMessageResponseCallback callback,
+                            ByteData data) native "Window_sendPlatformMessage";
 
 }
 

shell/platform/android/BUILD.gn

@@ -64,6 +64,8 @@ android_library("java") {
   visibility = [ ":*" ]
 
   java_files = [
+    "io/flutter/plugin/common/JSONMessageListener.java",
+    "io/flutter/plugin/platform/PlatformPlugin.java",
     "io/flutter/view/AccessibilityBridge.java",
     "io/flutter/view/FlutterMain.java",
     "io/flutter/view/FlutterView.java",

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

+// Copyright 2016 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.util.Log;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import io.flutter.view.FlutterView;
+
+public abstract class JSONMessageListener implements FlutterView.OnMessageListener {
+    static final String TAG = "FlutterView";
+
+    @Override
+    public String onMessage(FlutterView view, String message) {
+        try {
+            JSONObject response = onJSONMessage(view, new JSONObject(message));
+            if (response == null)
+                return null;
+            return response.toString();
+        } catch (JSONException e) {
+            Log.e(TAG, "JSON exception", e);
+            return null;
+        }
+    }
+
+    public abstract JSONObject onJSONMessage(FlutterView view, JSONObject message) throws JSONException;
+}

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

+// Copyright 2016 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.platform;
+
+import android.app.Activity;
+import android.view.SoundEffectConstants;
+import android.view.View;
+import android.util.Log;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import io.flutter.plugin.common.JSONMessageListener;
+import io.flutter.view.FlutterView;
+
+/**
+ * Android implementation of the platform plugin.
+ */
+public class PlatformPlugin extends JSONMessageListener {
+    private final Activity mActivity;
+
+    public PlatformPlugin(Activity activity) {
+        mActivity = activity;
+    }
+
+    @Override
+    public JSONObject onJSONMessage(FlutterView view, JSONObject message) throws JSONException {
+        if (message.getString("method").equals("SystemSound.play")) {
+          playSystemSound(message.getJSONArray("args").getString(0));
+          return null;
+        }
+        // TODO(abarth): We should throw an exception here that gets
+        // transmitted back to Dart.
+        return null;
+    }
+
+    void playSystemSound(String soundType) {
+        if (soundType.equals("SystemSoundType.click")) {
+            View view = mActivity.getWindow().getDecorView();
+            view.playSoundEffect(SoundEffectConstants.CLICK);
+        }
+    }
+}

shell/platform/android/io/flutter/view/FlutterView.java

@@ -60,6 +60,8 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 
+import io.flutter.plugin.platform.PlatformPlugin;
+
 import org.domokit.common.ActivityLifecycleListener;
 import org.domokit.activity.ActivityImpl;
 import org.domokit.editing.KeyboardImpl;
@@ -163,6 +165,8 @@ public class FlutterView extends SurfaceView
 
         setLocale(getResources().getConfiguration().locale);
 
+        mOnMessageListeners.put("flutter/platform", new PlatformPlugin((Activity)getContext()));
+
         if ((context.getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0) {
             discoveryReceiver = new DiscoveryReceiver();
             context.registerReceiver(discoveryReceiver, new IntentFilter(ACTION_DISCOVER));
@@ -585,14 +589,14 @@ public class FlutterView extends SurfaceView
     private static native void nativeInvokePlatformMessageResponseCallback(long nativePlatformViewAndroid, int responseId, String buffer);
 
     @CalledByNative
-    private void handlePlatformMessage(String messageName, String message, final int responseId) {
-        OnMessageListener listener = mOnMessageListeners.get(messageName);
+    private void handlePlatformMessage(String name, String message, final int responseId) {
+        OnMessageListener listener = mOnMessageListeners.get(name);
         if (listener != null) {
             nativeInvokePlatformMessageResponseCallback(mNativePlatformView, responseId, listener.onMessage(this, message));
             return;
         }
 
-        OnMessageListenerAsync asyncListener = mAsyncOnMessageListeners.get(messageName);
+        OnMessageListenerAsync asyncListener = mAsyncOnMessageListeners.get(name);
         if (asyncListener != null) {
             asyncListener.onMessage(this, message, new MessageResponse() {
               @Override

shell/platform/android/platform_view_android.cc

@@ -130,8 +130,9 @@ void PlatformViewAndroid::InvokePlatformMessageResponseCallback(
   auto it = pending_messages_.find(response_id);
   if (it == pending_messages_.end())
     return;
-  std::string response =
-      base::android::ConvertJavaStringToUTF8(env, java_response);
+  std::string response;
+  if (java_response)
+      response = base::android::ConvertJavaStringToUTF8(env, java_response);
   // TODO(abarth): There's an extra copy here.
   it->second->InvokeCallback(
       std::vector<char>(response.data(), response.data() + response.size()));