Remove old flutter messaging API (#3482)

Breaking change: removed facilities for JSON and string messaging from FlutterView/FlutterViewController, leaving only binary messaging there. All other use of flutter communication now goes through FlutterMessageChannel and FlutterMethodChannels. Retained use of String and JSON codecs for now.

Companion flutter PR: flutter/flutter#8837

shell/platform/android/BUILD.gn

@@ -82,18 +82,18 @@ android_library("java") {
     "io/flutter/app/FlutterActivity.java",
     "io/flutter/app/FlutterApplication.java",
     "io/flutter/plugin/common/ActivityLifecycleListener.java",
-    "io/flutter/plugin/common/BinaryMessageCodec.java",
+    "io/flutter/plugin/common/BinaryCodec.java",
+    "io/flutter/plugin/common/FlutterException.java",
     "io/flutter/plugin/common/FlutterMessageChannel.java",
     "io/flutter/plugin/common/FlutterMethodChannel.java",
     "io/flutter/plugin/common/JSONMessageCodec.java",
-    "io/flutter/plugin/common/JSONMessageListener.java",
     "io/flutter/plugin/common/JSONMethodCodec.java",
     "io/flutter/plugin/common/MessageCodec.java",
     "io/flutter/plugin/common/MethodCodec.java",
     "io/flutter/plugin/common/MethodCall.java",
     "io/flutter/plugin/common/StandardMessageCodec.java",
     "io/flutter/plugin/common/StandardMethodCodec.java",
-    "io/flutter/plugin/common/StringMessageCodec.java",
+    "io/flutter/plugin/common/StringCodec.java",
     "io/flutter/plugin/editing/InputConnectionAdaptor.java",
     "io/flutter/plugin/editing/TextInputPlugin.java",
     "io/flutter/plugin/platform/PlatformPlugin.java",

shell/platform/android/io/flutter/plugin/common/BinaryMessageCodec.java → shell/platform/android/io/flutter/plugin/common/BinaryCodec.java

@@ -9,11 +9,11 @@ import java.nio.ByteBuffer;
 /**
  * A {@link MessageCodec} using unencoded binary messages, represented as {@link ByteBuffer}s.
  */
-public final class BinaryMessageCodec implements MessageCodec<ByteBuffer> {
+public final class BinaryCodec implements MessageCodec<ByteBuffer> {
     // This codec must match the Dart codec of the same name in package flutter/services.
-    public static final BinaryMessageCodec INSTANCE = new BinaryMessageCodec();
+    public static final BinaryCodec INSTANCE = new BinaryCodec();
 
-    private BinaryMessageCodec() {
+    private BinaryCodec() {
     }
 
     @Override

shell/platform/android/io/flutter/plugin/common/FlutterException.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;
+
+/**
+ * Thrown to indicate that a Flutter method invocation failed on the Flutter side.
+ */
+public class FlutterException extends RuntimeException {
+  public final String code;
+  public final Object details;
+  
+  FlutterException(String code, String message, Object details) {
+    super(message);
+    assert code != null;
+    this.code = code;
+    this.details = details;
+  }
+}

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

@@ -6,6 +6,7 @@ package io.flutter.plugin.common;
 
 import android.util.Log;
 import io.flutter.view.FlutterView;
+import io.flutter.view.FlutterView.BinaryMessageReplyCallback;
 import io.flutter.view.FlutterView.BinaryMessageResponse;
 import io.flutter.view.FlutterView.OnBinaryMessageListenerAsync;
 import java.nio.ByteBuffer;
@@ -60,6 +61,27 @@ public final class FlutterMethodChannel {
         this.codec = codec;
     }
 
+    /**
+     * Invokes a method on this channel, expecting no result.
+     *
+     * @param method the name String of the method.
+     * @param arguments the arguments for the invocation, possibly null.
+     */
+    public void invokeMethod(String method, Object arguments) {
+        invokeMethod(method, arguments, null);
+    }
+
+    /**
+     * Invokes a method on this channel.
+     *
+     * @param call a {@link MethodCall}.
+     * @param handler a {@link Response} handler for the invocation result.
+     */
+    public void invokeMethod(String method, Object arguments, Response handler) {
+        view.sendBinaryMessage(name, codec.encodeMethodCall(new MethodCall(method, arguments)),
+            handler == null ? null : new MethodCallResultCallback(handler));
+    }
+
     /**
      * Registers a method call handler on this channel.
      *
@@ -106,7 +128,8 @@ public final class FlutterMethodChannel {
          * Handles a stream setup request.
          *
          * @param arguments Stream configuration arguments, possibly null.
-         * @param eventSink A {@link EventSink} used to emit events once the stream has been set up.
+         * @param eventSink An {@link EventSink} used to emit events once the stream has been set
+         * up.
          */
         void listen(Object arguments, EventSink eventSink);
 
@@ -150,6 +173,24 @@ public final class FlutterMethodChannel {
         void done();
     }
 
+    private final class MethodCallResultCallback implements BinaryMessageReplyCallback {
+        private final Response handler;
+
+        MethodCallResultCallback(Response handler) {
+            this.handler = handler;
+        }
+
+        @Override
+        public void onReply(ByteBuffer reply) {
+            try {
+                final Object result = codec.decodeEnvelope(reply);
+                handler.success(result);
+            } catch (FlutterException e) {
+                handler.error(e.code, e.getMessage(), e.details);
+            }
+        }
+    }
+
     private final class MethodCallListener implements OnBinaryMessageListenerAsync {
         private final MethodCallHandler handler;
 
@@ -188,7 +229,7 @@ public final class FlutterMethodChannel {
                 });
             } catch (Exception e) {
                 Log.e(TAG + name, "Failed to handle method call", e);
-                response.send(codec.encodeErrorEnvelope("error", e.getMessage(),null));
+                response.send(codec.encodeErrorEnvelope("error", e.getMessage(), null));
             }
         }
     }
@@ -236,13 +277,13 @@ public final class FlutterMethodChannel {
                             if (cancelled.get()) {
                                 return;
                             }
-                            FlutterMethodChannel.this.view.sendToFlutter(name,null);
+                            FlutterMethodChannel.this.view.sendBinaryMessage(name, null, null);
                         }
                     });
                     response.send(codec.encodeSuccessEnvelope(null));
                 } catch (Exception e) {
                     Log.e(TAG + name, "Failed to open event stream", e);
-                    response.send(codec.encodeErrorEnvelope("error", e.getMessage(),null));
+                    response.send(codec.encodeErrorEnvelope("error", e.getMessage(), null));
                 }
             } else if (call.method.equals("cancel")) {
                 cancelled.set(true);
@@ -251,7 +292,7 @@ public final class FlutterMethodChannel {
                     response.send(codec.encodeSuccessEnvelope(null));
                 } catch (Exception e) {
                     Log.e(TAG + name, "Failed to close event stream", e);
-                    response.send(codec.encodeErrorEnvelope("error", e.getMessage(),null));
+                    response.send(codec.encodeErrorEnvelope("error", e.getMessage(), null));
                 }
             }
         }

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

@@ -26,7 +26,7 @@ public final class JSONMessageCodec implements MessageCodec<Object> {
         if (message == null) {
             return null;
         }
-        return StringMessageCodec.INSTANCE.encodeMessage(JSONObject.wrap(message).toString());
+        return StringCodec.INSTANCE.encodeMessage(JSONObject.wrap(message).toString());
     }
 
     @Override
@@ -35,7 +35,7 @@ public final class JSONMessageCodec implements MessageCodec<Object> {
             return null;
         }
         try {
-            final String json = StringMessageCodec.INSTANCE.decodeMessage(message);
+            final String json = StringCodec.INSTANCE.decodeMessage(message);
             final JSONTokener tokener = new JSONTokener(json);
             final Object value = tokener.nextValue();
             if (tokener.more()) {

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;
-
-/** @deprecated Use {@link FlutterMessageChannel} and {@link JSONMessageCodec} instead. */
-@Deprecated
-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;
-
-    public static String getStringOrNull(JSONObject object, String name) throws JSONException {
-        return object.isNull(name) ? null : object.getString(name);
-    }
-}

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

@@ -11,37 +11,77 @@ import org.json.JSONObject;
  * {@link JSONMessageCodec}.
  */
 public final class JSONMethodCodec implements MethodCodec {
-  public static final JSONMethodCodec INSTANCE = new JSONMethodCodec();
-
-  private JSONMethodCodec() {
-  }
-
-  @Override
-  public MethodCall decodeMethodCall(ByteBuffer message) {
-    try {
-      final Object json = JSONMessageCodec.INSTANCE.decodeMessage(message);
-      if (json instanceof JSONArray) {
-        final JSONArray pair = (JSONArray) json;
-        if (pair.length() == 2 && pair.get(0) instanceof String) {
-          return new MethodCall(pair.getString(0), pair.get(1));
+    public static final JSONMethodCodec INSTANCE = new JSONMethodCodec();
+
+    private JSONMethodCodec() {
+    }
+
+    @Override
+    public ByteBuffer encodeMethodCall(MethodCall methodCall) {
+       try {
+          final JSONObject map = new JSONObject();
+          map.put("method", methodCall.method);
+          map.put("args", JSONObject.wrap(methodCall.arguments));
+          return JSONMessageCodec.INSTANCE.encodeMessage(map);
+       } catch (JSONException e) {
+          throw new IllegalArgumentException("Invalid JSON", e);
+       }
+    }
+
+    @Override
+    public MethodCall decodeMethodCall(ByteBuffer message) {
+        try {
+            final Object json = JSONMessageCodec.INSTANCE.decodeMessage(message);
+            if (json instanceof JSONObject) {
+                final JSONObject map = (JSONObject) json;
+                final Object method = map.get("method");
+                final Object arguments = map.get("args");
+                if (method instanceof String) {
+                    return new MethodCall((String) method, arguments);
+                }
+            }
+            throw new IllegalArgumentException("Invalid method call: " + json);
+        } catch (JSONException e) {
+            throw new IllegalArgumentException("Invalid JSON", e);
+        }
+    }
+
+    @Override
+    public ByteBuffer encodeSuccessEnvelope(Object result) {
+        return JSONMessageCodec.INSTANCE
+            .encodeMessage(new JSONArray().put(JSONObject.wrap(result)));
+    }
+
+    @Override
+    public ByteBuffer encodeErrorEnvelope(String errorCode, String errorMessage,
+        Object errorDetails) {
+        return JSONMessageCodec.INSTANCE.encodeMessage(new JSONArray()
+            .put(errorCode)
+            .put(errorMessage)
+            .put(JSONObject.wrap(errorDetails)));
+    }
+
+    @Override
+    public Object decodeEnvelope(ByteBuffer envelope) {
+        try {
+            final Object json = JSONMessageCodec.INSTANCE.decodeMessage(envelope);
+            if (json instanceof JSONArray) {
+                final JSONArray array = (JSONArray) json;
+                if (array.length() == 1) {
+                    return array.get(0);
+                }
+                if (array.length() == 3) {
+                    final Object code = array.get(0);
+                    final Object message = array.get(1);
+                    final Object details = array.get(2);
+                    if (code instanceof String && (message == null || message instanceof String)) {
+                        throw new FlutterException((String) code, (String) message, details);
+                    }
+                }
+            }
+            throw new IllegalArgumentException("Invalid method call: " + json);
+        } catch (JSONException e) {
+            throw new IllegalArgumentException("Invalid JSON", e);
         }
-      }
-      throw new IllegalArgumentException("Invalid method call: " + json);
-    } catch (JSONException e) {
-      throw new IllegalArgumentException("Invalid JSON", e);
     }
-  }
-
-  @Override
-  public ByteBuffer encodeSuccessEnvelope(Object result) {
-    return JSONMessageCodec.INSTANCE.encodeMessage(new JSONArray().put(JSONObject.wrap(result)));
-  }
-
-  @Override
-  public ByteBuffer encodeErrorEnvelope(String errorCode, String errorMessage, Object errorDetails) {
-    return JSONMessageCodec.INSTANCE.encodeMessage(new JSONArray()
-        .put(errorCode)
-        .put(errorMessage)
-        .put(JSONObject.wrap(errorDetails)));
-  }
 }

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

@@ -4,8 +4,6 @@
 
 package io.flutter.plugin.common;
 
-import java.util.Objects;
-
 /**
  * Command object representing a method call on a {@link FlutterMessageChannel}.
  */

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

@@ -16,6 +16,15 @@ import java.nio.ByteBuffer;
  * All operations throw {@link IllegalArgumentException}, if conversion fails.
  */
 public interface MethodCodec {
+    /**
+     * Encodes a message call into binary.
+     *
+     * @param methodCall a {@link MethodCall}.
+     * @return a {@link ByteBuffer} containing the encoding between position 0 and
+     * the current position.
+     */
+    ByteBuffer encodeMethodCall(MethodCall methodCall);
+
     /**
      * Decodes a message call from binary.
      *
@@ -29,7 +38,7 @@ public interface MethodCodec {
      * Encodes a successful result into a binary envelope message.
      *
      * @param result The result value, possibly null.
-     * @return a ByteBuffer containing the encoding between position 0 and
+     * @return a {@link ByteBuffer} containing the encoding between position 0 and
      * the current position.
      */
     ByteBuffer encodeSuccessEnvelope(Object result);
@@ -40,8 +49,17 @@ public interface MethodCodec {
      * @param errorCode An error code String.
      * @param errorMessage An error message String, possibly null.
      * @param errorDetails Error details, possibly null.
-     * @return a ByteBuffer containing the encoding between position 0 and
+     * @return a {@link ByteBuffer} containing the encoding between position 0 and
      * the current position.
      */
     ByteBuffer encodeErrorEnvelope(String errorCode, String errorMessage, Object errorDetails);
+
+    /**
+     * Decodes a result envelope from binary.
+     *
+     * @param envelope the binary encoding of a result envelope as a {@link ByteBuffer}.
+     * @return the enveloped result Object.
+     * @throws FlutterException if the envelope was an error envelope.
+     */
+    Object decodeEnvelope(ByteBuffer envelope);
 }

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

@@ -25,12 +25,22 @@ public final class StandardMethodCodec implements MethodCodec {
     private StandardMethodCodec() {
     }
 
+    @Override
+    public ByteBuffer encodeMethodCall(MethodCall methodCall) {
+        final ExposedByteArrayOutputStream stream = new ExposedByteArrayOutputStream();
+        StandardMessageCodec.writeValue(stream, methodCall.method);
+        StandardMessageCodec.writeValue(stream, methodCall.arguments);
+        final ByteBuffer buffer = ByteBuffer.allocateDirect(stream.size());
+        buffer.put(stream.buffer(), 0, stream.size());
+        return buffer;
+    }
+
     @Override
     public MethodCall decodeMethodCall(ByteBuffer methodCall) {
         methodCall.order(ByteOrder.nativeOrder());
         final Object method = StandardMessageCodec.readValue(methodCall);
         final Object arguments = StandardMessageCodec.readValue(methodCall);
-        if (method instanceof String) {
+        if (method instanceof String && !methodCall.hasRemaining()) {
             return new MethodCall((String) method, arguments);
         }
         throw new IllegalArgumentException("Method call corrupted");
@@ -58,4 +68,29 @@ public final class StandardMethodCodec implements MethodCodec {
         buffer.put(stream.buffer(), 0, stream.size());
         return buffer;
     }
+
+    @Override
+    public Object decodeEnvelope(ByteBuffer envelope) {
+        envelope.order(ByteOrder.nativeOrder());
+        final byte flag = envelope.get();
+        switch (flag) {
+            case 0: {
+                final Object result = StandardMessageCodec.readValue(envelope);
+                if (!envelope.hasRemaining()) {
+                    return result;
+                }
+            }
+            case 1: {
+                final Object code = StandardMessageCodec.readValue(envelope);
+                final Object message = StandardMessageCodec.readValue(envelope);
+                final Object details = StandardMessageCodec.readValue(envelope);
+                if (code instanceof String
+                    && (message == null || message instanceof String)
+                    && !envelope.hasRemaining()) {
+                    throw new FlutterException((String) code, (String) message, details);
+                }
+            }
+        }
+        throw new IllegalArgumentException("Envelope corrupted");
+    }
 }

shell/platform/android/io/flutter/plugin/common/StringMessageCodec.java → shell/platform/android/io/flutter/plugin/common/StringCodec.java

@@ -10,12 +10,12 @@ import java.nio.charset.Charset;
 /**
  * A {@link MessageCodec} using UTF-8 encoded String messages.
  */
-public final class StringMessageCodec implements MessageCodec<String> {
+public final class StringCodec implements MessageCodec<String> {
     // This codec must match the Dart codec of the same name in package flutter/services.
     private static final Charset UTF8 = Charset.forName("UTF8");
-    public static final StringMessageCodec INSTANCE = new StringMessageCodec();
+    public static final StringCodec INSTANCE = new StringCodec();
 
-    private StringMessageCodec() {
+    private StringCodec() {
     }
 
     @Override

shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java

@@ -6,56 +6,41 @@ package io.flutter.plugin.editing;
 
 import android.text.Editable;
 import android.text.Selection;
-import android.util.Log;
 import android.view.inputmethod.BaseInputConnection;
-import android.view.inputmethod.CompletionInfo;
-import android.view.inputmethod.CorrectionInfo;
-import android.view.inputmethod.EditorInfo;
 import android.view.KeyEvent;
-import android.view.View;
+
+import io.flutter.plugin.common.FlutterMethodChannel;
 import io.flutter.view.FlutterView;
-import org.json.JSONArray;
-import org.json.JSONException;
-import org.json.JSONObject;
 
-class InputConnectionAdaptor extends BaseInputConnection {
-    static final String TAG = "FlutterView";
-    static final String MESSAGE_NAME = "flutter/textinputclient";
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
 
-    private FlutterView mView;
-    private int mClient;
-    private TextInputPlugin mPlugin;
-    private JSONObject mOutgoingState;
+class InputConnectionAdaptor extends BaseInputConnection {
+    private final int mClient;
+    private final TextInputPlugin mPlugin;
+    private final FlutterMethodChannel mFlutterChannel;
+    private final Map<String, Object> mOutgoingState;
 
-    public InputConnectionAdaptor(FlutterView view, int client, TextInputPlugin plugin) {
+    public InputConnectionAdaptor(FlutterView view, int client,
+        TextInputPlugin plugin, FlutterMethodChannel flutterChannel) {
         super(view, true);
-        mView = view;
         mClient = client;
         mPlugin = plugin;
-        mOutgoingState = new JSONObject();
+        mFlutterChannel = flutterChannel;
+        mOutgoingState = new HashMap<>();
     }
 
     private void updateEditingState() {
-        try {
-            final Editable content = getEditable();
-            mOutgoingState.put("text", content.toString());
-            mOutgoingState.put("selectionBase", Selection.getSelectionStart(content));
-            mOutgoingState.put("selectionExtent", Selection.getSelectionEnd(content));
-            mOutgoingState.put("composingBase", BaseInputConnection.getComposingSpanStart(content));
-            mOutgoingState.put("composingExtent", BaseInputConnection.getComposingSpanEnd(content));
-
-            final JSONArray args = new JSONArray();
-            args.put(0, mClient);
-            args.put(1, mOutgoingState);
-            final JSONObject message = new JSONObject();
-            message.put("method", "TextInputClient.updateEditingState");
-            message.put("args", args);
-            mView.sendPlatformMessage(MESSAGE_NAME, message.toString(), null);
-
-            mPlugin.setLatestEditingState(mOutgoingState);
-        } catch (JSONException e) {
-            Log.e(TAG, "Unexpected error serializing editing state", e);
-        }
+        final Editable content = getEditable();
+        mOutgoingState.put("text", content.toString());
+        mOutgoingState.put("selectionBase", Selection.getSelectionStart(content));
+        mOutgoingState.put("selectionExtent", Selection.getSelectionEnd(content));
+        mOutgoingState.put("composingBase", BaseInputConnection.getComposingSpanStart(content));
+        mOutgoingState.put("composingExtent", BaseInputConnection.getComposingSpanEnd(content));
+        mFlutterChannel.invokeMethod("TextInputClient.updateEditingState", Arrays
+            .asList(mClient, mOutgoingState));
+        mPlugin.setLatestEditingState(mOutgoingState);
     }
 
     @Override
@@ -103,7 +88,7 @@ class InputConnectionAdaptor extends BaseInputConnection {
             // 2. There is a selection. In that case, we want to delete the selection.
             //    event.getNumber() is 0, and commitText("", 1) will do what we want.
             if (event.getKeyCode() == KeyEvent.KEYCODE_DEL &&
-                mOutgoingState.optInt("selectionBase", -1) == mOutgoingState.optInt("selectionExtent", -1)) {
+                optInt("selectionBase", -1) == optInt("selectionExtent", -1)) {
                 deleteSurroundingText(1, 0);
             } else {
                 String text = event.getNumber() == 0 ? "" : String.valueOf(event.getNumber());
@@ -113,21 +98,15 @@ class InputConnectionAdaptor extends BaseInputConnection {
         return result;
     }
 
+    private int optInt(String key, int defaultValue) {
+        return mOutgoingState.containsKey(key) ? (Integer) mOutgoingState.get(key) : defaultValue;
+    }
+
     @Override
     public boolean performEditorAction(int actionCode) {
-        try {
-            // TODO(abarth): Support more actions.
-            final JSONArray args = new JSONArray();
-            args.put(0, mClient);
-            args.put(1, "TextInputAction.done");
-            final JSONObject message = new JSONObject();
-            message.put("method", "TextInputClient.performAction");
-            message.put("args", args);
-            mView.sendPlatformMessage(MESSAGE_NAME, message.toString(), null);
-            return true;
-        } catch (JSONException e) {
-            Log.e(TAG, "Unexpected error serializing editor action", e);
-            return false;
-        }
+        // TODO(abarth): Support more actions.
+        mFlutterChannel.invokeMethod("TextInputClient.performAction",
+            Arrays.asList(mClient, "TextInputAction.done"));
+        return true;
     }
 }

shell/platform/android/io/flutter/plugin/editing/TextInputPlugin.java

@@ -6,17 +6,19 @@ package io.flutter.plugin.editing;
 
 import android.app.Activity;
 import android.content.Context;
-import android.text.Editable;
 import android.text.InputType;
-import android.text.Selection;
-import android.text.SpannableStringBuilder;
-import android.util.Log;
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputConnection;
 import android.view.inputmethod.InputMethodManager;
-import android.view.View;
-import io.flutter.plugin.common.JSONMessageListener;
+
+import io.flutter.plugin.common.FlutterMethodChannel;
+import io.flutter.plugin.common.FlutterMethodChannel.MethodCallHandler;
+import io.flutter.plugin.common.FlutterMethodChannel.Response;
+import io.flutter.plugin.common.JSONMethodCodec;
+import io.flutter.plugin.common.MethodCall;
 import io.flutter.view.FlutterView;
+
+import java.util.Map;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -24,37 +26,50 @@ import org.json.JSONObject;
 /**
  * Android implementation of the text input plugin.
  */
-public class TextInputPlugin extends JSONMessageListener {
-    private static final String TAG = "FlutterView";
+public class TextInputPlugin implements MethodCallHandler {
 
     private final Activity mActivity;
+    private final FlutterView mView;
+    private final FlutterMethodChannel mFlutterChannel;
     private int mClient = 0;
     private JSONObject mConfiguration;
     private JSONObject mLatestState;
 
-    public TextInputPlugin(Activity activity) {
+    public TextInputPlugin(Activity activity, FlutterView view) {
         mActivity = activity;
+        mView = view;
+        mFlutterChannel = new FlutterMethodChannel(view, "flutter/textinput",
+            JSONMethodCodec.INSTANCE);
+        mFlutterChannel.setMethodCallHandler(this);
     }
 
     @Override
-    public JSONObject onJSONMessage(FlutterView view, JSONObject message) throws JSONException {
-        String method = message.getString("method");
-        JSONArray args = message.getJSONArray("args");
-        if (method.equals("TextInput.show")) {
-            showTextInput(view);
-        } else if (method.equals("TextInput.hide")) {
-            hideTextInput(view);
-        } else if (method.equals("TextInput.setClient")) {
-            setTextInputClient(view, args.getInt(0), args.getJSONObject(1));
-        } else if (method.equals("TextInput.setEditingState")) {
-            setTextInputEditingState(view, args.getJSONObject(0));
-        } else if (method.equals("TextInput.clearClient")) {
-            clearTextInputClient();
-        } else {
-            // TODO(abarth): We should throw an exception here that gets
-            // transmitted back to Dart.
+    public void onMethodCall(MethodCall call, Response response) {
+        String method = call.method;
+        Object args = call.arguments;
+        try {
+            if (method.equals("TextInput.show")) {
+                showTextInput(mView);
+                response.success(null);
+            } else if (method.equals("TextInput.hide")) {
+                hideTextInput(mView);
+                response.success(null);
+            } else if (method.equals("TextInput.setClient")) {
+                final JSONArray argumentList = (JSONArray) args;
+                setTextInputClient(mView, argumentList.getInt(0), argumentList.getJSONObject(1));
+                response.success(null);
+            } else if (method.equals("TextInput.setEditingState")) {
+                setTextInputEditingState(mView, (JSONObject) args);
+                response.success(null);
+            } else if (method.equals("TextInput.clearClient")) {
+                clearTextInputClient();
+                response.success(null);
+            } else {
+                response.error("unknown", "Unknown method: " + call.method, null);
+            }
+        } catch (JSONException e) {
+            response.error("error", "JSON error: " + e.getMessage(), null);
         }
-        return null;
     }
 
     private static int inputTypeFromTextInputType(String inputType) {
@@ -67,67 +82,64 @@ public class TextInputPlugin extends JSONMessageListener {
         return InputType.TYPE_CLASS_TEXT;
     }
 
-    public InputConnection createInputConnection(FlutterView view, EditorInfo outAttrs) {
+    public InputConnection createInputConnection(FlutterView view, EditorInfo outAttrs)
+        throws JSONException {
         if (mClient == 0)
             return null;
-        try {
-            outAttrs.inputType = inputTypeFromTextInputType(mConfiguration.getString("inputType"));
-            outAttrs.actionLabel = getStringOrNull(mConfiguration, "actionLabel");
-            outAttrs.imeOptions = EditorInfo.IME_ACTION_DONE | EditorInfo.IME_FLAG_NO_FULLSCREEN;
-            InputConnectionAdaptor connection = new InputConnectionAdaptor(view, mClient, this);
-            if (mLatestState != null) {
-                int selectionBase = mLatestState.getInt("selectionBase");
-                int selectionExtent = mLatestState.getInt("selectionExtent");
-                outAttrs.initialSelStart = selectionBase;
-                outAttrs.initialSelEnd = selectionExtent;
-                connection.getEditable().append(mLatestState.getString("text"));
-                connection.setSelection(Math.max(selectionBase, 0),
-                                        Math.max(selectionExtent, 0));
-                connection.setComposingRegion(mLatestState.getInt("composingBase"),
-                                              mLatestState.getInt("composingExtent"));
-            } else {
-                outAttrs.initialSelStart = 0;
-                outAttrs.initialSelEnd = 0;
-            }
-            return connection;
-        } catch (JSONException e) {
-            Log.e(TAG, "Failed to create input connection", e);
+        outAttrs.inputType = inputTypeFromTextInputType(mConfiguration.getString("inputType"));
+        outAttrs.actionLabel = mConfiguration.getString("actionLabel");
+        outAttrs.imeOptions = EditorInfo.IME_ACTION_DONE | EditorInfo.IME_FLAG_NO_FULLSCREEN;
+        InputConnectionAdaptor connection = new InputConnectionAdaptor(view, mClient, this,
+            mFlutterChannel);
+        if (mLatestState != null) {
+            int selectionBase = (Integer) mLatestState.get("selectionBase");
+            int selectionExtent = (Integer) mLatestState.get("selectionExtent");
+            outAttrs.initialSelStart = selectionBase;
+            outAttrs.initialSelEnd = selectionExtent;
+            connection.getEditable().append((String) mLatestState.get("text"));
+            connection.setSelection(Math.max(selectionBase, 0),
+                Math.max(selectionExtent, 0));
+            connection.setComposingRegion((Integer) mLatestState.get("composingBase"),
+                (Integer) mLatestState.get("composingExtent"));
+        } else {
+            outAttrs.initialSelStart = 0;
+            outAttrs.initialSelEnd = 0;
         }
-        return null;
+        return connection;
     }
 
     private void showTextInput(FlutterView view) {
         InputMethodManager imm =
-                (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
+            (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
         imm.showSoftInput(view, 0);
     }
 
     private void hideTextInput(FlutterView view) {
         InputMethodManager imm =
-                (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
+            (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
         imm.hideSoftInputFromWindow(view.getApplicationWindowToken(), 0);
     }
 
-    private void setTextInputClient(FlutterView view, int client, JSONObject configuration) throws JSONException {
+    private void setTextInputClient(FlutterView view, int client, JSONObject configuration) {
         mLatestState = null;
         mClient = client;
         mConfiguration = configuration;
         InputMethodManager imm =
-                (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
+            (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
         imm.restartInput(view);
     }
 
-    private void setTextInputEditingState(FlutterView view, JSONObject state) throws JSONException {
+    private void setTextInputEditingState(FlutterView view, JSONObject state) {
         mLatestState = state;
         InputMethodManager imm =
-                (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
+            (InputMethodManager) mActivity.getSystemService(Context.INPUT_METHOD_SERVICE);
         imm.restartInput(view);
     }
 
-    void setLatestEditingState(JSONObject state) {
-        mLatestState = state;
+    void setLatestEditingState(Map<String, Object> state) {
+        mLatestState = (JSONObject) JSONObject.wrap(state);
     }
-    
+
     private void clearTextInputClient() {
         mClient = 0;
     }

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

@@ -16,9 +16,12 @@ import android.os.Build;
 import android.view.HapticFeedbackConstants;
 import android.view.SoundEffectConstants;
 import android.view.View;
+
 import io.flutter.plugin.common.ActivityLifecycleListener;
-import io.flutter.plugin.common.JSONMessageListener;
-import io.flutter.view.FlutterView;
+import io.flutter.plugin.common.FlutterMethodChannel.MethodCallHandler;
+import io.flutter.plugin.common.FlutterMethodChannel.Response;
+import io.flutter.plugin.common.MethodCall;
+
 import org.chromium.base.PathUtils;
 import org.json.JSONArray;
 import org.json.JSONException;
@@ -27,7 +30,7 @@ import org.json.JSONObject;
 /**
  * Android implementation of the platform plugin.
  */
-public class PlatformPlugin extends JSONMessageListener implements ActivityLifecycleListener {
+public class PlatformPlugin implements MethodCallHandler, ActivityLifecycleListener {
     private final Activity mActivity;
     public static final int DEFAULT_SYSTEM_UI = View.SYSTEM_UI_FLAG_LAYOUT_STABLE
             | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
@@ -39,38 +42,49 @@ public class PlatformPlugin extends JSONMessageListener implements ActivityLifec
     }
 
     @Override
-    public JSONObject onJSONMessage(FlutterView view, JSONObject message) throws JSONException {
-        String method = message.getString("method");
-        JSONArray args = message.getJSONArray("args");
-        if (method.equals("SystemSound.play")) {
-            playSystemSound(args.getString(0));
-        } else if (method.equals("HapticFeedback.vibrate")) {
-            vibrateHapticFeedback();
-        } else if (method.equals("UrlLauncher.launch")) {
-            launchURL(args.getString(0));
-        } else if (method.equals("SystemChrome.setPreferredOrientations")) {
-            setSystemChromePreferredOrientatations(args.getJSONArray(0));
-        } else if (method.equals("SystemChrome.setApplicationSwitcherDescription")) {
-            setSystemChromeApplicationSwitcherDescription(args.getJSONObject(0));
-        } else if (method.equals("SystemChrome.setEnabledSystemUIOverlays")) {
-            setSystemChromeEnabledSystemUIOverlays(args.getJSONArray(0));
-        } else if (method.equals("SystemChrome.setSystemUIOverlayStyle")) {
-            setSystemChromeSystemUIOverlayStyle(args.getString(0));
-        } else if (method.equals("SystemNavigator.pop")) {
-            popSystemNavigator();
-        } else if (method.equals("Clipboard.getData")) {
-            return getClipboardData(args.getString(0));
-        } else if (method.equals("Clipboard.setData")) {
-            setClipboardData(args.getJSONObject(0));
-        } else if (method.equals("PathProvider.getTemporaryDirectory")) {
-            return getPathProviderTemporaryDirectory();
-        } else if (method.equals("PathProvider.getApplicationDocumentsDirectory")) {
-            return getPathProviderApplicationDocumentsDirectory();
-        } else {
-            // TODO(abarth): We should throw an exception here that gets
-            // transmitted back to Dart.
+    public void onMethodCall(MethodCall call, Response response) {
+        String method = call.method;
+        Object arguments = call.arguments;
+        try {
+            if (method.equals("SystemSound.play")) {
+                playSystemSound((String) arguments);
+                response.success(null);
+            } else if (method.equals("HapticFeedback.vibrate")) {
+                vibrateHapticFeedback();
+                response.success(null);
+            } else if (method.equals("UrlLauncher.launch")) {
+                launchURL((String) arguments);
+                response.success(null);
+            } else if (method.equals("SystemChrome.setPreferredOrientations")) {
+                setSystemChromePreferredOrientations((JSONArray) arguments);
+                response.success(null);
+            } else if (method.equals("SystemChrome.setApplicationSwitcherDescription")) {
+                setSystemChromeApplicationSwitcherDescription((JSONObject) arguments);
+                response.success(null);
+            } else if (method.equals("SystemChrome.setEnabledSystemUIOverlays")) {
+                setSystemChromeEnabledSystemUIOverlays((JSONArray) arguments);
+                response.success(null);
+            } else if (method.equals("SystemChrome.setSystemUIOverlayStyle")) {
+                setSystemChromeSystemUIOverlayStyle((String) arguments);
+                response.success(null);
+            } else if (method.equals("SystemNavigator.pop")) {
+                popSystemNavigator();
+                response.success(null);
+            } else if (method.equals("Clipboard.getData")) {
+                response.success(getClipboardData((String) arguments));
+            } else if (method.equals("Clipboard.setData")) {
+                setClipboardData((JSONObject) arguments);
+                response.success(null);
+            } else if (method.equals("PathProvider.getTemporaryDirectory")) {
+                response.success(getPathProviderTemporaryDirectory());
+            } else if (method.equals("PathProvider.getApplicationDocumentsDirectory")) {
+                response.success(getPathProviderApplicationDocumentsDirectory());
+            } else {
+                response.error("unknown", "Unknown method: " + method, null);
+            }
+        } catch (JSONException e) {
+            response.error("error", "JSON error: " + e.getMessage(), null);
         }
-        return null;
     }
 
     private void playSystemSound(String soundType) {
@@ -95,19 +109,19 @@ public class PlatformPlugin extends JSONMessageListener implements ActivityLifec
         }
     }
 
-    private void setSystemChromePreferredOrientatations(JSONArray orientatations) throws JSONException {
+    private void setSystemChromePreferredOrientations(JSONArray orientations) throws JSONException {
         // Currently the Android implementation only supports masks with zero or one
         // selected device orientations.
         int androidOrientation;
-        if (orientatations.length() == 0) {
+        if (orientations.length() == 0) {
             androidOrientation = ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
-        } else if (orientatations.getString(0).equals("DeviceOrientation.portraitUp")) {
+        } else if (orientations.getString(0).equals("DeviceOrientation.portraitUp")) {
             androidOrientation = ActivityInfo.SCREEN_ORIENTATION_PORTRAIT;
-        } else if (orientatations.getString(0).equals("DeviceOrientation.landscapeLeft")) {
+        } else if (orientations.getString(0).equals("DeviceOrientation.landscapeLeft")) {
             androidOrientation = ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;
-        } else if (orientatations.getString(0).equals("DeviceOrientation.portraitDown")) {
+        } else if (orientations.getString(0).equals("DeviceOrientation.portraitDown")) {
             androidOrientation = ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT;
-        } else if (orientatations.getString(0).equals("DeviceOrientation.landscapeRight")) {
+        } else if (orientations.getString(0).equals("DeviceOrientation.landscapeRight")) {
             androidOrientation = ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE;
         } else {
             return;
@@ -127,11 +141,11 @@ public class PlatformPlugin extends JSONMessageListener implements ActivityLifec
         }
 
         mActivity.setTaskDescription(
-                new android.app.ActivityManager.TaskDescription(
-                        description.getString("label"),
-                        null,
-                        color
-                )
+            new android.app.ActivityManager.TaskDescription(
+                description.getString("label"),
+                null,
+                color
+            )
         );
     }
 
@@ -143,9 +157,9 @@ public class PlatformPlugin extends JSONMessageListener implements ActivityLifec
             | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
             | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION;
 
-         if (overlays.length() == 0) {
-             enabledOverlays |= View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;
-         }
+        if (overlays.length() == 0) {
+            enabledOverlays |= View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;
+        }
 
         for (int i = 0; i < overlays.length(); ++i) {
             String overlay = overlays.getString(i);
@@ -183,9 +197,9 @@ public class PlatformPlugin extends JSONMessageListener implements ActivityLifec
 
         if ((format == null || format.equals(kTextPlainFormat)) &&
             clip.getDescription().hasMimeType(ClipDescription.MIMETYPE_TEXT_PLAIN)) {
-              JSONObject result = new JSONObject();
-              result.put("text", clip.getItemAt(0).getText().toString());
-              return result;
+            JSONObject result = new JSONObject();
+            result.put("text", clip.getItemAt(0).getText().toString());
+            return result;
         }
 
         return null;
@@ -197,16 +211,12 @@ public class PlatformPlugin extends JSONMessageListener implements ActivityLifec
         clipboard.setPrimaryClip(clip);
     }
 
-    private JSONObject getPathProviderTemporaryDirectory() throws JSONException {
-        JSONObject result = new JSONObject();
-        result.put("path", mActivity.getCacheDir().getPath());
-        return result;
+    private String getPathProviderTemporaryDirectory() {
+        return mActivity.getCacheDir().getPath();
     }
 
-    private JSONObject getPathProviderApplicationDocumentsDirectory() throws JSONException {
-        JSONObject result = new JSONObject();
-        result.put("path", PathUtils.getDataDirectory(mActivity));
-        return result;
+    private String getPathProviderApplicationDocumentsDirectory() {
+        return PathUtils.getDataDirectory(mActivity);
     }
 
     @Override

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

@@ -10,12 +10,10 @@ import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
 import android.view.accessibility.AccessibilityEvent;
-import android.view.accessibility.AccessibilityManager;
 import android.view.accessibility.AccessibilityNodeInfo;
 import android.view.accessibility.AccessibilityNodeProvider;
 
 import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;

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

@@ -10,10 +10,8 @@ import android.content.pm.PackageManager;
 import android.content.res.AssetManager;
 import android.os.Bundle;
 import android.os.SystemClock;
-import java.io.BufferedReader;
+
 import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.InputStreamReader;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -21,9 +19,6 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
-import org.json.JSONArray;
-import org.json.JSONObject;
-import org.json.JSONTokener;
 
 import org.chromium.base.JNINamespace;
 import org.chromium.base.PathUtils;

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

@@ -11,7 +11,6 @@ import android.util.Log;
 
 import java.io.File;
 import java.io.FilenameFilter;
-import java.io.IOException;
 
 /**
  * A class to clean up orphaned resource directories after unclean shutdowns.

shell/platform/darwin/ios/BUILD.gn

@@ -17,14 +17,11 @@ shared_library("flutter_framework_dylib") {
   sources = [
     "framework/Headers/Flutter.h",
     "framework/Headers/FlutterAppDelegate.h",
-    "framework/Headers/FlutterAsyncMessageListener.h",
     "framework/Headers/FlutterChannels.h",
     "framework/Headers/FlutterCodecs.h",
     "framework/Headers/FlutterBinaryMessenger.h",
     "framework/Headers/FlutterDartProject.h",
-    "framework/Headers/FlutterJSONMessageListener.h",
     "framework/Headers/FlutterMacros.h",
-    "framework/Headers/FlutterMessageListener.h",
     "framework/Headers/FlutterViewController.h",
     "framework/Source/FlutterAppDelegate.mm",
     "framework/Source/FlutterChannels.mm",
@@ -33,7 +30,6 @@ shared_library("flutter_framework_dylib") {
     "framework/Source/FlutterDartProject_Internal.h",
     "framework/Source/FlutterDartSource.h",
     "framework/Source/FlutterDartSource.mm",
-    "framework/Source/FlutterJSONMessageListener.mm",
     "framework/Source/FlutterPlatformPlugin.h",
     "framework/Source/FlutterPlatformPlugin.mm",
     "framework/Source/FlutterStandardCodec_Internal.h",
@@ -158,14 +154,11 @@ copy("framework_headers") {
   sources = [
     "framework/Headers/Flutter.h",
     "framework/Headers/FlutterAppDelegate.h",
-    "framework/Headers/FlutterAsyncMessageListener.h",
     "framework/Headers/FlutterBinaryMessenger.h",
     "framework/Headers/FlutterChannels.h",
     "framework/Headers/FlutterCodecs.h",
     "framework/Headers/FlutterDartProject.h",
-    "framework/Headers/FlutterJSONMessageListener.h",
     "framework/Headers/FlutterMacros.h",
-    "framework/Headers/FlutterMessageListener.h",
     "framework/Headers/FlutterViewController.h",
   ]
   outputs = [

shell/platform/darwin/ios/framework/Headers/Flutter.h

@@ -6,14 +6,11 @@
 #define FLUTTER_FLUTTER_H_
 
 #include "FlutterAppDelegate.h"
-#include "FlutterAsyncMessageListener.h"
 #include "FlutterBinaryMessenger.h"
 #include "FlutterChannels.h"
 #include "FlutterCodecs.h"
 #include "FlutterDartProject.h"
-#include "FlutterJSONMessageListener.h"
 #include "FlutterMacros.h"
-#include "FlutterMessageListener.h"
 #include "FlutterViewController.h"
 
 #endif  // FLUTTER_FLUTTER_H_

shell/platform/darwin/ios/framework/Headers/FlutterAsyncMessageListener.h

-// 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.
-
-#ifndef FLUTTER_FLUTTERASYNCMESSAGELISTENER_H_
-#define FLUTTER_FLUTTERASYNCMESSAGELISTENER_H_
-
-#import <Foundation/Foundation.h>
-
-#include "FlutterMacros.h"
-
-FLUTTER_EXPORT
-@protocol FlutterAsyncMessageListener<NSObject>
-
-- (void)didReceiveString:(NSString*)message
-                callback:(void(^)(NSString*))sendResponse;
-
-@property(readonly, strong, nonatomic) NSString* messageName;
-
-@end
-
-#endif  // FLUTTER_FLUTTERASYNCMESSAGELISTENER_H_

shell/platform/darwin/ios/framework/Headers/FlutterChannels.h

@@ -17,6 +17,10 @@ FLUTTER_EXPORT
 + (instancetype)messageChannelNamed:(NSString*)name
                     binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger
                               codec:(NSObject<FlutterMessageCodec>*)codec;
+- (instancetype)initWithName:(NSString*)name
+             binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger
+                       codec:(NSObject<FlutterMessageCodec>*)codec;
+- (void)sendMessage:(id)message;
 - (void)sendMessage:(id)message replyHandler:(FlutterReplyHandler)handler;
 - (void)setMessageHandler:(FlutterMessageHandler)handler;
 @end
@@ -37,6 +41,13 @@ FLUTTER_EXPORT
 + (instancetype)methodChannelNamed:(NSString*)name
                    binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger
                              codec:(NSObject<FlutterMethodCodec>*)codec;
+- (instancetype)initWithName:(NSString*)name
+                   binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger
+                             codec:(NSObject<FlutterMethodCodec>*)codec;
+- (void)invokeMethod:(NSString*)method arguments:(id)arguments;
+- (void)invokeMethod:(NSString*)method
+           arguments:(id)arguments
+      resultReceiver:(FlutterResultReceiver)resultReceiver;
 - (void)setMethodCallHandler:(FlutterMethodCallHandler)handler;
 - (void)setStreamHandler:(FlutterStreamHandler)handler;
 @end

shell/platform/darwin/ios/framework/Headers/FlutterCodecs.h

@@ -35,8 +35,8 @@ FLUTTER_EXPORT
 @interface FlutterMethodCall : NSObject
 + (instancetype)methodCallWithMethodName:(NSString*)method
                                arguments:(id)arguments;
-@property(readonly) NSString* method;
-@property(readonly) id arguments;
+@property(readonly, nonatomic) NSString* method;
+@property(readonly, nonatomic) id arguments;
 @end
 
 FLUTTER_EXPORT
@@ -44,9 +44,9 @@ FLUTTER_EXPORT
 + (instancetype)errorWithCode:(NSString*)code
                       message:(NSString*)message
                       details:(id)details;
-@property(readonly) NSString* code;
-@property(readonly) NSString* message;
-@property(readonly) id details;
+@property(readonly, nonatomic) NSString* code;
+@property(readonly, nonatomic) NSString* message;
+@property(readonly, nonatomic) id details;
 @end
 
 typedef NS_ENUM(NSInteger, FlutterStandardDataType) {
@@ -62,24 +62,26 @@ FLUTTER_EXPORT
 + (instancetype)typedDataWithInt32:(NSData*)data;
 + (instancetype)typedDataWithInt64:(NSData*)data;
 + (instancetype)typedDataWithFloat64:(NSData*)data;
-@property(readonly) NSData* data;
-@property(readonly) FlutterStandardDataType type;
-@property(readonly) UInt32 elementCount;
-@property(readonly) UInt8 elementSize;
+@property(readonly, nonatomic) NSData* data;
+@property(readonly, nonatomic) FlutterStandardDataType type;
+@property(readonly, nonatomic) UInt32 elementCount;
+@property(readonly, nonatomic) UInt8 elementSize;
 @end
 
 FLUTTER_EXPORT
 @interface FlutterStandardBigInteger : NSObject
 + (instancetype)bigIntegerWithHex:(NSString*)hex;
-@property(readonly) NSString* hex;
+@property(readonly, nonatomic) NSString* hex;
 @end
 
 FLUTTER_EXPORT
 @protocol FlutterMethodCodec
 + (instancetype)sharedInstance;
-- (FlutterMethodCall*)decodeMethodCall:(NSData*)message;
+- (NSData*)encodeMethodCall:(FlutterMethodCall*)methodCall;
+- (FlutterMethodCall*)decodeMethodCall:(NSData*)methodCall;
 - (NSData*)encodeSuccessEnvelope:(id)result;
 - (NSData*)encodeErrorEnvelope:(FlutterError*)error;
+- (id)decodeEnvelope:(NSData*)envelope error:(FlutterError**)error;
 @end
 
 FLUTTER_EXPORT

shell/platform/darwin/ios/framework/Headers/FlutterJSONMessageListener.h

-// 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.
-
-#ifndef FLUTTER_FLUTTERJSONMESSAGELISTENER_H_
-#define FLUTTER_FLUTTERJSONMESSAGELISTENER_H_
-
-#include "FlutterMessageListener.h"
-
-FLUTTER_EXPORT
-@interface FlutterJSONMessageListener : NSObject<FlutterMessageListener>
-
-- (NSDictionary*)didReceiveJSON:(NSDictionary*)message;
-
-@end
-
-#endif  // FLUTTER_FLUTTERJSONMESSAGELISTENER_H_

shell/platform/darwin/ios/framework/Headers/FlutterMessageListener.h

-// 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.
-
-#ifndef FLUTTER_FLUTTERMESSAGELISTENER_H_
-#define FLUTTER_FLUTTERMESSAGELISTENER_H_
-
-#import <Foundation/Foundation.h>
-
-#include "FlutterMacros.h"
-
-FLUTTER_EXPORT
-@protocol FlutterMessageListener<NSObject>
-
-- (NSString*)didReceiveString:(NSString*)message;
-
-@property(readonly, strong, nonatomic) NSString* messageName;
-
-@end
-
-#endif  // FLUTTER_FLUTTERMESSAGELISTENER_H_

shell/platform/darwin/ios/framework/Headers/FlutterViewController.h

@@ -8,11 +8,9 @@
 #import <UIKit/UIKit.h>
 #include <sys/cdefs.h>
 
-#include "FlutterAsyncMessageListener.h"
 #include "FlutterBinaryMessenger.h"
 #include "FlutterDartProject.h"
 #include "FlutterMacros.h"
-#include "FlutterMessageListener.h"
 
 FLUTTER_EXPORT
 @interface FlutterViewController : UIViewController<FlutterBinaryMessenger>
@@ -22,22 +20,6 @@ FLUTTER_EXPORT
                          bundle:(NSBundle*)nibBundleOrNil
     NS_DESIGNATED_INITIALIZER;
 
-- (void)sendString:(NSString*)message withMessageName:(NSString*)messageName;
-
-- (void)sendString:(NSString*)message
-    withMessageName:(NSString*)messageName
-           callback:(void (^)(NSString*))callback;
-
-- (void)addMessageListener:(NSObject<FlutterMessageListener>*)listener;
-
-- (void)removeMessageListener:(NSObject<FlutterMessageListener>*)listener;
-
-- (void)addAsyncMessageListener:
-    (NSObject<FlutterAsyncMessageListener>*)listener;
-
-- (void)removeAsyncMessageListener:
-    (NSObject<FlutterAsyncMessageListener>*)listener;
-
 - (void)handleStatusBarTouches:(UIEvent*)event;
 @end
 

shell/platform/darwin/ios/framework/Source/FlutterChannels.mm

@@ -37,6 +37,11 @@
   [super dealloc];
 }
 
+- (void)sendMessage:(id)message {
+  [_messenger sendBinaryMessage:[_codec encode:message]
+                    channelName:_name];
+}
+
 - (void)sendMessage:(id)message replyHandler:(FlutterReplyHandler)handler {
   [_messenger sendBinaryMessage:[_codec encode:message]
                     channelName:_name
@@ -147,6 +152,25 @@
   [super dealloc];
 }
 
+- (void)invokeMethod:(NSString*)method arguments:(id)arguments {
+  [_messenger sendBinaryMessage:[_codec encodeMethodCall:[FlutterMethodCall methodCallWithMethodName:method arguments:arguments]]
+                    channelName:_name];
+}
+
+- (void)invokeMethod:(NSString*)method
+           arguments:(id)arguments
+      resultReceiver:(FlutterResultReceiver)resultReceiver {
+        [_messenger sendBinaryMessage:[_codec encodeMethodCall:[FlutterMethodCall methodCallWithMethodName:method arguments:arguments]]
+                          channelName:_name
+                   binaryReplyHandler:^(NSData* reply) {
+                            if (resultReceiver) {
+                              FlutterError* flutterError = nil;
+                              id result = [_codec decodeEnvelope:reply error:&flutterError];
+                              resultReceiver(result, flutterError);
+                            }
+                          }];
+}
+
 - (void)setMethodCallHandler:(FlutterMethodCallHandler)handler {
   [_messenger
       setBinaryMessageHandlerOnChannel:_name

shell/platform/darwin/ios/framework/Source/FlutterCodecs.mm

@@ -78,20 +78,43 @@
   return _sharedInstance;
 }
 
+- (NSData*)encodeMethodCall:(FlutterMethodCall*)call {
+  return [[FlutterJSONMessageCodec sharedInstance] encode:@{
+    @"method": call.method,
+    @"args": (call.arguments == nil ? [NSNull null] : call.arguments),
+  }];
+}
+
 - (NSData*)encodeSuccessEnvelope:(id)result {
-  return [[FlutterJSONMessageCodec sharedInstance] encode:@[ result ]];
+  return [[FlutterJSONMessageCodec sharedInstance] encode:@[
+    result == nil ? [NSNull null] : result
+  ]];
 }
 
 - (NSData*)encodeErrorEnvelope:(FlutterError*)error {
-  return [[FlutterJSONMessageCodec sharedInstance]
-      encode:@[ error.code, error.message, error.details ]];
+  return [[FlutterJSONMessageCodec sharedInstance] encode:@[
+    error.code,
+    error.message == nil ? [NSNull null] : error.message,
+    error.details == nil ? [NSNull null] : error.details,
+  ]];
 }
 
 - (FlutterMethodCall*)decodeMethodCall:(NSData*)message {
-  NSArray* call = [[FlutterJSONMessageCodec sharedInstance] decode:message];
-  NSAssert(call.count == 2, @"Invalid JSON method call");
-  NSAssert([call[0] isKindOfClass:[NSString class]],
-           @"Invalid JSON method call");
-  return [FlutterMethodCall methodCallWithMethodName:call[0] arguments:call[1]];
+  NSDictionary* dictionary = [[FlutterJSONMessageCodec sharedInstance] decode:message];
+  id method = dictionary[@"method"];
+  id arguments = dictionary[@"args"];
+  NSAssert([method isKindOfClass:[NSString class]], @"Invalid JSON method call");
+  return [FlutterMethodCall methodCallWithMethodName:method arguments:arguments];
+}
+
+- (id)decodeEnvelope:(NSData*)envelope error:(FlutterError**)error {
+  NSArray* array = [[FlutterJSONMessageCodec sharedInstance] decode:envelope];
+  if (array.count == 1)
+    return array[0];
+  NSAssert(array.count == 3, @"Invalid JSON envelope");
+  NSAssert([array[0] isKindOfClass:[NSString class]], @"Invalid JSON envelope");
+  NSAssert(array[1] == nil || [array[1] isKindOfClass:[NSString class]], @"Invalid JSON envelope");
+  *error = [FlutterError errorWithCode:array[0] message:array[1] details:array[2]];
+  return nil;
 }
 @end

shell/platform/darwin/ios/framework/Source/FlutterJSONMessageListener.mm

-// 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.
-
-#include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterJSONMessageListener.h"
-
-@implementation FlutterJSONMessageListener
-
-- (NSString*)didReceiveString:(NSString*)message {
-  if (!message)
-    return nil;
-  NSError *error = nil;
-  NSData* data = [message dataUsingEncoding:NSUTF8StringEncoding];
-  NSDictionary* jsonObject = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
-  if (error)
-    return nil;
-  NSDictionary* response = [self didReceiveJSON:jsonObject];
-  if (!response)
-    return nil;
-  NSData* responseData = [NSJSONSerialization dataWithJSONObject:response options:0 error:nil];
-  if (!responseData)
-    return nil;
-  return [[[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding] autorelease];
-}
-
-- (NSDictionary*)didReceiveJSON:(NSDictionary*)message {
-  return nil;
-}
-
-- (NSString *)messageName {
-  return nil;
-}
-
-@end

shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.h

@@ -5,9 +5,11 @@
 #ifndef SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTERPLATFORMPLUGIN_H_
 #define SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTERPLATFORMPLUGIN_H_
 
-#include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterJSONMessageListener.h"
+#include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterChannels.h"
 
-@interface FlutterPlatformPlugin : FlutterJSONMessageListener
+@interface FlutterPlatformPlugin : NSObject
+
+-(void)handleMethodCall:(FlutterMethodCall*)call resultReceiver:(FlutterResultReceiver)resultReceiver;
 
 @end
 

shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.mm

@@ -41,42 +41,45 @@ using namespace shell;
 
 @implementation FlutterPlatformPlugin
 
-- (NSString *)messageName {
-  return @"flutter/platform";
-}
-
-- (NSDictionary*)didReceiveJSON:(NSDictionary*)message {
-  NSString* method = message[@"method"];
-  NSArray* args = message[@"args"];
+- (void)handleMethodCall:(FlutterMethodCall*)call resultReceiver:(FlutterResultReceiver)resultReceiver {
+  NSString* method = call.method;
+  id args = call.arguments;
   if ([method isEqualToString:@"SystemSound.play"]) {
-    [self playSystemSound:args.firstObject];
+    [self playSystemSound:args];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"HapticFeedback.vibrate"]) {
     [self vibrateHapticFeedback];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"UrlLauncher.launch"]) {
-    [self launchURL:args.firstObject];
+    [self launchURL:args];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"SystemChrome.setPreferredOrientations"]) {
-    [self setSystemChromePreferredOrientatations:args.firstObject];
+    [self setSystemChromePreferredOrientations:args];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"SystemChrome.setApplicationSwitcherDescription"]) {
-    [self setSystemChromeApplicationSwitcherDescription:args.firstObject];
+    [self setSystemChromeApplicationSwitcherDescription:args];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"SystemChrome.setEnabledSystemUIOverlays"]) {
-    [self setSystemChromeEnabledSystemUIOverlays:args.firstObject];
+    [self setSystemChromeEnabledSystemUIOverlays:args];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"SystemChrome.setSystemUIOverlayStyle"]) {
-    [self setSystemChromeSystemUIOverlayStyle:args.firstObject];
+    [self setSystemChromeSystemUIOverlayStyle:args];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"SystemNavigator.pop"]) {
     [self popSystemNavigator];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"Clipboard.getData"]) {
-    return [self getClipboardData:args.firstObject];
+    resultReceiver([self getClipboardData:args], nil);
   } else if ([method isEqualToString:@"Clipboard.setData"]) {
-    [self setClipboardData:args.firstObject];
+    [self setClipboardData:args];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"PathProvider.getTemporaryDirectory"]) {
-    return [self getPathProviderTemporaryDirectory];
+    resultReceiver([self getPathProviderTemporaryDirectory], nil);
   } else if ([method isEqualToString:@"PathProvider.getApplicationDocumentsDirectory"]) {
-    return [self getPathProviderApplicationDocumentsDirectory];
+    resultReceiver([self getPathProviderApplicationDocumentsDirectory], nil);
   } else {
-    // TODO(abarth): We should signal an error here that gets reported back to
-    // Dart.
+    resultReceiver(nil, [FlutterError errorWithCode:@"UNKNOWN" message:@"Unknown method" details: nil]);
   }
-  return nil;
 }
 
 - (void)playSystemSound:(NSString*)soundType {
@@ -99,7 +102,7 @@ using namespace shell;
   return @{ @"succes": @(success) };
 }
 
-- (void)setSystemChromePreferredOrientatations:(NSArray*)orientations {
+- (void)setSystemChromePreferredOrientations:(NSArray*)orientations {
   UIInterfaceOrientationMask mask = 0;
 
   if (orientations.count == 0) {

shell/platform/darwin/ios/framework/Source/FlutterStandardCodec.mm

@@ -42,6 +42,14 @@
   return _sharedInstance;
 }
 
+- (NSData*)encodeMethodCall:(FlutterMethodCall*)call {
+  NSMutableData* data = [NSMutableData dataWithCapacity:32];
+  FlutterStandardWriter* writer = [FlutterStandardWriter writerWithData:data];
+  [writer writeValue:call.method];
+  [writer writeValue:call.arguments];
+  return data;
+}
+
 - (NSData*)encodeSuccessEnvelope:(id)result {
   NSMutableData* data = [NSMutableData dataWithCapacity:32];
   FlutterStandardWriter* writer = [FlutterStandardWriter writerWithData:data];
@@ -70,6 +78,33 @@
            @"Corrupted standard method call");
   return [FlutterMethodCall methodCallWithMethodName:value1 arguments:value2];
 }
+
+- (id)decodeEnvelope:(NSData*)envelope error:(FlutterError**)error {
+  FlutterStandardReader* reader =
+      [FlutterStandardReader readerWithData:envelope];
+  UInt8 flag = [reader readByte];
+  NSAssert(flag <= 1, @"Corrupted standard envelope");
+  id result;
+  switch (flag) {
+    case 0: {
+      result = [reader readValue];
+      NSAssert(![reader hasMore], @"Corrupted standard envelope");
+    }
+    break;
+    case 1: {
+      id code = [reader readValue];
+      id message = [reader readValue];
+      id details = [reader readValue];
+      NSAssert(![reader hasMore], @"Corrupted standard envelope");
+      NSAssert([code isKindOfClass:[NSString class]], @"Invalid standard envelope");
+      NSAssert(message == nil || [message isKindOfClass:[NSString class]], @"Invalid standard envelope");
+      *error = [FlutterError errorWithCode:code message:message details:details];
+      result = nil;
+    }
+    break;
+  }
+  return result;
+}
 @end
 
 using namespace shell;

shell/platform/darwin/ios/framework/Source/FlutterStandardCodec_Internal.h

@@ -56,6 +56,7 @@ UInt8 elementSizeForFlutterStandardDataType(FlutterStandardDataType type) {
 @interface FlutterStandardReader : NSObject
 + (instancetype)readerWithData:(NSData*)data;
 - (BOOL)hasMore;
+- (UInt8)readByte;
 - (id)readValue;
 @end
 

shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.h

@@ -5,12 +5,13 @@
 #ifndef SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTERTEXTINPUTPLUGIN_H_
 #define SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTERTEXTINPUTPLUGIN_H_
 
-#include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterJSONMessageListener.h"
+#include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterChannels.h"
 #include "flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputDelegate.h"
 
-@interface FlutterTextInputPlugin : FlutterJSONMessageListener
+@interface FlutterTextInputPlugin : NSObject
 
 @property(nonatomic, assign) id<FlutterTextInputDelegate> textInputDelegate;
+-(void)handleMethodCall:(FlutterMethodCall*)call resultReceiver:(FlutterResultReceiver)resultReceiver;
 
 @end
 

shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.mm

@@ -154,30 +154,27 @@ static UIKeyboardType ToUIKeyboardType(NSString* inputType) {
   [super dealloc];
 }
 
-- (NSString *)messageName {
-  return @"flutter/textinput";
-}
-
-- (NSDictionary*)didReceiveJSON:(NSDictionary*)message {
-  NSString* method = message[@"method"];
-  NSArray* args = message[@"args"];
-  if (!args)
-    return nil;
+- (void)handleMethodCall:(FlutterMethodCall*)call resultReceiver:(FlutterResultReceiver)resultReceiver {
+  NSString* method = call.method;
+  id args = call.arguments;
   if ([method isEqualToString:@"TextInput.show"]) {
     [self showTextInput];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"TextInput.hide"]) {
     [self hideTextInput];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"TextInput.setClient"]) {
     [self setTextInputClient:[args[0] intValue] withConfiguration:args[1]];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"TextInput.setEditingState"]) {
-    [self setTextInputEditingState:args.firstObject];
+    [self setTextInputEditingState:args];
+    resultReceiver(nil, nil);
   } else if ([method isEqualToString:@"TextInput.clearClient"]) {
     [self clearTextInputClient];
+    resultReceiver(nil, nil);
   } else {
-    // TODO(abarth): We should signal an error here that gets reported back to
-    // Dart.
+    resultReceiver(nil, [FlutterError errorWithCode:@"UNKNOWN" message:@"Unknown method" details: nil]);
   }
-  return nil;
 }
 
 - (void)showTextInput {

shell/platform/darwin/ios/framework/Source/FlutterViewController.mm

@@ -68,7 +68,12 @@ void FlutterInit(int argc, const char* argv[]) {
   std::unique_ptr<shell::PlatformViewIOS> _platformView;
   base::scoped_nsprotocol<FlutterPlatformPlugin*> _platformPlugin;
   base::scoped_nsprotocol<FlutterTextInputPlugin*> _textInputPlugin;
-
+  base::scoped_nsprotocol<FlutterMethodChannel*> _localizationChannel;
+  base::scoped_nsprotocol<FlutterMethodChannel*> _navigationChannel;
+  base::scoped_nsprotocol<FlutterMethodChannel*> _platformChannel;
+  base::scoped_nsprotocol<FlutterMethodChannel*> _textInputChannel;
+  base::scoped_nsprotocol<FlutterMessageChannel*> _lifecycleChannel;
+  base::scoped_nsprotocol<FlutterMessageChannel*> _systemChannel;
   BOOL _initialized;
 }
 
@@ -118,15 +123,49 @@ void FlutterInit(int argc, const char* argv[]) {
   _orientationPreferences = UIInterfaceOrientationMaskAll;
   _statusBarStyle = UIStatusBarStyleDefault;
   _platformView = std::make_unique<shell::PlatformViewIOS>(
-      reinterpret_cast<CAEAGLLayer*>(self.view.layer));
+    reinterpret_cast<CAEAGLLayer*>(self.view.layer));
   _platformView->SetupResourceContextOnIOThread();
 
+  _localizationChannel.reset([[FlutterMethodChannel alloc]
+      initWithName:@"flutter/localization"
+      binaryMessenger:self
+      codec:[FlutterJSONMethodCodec sharedInstance]]);
+
+  _navigationChannel.reset([[FlutterMethodChannel alloc]
+      initWithName:@"flutter/navigation"
+      binaryMessenger:self
+      codec:[FlutterJSONMethodCodec sharedInstance]]);
+
+  _platformChannel.reset([[FlutterMethodChannel alloc]
+      initWithName:@"flutter/platform"
+      binaryMessenger:self
+      codec:[FlutterJSONMethodCodec sharedInstance]]);
+
+  _textInputChannel.reset([[FlutterMethodChannel alloc]
+      initWithName:@"flutter/textinput"
+      binaryMessenger:self
+      codec:[FlutterJSONMethodCodec sharedInstance]]);
+
+  _lifecycleChannel.reset([[FlutterMessageChannel alloc]
+      initWithName:@"flutter/lifecycle"
+      binaryMessenger:self
+      codec:[FlutterStringCodec sharedInstance]]);
+
+  _systemChannel.reset([[FlutterMessageChannel alloc]
+      initWithName:@"flutter/system"
+      binaryMessenger:self
+      codec:[FlutterJSONMessageCodec sharedInstance]]);
+
   _platformPlugin.reset([[FlutterPlatformPlugin alloc] init]);
-  [self addMessageListener:_platformPlugin.get()];
+  [_platformChannel.get() setMethodCallHandler:^(FlutterMethodCall* call, FlutterResultReceiver resultReceiver) {
+   [_platformPlugin.get() handleMethodCall:call resultReceiver:resultReceiver];
+  }];
 
   _textInputPlugin.reset([[FlutterTextInputPlugin alloc] init]);
   _textInputPlugin.get().textInputDelegate = self;
-  [self addMessageListener:_textInputPlugin.get()];
+  [_textInputChannel.get() setMethodCallHandler:^(FlutterMethodCall* call, FlutterResultReceiver resultReceiver) {
+   [_textInputPlugin.get() handleMethodCall:call resultReceiver:resultReceiver];
+  }];
 
   [self setupNotificationCenterObservers];
 
@@ -227,13 +266,11 @@ void FlutterInit(int argc, const char* argv[]) {
 #pragma mark - Application lifecycle notifications
 
 - (void)applicationBecameActive:(NSNotification*)notification {
-  [self sendString:@"AppLifecycleState.resumed"
-      withMessageName:@"flutter/lifecycle"];
+  [_lifecycleChannel.get() sendMessage:@"AppLifecycleState.resumed"];
 }
 
 - (void)applicationWillResignActive:(NSNotification*)notification {
-  [self sendString:@"AppLifecycleState.paused"
-      withMessageName:@"flutter/lifecycle"];
+  [_lifecycleChannel.get() sendMessage:@"AppLifecycleState.paused"];
 }
 
 #pragma mark - Touch event handling
@@ -392,11 +429,7 @@ static inline PointerChangeMapperPhase PointerChangePhaseFromUITouchPhase(
 #pragma mark - Text input delegate
 
 - (void)updateEditingClient:(int)client withState:(NSDictionary*)state {
-  NSDictionary* message = @{
-    @"method" : @"TextInputClient.updateEditingState",
-    @"args" : @[ @(client), state ],
-  };
-  [self sendJSON:message withMessageName:@"flutter/textinputclient"];
+  [_textInputChannel.get() invokeMethod:@"TextInputClient.updateEditingState" arguments:@[ @(client), state ]];
 }
 
 #pragma mark - Orientation updates
@@ -446,8 +479,7 @@ static inline PointerChangeMapperPhase PointerChangePhaseFromUITouchPhase(
 #pragma mark - Memory Notifications
 
 - (void)onMemoryWarning:(NSNotification*)notification {
-  NSDictionary* message = @{ @"type" : @"memoryPressure" };
-  [self sendJSON:message withMessageName:@"flutter/system"];
+  [_systemChannel.get() sendMessage:@{ @"type" : @"memoryPressure" }];
 }
 
 #pragma mark - Locale updates
@@ -456,10 +488,7 @@ static inline PointerChangeMapperPhase PointerChangePhaseFromUITouchPhase(
   NSLocale* currentLocale = [NSLocale currentLocale];
   NSString* languageCode = [currentLocale objectForKey:NSLocaleLanguageCode];
   NSString* countryCode = [currentLocale objectForKey:NSLocaleCountryCode];
-  NSDictionary* message =
-      @{ @"method" : @"setLocale",
-         @"args" : @[ languageCode, countryCode ] };
-  [self sendJSON:message withMessageName:@"flutter/localization"];
+  [_localizationChannel.get() invokeMethod:@"setLocale" arguments: @[ languageCode, countryCode ]];
 }
 
 #pragma mark - Surface creation and teardown updates
@@ -549,79 +578,6 @@ constexpr CGFloat kStandardStatusBarHeight = 20.0;
 
 #pragma mark - Application Messages
 
-- (void)sendString:(NSString*)message withMessageName:(NSString*)channel {
-  NSAssert(message, @"The message must not be null");
-  NSAssert(channel, @"The channel must not be null");
-  FlutterStringCodec* codec = [FlutterStringCodec sharedInstance];
-  [self sendBinaryMessage:[codec encode:message] channelName:channel];
-}
-
-- (void)sendString:(NSString*)message
-    withMessageName:(NSString*)channel
-           callback:(void (^)(NSString*))callback {
-  NSAssert(message, @"The message must not be null");
-  NSAssert(channel, @"The channel must not be null");
-  NSAssert(callback, @"The callback must not be null");
-  FlutterStringCodec* codec = [FlutterStringCodec sharedInstance];
-  [self sendBinaryMessage:[codec encode:message]
-              channelName:channel
-       binaryReplyHandler:^(NSData* data) {
-         callback([codec decode:data]);
-       }];
-}
-
-- (void)sendJSON:(NSDictionary*)message withMessageName:(NSString*)channel {
-  NSData* data = [[FlutterJSONMessageCodec sharedInstance] encode:message];
-  [self sendBinaryMessage:data channelName:channel];
-}
-
-- (void)addMessageListener:(NSObject<FlutterMessageListener>*)listener {
-  NSAssert(listener, @"The listener must not be null");
-  NSString* messageName = listener.messageName;
-  NSAssert(messageName, @"The messageName must not be null");
-  FlutterStringCodec* codec = [FlutterStringCodec sharedInstance];
-  [self
-      setBinaryMessageHandlerOnChannel:messageName
-                  binaryMessageHandler:^(
-                      NSData* message, FlutterBinaryReplyHandler replyHandler) {
-                    NSString* reply =
-                        [listener didReceiveString:[codec decode:message]];
-                    replyHandler([codec encode:reply]);
-                  }];
-}
-
-- (void)removeMessageListener:(NSObject<FlutterMessageListener>*)listener {
-  NSAssert(listener, @"The listener must not be null");
-  NSString* messageName = listener.messageName;
-  NSAssert(messageName, @"The messageName must not be null");
-  [self setBinaryMessageHandlerOnChannel:messageName binaryMessageHandler:nil];
-}
-
-- (void)addAsyncMessageListener:
-    (NSObject<FlutterAsyncMessageListener>*)listener {
-  NSAssert(listener, @"The listener must not be null");
-  NSString* messageName = listener.messageName;
-  NSAssert(messageName, @"The messageName must not be null");
-  FlutterStringCodec* codec = [FlutterStringCodec sharedInstance];
-  [self
-      setBinaryMessageHandlerOnChannel:messageName
-                  binaryMessageHandler:^(
-                      NSData* message, FlutterBinaryReplyHandler replyHandler) {
-                    [listener didReceiveString:[codec decode:message]
-                                      callback:^(NSString* reply) {
-                                        replyHandler([codec encode:reply]);
-                                      }];
-                  }];
-}
-
-- (void)removeAsyncMessageListener:
-    (NSObject<FlutterAsyncMessageListener>*)listener {
-  NSAssert(listener, @"The listener must not be null");
-  NSString* messageName = listener.messageName;
-  NSAssert(messageName, @"The messageName must not be null");
-  [self setBinaryMessageHandlerOnChannel:messageName binaryMessageHandler:nil];
-}
-
 - (void)sendBinaryMessage:(NSData*)message channelName:(NSString*)channel {
   NSAssert(message, @"The message must not be null");
   NSAssert(channel, @"The channel must not be null");

travis/licenses_golden/licenses_flutter

@@ -1781,7 +1781,6 @@ FILE: ../../../flutter/shell/platform/android/android_surface_gl.h
 FILE: ../../../flutter/shell/platform/android/android_surface_vulkan.cc
 FILE: ../../../flutter/shell/platform/android/android_surface_vulkan.h
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/ActivityLifecycleListener.java
-FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/JSONMessageListener.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/editing/TextInputPlugin.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/platform/PlatformPlugin.java
@@ -1794,17 +1793,13 @@ FILE: ../../../flutter/shell/platform/darwin/common/process_info_mac.h
 FILE: ../../../flutter/shell/platform/darwin/desktop/vsync_waiter_mac.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/Flutter.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterAppDelegate.h
-FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterAsyncMessageListener.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterDartProject.h
-FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterJSONMessageListener.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterMacros.h
-FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterMessageListener.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterViewController.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterDartProject.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterDartProject_Internal.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterDartSource.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterDartSource.mm
-FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterJSONMessageListener.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputDelegate.h
@@ -1915,7 +1910,8 @@ FILE: ../../../flutter/fml/platform/darwin/cf_utils.cc
 FILE: ../../../flutter/fml/platform/darwin/cf_utils.h
 FILE: ../../../flutter/shell/gpu/gpu_surface_software.cc
 FILE: ../../../flutter/shell/gpu/gpu_surface_software.h
-FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/BinaryMessageCodec.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/BinaryCodec.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/FlutterException.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/FlutterMessageChannel.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/FlutterMethodChannel.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/JSONMessageCodec.java
@@ -1924,7 +1920,7 @@ FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/MethodCal
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/MethodCodec.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/StringMessageCodec.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/StringCodec.java
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterBinaryMessenger.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterChannels.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterCodecs.h