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 @@
 /**
  * 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

@@ -0,0 +1,20 @@
+// 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 @@
 
 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 FlutterMethodChannel(FlutterView view, String name, MethodCodec codec) {
         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 interface StreamHandler {
          * 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 interface EventSink extends Response {
         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 @@ private void checkDone() {
                 });
             } 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 void done() {
                             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 void done() {
                     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 ByteBuffer encodeMessage(Object message) {
         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 Object decodeMessage(ByteBuffer message) {
             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/JSONMethodCodec.java

@@ -11,37 +11,77 @@
  * {@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 @@
  * 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);
 }