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// 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.
import 'dart:async';
import 'package:mojo/core.dart' as core;
import 'package:sky_services/flutter/platform/app_messages.mojom.dart';
import 'shell.dart';
// APIs for exchanging messages with the host application.
ApplicationMessagesProxy _initHostAppMessagesProxy() {
ApplicationMessagesProxy proxy = new ApplicationMessagesProxy.unbound();
shell.connectToViewAssociatedService(proxy);
return proxy;
}
final ApplicationMessagesProxy _hostAppMessagesProxy = _initHostAppMessagesProxy();
typedef Future<String> HostMessageCallback(String message);
typedef Object _SendStringResponseFactory(String response);
class _ApplicationMessagesImpl extends ApplicationMessages {
final Map<String, HostMessageCallback> handlers = <String, HostMessageCallback>{};
_ApplicationMessagesImpl() {
shell.provideService(ApplicationMessages.serviceName,
(core.MojoMessagePipeEndpoint endpoint) {
ApplicationMessagesStub stub = new ApplicationMessagesStub.fromEndpoint(endpoint);
stub.impl = this;
}
);
}
@override
dynamic sendString(String messageName, String message, [_SendStringResponseFactory responseFactory]) {
HostMessageCallback callback = handlers[messageName];
if (callback == null)
return responseFactory(null);
return callback(message).then((String s) => responseFactory(s));
}
}
final _ApplicationMessagesImpl _appMessages = new _ApplicationMessagesImpl();
class HostMessages {
/// Send a message to the host application.
static Future<String> sendToHost(String messageName, String message) async {
return (await _hostAppMessagesProxy.ptr.sendString(messageName, message)).reply;
}
/// Register a callback for messages received from the host application.
/// The callback function must return a String, Future<String>, or null.
static void addMessageHandler(String messageName, HostMessageCallback callback) {
_appMessages.handlers[messageName] = callback;
}
}