Enable posting a message from JS to Android webview.

android_webview/native/aw_message_port_service_impl.cc

+// Copyright 2014 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 "android_webview/native/aw_message_port_service_impl.h"
+
+#include "android_webview/browser/aw_browser_context.h"
+#include "android_webview/browser/aw_message_port_message_filter.h"
+#include "android_webview/native/aw_contents.h"
+#include "base/android/jni_array.h"
+#include "base/android/jni_string.h"
+#include "base/bind.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/message_port_provider.h"
+#include "jni/AwMessagePortService_jni.h"
+
+namespace android_webview {
+
+using base::android::AttachCurrentThread;
+using base::android::ConvertUTF16ToJavaString;
+using base::android::ScopedJavaGlobalRef;
+using base::android::ScopedJavaLocalRef;
+using base::android::ToJavaIntArray;
+using content::BrowserThread;
+using content::MessagePortProvider;
+
+namespace {
+
+void PostMessageOnUIThread(ScopedJavaGlobalRef<jobject>* jobj,
+                           int message_port_id,
+                           ScopedJavaGlobalRef<jstring>* jmsg,
+                           ScopedJavaGlobalRef<jintArray>* jports) {
+  JNIEnv* env = AttachCurrentThread();
+  Java_AwMessagePortService_onPostMessage(env,
+                                          jobj->obj(),
+                                          message_port_id,
+                                          jmsg->obj(),
+                                          jports->obj());
+}
+
+}
+
+//static
+AwMessagePortServiceImpl* AwMessagePortServiceImpl::GetInstance() {
+  return static_cast<AwMessagePortServiceImpl*>(
+      AwBrowserContext::GetDefault()->GetMessagePortService());
+}
+
+AwMessagePortServiceImpl::AwMessagePortServiceImpl() {
+}
+
+AwMessagePortServiceImpl::~AwMessagePortServiceImpl() {
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+  if (obj.is_null())
+    return;
+  Java_AwMessagePortService_unregisterNativeAwMessagePortService(env,
+                                                                 obj.obj());
+}
+
+void AwMessagePortServiceImpl::Init(JNIEnv* env, jobject obj) {
+  java_ref_ = JavaObjectWeakGlobalRef(env, obj);
+}
+
+void AwMessagePortServiceImpl::OnMessageChannelCreated(
+    AwMessagePortMessageFilter* filter,
+    ScopedJavaGlobalRef<jobject>* callback,
+    int* port1,
+    int* port2) {
+  // TODO(sgurun) if filter is closed return.
+
+  AddPort(*port1, filter);
+  AddPort(*port2, filter);
+
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+  if (obj.is_null())
+    return;
+  Java_AwMessagePortService_onMessageChannelCreated(env, obj.obj(), *port1,
+      *port2, callback->obj());
+}
+
+void AwMessagePortServiceImpl::OnConvertedMessage(
+    int message_port_id,
+    const base::ListValue& message,
+    const std::vector<int>& sent_message_port_ids) {
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaGlobalRef<jobject>* jobj = new ScopedJavaGlobalRef<jobject>();
+  jobj->Reset(java_ref_.get(env));
+
+  if (message.GetSize() != 1) {
+    NOTREACHED();
+    return;
+  }
+
+  base::string16 value;
+  if (!message.GetString(0, &value)) {
+    LOG(WARNING) << "Converting post message to a string failed for port "
+        << message_port_id;
+    return;
+  }
+  ScopedJavaGlobalRef<jstring>* jmsg = new ScopedJavaGlobalRef<jstring>();
+  jmsg->Reset(ConvertUTF16ToJavaString(env, value));
+
+  ScopedJavaGlobalRef<jintArray>* jports = new ScopedJavaGlobalRef<jintArray>();
+  jports->Reset(ToJavaIntArray(env, sent_message_port_ids));
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&PostMessageOnUIThread, base::Owned(jobj),
+                                         message_port_id,
+                                         base::Owned(jmsg),
+                                         base::Owned(jports)));
+}
+
+void AwMessagePortServiceImpl::OnMessagePortMessageFilterClosing(
+    AwMessagePortMessageFilter* filter) {
+  for (MessagePorts::iterator iter = ports_.begin();
+       iter != ports_.end(); iter++) {
+    if (iter->second == filter) {
+      ports_.erase(iter);
+    }
+  }
+}
+
+void AwMessagePortServiceImpl::AddPort(int message_port_id,
+                                       AwMessagePortMessageFilter* filter) {
+  // TODO(sgurun) seems like we are accessing ports_ from both UI and IO thread.

[mnaganov (inactive), 2015/01/07 11:43:54]

What do we use |ports_| for?

[sgurun-gerrit only, 2015/01/10 02:36:29]

This will be used when posting the messages from Java to JS (to find the filter
associated with the message port). Maybe it is better if I add the logic when I
need it. 

+  if (ports_.count(message_port_id)) {
+    NOTREACHED();
+    return;
+  }
+  ports_[message_port_id] = filter;
+}
+
+bool RegisterAwMessagePortService(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+// static
+jlong InitAwMessagePortService(JNIEnv* env, jobject obj) {
+  AwMessagePortServiceImpl* service = AwMessagePortServiceImpl::GetInstance();
+  service->Init(env, obj);
+  return reinterpret_cast<intptr_t>(service);
+}
+
+}  // namespace android_webview