Adds the renderer component of the Java Bridge

content/renderer/java_bridge_dispatcher.cc

+// Copyright (c) 2011 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 "content/renderer/java_bridge_dispatcher.h"
+
+#include "content/common/child_process.h"
+#include "content/common/java_bridge_messages.h"
+#include "content/common/npobject_util.h"  // For CreateNPVariant()
+#include "content/public/renderer/render_thread.h"
+#include "content/public/renderer/render_view.h"
+#include "content/renderer/java_bridge_channel.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebBindings.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
+
+JavaBridgeDispatcher::JavaBridgeDispatcher(
+    content::RenderView* render_view,
+    const IPC::ChannelHandle& channel_handle)
+    : RenderViewObserver(render_view) {
+  channel_.reset(JavaBridgeChannel::GetJavaBridgeChannel(
+      channel_handle, ChildProcess::current()->io_message_loop_proxy()));
+}
+
+JavaBridgeDispatcher::~JavaBridgeDispatcher() {
+  for (ObjectMap::const_iterator iter = objects_.begin();
+      iter != objects_.end(); ++iter) {
+    WebKit::WebBindings::releaseObject(NPVARIANT_TO_OBJECT(iter->second));
+  }
+}
+
+bool JavaBridgeDispatcher::OnMessageReceived(const IPC::Message& msg) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(JavaBridgeDispatcher, msg)
+    IPC_MESSAGE_HANDLER(JavaBridgeMsg_AddNamedObject, OnAddNamedObject)
+    IPC_MESSAGE_HANDLER(JavaBridgeMsg_RemoveNamedObject,
+                        OnRemoveNamedObject)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void JavaBridgeDispatcher::DidClearWindowObject(WebKit::WebFrame* web_frame) {
+  // We only inject objects into the main frame.
+  if (web_frame != render_view()->GetWebView()->mainFrame())
+    return;
+
+  // Note that we have to (re)bind all objects, as they will have been unbound
+  // when the window object was cleared.
+  for (ObjectMap::const_iterator iter = objects_.begin();
+      iter != objects_.end(); ++iter) {
+    // This refs the NPObject. This reference is dropped when either the window
+    // object is later cleared, or the object is GC'ed. So the object may be
+    // deleted at any time after OnRemoveNamedObject() is called.
+    web_frame->bindToWindowObject(iter->first,
+        NPVARIANT_TO_OBJECT(iter->second));
+  }
+}
+
+void JavaBridgeDispatcher::OnAddNamedObject(
+    const string16& name,
+    const NPVariant_Param& variant_param) {
+  DCHECK_EQ(variant_param.type, NPVARIANT_PARAM_SENDER_OBJECT_ROUTING_ID);
+  // This creates an NPObject, wrapped as an NPVariant. We don't need the
+  // containing window or the page URL, as we don't do re-entrant sync IPC.
+  NPVariant variant;
+  bool created =
+      CreateNPVariant(variant_param, channel_.get(), &variant, NULL, GURL());
+  DCHECK(created);
+  DCHECK_EQ(variant.type, NPVariantType_Object);
+
+  // The NPObject is created with a ref count of one, which we remove when
+  // OnRemoveNamedObject() is called for that object.
+  ObjectMap::iterator iter = objects_.find(name);
+  if (iter != objects_.end()) {
+    WebKit::WebBindings::releaseObject(NPVARIANT_TO_OBJECT(iter->second));
+  }
+  objects_[name] = variant;
+}
+
+void JavaBridgeDispatcher::OnRemoveNamedObject(const string16& name) {
+  // Removing an object does not unbind it from JavaScript until the window
+  // object is next cleared. Note that the browser checks that the named object
+  // is present.
+  ObjectMap::iterator iter = objects_.find(name);
+  DCHECK(iter != objects_.end());
+  WebKit::WebBindings::releaseObject(NPVARIANT_TO_OBJECT(iter->second));
+  objects_.erase(iter);
+}