Browser side implementation of browser plugin

content/browser/browser_plugin/browser_plugin_web_contents_observer.cc

+// Copyright (c) 2012 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/browser/browser_plugin/browser_plugin_web_contents_observer.h"
+
+#include "base/lazy_instance.h"
+#include "content/browser/renderer_host/render_view_host_impl.h"
+#include "content/common/view_messages.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_details.h"
+#include "content/public/browser/notification_source.h"
+#include "content/public/browser/notification_types.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_widget_host.h"
+#include "content/public/browser/render_widget_host_view.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/site_instance.h"
+#include "content/public/browser/web_contents.h"
+#include "ppapi/proxy/ppapi_messages.h"
+
+typedef std::map<content::WebContents*,
+                 content::BrowserPluginWebContentsObserver*> Instances;
+
+namespace {
+base::LazyInstance<Instances>::Leaky g_instances = LAZY_INSTANCE_INITIALIZER;
+}  // namespace
+
+namespace content {
+
+// static
+BrowserPluginWebContentsObserver*
+BrowserPluginWebContentsObserver::Get(
+    WebContents* web_contents) {
+  Instances::iterator it = g_instances.Get().find(web_contents);
+  if (it != g_instances.Get().end())
+    return it->second;
+  return new BrowserPluginWebContentsObserver(web_contents);
+}
+
+BrowserPluginWebContentsObserver::BrowserPluginWebContentsObserver(
+    WebContents* web_contents)
+    : WebContentsObserver(web_contents),
+      host_(NULL),
+      instance_id_(0) {
+  registrar_.Add(this,
+                 NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED,
+                 Source<RenderViewHost>(
+                    web_contents->GetRenderViewHost()));
+  g_instances.Get()[web_contents] = this;
+}
+
+BrowserPluginWebContentsObserver::~BrowserPluginWebContentsObserver() {
+  g_instances.Get().erase(web_contents());
+}
+
+bool BrowserPluginWebContentsObserver::OnMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(BrowserPluginWebContentsObserver, message)
+    IPC_MESSAGE_HANDLER(PpapiHostMsg_ChannelCreated,
+                        OnRendererPluginChannelCreated)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_OpenChannelToBrowserPlugin,
+                        OnOpenChannelToBrowserPlugin)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_GuestReady, OnMsgGuestReady)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_ResizeGuest, OnMsgResizeGuest)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP_EX()
+  return handled;
+}
+
+void BrowserPluginWebContentsObserver::OnMsgGuestReady() {

[jam, 2012/04/04 00:54:45]

nit: just name handlers OnFoo, no need for "OnMsgFoo" (this was an old
convention that we don't use anymore)

[Fady Samuel, 2012/04/04 16:45:40]

Done.

+  // We only care about handling this message on guests.
+  if (!host())
+    return;
+
+  // The renderer is now ready to receive ppapi messages.
+  // Let's tell it create a channel with the embedder/host.
+  PpapiMsg_CreateChannel* msg =
+      new PpapiMsg_CreateChannel(host()->GetRenderProcessHost()->GetHandle(),
+                                 host()->GetRenderProcessHost()->GetID());
+  msg->set_routing_id(web_contents()->GetRenderViewHost()->GetRoutingID());
+  msg->set_unblock(true);

[jam, 2012/04/04 00:54:45]

are you sure you want this (set the unblock flag)?

also, you're sending this message to the renderer, while this is a message
that's dispatched in the pppapi process. how is this being dispatched?

[Fady Samuel, 2012/04/04 16:45:40]

I believe you're right, I don't want the set_unblock(true) from browser to guest
renderer. Will verify tomorrow.

The message is handled in GuestRenderViewObserver . Please see the renderer-side
of the browser plugin.

[jam, 2012/04/04 21:07:19]

ping. are you sure you need this? check the documentation of that flag to see
what it's used for, which i suspect you don't need in this case.
ah, I hadn't seen the other change yet because I thought it wasn't ready.

it's confusing that you're reusing these pepper messages (which are originally
between renderer-pepper process) and reuse them between browser-renderer. i
think it would be more readable to have separate messages.

it also seems there are enough browser plugin messages that they belong in their
own messages file (i.e. content/common/browser_plugin_messages.h) and they can
have their own BrowserPluginMsg/BrowserPluginHostMsg prefix.

[Fady Samuel, 2012/04/05 19:35:40]

Removed.
Done

+  // TODO(fsamuel): If we aren't able to successfully send this message
+  // to the guest then that probably means it crashed. Is there anything
+  // we can do that's cleaner than failing a check?
+  CHECK(Send(msg));
+}
+
+void BrowserPluginWebContentsObserver::OnMsgResizeGuest(
+    int width, int height) {
+  // Tell the RenderWidgetHostView to adjust its size.
+  web_contents()->GetRenderViewHost()->GetView()->SetSize(
+      gfx::Size(width, height));
+}
+
+void BrowserPluginWebContentsObserver::OnOpenChannelToBrowserPlugin(
+    int instance_id,
+    long long frame_id,
+    const std::string& src,
+    const gfx::Size& size) {
+  BrowserContext* browser_context =
+      web_contents()->GetRenderViewHost()->GetProcess()->GetBrowserContext();
+  DCHECK(browser_context);
+
+  GURL url(src);
+  SiteInstance* site_instance =
+      SiteInstance::CreateForURL(
+          browser_context, url);
+  WebContents* guest_web_contents =
+      WebContents::Create(
+          browser_context,
+          site_instance,
+          MSG_ROUTING_NONE,
+          NULL, // base tab contents
+          NULL  // session storage namespace
+      );
+  // TODO(fsamuel): Set the WebContentsDelegate here.
+  RenderViewHostImpl* guest_render_view_host =
+      static_cast<RenderViewHostImpl*>(
+          guest_web_contents->GetRenderViewHost());
+
+  // We need to make sure that the RenderViewHost knows that it's
+  // hosting a guest RenderView so that it informs the RenderView
+  // on a ViewMsg_New. Guest RenderViews will avoid compositing
+  // until a guest-to-host channel has been initialized.
+  guest_render_view_host->set_guest(true);
+
+  guest_web_contents->GetController().LoadURL(
+      url,
+      Referrer(),
+      PAGE_TRANSITION_HOME_PAGE,
+      std::string());
+
+  guest_render_view_host->GetView()->SetSize(size);
+  BrowserPluginWebContentsObserver* guest_observer = Get(guest_web_contents);
+  guest_observer->set_host(web_contents());
+  guest_observer->set_instance_id(instance_id);
+
+  AddGuest(guest_web_contents, frame_id);
+}
+
+// Called when a new plugin <--> renderer channel has been created.

[jam, 2012/04/04 00:54:45]

nit: no need to document message handlers above the function definition. they're
already documented in the messages.h file

[Fady Samuel, 2012/04/04 16:45:40]

Done.

+void BrowserPluginWebContentsObserver::OnRendererPluginChannelCreated(
+    const IPC::ChannelHandle& channel_handle) {
+  DCHECK(host());
+  // Prepare the handle to send to the renderer.
+  base::ProcessHandle plugin_process =
+      web_contents()->GetRenderProcessHost()->GetHandle();
+#if defined(OS_WIN)
+  base::ProcessHandle renderer_process =
+      host()->GetRenderProcessHost()->GetHandle();
+  int renderer_id = host()->GetRenderProcessHost()->GetID();
+
+  base::ProcessHandle renderers_plugin_handle = NULL;
+  ::DuplicateHandle(::GetCurrentProcess(), plugin_process,
+                    renderer_process, &renderers_plugin_handle,
+                    0, FALSE, DUPLICATE_SAME_ACCESS);
+#elif defined(OS_POSIX)
+  // Don't need to duplicate anything on POSIX since it's just a PID.
+  base::ProcessHandle renderers_plugin_handle = plugin_process;
+#endif
+  // Tell the browser loading placeholder that we're done.
+  // and that it can begin using the guest renderer.
+  host()->GetRenderProcessHost()->Send(
+      new ViewMsg_GuestReady_ACK(
+          host()->GetRenderViewHost()->GetRoutingID(),
+          instance_id(),
+          renderers_plugin_handle,
+          channel_handle));
+}
+
+void BrowserPluginWebContentsObserver::AddGuest(
+    WebContents* guest,
+    int64 frame_id) {
+  guests_[guest] = frame_id;
+}
+
+void BrowserPluginWebContentsObserver::RemoveGuest(
+    WebContents* guest) {
+  guests_.erase(guest);
+}
+
+void BrowserPluginWebContentsObserver::DestroyGuests() {
+  for (GuestMap::const_iterator it = guests_.begin();
+       it != guests_.end(); ++it) {
+    const WebContents* contents = it->first;
+    delete contents;
+  }
+  guests_.clear();
+}
+
+void BrowserPluginWebContentsObserver::DidCommitProvisionalLoadForFrame(
+    int64 frame_id,
+    bool is_main_frame,
+    const GURL& url,
+    PageTransition transition_type) {
+  GuestSet guests_to_delete;
+  for (GuestMap::const_iterator it = guests_.begin();
+       it != guests_.end(); ++it) {
+    WebContents* contents = it->first;
+    if (it->second == frame_id) {
+      guests_to_delete.insert(contents);
+    }
+  }
+  for (GuestSet::const_iterator it = guests_to_delete.begin();
+       it != guests_to_delete.end(); ++it) {
+    delete *it;
+    guests_.erase(*it);
+  }
+}
+
+void BrowserPluginWebContentsObserver::RenderViewDeleted(
+    RenderViewHost* render_view_host) {
+  DestroyGuests();
+}
+
+void BrowserPluginWebContentsObserver::RenderViewGone(
+    base::TerminationStatus status) {
+  DestroyGuests();
+}
+
+void BrowserPluginWebContentsObserver::WebContentsDestroyed(
+    WebContents* web_contents) {
+  DestroyGuests();
+}
+
+void BrowserPluginWebContentsObserver::Observe(
+    int type,
+    const NotificationSource& source,
+    const NotificationDetails& details) {
+  DCHECK(type == NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED);
+  bool visible = *Details<bool>(details).ptr();
+
+  // If the host is hidden we need to hide the guests as well.
+  for (GuestMap::const_iterator it = guests_.begin();
+       it != guests_.end(); ++it) {
+    WebContents* contents = it->first;
+    if (visible)
+      contents->ShowContents();
+    else
+      contents->HideContents();
+  }
+}
+
+}  // namespace content