Browser Plugin: New Implementation (Browser Side)

content/browser/browser_plugin/browser_plugin_embedder.h

+// 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.
+
+// A BrowserPluginEmbedder has a list of guest it manages.
+// In the beginning when a renderer sees one or more guests (BrowserPlugin
+// instance(s)) and there is a request to navigate to them, the WebContents for
+// that renderer creates a BrowserPluginEmbedder for itself. The
+// BrowserPluginEmbedder, in turn, manages a set of BrowserPluginGuests -- one
+// BrowserPluginGuest for each guest in the embedding WebContents.
+// BrowserPluginEmbedder routes any messages directed to a guest from the
+// renderer (BrowserPlugin) to the appropriate guest (identified by the guest's
+// |instance_id|).
+//
+// BrowserPluginEmbedder is responsible for cleaning up the guests when the
+// embedder frame navigates away to a different page.
+
+#ifndef CONTENT_BROWSER_BROWSER_PLUGIN_BROWSER_PLUGIN_EMBEDDER_H_
+#define CONTENT_BROWSER_BROWSER_PLUGIN_BROWSER_PLUGIN_EMBEDDER_H_
+
+#include <map>
+#include <string>
+
+#include "base/compiler_specific.h"
+#include "content/browser/browser_plugin/browser_plugin_host_factory.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/render_view_host_observer.h"
+#include "content/public/browser/web_contents_delegate.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "ipc/ipc_channel_handle.h"
+#include "ipc/ipc_sync_message.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
+#include "ui/surface/transport_dib.h"
+#include "webkit/glue/webcursor.h"
+
+namespace gfx {
+class Size;
+}
+
+class WebContentsImpl;
+
+struct BrowserPluginHostMsg_ResizeGuest_Params;
+struct ViewHostMsg_UpdateRect_Params;
+
+namespace content {
+
+class BrowserPluginGuest;
+class BrowserPluginHostFactory;
+
+typedef std::map<WebContents*, int64> GuestWebContentsMap;

[awong, 2012/09/09 18:08:09]

Move these typedefs into the private section of BrowserPluginEmbedder.

[lazyboy, 2012/09/10 16:30:17]

Done.

[lazyboy, 2012/09/10 18:02:47]

Had to move one back since the browsertest needs it.

[awong, 2012/09/10 19:21:07]

Can we at put them in the public section of BrowserPluginEmbedder then?  Or
maybe just friend the test?  That reduces pollution of the content namespace.

[lazyboy, 2012/09/10 23:40:57]

Moved to public section.
*TEST_F method doesn't run on the context of the BrowserPluginHostTest, so
friending BrowserPluginHostTest doesn't seem to help.
Done.

+typedef std::map<int, BrowserPluginGuest*> ContainerInstanceMap;
+
+// A browser plugin embedder provides functionality for WebContents to operate
+// in the 'embedder' role. It manages list of guests inside the embedder.
+//
+// The embedder's WebContents manages the lifetime of the embedder. They are
+// created when a renderer asks WebContents to navigate (for the first time) to
+// some guest. It gets destroyed when either the WebContents goes away or there
+// is a RenderViewHost swap in WebContents.
+class CONTENT_EXPORT BrowserPluginEmbedder : public WebContentsObserver,
+                                             public NotificationObserver {
+ public:
+  virtual ~BrowserPluginEmbedder();
+
+  static BrowserPluginEmbedder* Create(WebContentsImpl* web_contents,
+                                       RenderViewHost* render_view_host);
+
+  // Navigates in a guest (new or existing).
+  void NavigateGuest(RenderViewHost* render_view_host,
+                     int instance_id,
+                     int64 frame_id,
+                     const std::string& src,
+                     const gfx::Size& size);
+
+  // Overrides factory for testing. Default (NULL) value indicates regular
+  // (non-test) environment.
+  static void set_factory_for_testing(BrowserPluginHostFactory* factory) {
+    factory_ = factory;
+  }
+
+ private:
+  friend class BrowserPluginEmbedderHelper;
+  friend class TestBrowserPluginEmbedder;
+
+  BrowserPluginEmbedder(WebContentsImpl* web_contents,
+                        RenderViewHost* render_view_host);
+
+  // Returns a guest browser plugin delegate by its container ID specified
+  // in BrowserPlugin.
+  BrowserPluginGuest* GetGuestByInstanceID(int instance_id) const;
+  // Adds a new guest to the embedder (overridable in test).
+  virtual void AddGuest(int instance_id,

[awong, 2012/09/09 18:08:09]

Take a scoped_ptr<BrowserPluginGuest> as the argument to indicate ownership
transfer?

[lazyboy, 2012/09/10 16:30:17]

Hmmm, can you explain a bit more? AddGuest is a convenience method to insert the
guest object ptr in a container here.

[awong, 2012/09/10 19:21:07]

Sorry, I misunderstood the lifetime and though that the embedder deleted the
guest directly. Instead, the embedder actually only owns the guest_web_contents.

This brings up another question.  What if you kept 

  instance_id -> guest_web_contents
  guest_web_contents -> frame_id

Then in GetGuestByInstanceID(), you get the guest via the WebContents pointer?

The advantage here is BrowserPluginEmbedder only holds pointers to things it
owns (the web contents) and the relationship of objects becomes more tree-like.

[lazyboy, 2012/09/10 23:40:57]

Done.

+                        BrowserPluginGuest* guest,
+                        int64 frame_id);
+  void DestroyGuestByInstanceID(int instance_id);
+  void DestroyGuests();
+
+  // Message handlers (direct/indirect via BrowserPluginEmbedderHelper).
+  // Routes update rect ack message to the appropriate guest.
+  void UpdateRectACK(int instance_id, int message_id, const gfx::Size& size);
+  void SetFocus(int instance_id, bool focused);
+  void ResizeGuest(int instance_id,
+                   TransportDIB* damage_buffer,
+                   int width,
+                   int height,
+                   bool resize_pending,
+                   float scale_factor);
+  // Handles input events sent from the BrowserPlugin (embedder's renderer
+  // process) by passing them to appropriate guest's input handler.
+  void HandleInputEvent(int instance_id,
+                        RenderViewHost* render_view_host,
+                        const gfx::Rect& guest_rect,
+                        const WebKit::WebInputEvent& event,
+                        IPC::Message* reply_message);
+  void PluginDestroyed(int instance_id);
+
+  // WebContentsObserver implementation.

[awong, 2012/09/09 18:08:09]

Interface implementations should retain the same access privileges as what they
are overriding.

[lazyboy, 2012/09/10 16:30:17]

Done.

+  // Used to monitor frame navigation to clean up guests when a frame navigates
+  // away from the browser plugin it's hosting.
+  virtual void DidCommitProvisionalLoadForFrame(
+      int64 frame_id,
+      bool is_main_frame,
+      const GURL& url,
+      PageTransition transition_type,
+      RenderViewHost* render_view_host) OVERRIDE;
+  virtual void RenderViewDeleted(RenderViewHost* render_view_host) OVERRIDE;
+  virtual void RenderViewGone(base::TerminationStatus status) OVERRIDE;
+
+  // NotificationObserver method override.
+  virtual void Observe(int type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details) OVERRIDE;
+
+  // Called when visiblity of web_contents changes, so the embedder will
+  // show/hide its guest.
+  void WebContentsVisibilityChanged(bool visible);
+
+  // Static factory instance (always NULL for non-test).
+  static BrowserPluginHostFactory* factory_;
+
+  // A scoped container for notification registries.
+  NotificationRegistrar registrar_;
+
+  // Contains guests' WebContents, mapping to their frame ids.
+  GuestWebContentsMap guest_web_contents_container_;
+  ContainerInstanceMap guests_by_instance_id_;
+  RenderViewHost* render_view_host_;
+
+  DISALLOW_COPY_AND_ASSIGN(BrowserPluginEmbedder);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BROWSER_PLUGIN_BROWSER_PLUGIN_EMBEDDER_H_