// Copyright 2013 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.
#ifndef CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_
#define CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_
#include <string>
#include "base/callback.h"
#include "base/memory/scoped_ptr.h"
#include "content/browser/frame_host/frame_tree_node.h"
#include "content/common/content_export.h"
namespace content {
class FrameTreeNode;
class Navigator;
class RenderFrameHostDelegate;
class RenderProcessHost;
class RenderViewHostDelegate;
class RenderViewHostImpl;
class RenderFrameHostManager;
class RenderWidgetHostDelegate;
// Represents the frame tree for a page. With the exception of the main frame,
// all FrameTreeNodes will be created/deleted in response to frame attach and
// detach events in the DOM.
//
// The main frame's FrameTreeNode is special in that it is reused. This allows
// it to serve as an anchor for state that needs to persist across top-level
// page navigations.
//
// TODO(ajwong): Move NavigationController ownership to the main frame
// FrameTreeNode. Possibly expose access to it from here.
//
// This object is only used on the UI thread.
class CONTENT_EXPORT FrameTree {
public:
// Each FrameTreeNode will default to using the given |navigator| for
// navigation tasks in the frame.
// A set of delegates are remembered here so that we can create
// RenderFrameHostManagers.
// TODO(creis): This set of delegates will change as we move things to
// Navigator.
FrameTree(Navigator* navigator,
RenderFrameHostDelegate* render_frame_delegate,
RenderViewHostDelegate* render_view_delegate,
RenderWidgetHostDelegate* render_widget_delegate,
RenderFrameHostManager::Delegate* manager_delegate);
~FrameTree();
FrameTreeNode* root() const { return root_.get(); }
// Returns the FrameTreeNode with the given |frame_tree_node_id|.
FrameTreeNode* FindByID(int64 frame_tree_node_id);
// Returns the FrameTreeNode with the given renderer-specific |routing_id|.
FrameTreeNode* FindByRoutingID(int routing_id, int process_id);
// Executes |on_node| on each node in the frame tree. If |on_node| returns
// false, terminates the iteration immediately. Returning false is useful
// if |on_node| is just doing a search over the tree. The iteration proceeds
// top-down and visits a node before adding its children to the queue, making
// it safe to remove children during the callback.
void ForEach(const base::Callback<bool(FrameTreeNode*)>& on_node) const;
// Frame tree manipulation routines.
RenderFrameHostImpl* AddFrame(FrameTreeNode* parent,
int new_routing_id,
const std::string& frame_name);
void RemoveFrame(FrameTreeNode* child);
// Clears process specific-state after a main frame process swap.
// This destroys most of the frame tree but retains the root node so that
// navigation state may be kept on it between process swaps. Used to
// support bookkeeping for top-level navigations.
// TODO(creis): Look into how we can remove the need for this method.
void ResetForMainFrameSwap();
// Update the frame tree after a process exits. Any nodes currently using the
// given |render_view_host| will lose all their children.
// TODO(creis): This should take a RenderProcessHost once RenderFrameHost
// knows its process. Until then, we would just be asking the RenderViewHost
// for its process, so we'll skip that step.
void RenderProcessGone(RenderViewHost* render_view_host);
// Convenience accessor for the main frame's RenderFrameHostImpl.
RenderFrameHostImpl* GetMainFrame() const;
// Returns the focused frame.
FrameTreeNode* GetFocusedFrame();
// Sets the focused frame.
void SetFocusedFrame(FrameTreeNode* node);
// Allows a client to listen for frame removal. The listener should expect
// to receive the RenderViewHostImpl containing the frame and the renderer-
// specific frame routing ID of the removed frame.
// TODO(creis): These parameters will later change to be the RenderFrameHost.
void SetFrameRemoveListener(
const base::Callback<void(RenderViewHostImpl*, int)>& on_frame_removed);
// Creates a RenderViewHost for a new main frame RenderFrameHost in the given
// |site_instance|. The RenderViewHost will have its Shutdown method called
// when all of the RenderFrameHosts using it are deleted.
RenderViewHostImpl* CreateRenderViewHostForMainFrame(
SiteInstance* site_instance,
int routing_id,
int main_frame_routing_id,
bool swapped_out,
bool hidden);
// Returns the existing RenderViewHost for a new subframe RenderFrameHost.
// There should always be such a RenderViewHost, because the main frame
// RenderFrameHost for each SiteInstance should be created before subframes.
RenderViewHostImpl* GetRenderViewHostForSubFrame(SiteInstance* site_instance);
// Keeps track of which RenderFrameHosts are using each RenderViewHost. When
// the number drops to zero, we call Shutdown on the RenderViewHost.
void RegisterRenderFrameHost(RenderFrameHostImpl* render_frame_host);
void UnregisterRenderFrameHost(RenderFrameHostImpl* render_frame_host);
private:
typedef base::hash_map<int, RenderViewHostImpl*> RenderViewHostMap;
typedef std::multimap<int, RenderViewHostImpl*> RenderViewHostMultiMap;
// These delegates are installed into all the RenderViewHosts and
// RenderFrameHosts that we create.
RenderFrameHostDelegate* render_frame_delegate_;
RenderViewHostDelegate* render_view_delegate_;
RenderWidgetHostDelegate* render_widget_delegate_;
RenderFrameHostManager::Delegate* manager_delegate_;
// Map of SiteInstance ID to a RenderViewHost. This allows us to look up the
// RenderViewHost for a given SiteInstance when creating RenderFrameHosts.
// Combined with the refcount on RenderViewHost, this allows us to call
// Shutdown on the RenderViewHost and remove it from the map when no more
// RenderFrameHosts are using it.
//
// Must be declared before |root_| so that it is deleted afterward. Otherwise
// the map will be cleared before we delete the RenderFrameHosts in the tree.
RenderViewHostMap render_view_host_map_;
// Map of SiteInstance ID to RenderViewHosts that are pending shutdown. The
// renderers of these RVH are currently executing the unload event in
// background. When the SwapOutACK is received, they will be deleted. In the
// meantime, they are kept in this map, as they should not be reused (part of
// their state is already gone away).
RenderViewHostMultiMap render_view_host_pending_shutdown_map_;
scoped_ptr<FrameTreeNode> root_;
int64 focused_frame_tree_node_id_;
base::Callback<void(RenderViewHostImpl*, int)> on_frame_removed_;
DISALLOW_COPY_AND_ASSIGN(FrameTree);
};
} // namespace content
#endif // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_