content/browser/frame_host/frame_tree.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_
   6 #define CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "content/browser/frame_host/frame_tree_node.h"
  13 #include "content/common/content_export.h"
  14
  15 namespace content {
  16
  17 class FrameTreeNode;
  18 class Navigator;
  19 class RenderFrameHostDelegate;
  20 class RenderProcessHost;
  21 class RenderViewHostDelegate;
  22 class RenderViewHostImpl;
  23 class RenderFrameHostManager;
  24 class RenderWidgetHostDelegate;
  25
  26 // Represents the frame tree for a page. With the exception of the main frame,
  27 // all FrameTreeNodes will be created/deleted in response to frame attach and
  28 // detach events in the DOM.
  29 //
  30 // The main frame's FrameTreeNode is special in that it is reused. This allows
  31 // it to serve as an anchor for state that needs to persist across top-level
  32 // page navigations.
  33 //
  34 // TODO(ajwong): Move NavigationController ownership to the main frame
  35 // FrameTreeNode. Possibly expose access to it from here.
  36 //
  37 // This object is only used on the UI thread.
  38 class CONTENT_EXPORT FrameTree {
  39  public:
  40   // Each FrameTreeNode will default to using the given |navigator| for
  41   // navigation tasks in the frame.
  42   // A set of delegates are remembered here so that we can create
  43   // RenderFrameHostManagers.
  44   // TODO(creis): This set of delegates will change as we move things to
  45   // Navigator.
  46   FrameTree(Navigator* navigator,
  47             RenderFrameHostDelegate* render_frame_delegate,
  48             RenderViewHostDelegate* render_view_delegate,
  49             RenderWidgetHostDelegate* render_widget_delegate,
  50             RenderFrameHostManager::Delegate* manager_delegate);
  51   ~FrameTree();
  52
  53   // Returns the FrameTreeNode with the given |frame_tree_node_id|.
  54   static FrameTreeNode* GloballyFindByID(int64 frame_tree_node_id);
  55
  56   FrameTreeNode* root() const { return root_.get(); }
  57
  58   // Returns the FrameTreeNode with the given |frame_tree_node_id| if it is part
  59   // of this FrameTree.
  60   FrameTreeNode* FindByID(int64 frame_tree_node_id);
  61
  62   // Returns the FrameTreeNode with the given renderer-specific |routing_id|.
  63   FrameTreeNode* FindByRoutingID(int routing_id, int process_id);
  64
  65   // Executes |on_node| on each node in the frame tree.  If |on_node| returns
  66   // false, terminates the iteration immediately. Returning false is useful
  67   // if |on_node| is just doing a search over the tree.  The iteration proceeds
  68   // top-down and visits a node before adding its children to the queue, making
  69   // it safe to remove children during the callback.
  70   void ForEach(const base::Callback<bool(FrameTreeNode*)>& on_node) const;
  71
  72   // Frame tree manipulation routines.
  73   RenderFrameHostImpl* AddFrame(FrameTreeNode* parent,
  74                                 int new_routing_id,
  75                                 const std::string& frame_name);
  76   void RemoveFrame(FrameTreeNode* child);
  77
  78   // This method walks the entire frame tree and creates a RenderFrameProxyHost
  79   // for the given |site_instance| in each node except the |source| one --
  80   // the source will have a RenderFrameHost. It assumes that no frame tree
  81   // nodes already have RenderFrameProxyHost for the given |site_instance|.
  82   void CreateProxiesForSiteInstance(
  83       FrameTreeNode* source,
  84       SiteInstance* site_instance);
  85
  86   // Clears process specific-state after a main frame process swap.
  87   // This destroys most of the frame tree but retains the root node so that
  88   // navigation state may be kept on it between process swaps. Used to
  89   // support bookkeeping for top-level navigations.
  90   // TODO(creis): Look into how we can remove the need for this method.
  91   void ResetForMainFrameSwap();
  92
  93   // Update the frame tree after a process exits.  Any nodes currently using the
  94   // given |render_view_host| will lose all their children.
  95   // TODO(creis): This should take a RenderProcessHost once RenderFrameHost
  96   // knows its process.  Until then, we would just be asking the RenderViewHost
  97   // for its process, so we'll skip that step.
  98   void RenderProcessGone(RenderViewHost* render_view_host);
  99
 100   // Convenience accessor for the main frame's RenderFrameHostImpl.
 101   RenderFrameHostImpl* GetMainFrame() const;
 102
 103   // Returns the focused frame.
 104   FrameTreeNode* GetFocusedFrame();
 105
 106   // Sets the focused frame.
 107   void SetFocusedFrame(FrameTreeNode* node);
 108
 109   // Allows a client to listen for frame removal.  The listener should expect
 110   // to receive the RenderViewHostImpl containing the frame and the renderer-
 111   // specific frame routing ID of the removed frame.
 112   void SetFrameRemoveListener(
 113       const base::Callback<void(RenderFrameHost*)>& on_frame_removed);
 114
 115   // Creates a RenderViewHost for a new RenderFrameHost in the given
 116   // |site_instance|.  The RenderViewHost will have its Shutdown method called
 117   // when all of the RenderFrameHosts using it are deleted.
 118   RenderViewHostImpl* CreateRenderViewHost(SiteInstance* site_instance,
 119                                            int routing_id,
 120                                            int main_frame_routing_id,
 121                                            bool swapped_out,
 122                                            bool hidden);
 123
 124   // Returns the existing RenderViewHost for a new RenderFrameHost.
 125   // There should always be such a RenderViewHost, because the main frame
 126   // RenderFrameHost for each SiteInstance should be created before subframes.
 127   RenderViewHostImpl* GetRenderViewHost(SiteInstance* site_instance);
 128
 129   // Keeps track of which RenderFrameHosts are using each RenderViewHost.  When
 130   // the number drops to zero, we call Shutdown on the RenderViewHost.
 131   void RegisterRenderFrameHost(RenderFrameHostImpl* render_frame_host);
 132   void UnregisterRenderFrameHost(RenderFrameHostImpl* render_frame_host);
 133
 134  private:
 135   typedef base::hash_map<int, RenderViewHostImpl*> RenderViewHostMap;
 136   typedef std::multimap<int, RenderViewHostImpl*> RenderViewHostMultiMap;
 137
 138   // These delegates are installed into all the RenderViewHosts and
 139   // RenderFrameHosts that we create.
 140   RenderFrameHostDelegate* render_frame_delegate_;
 141   RenderViewHostDelegate* render_view_delegate_;
 142   RenderWidgetHostDelegate* render_widget_delegate_;
 143   RenderFrameHostManager::Delegate* manager_delegate_;
 144
 145   // Map of SiteInstance ID to a RenderViewHost.  This allows us to look up the
 146   // RenderViewHost for a given SiteInstance when creating RenderFrameHosts.
 147   // Combined with the refcount on RenderViewHost, this allows us to call
 148   // Shutdown on the RenderViewHost and remove it from the map when no more
 149   // RenderFrameHosts are using it.
 150   //
 151   // Must be declared before |root_| so that it is deleted afterward.  Otherwise
 152   // the map will be cleared before we delete the RenderFrameHosts in the tree.
 153   RenderViewHostMap render_view_host_map_;
 154
 155   // Map of SiteInstance ID to RenderViewHosts that are pending shutdown. The
 156   // renderers of these RVH are currently executing the unload event in
 157   // background. When the SwapOutACK is received, they will be deleted. In the
 158   // meantime, they are kept in this map, as they should not be reused (part of
 159   // their state is already gone away).
 160   RenderViewHostMultiMap render_view_host_pending_shutdown_map_;
 161
 162   scoped_ptr<FrameTreeNode> root_;
 163
 164   int64 focused_frame_tree_node_id_;
 165
 166   base::Callback<void(RenderFrameHost*)> on_frame_removed_;
 167
 168   DISALLOW_COPY_AND_ASSIGN(FrameTree);
 169 };
 170
 171 }  // namespace content
 172
 173 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_