cc/trees/swap_promise_monitor.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 CC_TREES_SWAP_PROMISE_MONITOR_H_
   6 #define CC_TREES_SWAP_PROMISE_MONITOR_H_
   7
   8 #include "cc/base/cc_export.h"
   9
  10 namespace cc {
  11
  12 class LayerTreeHost;
  13 class LayerTreeHostImpl;
  14
  15 // A SwapPromiseMonitor is used to monitor compositor state change that
  16 // should be associated with a SwapPromise, e.g. SetNeedsCommit() is
  17 // called on main thread or SetNeedsRedraw() is called on impl thread.
  18 // Creating a SwapPromiseMonitor will insert itself into a LayerTreeHost
  19 // or LayerTreeHostImpl. You must provide a pointer to the appropriate
  20 // structure to the monitor (and only one of the two). Notification of
  21 // compositor state change will be sent through OnSetNeedsCommitOnMain()
  22 // or OnSetNeedsRedrawOnImpl(). When SwapPromiseMonitor is destroyed, it
  23 // will unregister itself from LayerTreeHost or LayerTreeHostImpl.
  24 class CC_EXPORT SwapPromiseMonitor {
  25  public:
  26   // If the monitor lives on the main thread, pass in layer_tree_host
  27   // and set layer_tree_host_impl to nullptr.
  28   // If the monitor lives on the impl thread, pass in layer_tree_host_impl
  29   // and set layer_tree_host to nullptr.
  30   SwapPromiseMonitor(LayerTreeHost* layer_tree_host,
  31                      LayerTreeHostImpl* layer_tree_host_impl);
  32   virtual ~SwapPromiseMonitor();
  33
  34   virtual void OnSetNeedsCommitOnMain() = 0;
  35   virtual void OnSetNeedsRedrawOnImpl() = 0;
  36   virtual void OnForwardScrollUpdateToMainThreadOnImpl() = 0;
  37
  38  protected:
  39   LayerTreeHost* layer_tree_host_;
  40   LayerTreeHostImpl* layer_tree_host_impl_;
  41 };
  42
  43 }  // namespace cc
  44
  45 #endif  // CC_TREES_SWAP_PROMISE_MONITOR_H_