ash/wm/mru_window_tracker.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 ASH_WM_MRU_WINDOW_TRACKER_H_
   6 #define ASH_WM_MRU_WINDOW_TRACKER_H_
   7
   8 #include <list>
   9 #include <vector>
  10
  11 #include "ash/ash_export.h"
  12 #include "base/basictypes.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "ui/aura/window_observer.h"
  15 #include "ui/wm/public/activation_change_observer.h"
  16
  17 namespace aura {
  18 class RootWindow;
  19 class Window;
  20 namespace client {
  21 class ActivationClient;
  22 }
  23 }
  24
  25 namespace ash {
  26
  27 // Maintains a most recently used list of windows. This is used for window
  28 // cycling using Alt+Tab and overview mode.
  29 class ASH_EXPORT MruWindowTracker
  30     : public aura::client::ActivationChangeObserver,
  31       public aura::WindowObserver {
  32  public:
  33   typedef std::vector<aura::Window*> WindowList;
  34
  35   explicit MruWindowTracker(
  36       aura::client::ActivationClient* activation_client);
  37   ~MruWindowTracker() override;
  38
  39   // Returns the set of windows which can be cycled through. This method creates
  40   // the vector based on the current set of windows across all valid root
  41   // windows. As a result it is not necessarily the same as the set of
  42   // windows being iterated over.
  43   // The returned window list will be in descending (top most window first)
  44   // order.
  45   static WindowList BuildWindowList();
  46
  47   // Returns the set of windows which can be cycled through using the tracked
  48   // list of most recently used windows.
  49   WindowList BuildMruWindowList();
  50
  51   // Starts or stops ignoring window activations. If no longer ignoring
  52   // activations the currently active window is moved to the front of the
  53   // MRU window list. Used by WindowCycleList to avoid adding all cycled
  54   // windows to the front of the MRU window list.
  55   void SetIgnoreActivations(bool ignore);
  56
  57  private:
  58   // Updates the mru_windows_ list to insert/move |active_window| at/to the
  59   // front.
  60   void SetActiveWindow(aura::Window* active_window);
  61
  62   // Overridden from aura::client::ActivationChangeObserver:
  63   void OnWindowActivated(aura::Window* gained_active,
  64                          aura::Window* lost_active) override;
  65
  66   // Overridden from WindowObserver:
  67   void OnWindowDestroyed(aura::Window* window) override;
  68
  69   // List of windows that have been activated in containers that we cycle
  70   // through, sorted by most recently used.
  71   std::list<aura::Window*> mru_windows_;
  72
  73   aura::client::ActivationClient* activation_client_;
  74
  75   bool ignore_window_activations_;
  76
  77   DISALLOW_COPY_AND_ASSIGN(MruWindowTracker);
  78 };
  79
  80 }  // namespace ash
  81
  82 #endif  // ASH_WM_MRU_WINDOW_TRACKER_H_