ash/wm/window_cycle_list.h

   1 // Copyright (c) 2012 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_WINDOW_CYCLE_LIST_H_
   6 #define ASH_WM_WINDOW_CYCLE_LIST_H_
   7
   8 #include <vector>
   9
  10 #include "ash/ash_export.h"
  11 #include "base/basictypes.h"
  12 #include "base/compiler_specific.h"
  13 #include "ui/aura/window_observer.h"
  14
  15 namespace ash {
  16
  17 // Tracks a set of Windows that can be stepped through. This class is used by
  18 // the WindowCycleController.
  19 class ASH_EXPORT WindowCycleList : public aura::WindowObserver {
  20  public:
  21   typedef std::vector<aura::Window*> WindowList;
  22
  23   enum Direction {
  24     FORWARD,
  25     BACKWARD
  26   };
  27
  28   explicit WindowCycleList(const WindowList& windows);
  29   virtual ~WindowCycleList();
  30
  31   bool empty() const { return windows_.empty(); }
  32
  33   // Cycles to the next or previous window based on |direction|.
  34   void Step(Direction direction);
  35
  36   const WindowList& windows() const { return windows_; }
  37
  38  private:
  39   // Returns the index of |window| in |windows_| or -1 if it isn't there.
  40   int GetWindowIndex(aura::Window* window);
  41
  42   // aura::WindowObserver overrides:
  43   virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
  44
  45   // List of weak pointers to windows to use while cycling with the keyboard.
  46   // List is built when the user initiates the gesture (e.g. hits alt-tab the
  47   // first time) and is emptied when the gesture is complete (e.g. releases the
  48   // alt key).
  49   WindowList windows_;
  50
  51   // Current position in the |windows_| list or -1 if we're not cycling.
  52   int current_index_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(WindowCycleList);
  55 };
  56
  57 }  // namespace ash
  58
  59 #endif  // ASH_WM_WINDOW_CYCLE_LIST_H_