ash/wm/overview/window_selector.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_OVERVIEW_WINDOW_SELECTOR_H_
   6 #define ASH_WM_OVERVIEW_WINDOW_SELECTOR_H_
   7
   8 #include <set>
   9 #include <vector>
  10
  11 #include "ash/ash_export.h"
  12 #include "base/compiler_specific.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/scoped_vector.h"
  15 #include "base/timer/timer.h"
  16 #include "ui/aura/client/activation_change_observer.h"
  17 #include "ui/aura/window_observer.h"
  18
  19 namespace aura {
  20 class RootWindow;
  21 }
  22
  23 namespace ui {
  24 class EventHandler;
  25 }
  26
  27 namespace ash {
  28
  29 namespace internal {
  30 class WindowSelectorTest;
  31 }
  32
  33 class WindowOverview;
  34 class WindowSelectorDelegate;
  35 class WindowSelectorItem;
  36
  37 // The WindowSelector allows selecting a window by alt-tabbing (CYCLE mode) or
  38 // by clicking or tapping on it (OVERVIEW mode). A WindowOverview will be shown
  39 // in OVERVIEW mode or if the user lingers on a window while alt tabbing.
  40 class ASH_EXPORT WindowSelector
  41     : public aura::WindowObserver,
  42       public aura::client::ActivationChangeObserver {
  43  public:
  44   enum Direction {
  45     FORWARD,
  46     BACKWARD
  47   };
  48   enum Mode {
  49     CYCLE,
  50     OVERVIEW
  51   };
  52
  53   typedef std::vector<aura::Window*> WindowList;
  54
  55   WindowSelector(const WindowList& windows,
  56                  Mode mode,
  57                  WindowSelectorDelegate* delegate);
  58   virtual ~WindowSelector();
  59
  60   // Step to the next window in |direction|.
  61   void Step(Direction direction);
  62
  63   // Choose the currently selected window.
  64   void SelectWindow();
  65
  66   // Choose |window| from the available windows to select.
  67   void SelectWindow(aura::Window* window);
  68
  69   // Cancels window selection.
  70   void CancelSelection();
  71
  72   Mode mode() { return mode_; }
  73
  74   // aura::WindowObserver:
  75   virtual void OnWindowAdded(aura::Window* new_window) OVERRIDE;
  76   virtual void OnWindowBoundsChanged(aura::Window* window,
  77                                      const gfx::Rect& old_bounds,
  78                                      const gfx::Rect& new_bounds) OVERRIDE;
  79   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
  80
  81   // Overridden from aura::client::ActivationChangeObserver:
  82   virtual void OnWindowActivated(aura::Window* gained_active,
  83                                  aura::Window* lost_active) OVERRIDE;
  84   virtual void OnAttemptToReactivateWindow(
  85       aura::Window* request_active,
  86       aura::Window* actual_active) OVERRIDE;
  87
  88  private:
  89   friend class internal::WindowSelectorTest;
  90
  91   // Begins positioning windows such that all windows are visible on the screen.
  92   void StartOverview();
  93
  94   // Stores the currently focused window and removes focus from it.
  95   void RemoveFocusAndSetRestoreWindow();
  96
  97   // Resets the stored window from RemoveFocusAndSetRestoreWindow to NULL. If
  98   // |focus|, restores focus to the stored window.
  99   void ResetFocusRestoreWindow(bool focus);
 100
 101   // The collection of items in the overview wrapped by a helper class which
 102   // restores their state and helps transform them to other root windows.
 103   ScopedVector<WindowSelectorItem> windows_;
 104
 105   // Tracks observed windows.
 106   std::set<aura::Window*> observed_windows_;
 107
 108   // The window selection mode.
 109   Mode mode_;
 110
 111   // An event handler listening for the release of the alt key during alt-tab
 112   // cycling.
 113   scoped_ptr<ui::EventHandler> event_handler_;
 114
 115   base::DelayTimer<WindowSelector> start_overview_timer_;
 116   scoped_ptr<WindowOverview> window_overview_;
 117
 118   // Weak pointer to the selector delegate which will be called when a
 119   // selection is made.
 120   WindowSelectorDelegate* delegate_;
 121
 122   // Index of the currently selected window if the mode is CYCLE.
 123   size_t selected_window_;
 124
 125   // A weak pointer to the window which was focused on entering overview mode.
 126   // If overview mode is canceled the focus should be restored to this window.
 127   aura::Window* restore_focus_window_;
 128
 129   // True when restoring focus to the window. This is used to prevent handling
 130   // the resulting activation.
 131   bool restoring_focus_;
 132
 133   DISALLOW_COPY_AND_ASSIGN(WindowSelector);
 134 };
 135
 136 }  // namespace ash
 137
 138 #endif  // ASH_WM_OVERVIEW_WINDOW_SELECTOR_H_