Torne (Richard Coles) | cedac22 | 2014-06-03 10:58:34 +0100 | [diff] [blame] | 1 | // Copyright 2014 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_CONTROLLER_H_ |
| 6 | #define ASH_WM_WINDOW_CYCLE_CONTROLLER_H_ |
| 7 | |
| 8 | #include "ash/ash_export.h" |
| 9 | #include "base/basictypes.h" |
| 10 | #include "base/memory/scoped_ptr.h" |
Torne (Richard Coles) | f8ee788 | 2014-06-20 14:52:04 +0100 | [diff] [blame] | 11 | #include "base/time/time.h" |
Torne (Richard Coles) | cedac22 | 2014-06-03 10:58:34 +0100 | [diff] [blame] | 12 | |
| 13 | namespace ui { |
| 14 | class EventHandler; |
| 15 | } |
| 16 | |
| 17 | namespace ash { |
| 18 | |
| 19 | class WindowCycleList; |
| 20 | |
| 21 | // Controls cycling through windows with the keyboard via alt-tab. |
| 22 | // Windows are sorted primarily by most recently used, and then by screen order. |
| 23 | // We activate windows as you cycle through them, so the order on the screen |
| 24 | // may change during the gesture, but the most recently used list isn't updated |
| 25 | // until the cycling ends. Thus we maintain the state of the windows |
| 26 | // at the beginning of the gesture so you can cycle through in a consistent |
| 27 | // order. |
| 28 | class ASH_EXPORT WindowCycleController { |
| 29 | public: |
| 30 | enum Direction { |
| 31 | FORWARD, |
| 32 | BACKWARD |
| 33 | }; |
| 34 | |
| 35 | WindowCycleController(); |
| 36 | virtual ~WindowCycleController(); |
| 37 | |
| 38 | // Returns true if cycling through windows is enabled. This is false at |
| 39 | // certain times, such as when the lock screen is visible. |
| 40 | static bool CanCycle(); |
| 41 | |
| 42 | // Cycles between windows in the given |direction|. |
| 43 | void HandleCycleWindow(Direction direction); |
| 44 | |
| 45 | // Returns true if we are in the middle of a window cycling gesture. |
| 46 | bool IsCycling() const { return window_cycle_list_.get() != NULL; } |
| 47 | |
| 48 | // Call to start cycling windows. This funtion adds a pre-target handler to |
| 49 | // listen to the alt key release. |
| 50 | void StartCycling(); |
| 51 | |
| 52 | // Stops the current window cycle and removes the event filter. |
| 53 | void StopCycling(); |
| 54 | |
| 55 | // Returns the WindowCycleList. Really only useful for testing. |
| 56 | const WindowCycleList* window_cycle_list() const { |
| 57 | return window_cycle_list_.get(); |
| 58 | } |
| 59 | |
| 60 | private: |
| 61 | // Cycles to the next or previous window based on |direction|. |
| 62 | void Step(Direction direction); |
| 63 | |
| 64 | scoped_ptr<WindowCycleList> window_cycle_list_; |
| 65 | |
| 66 | // Event handler to watch for release of alt key. |
| 67 | scoped_ptr<ui::EventHandler> event_handler_; |
| 68 | |
Torne (Richard Coles) | f8ee788 | 2014-06-20 14:52:04 +0100 | [diff] [blame] | 69 | base::Time cycle_start_time_; |
| 70 | |
Torne (Richard Coles) | cedac22 | 2014-06-03 10:58:34 +0100 | [diff] [blame] | 71 | DISALLOW_COPY_AND_ASSIGN(WindowCycleController); |
| 72 | }; |
| 73 | |
| 74 | } // namespace ash |
| 75 | |
| 76 | #endif // ASH_WM_WINDOW_CYCLE_CONTROLLER_H_ |