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_SCREEN_DIMMER_H_ 6 #define ASH_WM_SCREEN_DIMMER_H_ 7 8 #include "ash/ash_export.h" 9 #include "base/basictypes.h" 10 #include "base/compiler_specific.h" 11 #include "base/memory/scoped_ptr.h" 12 #include "ui/aura/window_observer.h" 13 14 namespace ui { 15 class Layer; 16 } 17 18 namespace ash { 19 namespace internal { 20 21 // ScreenDimmer displays a partially-opaque layer above everything 22 // else in the root window to darken the display. It shouldn't be used 23 // for long-term brightness adjustments due to performance 24 // considerations -- it's only intended for cases where we want to 25 // briefly dim the screen (e.g. to indicate to the user that we're 26 // about to suspend a machine that lacks an internal backlight that 27 // can be adjusted). 28 class ASH_EXPORT ScreenDimmer : public aura::WindowObserver { 29 public: 30 class TestApi { 31 public: TestApi(ScreenDimmer * dimmer)32 explicit TestApi(ScreenDimmer* dimmer) : dimmer_(dimmer) {} 33 layer()34 ui::Layer* layer() { return dimmer_->dimming_layer_.get(); } 35 36 private: 37 ScreenDimmer* dimmer_; // not owned 38 39 DISALLOW_COPY_AND_ASSIGN(TestApi); 40 }; 41 42 explicit ScreenDimmer(aura::Window* root_window); 43 virtual ~ScreenDimmer(); 44 45 // Dim or undim the root window. 46 void SetDimming(bool should_dim); 47 48 // aura::WindowObserver overrides: 49 virtual void OnWindowBoundsChanged(aura::Window* root_window, 50 const gfx::Rect& old_bounds, 51 const gfx::Rect& new_bounds) OVERRIDE; 52 53 private: 54 friend class TestApi; 55 56 aura::Window* root_window_; 57 58 // Partially-opaque layer that's stacked above all of the root window's 59 // children and used to dim the screen. NULL until the first time we dim. 60 scoped_ptr<ui::Layer> dimming_layer_; 61 62 // Are we currently dimming the screen? 63 bool currently_dimming_; 64 65 DISALLOW_COPY_AND_ASSIGN(ScreenDimmer); 66 }; 67 68 } // namespace internal 69 } // namespace ash 70 71 #endif // ASH_WM_SCREEN_DIMMER_H_ 72