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 CHROME_BROWSER_UI_AURA_ACTIVE_DESKTOP_MONITOR_H_ 6 #define CHROME_BROWSER_UI_AURA_ACTIVE_DESKTOP_MONITOR_H_ 7 8 #include "base/basictypes.h" 9 #include "base/compiler_specific.h" 10 #include "chrome/browser/ui/host_desktop.h" 11 #include "ui/aura/env_observer.h" 12 13 // Tracks the most-recently activated host desktop type by observing 14 // WindowTreeHost activations. 15 class ActiveDesktopMonitor : public aura::EnvObserver { 16 public: 17 // Constructs an ActiveDesktopMonitor which initially uses |initial_desktop| 18 // as the |last_activated_desktop_| until a root window is activated. 19 explicit ActiveDesktopMonitor(chrome::HostDesktopType initial_desktop); 20 virtual ~ActiveDesktopMonitor(); 21 22 // Returns the host desktop type of the most-recently activated 23 // WindowTreeHost. This desktop type may no longer exist (e.g., the Ash 24 // desktop may have closed since being active, and no RWHs on the native 25 // desktop have yet been activated). 26 static chrome::HostDesktopType GetLastActivatedDesktopType(); 27 28 private: 29 // Returns true if |host| is a DesktopWindowTreeHost. 30 static bool IsDesktopWindow(aura::WindowTreeHost* host); 31 32 // aura::EnvObserver methods. 33 virtual void OnWindowInitialized(aura::Window* window) OVERRIDE; 34 virtual void OnHostActivated(aura::WindowTreeHost* host) OVERRIDE; 35 36 static ActiveDesktopMonitor* g_instance_; 37 chrome::HostDesktopType last_activated_desktop_; 38 39 DISALLOW_COPY_AND_ASSIGN(ActiveDesktopMonitor); 40 }; 41 42 #endif // CHROME_BROWSER_UI_AURA_ACTIVE_DESKTOP_MONITOR_H_ 43
