ui/wm/core/focus_controller.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 UI_WM_CORE_FOCUS_CONTROLLER_H_
   6 #define UI_WM_CORE_FOCUS_CONTROLLER_H_
   7
   8 #include "base/compiler_specific.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/observer_list.h"
  11 #include "base/scoped_observer.h"
  12 #include "ui/aura/client/focus_client.h"
  13 #include "ui/aura/window_observer.h"
  14 #include "ui/events/event_handler.h"
  15 #include "ui/wm/public/activation_client.h"
  16 #include "ui/wm/wm_export.h"
  17
  18 namespace wm {
  19
  20 class FocusRules;
  21
  22 // FocusController handles focus and activation changes for an environment
  23 // encompassing one or more RootWindows. Within an environment there can be
  24 // only one focused and one active window at a time. When focus or activation
  25 // changes notifications are sent using the
  26 // aura::client::Focus/ActivationChangeObserver interfaces.
  27 // Changes to focus and activation can be from three sources:
  28 // . the Aura Client API (implemented here in aura::client::ActivationClient).
  29 //   (The FocusController must be set as the ActivationClient implementation
  30 //    for all RootWindows).
  31 // . input events (implemented here in ui::EventHandler).
  32 //   (The FocusController must be registered as a pre-target handler for
  33 //    the applicable environment owner, either a RootWindow or another type).
  34 // . Window disposition changes (implemented here in aura::WindowObserver).
  35 //   (The FocusController registers itself as an observer of the active and
  36 //    focused windows).
  37 class WM_EXPORT FocusController : public aura::client::ActivationClient,
  38                                   public aura::client::FocusClient,
  39                                   public ui::EventHandler,
  40                                   public aura::WindowObserver {
  41  public:
  42   // |rules| cannot be NULL.
  43   explicit FocusController(FocusRules* rules);
  44   virtual ~FocusController();
  45
  46  private:
  47   // Overridden from aura::client::ActivationClient:
  48   virtual void AddObserver(
  49       aura::client::ActivationChangeObserver* observer) OVERRIDE;
  50   virtual void RemoveObserver(
  51       aura::client::ActivationChangeObserver* observer) OVERRIDE;
  52   virtual void ActivateWindow(aura::Window* window) OVERRIDE;
  53   virtual void DeactivateWindow(aura::Window* window) OVERRIDE;
  54   virtual aura::Window* GetActiveWindow() OVERRIDE;
  55   virtual aura::Window* GetActivatableWindow(aura::Window* window) OVERRIDE;
  56   virtual aura::Window* GetToplevelWindow(aura::Window* window) OVERRIDE;
  57   virtual bool CanActivateWindow(aura::Window* window) const OVERRIDE;
  58
  59   // Overridden from aura::client::FocusClient:
  60   virtual void AddObserver(
  61       aura::client::FocusChangeObserver* observer) OVERRIDE;
  62   virtual void RemoveObserver(
  63       aura::client::FocusChangeObserver* observer) OVERRIDE;
  64   virtual void FocusWindow(aura::Window* window) OVERRIDE;
  65   virtual void ResetFocusWithinActiveWindow(aura::Window* window) OVERRIDE;
  66   virtual aura::Window* GetFocusedWindow() OVERRIDE;
  67
  68   // Overridden from ui::EventHandler:
  69   virtual void OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
  70   virtual void OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
  71   virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
  72   virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
  73   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
  74
  75   // Overridden from aura::WindowObserver:
  76   virtual void OnWindowVisibilityChanged(aura::Window* window,
  77                                          bool visible) OVERRIDE;
  78   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
  79   virtual void OnWindowHierarchyChanging(
  80       const HierarchyChangeParams& params) OVERRIDE;
  81   virtual void OnWindowHierarchyChanged(
  82       const HierarchyChangeParams& params) OVERRIDE;
  83
  84   // Internal implementation that sets the focused window, fires events etc.
  85   // This function must be called with a valid focusable window.
  86   void SetFocusedWindow(aura::Window* window);
  87
  88   // Internal implementation that sets the active window, fires events etc.
  89   // This function must be called with a valid |activatable_window|.
  90   // |requested window| refers to the window that was passed in to an external
  91   // request (e.g. FocusWindow or ActivateWindow). It may be NULL, e.g. if
  92   // SetActiveWindow was not called by an external request. |activatable_window|
  93   // refers to the actual window to be activated, which may be different.
  94   void SetActiveWindow(aura::Window* requested_window,
  95                        aura::Window* activatable_window);
  96
  97   // Called when a window's disposition changed such that it and its hierarchy
  98   // are no longer focusable/activatable. |next| is a valid window that is used
  99   // as a starting point for finding a window to focus next based on rules.
 100   void WindowLostFocusFromDispositionChange(aura::Window* window,
 101                                             aura::Window* next);
 102
 103   // Called when an attempt is made to focus or activate a window via an input
 104   // event targeted at that window. Rules determine the best focusable window
 105   // for the input window.
 106   void WindowFocusedFromInputEvent(aura::Window* window);
 107
 108   aura::Window* active_window_;
 109   aura::Window* focused_window_;
 110
 111   bool updating_focus_;
 112   bool updating_activation_;
 113
 114   scoped_ptr<FocusRules> rules_;
 115
 116   ObserverList<aura::client::ActivationChangeObserver> activation_observers_;
 117   ObserverList<aura::client::FocusChangeObserver> focus_observers_;
 118
 119   ScopedObserver<aura::Window, aura::WindowObserver> observer_manager_;
 120
 121   DISALLOW_COPY_AND_ASSIGN(FocusController);
 122 };
 123
 124 }  // namespace wm
 125
 126 #endif  // UI_WM_CORE_FOCUS_CONTROLLER_H_