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   ~FocusController() override;
  45
  46  private:
  47   // Overridden from aura::client::ActivationClient:
  48   void AddObserver(aura::client::ActivationChangeObserver* observer) override;
  49   void RemoveObserver(
  50       aura::client::ActivationChangeObserver* observer) override;
  51   void ActivateWindow(aura::Window* window) override;
  52   void DeactivateWindow(aura::Window* window) override;
  53   aura::Window* GetActiveWindow() override;
  54   aura::Window* GetActivatableWindow(aura::Window* window) override;
  55   aura::Window* GetToplevelWindow(aura::Window* window) override;
  56   bool CanActivateWindow(aura::Window* window) const override;
  57
  58   // Overridden from aura::client::FocusClient:
  59   void AddObserver(aura::client::FocusChangeObserver* observer) override;
  60   void RemoveObserver(aura::client::FocusChangeObserver* observer) override;
  61   void FocusWindow(aura::Window* window) override;
  62   void ResetFocusWithinActiveWindow(aura::Window* window) override;
  63   aura::Window* GetFocusedWindow() override;
  64
  65   // Overridden from ui::EventHandler:
  66   void OnKeyEvent(ui::KeyEvent* event) override;
  67   void OnMouseEvent(ui::MouseEvent* event) override;
  68   void OnScrollEvent(ui::ScrollEvent* event) override;
  69   void OnTouchEvent(ui::TouchEvent* event) override;
  70   void OnGestureEvent(ui::GestureEvent* event) override;
  71
  72   // Overridden from aura::WindowObserver:
  73   void OnWindowVisibilityChanged(aura::Window* window, bool visible) override;
  74   void OnWindowDestroying(aura::Window* window) override;
  75   void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override;
  76   void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
  77
  78   // Internal implementation that sets the focused window, fires events etc.
  79   // This function must be called with a valid focusable window.
  80   void SetFocusedWindow(aura::Window* window);
  81
  82   // Internal implementation that sets the active window, fires events etc.
  83   // This function must be called with a valid |activatable_window|.
  84   // |requested window| refers to the window that was passed in to an external
  85   // request (e.g. FocusWindow or ActivateWindow). It may be NULL, e.g. if
  86   // SetActiveWindow was not called by an external request. |activatable_window|
  87   // refers to the actual window to be activated, which may be different.
  88   void SetActiveWindow(aura::Window* requested_window,
  89                        aura::Window* activatable_window);
  90
  91   // Called when a window's disposition changed such that it and its hierarchy
  92   // are no longer focusable/activatable. |next| is a valid window that is used
  93   // as a starting point for finding a window to focus next based on rules.
  94   void WindowLostFocusFromDispositionChange(aura::Window* window,
  95                                             aura::Window* next);
  96
  97   // Called when an attempt is made to focus or activate a window via an input
  98   // event targeted at that window. Rules determine the best focusable window
  99   // for the input window.
 100   void WindowFocusedFromInputEvent(aura::Window* window);
 101
 102   aura::Window* active_window_;
 103   aura::Window* focused_window_;
 104
 105   bool updating_focus_;
 106   bool updating_activation_;
 107
 108   scoped_ptr<FocusRules> rules_;
 109
 110   ObserverList<aura::client::ActivationChangeObserver> activation_observers_;
 111   ObserverList<aura::client::FocusChangeObserver> focus_observers_;
 112
 113   ScopedObserver<aura::Window, aura::WindowObserver> observer_manager_;
 114
 115   DISALLOW_COPY_AND_ASSIGN(FocusController);
 116 };
 117
 118 }  // namespace wm
 119
 120 #endif  // UI_WM_CORE_FOCUS_CONTROLLER_H_