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_change_observer.h"
  16 #include "ui/wm/public/activation_client.h"
  17 #include "ui/wm/wm_export.h"
  18
  19 namespace wm {
  20
  21 class FocusRules;
  22
  23 // FocusController handles focus and activation changes for an environment
  24 // encompassing one or more RootWindows. Within an environment there can be
  25 // only one focused and one active window at a time. When focus or activation
  26 // changes notifications are sent using the
  27 // aura::client::Focus/ActivationChangeObserver interfaces.
  28 // Changes to focus and activation can be from three sources. The source can be
  29 // determined by the ActivationReason parameter in
  30 // ActivationChangeObserver::OnWindowActivated(...).
  31 // . ActivationReason::ACTIVATION_CLIENT: The Aura Client API (implemented here
  32 //   in aura::client::ActivationClient). (The FocusController must be set as the
  33 //   ActivationClient implementation for all RootWindows).
  34 // . ActivationReason::INPUT_EVENT: Input events (implemented here in
  35 //   ui::EventHandler). (The FocusController must be registered as a pre-target
  36 //   handler for the applicable environment owner, either a RootWindow or
  37 //   another type).
  38 // . ActivationReason::WINDOW_DISPOSITION_CHANGED: Window disposition changes
  39 //   (implemented here in aura::WindowObserver). (The FocusController registers
  40 //   itself as an observer of the active and focused windows).
  41 class WM_EXPORT FocusController : public aura::client::ActivationClient,
  42                                   public aura::client::FocusClient,
  43                                   public ui::EventHandler,
  44                                   public aura::WindowObserver {
  45  public:
  46   // |rules| cannot be NULL.
  47   explicit FocusController(FocusRules* rules);
  48   ~FocusController() override;
  49
  50  private:
  51   // Overridden from aura::client::ActivationClient:
  52   void AddObserver(aura::client::ActivationChangeObserver* observer) override;
  53   void RemoveObserver(
  54       aura::client::ActivationChangeObserver* observer) override;
  55   void ActivateWindow(aura::Window* window) override;
  56   void DeactivateWindow(aura::Window* window) override;
  57   aura::Window* GetActiveWindow() override;
  58   aura::Window* GetActivatableWindow(aura::Window* window) override;
  59   aura::Window* GetToplevelWindow(aura::Window* window) override;
  60   bool CanActivateWindow(aura::Window* window) const override;
  61
  62   // Overridden from aura::client::FocusClient:
  63   void AddObserver(aura::client::FocusChangeObserver* observer) override;
  64   void RemoveObserver(aura::client::FocusChangeObserver* observer) override;
  65   void FocusWindow(aura::Window* window) override;
  66   void ResetFocusWithinActiveWindow(aura::Window* window) override;
  67   aura::Window* GetFocusedWindow() override;
  68
  69   // Overridden from ui::EventHandler:
  70   void OnKeyEvent(ui::KeyEvent* event) override;
  71   void OnMouseEvent(ui::MouseEvent* event) override;
  72   void OnScrollEvent(ui::ScrollEvent* event) override;
  73   void OnTouchEvent(ui::TouchEvent* event) override;
  74   void OnGestureEvent(ui::GestureEvent* event) override;
  75
  76   // Overridden from aura::WindowObserver:
  77   void OnWindowVisibilityChanged(aura::Window* window, bool visible) override;
  78   void OnWindowDestroying(aura::Window* window) override;
  79   void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override;
  80   void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
  81
  82   // Internal implementation that coordinates window focus and activation
  83   // changes.
  84   void FocusAndActivateWindow(
  85       aura::client::ActivationChangeObserver::ActivationReason reason,
  86       aura::Window* window);
  87
  88   // Internal implementation that sets the focused window, fires events etc.
  89   // This function must be called with a valid focusable window.
  90   void SetFocusedWindow(aura::Window* window);
  91
  92   // Internal implementation that sets the active window, fires events etc.
  93   // This function must be called with a valid |activatable_window|.
  94   // |requested_window| refers to the window that was passed in to an external
  95   // request (e.g. FocusWindow or ActivateWindow). It may be NULL, e.g. if
  96   // SetActiveWindow was not called by an external request. |activatable_window|
  97   // refers to the actual window to be activated, which may be different.
  98   void SetActiveWindow(
  99       aura::client::ActivationChangeObserver::ActivationReason reason,
 100       aura::Window* requested_window,
 101       aura::Window* activatable_window);
 102
 103   // Stack the |active_window_| on top of the window stack. This function is
 104   // called when activating a window or re-activating the current active window.
 105   void StackActiveWindow();
 106
 107   // Called when a window's disposition changed such that it and its hierarchy
 108   // are no longer focusable/activatable. |next| is a valid window that is used
 109   // as a starting point for finding a window to focus next based on rules.
 110   void WindowLostFocusFromDispositionChange(aura::Window* window,
 111                                             aura::Window* next);
 112
 113   // Called when an attempt is made to focus or activate a window via an input
 114   // event targeted at that window. Rules determine the best focusable window
 115   // for the input window.
 116   void WindowFocusedFromInputEvent(aura::Window* window);
 117
 118   aura::Window* active_window_;
 119   aura::Window* focused_window_;
 120
 121   bool updating_focus_;
 122   bool updating_activation_;
 123
 124   scoped_ptr<FocusRules> rules_;
 125
 126   base::ObserverList<aura::client::ActivationChangeObserver>
 127       activation_observers_;
 128   base::ObserverList<aura::client::FocusChangeObserver> focus_observers_;
 129
 130   ScopedObserver<aura::Window, aura::WindowObserver> observer_manager_;
 131
 132   DISALLOW_COPY_AND_ASSIGN(FocusController);
 133 };
 134
 135 }  // namespace wm
 136
 137 #endif  // UI_WM_CORE_FOCUS_CONTROLLER_H_