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
18namespace wm {
19
20class 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).
37class 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_
127