ash/wm/window_selector_controller.cc

   1 // Copyright 2013 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 #include "ash/wm/window_selector_controller.h"
   6
   7 #include "ash/session_state_delegate.h"
   8 #include "ash/shell.h"
   9 #include "ash/wm/mru_window_tracker.h"
  10 #include "ash/wm/window_selector.h"
  11 #include "ash/wm/window_util.h"
  12 #include "ui/base/events/event.h"
  13 #include "ui/base/events/event_handler.h"
  14
  15 namespace ash {
  16
  17 namespace {
  18
  19 // Filter to watch for the termination of a keyboard gesture to cycle through
  20 // multiple windows.
  21 class WindowSelectorEventFilter : public ui::EventHandler {
  22  public:
  23   WindowSelectorEventFilter();
  24   virtual ~WindowSelectorEventFilter();
  25
  26   // Overridden from ui::EventHandler:
  27   virtual void OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
  28
  29  private:
  30   DISALLOW_COPY_AND_ASSIGN(WindowSelectorEventFilter);
  31 };
  32
  33 // Watch for all keyboard events by filtering the root window.
  34 WindowSelectorEventFilter::WindowSelectorEventFilter() {
  35   Shell::GetInstance()->AddPreTargetHandler(this);
  36 }
  37
  38 WindowSelectorEventFilter::~WindowSelectorEventFilter() {
  39   Shell::GetInstance()->RemovePreTargetHandler(this);
  40 }
  41
  42 void WindowSelectorEventFilter::OnKeyEvent(ui::KeyEvent* event) {
  43   // Views uses VKEY_MENU for both left and right Alt keys.
  44   if (event->key_code() == ui::VKEY_MENU &&
  45       event->type() == ui::ET_KEY_RELEASED) {
  46     Shell::GetInstance()->window_selector_controller()->AltKeyReleased();
  47     // Warning: |this| will be deleted from here on.
  48   }
  49 }
  50
  51 }  // namespace
  52
  53 WindowSelectorController::WindowSelectorController() {
  54 }
  55
  56 WindowSelectorController::~WindowSelectorController() {
  57 }
  58
  59 // static
  60 bool WindowSelectorController::CanSelect() {
  61   // Don't allow a window overview if the screen is locked or a modal dialog is
  62   // open.
  63   return !Shell::GetInstance()->session_state_delegate()->IsScreenLocked() &&
  64          !Shell::GetInstance()->IsSystemModalWindowOpen();
  65 }
  66
  67 void WindowSelectorController::ToggleOverview() {
  68   if (window_selector_.get()) {
  69     window_selector_.reset();
  70   } else {
  71     std::vector<aura::Window*> windows = ash::Shell::GetInstance()->
  72         mru_window_tracker()->BuildMruWindowList();
  73     // Don't enter overview mode with no windows.
  74     if (windows.empty())
  75       return;
  76
  77     // Deactivating the window will hide popup windows like the omnibar or
  78     // open menus.
  79     aura::Window* active_window = wm::GetActiveWindow();
  80     if (active_window)
  81       wm::DeactivateWindow(active_window);
  82     window_selector_.reset(
  83         new WindowSelector(windows, WindowSelector::OVERVIEW, this));
  84   }
  85 }
  86
  87 void WindowSelectorController::HandleCycleWindow(
  88     WindowSelector::Direction direction) {
  89   if (!CanSelect())
  90     return;
  91
  92   if (!IsSelecting()) {
  93     event_handler_.reset(new WindowSelectorEventFilter());
  94     std::vector<aura::Window*> windows = ash::Shell::GetInstance()->
  95         mru_window_tracker()->BuildMruWindowList();
  96     window_selector_.reset(
  97         new WindowSelector(windows, WindowSelector::CYCLE, this));
  98     window_selector_->Step(direction);
  99   } else if (window_selector_->mode() == WindowSelector::CYCLE) {
 100     window_selector_->Step(direction);
 101   }
 102 }
 103
 104 void WindowSelectorController::AltKeyReleased() {
 105   event_handler_.reset();
 106   window_selector_->SelectWindow();
 107 }
 108
 109 bool WindowSelectorController::IsSelecting() {
 110   return window_selector_.get() != NULL;
 111 }
 112
 113 void WindowSelectorController::OnWindowSelected(aura::Window* window) {
 114   window_selector_.reset();
 115   wm::ActivateWindow(window);
 116 }
 117
 118 void WindowSelectorController::OnSelectionCanceled() {
 119   window_selector_.reset();
 120 }
 121
 122 }  // namespace ash