ash/wm/overview/window_selector.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/overview/window_selector.h"
   6
   7 #include <algorithm>
   8 #include <functional>
   9 #include <set>
  10 #include <vector>
  11
  12 #include "ash/accessibility_delegate.h"
  13 #include "ash/ash_switches.h"
  14 #include "ash/metrics/user_metrics_recorder.h"
  15 #include "ash/root_window_controller.h"
  16 #include "ash/shell.h"
  17 #include "ash/shell_window_ids.h"
  18 #include "ash/switchable_windows.h"
  19 #include "ash/wm/overview/scoped_overview_animation_settings.h"
  20 #include "ash/wm/overview/scoped_transform_overview_window.h"
  21 #include "ash/wm/overview/window_grid.h"
  22 #include "ash/wm/overview/window_selector_delegate.h"
  23 #include "ash/wm/overview/window_selector_item.h"
  24 #include "ash/wm/panels/panel_layout_manager.h"
  25 #include "ash/wm/window_state.h"
  26 #include "base/auto_reset.h"
  27 #include "base/command_line.h"
  28 #include "base/metrics/histogram.h"
  29 #include "third_party/skia/include/core/SkPaint.h"
  30 #include "third_party/skia/include/core/SkPath.h"
  31 #include "ui/aura/client/focus_client.h"
  32 #include "ui/aura/window.h"
  33 #include "ui/aura/window_event_dispatcher.h"
  34 #include "ui/aura/window_observer.h"
  35 #include "ui/base/resource/resource_bundle.h"
  36 #include "ui/compositor/scoped_layer_animation_settings.h"
  37 #include "ui/events/event.h"
  38 #include "ui/gfx/canvas.h"
  39 #include "ui/gfx/screen.h"
  40 #include "ui/gfx/skia_util.h"
  41 #include "ui/views/border.h"
  42 #include "ui/views/controls/textfield/textfield.h"
  43 #include "ui/views/layout/box_layout.h"
  44 #include "ui/wm/core/window_util.h"
  45 #include "ui/wm/public/activation_client.h"
  46
  47 namespace ash {
  48
  49 namespace {
  50
  51 // The proportion of screen width that the text filter takes.
  52 const float kTextFilterScreenProportion = 0.25;
  53
  54 // The amount of padding surrounding the text in the text filtering textbox.
  55 const int kTextFilterHorizontalPadding = 8;
  56
  57 // The distance between the top of the screen and the top edge of the
  58 // text filtering textbox.
  59 const int kTextFilterDistanceFromTop = 32;
  60
  61 // The height of the text filtering textbox.
  62 const int kTextFilterHeight = 32;
  63
  64 // The font style used for text filtering.
  65 static const ::ui::ResourceBundle::FontStyle kTextFilterFontStyle =
  66     ::ui::ResourceBundle::FontStyle::MediumFont;
  67
  68 // The alpha value for the background of the text filtering textbox.
  69 const unsigned char kTextFilterOpacity = 180;
  70
  71 // The radius used for the rounded corners on the text filtering textbox.
  72 const int kTextFilterCornerRadius = 1;
  73
  74 // A comparator for locating a grid with a given root window.
  75 struct RootWindowGridComparator
  76     : public std::unary_function<WindowGrid*, bool> {
  77   explicit RootWindowGridComparator(const aura::Window* root_window)
  78       : root_window_(root_window) {
  79   }
  80
  81   bool operator()(WindowGrid* grid) const {
  82     return (grid->root_window() == root_window_);
  83   }
  84
  85   const aura::Window* root_window_;
  86 };
  87
  88 // A comparator for locating a selectable window given a targeted window.
  89 struct WindowSelectorItemTargetComparator
  90     : public std::unary_function<WindowSelectorItem*, bool> {
  91   explicit WindowSelectorItemTargetComparator(const aura::Window* target_window)
  92       : target(target_window) {
  93   }
  94
  95   bool operator()(WindowSelectorItem* window) const {
  96     return window->GetWindow() == target;
  97   }
  98
  99   const aura::Window* target;
 100 };
 101
 102 // A comparator for locating a selector item for a given root.
 103 struct WindowSelectorItemForRoot
 104     : public std::unary_function<WindowSelectorItem*, bool> {
 105   explicit WindowSelectorItemForRoot(const aura::Window* root)
 106       : root_window(root) {
 107   }
 108
 109   bool operator()(WindowSelectorItem* item) const {
 110     return item->root_window() == root_window;
 111   }
 112
 113   const aura::Window* root_window;
 114 };
 115
 116 // A View having rounded corners and a specified background color which is
 117 // only painted within the bounds defined by the rounded corners.
 118 // TODO(tdanderson): This duplicates code from RoundedImageView. Refactor these
 119 //                   classes and move into ui/views.
 120 class RoundedContainerView : public views::View {
 121  public:
 122   RoundedContainerView(int corner_radius, SkColor background)
 123       : corner_radius_(corner_radius),
 124         background_(background) {
 125   }
 126
 127   ~RoundedContainerView() override {}
 128
 129   void OnPaint(gfx::Canvas* canvas) override {
 130     views::View::OnPaint(canvas);
 131
 132     SkScalar radius = SkIntToScalar(corner_radius_);
 133     const SkScalar kRadius[8] = {radius, radius, radius, radius,
 134                                  radius, radius, radius, radius};
 135     SkPath path;
 136     gfx::Rect bounds(size());
 137     path.addRoundRect(gfx::RectToSkRect(bounds), kRadius);
 138
 139     SkPaint paint;
 140     paint.setAntiAlias(true);
 141     canvas->ClipPath(path, true);
 142     canvas->DrawColor(background_);
 143   }
 144
 145  private:
 146   int corner_radius_;
 147   SkColor background_;
 148
 149   DISALLOW_COPY_AND_ASSIGN(RoundedContainerView);
 150 };
 151
 152 // Triggers a shelf visibility update on all root window controllers.
 153 void UpdateShelfVisibility() {
 154   Shell::RootWindowControllerList root_window_controllers =
 155       Shell::GetInstance()->GetAllRootWindowControllers();
 156   for (Shell::RootWindowControllerList::iterator iter =
 157           root_window_controllers.begin();
 158        iter != root_window_controllers.end(); ++iter) {
 159     (*iter)->UpdateShelfVisibility();
 160   }
 161 }
 162
 163 // Initializes the text filter on the top of the main root window and requests
 164 // focus on its textfield.
 165 views::Widget* CreateTextFilter(views::TextfieldController* controller,
 166                                 aura::Window* root_window) {
 167   views::Widget* widget = new views::Widget;
 168   views::Widget::InitParams params;
 169   params.type = views::Widget::InitParams::TYPE_WINDOW_FRAMELESS;
 170   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
 171   params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
 172   params.parent = Shell::GetContainer(root_window,
 173                                       kShellWindowId_OverlayContainer);
 174   params.accept_events = true;
 175   params.bounds = gfx::Rect(
 176       root_window->bounds().width() / 2 * (1 - kTextFilterScreenProportion),
 177       kTextFilterDistanceFromTop,
 178       root_window->bounds().width() * kTextFilterScreenProportion,
 179       kTextFilterHeight);
 180   widget->Init(params);
 181
 182   // Use |container| to specify the padding surrounding the text and to give
 183   // the textfield rounded corners.
 184   views::View* container = new RoundedContainerView(
 185       kTextFilterCornerRadius, SkColorSetARGB(kTextFilterOpacity, 0, 0, 0));
 186   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
 187   int text_height = bundle.GetFontList(kTextFilterFontStyle).GetHeight();
 188   DCHECK(text_height);
 189   int vertical_padding = (kTextFilterHeight - text_height) / 2;
 190   container->SetLayoutManager(new views::BoxLayout(views::BoxLayout::kVertical,
 191                                                    kTextFilterHorizontalPadding,
 192                                                    vertical_padding,
 193                                                    0));
 194
 195   views::Textfield* textfield = new views::Textfield;
 196   textfield->set_controller(controller);
 197   textfield->SetBackgroundColor(SK_ColorTRANSPARENT);
 198   textfield->SetBorder(views::Border::NullBorder());
 199   textfield->SetTextColor(SK_ColorWHITE);
 200   textfield->SetFontList(bundle.GetFontList(kTextFilterFontStyle));
 201
 202   container->AddChildView(textfield);
 203   widget->SetContentsView(container);
 204
 205   // The textfield initially contains no text, so shift its position to be
 206   // outside the visible bounds of the screen.
 207   gfx::Transform transform;
 208   transform.Translate(0, -WindowSelector::kTextFilterBottomEdge);
 209   widget->GetNativeWindow()->SetTransform(transform);
 210   widget->Show();
 211   textfield->RequestFocus();
 212
 213   return widget;
 214 }
 215
 216 }  // namespace
 217
 218 const int WindowSelector::kTextFilterBottomEdge =
 219     kTextFilterDistanceFromTop + kTextFilterHeight;
 220
 221 WindowSelector::WindowSelector(WindowSelectorDelegate* delegate)
 222     : delegate_(delegate),
 223       restore_focus_window_(aura::client::GetFocusClient(
 224           Shell::GetPrimaryRootWindow())->GetFocusedWindow()),
 225       ignore_activations_(false),
 226       selected_grid_index_(0),
 227       overview_start_time_(base::Time::Now()),
 228       num_key_presses_(0),
 229       num_items_(0),
 230       showing_selection_widget_(false),
 231       text_filter_string_length_(0),
 232       num_times_textfield_cleared_(0),
 233       restoring_minimized_windows_(false) {
 234   DCHECK(delegate_);
 235 }
 236
 237 WindowSelector::~WindowSelector() {
 238   RemoveAllObservers();
 239 }
 240
 241 // NOTE: The work done in Init() is not done in the constructor because it may
 242 // cause other, unrelated classes, (ie PanelLayoutManager) to make indirect
 243 // calls to restoring_minimized_windows() on a partially constructed object.
 244 void WindowSelector::Init(const WindowList& windows) {
 245   if (restore_focus_window_)
 246     restore_focus_window_->AddObserver(this);
 247
 248   const aura::Window::Windows root_windows = Shell::GetAllRootWindows();
 249   for (aura::Window::Windows::const_iterator iter = root_windows.begin();
 250        iter != root_windows.end(); iter++) {
 251     // Observed switchable containers for newly created windows on all root
 252     // windows.
 253     for (size_t i = 0; i < kSwitchableWindowContainerIdsLength; ++i) {
 254       aura::Window* container = Shell::GetContainer(*iter,
 255           kSwitchableWindowContainerIds[i]);
 256       container->AddObserver(this);
 257       observed_windows_.insert(container);
 258     }
 259
 260     // Hide the callout widgets for panels. It is safe to call this for
 261     // root windows that don't contain any panel windows.
 262     static_cast<PanelLayoutManager*>(
 263         Shell::GetContainer(*iter, kShellWindowId_PanelContainer)
 264             ->layout_manager())->SetShowCalloutWidgets(false);
 265
 266     scoped_ptr<WindowGrid> grid(new WindowGrid(*iter, windows, this));
 267     if (grid->empty())
 268       continue;
 269     num_items_ += grid->size();
 270     grid_list_.push_back(grid.release());
 271   }
 272
 273   {
 274     // The calls to WindowGrid::PrepareForOverview() and CreateTextFilter(...)
 275     // requires some LayoutManagers (ie PanelLayoutManager) to perform layouts
 276     // so that windows are correctly visible and properly animated in overview
 277     // mode. Otherwise these layouts should be suppressed during overview mode
 278     // so they don't conflict with overview mode animations. The
 279     // |restoring_minimized_windows_| flag enables the PanelLayoutManager to
 280     // make this decision.
 281     base::AutoReset<bool> auto_restoring_minimized_windows(
 282         &restoring_minimized_windows_, true);
 283
 284     // Do not call PrepareForOverview until all items are added to window_list_
 285     // as we don't want to cause any window updates until all windows in
 286     // overview are observed. See http://crbug.com/384495.
 287     for (WindowGrid* window_grid : grid_list_) {
 288       window_grid->PrepareForOverview();
 289       window_grid->PositionWindows(true);
 290     }
 291
 292     text_filter_widget_.reset(
 293         CreateTextFilter(this, Shell::GetPrimaryRootWindow()));
 294   }
 295
 296   DCHECK(!grid_list_.empty());
 297   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.Items", num_items_);
 298
 299   Shell* shell = Shell::GetInstance();
 300
 301   shell->activation_client()->AddObserver(this);
 302
 303   shell->GetScreen()->AddObserver(this);
 304   shell->metrics()->RecordUserMetricsAction(UMA_WINDOW_OVERVIEW);
 305   HideAndTrackNonOverviewWindows();
 306   // Send an a11y alert.
 307   shell->accessibility_delegate()->TriggerAccessibilityAlert(
 308       ui::A11Y_ALERT_WINDOW_OVERVIEW_MODE_ENTERED);
 309
 310   UpdateShelfVisibility();
 311 }
 312
 313 // NOTE: The work done in Shutdown() is not done in the destructor because it
 314 // may cause other, unrelated classes, (ie PanelLayoutManager) to make indirect
 315 // calls to restoring_minimized_windows() on a partially destructed object.
 316 void WindowSelector::Shutdown() {
 317   ResetFocusRestoreWindow(true);
 318   RemoveAllObservers();
 319
 320   aura::Window::Windows root_windows = Shell::GetAllRootWindows();
 321   for (aura::Window::Windows::const_iterator iter = root_windows.begin();
 322        iter != root_windows.end(); iter++) {
 323     // Un-hide the callout widgets for panels. It is safe to call this for
 324     // root_windows that don't contain any panel windows.
 325     static_cast<PanelLayoutManager*>(
 326         Shell::GetContainer(*iter, kShellWindowId_PanelContainer)
 327             ->layout_manager())->SetShowCalloutWidgets(true);
 328   }
 329
 330   const aura::WindowTracker::Windows hidden_windows(hidden_windows_.windows());
 331   for (aura::WindowTracker::Windows::const_iterator iter =
 332        hidden_windows.begin(); iter != hidden_windows.end(); ++iter) {
 333     ScopedOverviewAnimationSettings animation_settings(
 334         OverviewAnimationType::OVERVIEW_ANIMATION_LAY_OUT_SELECTOR_ITEMS,
 335         *iter);
 336     (*iter)->layer()->SetOpacity(1);
 337     (*iter)->Show();
 338   }
 339
 340   size_t remaining_items = 0;
 341   for (WindowGrid* window_grid : grid_list_) {
 342     for (WindowSelectorItem* window_selector_item : window_grid->window_list())
 343       window_selector_item->RestoreWindow();
 344     remaining_items += window_grid->size();
 345   }
 346
 347   DCHECK(num_items_ >= remaining_items);
 348   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.OverviewClosedItems",
 349                            num_items_ - remaining_items);
 350   UMA_HISTOGRAM_MEDIUM_TIMES("Ash.WindowSelector.TimeInOverview",
 351                              base::Time::Now() - overview_start_time_);
 352
 353   // Record metrics related to text filtering.
 354   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.TextFilteringStringLength",
 355                            text_filter_string_length_);
 356   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.TextFilteringTextfieldCleared",
 357                            num_times_textfield_cleared_);
 358   if (text_filter_string_length_) {
 359     UMA_HISTOGRAM_MEDIUM_TIMES(
 360         "Ash.WindowSelector.TimeInOverviewWithTextFiltering",
 361         base::Time::Now() - overview_start_time_);
 362     UMA_HISTOGRAM_COUNTS_100(
 363         "Ash.WindowSelector.ItemsWhenTextFilteringUsed",
 364         remaining_items);
 365   }
 366
 367   // Clearing the window list resets the ignored_by_shelf flag on the windows.
 368   grid_list_.clear();
 369   UpdateShelfVisibility();
 370 }
 371
 372 void WindowSelector::RemoveAllObservers() {
 373   Shell* shell = Shell::GetInstance();
 374   for (aura::Window* window : observed_windows_)
 375     window->RemoveObserver(this);
 376
 377   shell->activation_client()->RemoveObserver(this);
 378   shell->GetScreen()->RemoveObserver(this);
 379   if (restore_focus_window_)
 380     restore_focus_window_->RemoveObserver(this);
 381 }
 382
 383 void WindowSelector::CancelSelection() {
 384   delegate_->OnSelectionEnded();
 385 }
 386
 387 void WindowSelector::OnGridEmpty(WindowGrid* grid) {
 388   ScopedVector<WindowGrid>::iterator iter =
 389       std::find(grid_list_.begin(), grid_list_.end(), grid);
 390   DCHECK(iter != grid_list_.end());
 391   grid_list_.erase(iter);
 392   // TODO(flackr): Use the previous index for more than two displays.
 393   selected_grid_index_ = 0;
 394   if (grid_list_.empty())
 395     CancelSelection();
 396 }
 397
 398 bool WindowSelector::HandleKeyEvent(views::Textfield* sender,
 399                                     const ui::KeyEvent& key_event) {
 400   if (key_event.type() != ui::ET_KEY_PRESSED)
 401     return false;
 402
 403   switch (key_event.key_code()) {
 404     case ui::VKEY_ESCAPE:
 405       CancelSelection();
 406       break;
 407     case ui::VKEY_UP:
 408       num_key_presses_++;
 409       Move(WindowSelector::UP, true);
 410       break;
 411     case ui::VKEY_DOWN:
 412       num_key_presses_++;
 413       Move(WindowSelector::DOWN, true);
 414       break;
 415     case ui::VKEY_RIGHT:
 416     case ui::VKEY_TAB:
 417       num_key_presses_++;
 418       Move(WindowSelector::RIGHT, true);
 419       break;
 420     case ui::VKEY_LEFT:
 421       num_key_presses_++;
 422       Move(WindowSelector::LEFT, true);
 423       break;
 424     case ui::VKEY_RETURN:
 425       // Ignore if no item is selected.
 426       if (!grid_list_[selected_grid_index_]->is_selecting())
 427         return false;
 428       UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.ArrowKeyPresses",
 429                                num_key_presses_);
 430       UMA_HISTOGRAM_CUSTOM_COUNTS(
 431           "Ash.WindowSelector.KeyPressesOverItemsRatio",
 432           (num_key_presses_ * 100) / num_items_, 1, 300, 30);
 433       Shell::GetInstance()->metrics()->RecordUserMetricsAction(
 434           UMA_WINDOW_OVERVIEW_ENTER_KEY);
 435       wm::GetWindowState(grid_list_[selected_grid_index_]->
 436                          SelectedWindow()->GetWindow())->Activate();
 437       break;
 438     default:
 439       // Not a key we are interested in, allow the textfield to handle it.
 440       return false;
 441   }
 442   return true;
 443 }
 444
 445 void WindowSelector::OnDisplayAdded(const gfx::Display& display) {
 446 }
 447
 448 void WindowSelector::OnDisplayRemoved(const gfx::Display& display) {
 449   // TODO(flackr): Keep window selection active on remaining displays.
 450   CancelSelection();
 451 }
 452
 453 void WindowSelector::OnDisplayMetricsChanged(const gfx::Display& display,
 454                                              uint32_t metrics) {
 455   PositionWindows(/* animate */ false);
 456 }
 457
 458 void WindowSelector::OnWindowAdded(aura::Window* new_window) {
 459   if (new_window->type() != ui::wm::WINDOW_TYPE_NORMAL &&
 460       new_window->type() != ui::wm::WINDOW_TYPE_PANEL) {
 461     return;
 462   }
 463
 464   for (size_t i = 0; i < kSwitchableWindowContainerIdsLength; ++i) {
 465     if (new_window->parent()->id() == kSwitchableWindowContainerIds[i] &&
 466         !::wm::GetTransientParent(new_window)) {
 467       // The new window is in one of the switchable containers, abort overview.
 468       CancelSelection();
 469       return;
 470     }
 471   }
 472 }
 473
 474 void WindowSelector::OnWindowDestroying(aura::Window* window) {
 475   window->RemoveObserver(this);
 476   observed_windows_.erase(window);
 477   if (window == restore_focus_window_)
 478     restore_focus_window_ = nullptr;
 479 }
 480
 481 void WindowSelector::OnWindowActivated(aura::Window* gained_active,
 482                                        aura::Window* lost_active) {
 483   if (ignore_activations_ ||
 484       !gained_active ||
 485       gained_active == text_filter_widget_->GetNativeWindow()) {
 486     return;
 487   }
 488
 489   ScopedVector<WindowGrid>::iterator grid =
 490       std::find_if(grid_list_.begin(), grid_list_.end(),
 491                    RootWindowGridComparator(gained_active->GetRootWindow()));
 492   if (grid == grid_list_.end())
 493     return;
 494   const std::vector<WindowSelectorItem*> windows = (*grid)->window_list();
 495
 496   ScopedVector<WindowSelectorItem>::const_iterator iter = std::find_if(
 497       windows.begin(), windows.end(),
 498       WindowSelectorItemTargetComparator(gained_active));
 499
 500   if (iter != windows.end())
 501     (*iter)->ShowWindowOnExit();
 502
 503   // Don't restore focus on exit if a window was just activated.
 504   ResetFocusRestoreWindow(false);
 505   CancelSelection();
 506 }
 507
 508 void WindowSelector::OnAttemptToReactivateWindow(aura::Window* request_active,
 509                                                  aura::Window* actual_active) {
 510   OnWindowActivated(request_active, actual_active);
 511 }
 512
 513 void WindowSelector::ContentsChanged(views::Textfield* sender,
 514                                      const base::string16& new_contents) {
 515   text_filter_string_length_ = new_contents.length();
 516   if (!text_filter_string_length_)
 517     num_times_textfield_cleared_++;
 518
 519   bool should_show_selection_widget = !new_contents.empty();
 520   if (showing_selection_widget_ != should_show_selection_widget) {
 521     ui::ScopedLayerAnimationSettings animation_settings(
 522         text_filter_widget_->GetNativeWindow()->layer()->GetAnimator());
 523     animation_settings.SetPreemptionStrategy(
 524         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 525     animation_settings.SetTweenType(showing_selection_widget_ ?
 526         gfx::Tween::FAST_OUT_LINEAR_IN : gfx::Tween::LINEAR_OUT_SLOW_IN);
 527
 528     gfx::Transform transform;
 529     if (should_show_selection_widget) {
 530       transform.Translate(0, 0);
 531       text_filter_widget_->GetNativeWindow()->layer()->SetOpacity(1);
 532     } else {
 533       transform.Translate(0, -kTextFilterBottomEdge);
 534       text_filter_widget_->GetNativeWindow()->layer()->SetOpacity(0);
 535     }
 536
 537     text_filter_widget_->GetNativeWindow()->SetTransform(transform);
 538     showing_selection_widget_ = should_show_selection_widget;
 539   }
 540   for (ScopedVector<WindowGrid>::iterator iter = grid_list_.begin();
 541        iter != grid_list_.end(); iter++) {
 542     (*iter)->FilterItems(new_contents);
 543   }
 544
 545   // If the selection widget is not active, execute a Move() command so that it
 546   // shows up on the first undimmed item.
 547   if (grid_list_[selected_grid_index_]->is_selecting())
 548     return;
 549   Move(WindowSelector::RIGHT, false);
 550 }
 551
 552 void WindowSelector::PositionWindows(bool animate) {
 553   for (ScopedVector<WindowGrid>::iterator iter = grid_list_.begin();
 554       iter != grid_list_.end(); iter++) {
 555     (*iter)->PositionWindows(animate);
 556   }
 557 }
 558
 559 void WindowSelector::HideAndTrackNonOverviewWindows() {
 560   // Add the windows to hidden_windows first so that if any are destroyed
 561   // while hiding them they are tracked.
 562   for (ScopedVector<WindowGrid>::iterator grid_iter = grid_list_.begin();
 563       grid_iter != grid_list_.end(); ++grid_iter) {
 564     for (size_t i = 0; i < kSwitchableWindowContainerIdsLength; ++i) {
 565       const aura::Window* container =
 566           Shell::GetContainer((*grid_iter)->root_window(),
 567                               kSwitchableWindowContainerIds[i]);
 568       for (aura::Window::Windows::const_iterator iter =
 569            container->children().begin(); iter != container->children().end();
 570            ++iter) {
 571         if (!(*iter)->IsVisible() || (*grid_iter)->Contains(*iter))
 572           continue;
 573         hidden_windows_.Add(*iter);
 574       }
 575     }
 576   }
 577
 578   // Copy the window list as it can change during iteration.
 579   const aura::WindowTracker::Windows hidden_windows(hidden_windows_.windows());
 580   for (aura::WindowTracker::Windows::const_iterator iter =
 581        hidden_windows.begin(); iter != hidden_windows.end(); ++iter) {
 582     if (!hidden_windows_.Contains(*iter))
 583       continue;
 584     ScopedOverviewAnimationSettings animation_settings(
 585         OverviewAnimationType::OVERVIEW_ANIMATION_HIDE_WINDOW,
 586         *iter);
 587     (*iter)->Hide();
 588     // Hiding the window can result in it being destroyed.
 589     if (!hidden_windows_.Contains(*iter))
 590       continue;
 591     (*iter)->layer()->SetOpacity(0);
 592   }
 593 }
 594
 595 void WindowSelector::ResetFocusRestoreWindow(bool focus) {
 596   if (!restore_focus_window_)
 597     return;
 598   if (focus) {
 599     base::AutoReset<bool> restoring_focus(&ignore_activations_, true);
 600     restore_focus_window_->Focus();
 601   }
 602   // If the window is in the observed_windows_ list it needs to continue to be
 603   // observed.
 604   if (observed_windows_.find(restore_focus_window_) ==
 605           observed_windows_.end()) {
 606     restore_focus_window_->RemoveObserver(this);
 607   }
 608   restore_focus_window_ = nullptr;
 609 }
 610
 611 void WindowSelector::Move(Direction direction, bool animate) {
 612   // Keep calling Move() on the grids until one of them reports no overflow or
 613   // we made a full cycle on all the grids.
 614   for (size_t i = 0;
 615       i <= grid_list_.size() &&
 616       grid_list_[selected_grid_index_]->Move(direction, animate); i++) {
 617     // TODO(flackr): If there are more than two monitors, move between grids
 618     // in the requested direction.
 619     selected_grid_index_ = (selected_grid_index_ + 1) % grid_list_.size();
 620   }
 621 }
 622
 623 }  // namespace ash