src/ash/wm/overview/window_overview.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_overview.h"
   6
   7 #include <algorithm>
   8
   9 #include "ash/screen_ash.h"
  10 #include "ash/shell.h"
  11 #include "ash/shell_delegate.h"
  12 #include "ash/shell_window_ids.h"
  13 #include "ash/wm/mru_window_tracker.h"
  14 #include "ash/wm/overview/scoped_transform_overview_window.h"
  15 #include "ash/wm/overview/window_selector.h"
  16 #include "ash/wm/overview/window_selector_item.h"
  17 #include "base/metrics/histogram.h"
  18 #include "third_party/skia/include/core/SkColor.h"
  19 #include "ui/aura/client/cursor_client.h"
  20 #include "ui/aura/root_window.h"
  21 #include "ui/aura/window.h"
  22 #include "ui/compositor/scoped_layer_animation_settings.h"
  23 #include "ui/events/event.h"
  24 #include "ui/views/widget/widget.h"
  25
  26 namespace ash {
  27
  28 namespace {
  29
  30 // Conceptually the window overview is a table or grid of cells having this
  31 // fixed aspect ratio. The number of columns is determined by maximizing the
  32 // area of them based on the number of windows.
  33 const float kCardAspectRatio = 4.0f / 3.0f;
  34
  35 // In the conceptual overview table, the window margin is the space reserved
  36 // around the window within the cell. This margin does not overlap so the
  37 // closest distance between adjacent windows will be twice this amount.
  38 const int kWindowMargin = 30;
  39
  40 // The minimum number of cards along the major axis (i.e. horizontally on a
  41 // landscape orientation).
  42 const int kMinCardsMajor = 3;
  43
  44 // The duration of transition animations on the overview selector.
  45 const int kOverviewSelectorTransitionMilliseconds = 100;
  46
  47 // The color and opacity of the overview selector.
  48 const SkColor kWindowOverviewSelectionColor = SK_ColorBLACK;
  49 const float kWindowOverviewSelectionOpacity = 0.5f;
  50
  51 // The padding or amount of the window selector widget visible around the edges
  52 // of the currently selected window.
  53 const int kWindowOverviewSelectionPadding = 25;
  54
  55 // A comparator for locating a given target window.
  56 struct WindowSelectorItemComparator
  57     : public std::unary_function<WindowSelectorItem*, bool> {
  58   explicit WindowSelectorItemComparator(const aura::Window* target_window)
  59       : target(target_window) {
  60   }
  61
  62   bool operator()(WindowSelectorItem* window) const {
  63     return window->TargetedWindow(target) != NULL;
  64   }
  65
  66   const aura::Window* target;
  67 };
  68
  69 // An observer which holds onto the passed widget until the animation is
  70 // complete.
  71 class CleanupWidgetAfterAnimationObserver : public ui::LayerAnimationObserver {
  72  public:
  73   explicit CleanupWidgetAfterAnimationObserver(
  74       scoped_ptr<views::Widget> widget);
  75
  76   // ui::LayerAnimationObserver:
  77   virtual void OnLayerAnimationEnded(
  78       ui::LayerAnimationSequence* sequence) OVERRIDE;
  79   virtual void OnLayerAnimationAborted(
  80       ui::LayerAnimationSequence* sequence) OVERRIDE;
  81   virtual void OnLayerAnimationScheduled(
  82       ui::LayerAnimationSequence* sequence) OVERRIDE;
  83
  84  private:
  85   virtual ~CleanupWidgetAfterAnimationObserver();
  86
  87   scoped_ptr<views::Widget> widget_;
  88
  89   DISALLOW_COPY_AND_ASSIGN(CleanupWidgetAfterAnimationObserver);
  90 };
  91
  92 CleanupWidgetAfterAnimationObserver::CleanupWidgetAfterAnimationObserver(
  93     scoped_ptr<views::Widget> widget)
  94     : widget_(widget.Pass()) {
  95   widget_->GetNativeWindow()->layer()->GetAnimator()->AddObserver(this);
  96 }
  97
  98 CleanupWidgetAfterAnimationObserver::~CleanupWidgetAfterAnimationObserver() {
  99   widget_->GetNativeWindow()->layer()->GetAnimator()->RemoveObserver(this);
 100 }
 101
 102 void CleanupWidgetAfterAnimationObserver::OnLayerAnimationEnded(
 103     ui::LayerAnimationSequence* sequence) {
 104   delete this;
 105 }
 106
 107 void CleanupWidgetAfterAnimationObserver::OnLayerAnimationAborted(
 108     ui::LayerAnimationSequence* sequence) {
 109   delete this;
 110 }
 111
 112 void CleanupWidgetAfterAnimationObserver::OnLayerAnimationScheduled(
 113     ui::LayerAnimationSequence* sequence) {
 114 }
 115
 116 }  // namespace
 117
 118 WindowOverview::WindowOverview(WindowSelector* window_selector,
 119                                WindowSelectorItemList* windows,
 120                                aura::Window* single_root_window)
 121     : window_selector_(window_selector),
 122       windows_(windows),
 123       selection_index_(0),
 124       single_root_window_(single_root_window),
 125       overview_start_time_(base::Time::Now()),
 126       cursor_client_(NULL) {
 127   for (WindowSelectorItemList::iterator iter = windows_->begin();
 128        iter != windows_->end(); ++iter) {
 129     (*iter)->PrepareForOverview();
 130   }
 131   PositionWindows();
 132   DCHECK(!windows_->empty());
 133   cursor_client_ = aura::client::GetCursorClient(
 134       windows_->front()->GetRootWindow());
 135   if (cursor_client_) {
 136     cursor_client_->SetCursor(ui::kCursorPointer);
 137     cursor_client_->ShowCursor();
 138     // TODO(flackr): Only prevent cursor changes for windows in the overview.
 139     // This will be easier to do without exposing the overview mode code if the
 140     // cursor changes are moved to ToplevelWindowEventHandler::HandleMouseMoved
 141     // as suggested there.
 142     cursor_client_->LockCursor();
 143   }
 144   ash::Shell::GetInstance()->PrependPreTargetHandler(this);
 145   Shell* shell = Shell::GetInstance();
 146   shell->delegate()->RecordUserMetricsAction(UMA_WINDOW_OVERVIEW);
 147   HideAndTrackNonOverviewWindows();
 148 }
 149
 150 WindowOverview::~WindowOverview() {
 151   const aura::WindowTracker::Windows hidden_windows = hidden_windows_.windows();
 152   for (aura::WindowTracker::Windows::const_iterator iter =
 153        hidden_windows.begin(); iter != hidden_windows.end(); ++iter) {
 154     ui::ScopedLayerAnimationSettings settings(
 155         (*iter)->layer()->GetAnimator());
 156     settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
 157         ScopedTransformOverviewWindow::kTransitionMilliseconds));
 158     settings.SetPreemptionStrategy(
 159         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 160     (*iter)->Show();
 161     (*iter)->layer()->SetOpacity(1);
 162   }
 163   if (cursor_client_)
 164     cursor_client_->UnlockCursor();
 165   ash::Shell::GetInstance()->RemovePreTargetHandler(this);
 166   UMA_HISTOGRAM_MEDIUM_TIMES(
 167       "Ash.WindowSelector.TimeInOverview",
 168       base::Time::Now() - overview_start_time_);
 169 }
 170
 171 void WindowOverview::SetSelection(size_t index) {
 172   gfx::Rect target_bounds(GetSelectionBounds(index));
 173
 174   if (selection_widget_) {
 175     // If the selection widget is already active, determine the animation to
 176     // use to animate the widget to the new bounds.
 177     int change = static_cast<int>(index) - static_cast<int>(selection_index_);
 178     int windows = static_cast<int>(windows_->size());
 179     // If moving from the first to the last or last to the first index,
 180     // convert the delta to be +/- 1.
 181     if (windows > 2 && abs(change) == windows - 1) {
 182       if (change < 0)
 183         change += windows;
 184       else
 185         change -= windows;
 186     }
 187     if (selection_index_ < windows_->size() &&
 188         (*windows_)[selection_index_]->target_bounds().y() !=
 189             (*windows_)[index]->target_bounds().y() &&
 190         abs(change) == 1) {
 191       // The selection has changed forward or backwards by one with a change
 192       // in the height of the target. In this case create a new selection widget
 193       // to fade in on the new position and animate and fade out the old one.
 194       gfx::Display dst_display = gfx::Screen::GetScreenFor(
 195           selection_widget_->GetNativeWindow())->GetDisplayMatching(
 196               target_bounds);
 197       gfx::Vector2d fade_out_direction(
 198           change * ((*windows_)[selection_index_]->target_bounds().width() +
 199                     2 * kWindowMargin), 0);
 200       aura::Window* old_selection = selection_widget_->GetNativeWindow();
 201
 202       // CleanupWidgetAfterAnimationObserver will delete itself (and the
 203       // widget) when the animation is complete.
 204       new CleanupWidgetAfterAnimationObserver(selection_widget_.Pass());
 205       ui::ScopedLayerAnimationSettings animation_settings(
 206           old_selection->layer()->GetAnimator());
 207       animation_settings.SetTransitionDuration(
 208           base::TimeDelta::FromMilliseconds(
 209               kOverviewSelectorTransitionMilliseconds));
 210       animation_settings.SetPreemptionStrategy(
 211           ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 212       old_selection->SetBoundsInScreen(
 213           GetSelectionBounds(selection_index_) + fade_out_direction,
 214           dst_display);
 215       old_selection->layer()->SetOpacity(0);
 216       InitializeSelectionWidget();
 217       selection_widget_->GetNativeWindow()->SetBoundsInScreen(
 218           target_bounds - fade_out_direction, dst_display);
 219     }
 220     ui::ScopedLayerAnimationSettings animation_settings(
 221         selection_widget_->GetNativeWindow()->layer()->GetAnimator());
 222     animation_settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
 223         kOverviewSelectorTransitionMilliseconds));
 224     animation_settings.SetPreemptionStrategy(
 225         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 226     selection_widget_->SetBounds(target_bounds);
 227     selection_widget_->GetNativeWindow()->layer()->SetOpacity(
 228         kWindowOverviewSelectionOpacity);
 229   } else {
 230     InitializeSelectionWidget();
 231     selection_widget_->SetBounds(target_bounds);
 232     selection_widget_->GetNativeWindow()->layer()->SetOpacity(
 233         kWindowOverviewSelectionOpacity);
 234   }
 235   selection_index_ = index;
 236 }
 237
 238 void WindowOverview::OnWindowsChanged() {
 239   PositionWindows();
 240 }
 241
 242 void WindowOverview::MoveToSingleRootWindow(aura::Window* root_window) {
 243   single_root_window_ = root_window;
 244   PositionWindows();
 245 }
 246
 247 void WindowOverview::OnKeyEvent(ui::KeyEvent* event) {
 248   if (GetTargetedWindow(static_cast<aura::Window*>(event->target())))
 249     event->StopPropagation();
 250   if (event->type() != ui::ET_KEY_PRESSED)
 251     return;
 252
 253   if (event->key_code() == ui::VKEY_ESCAPE)
 254     window_selector_->CancelSelection();
 255 }
 256
 257 void WindowOverview::OnMouseEvent(ui::MouseEvent* event) {
 258   aura::Window* target = GetEventTarget(event);
 259   if (!target)
 260     return;
 261
 262   event->StopPropagation();
 263   if (event->type() != ui::ET_MOUSE_RELEASED)
 264     return;
 265
 266   window_selector_->SelectWindow(target);
 267 }
 268
 269 void WindowOverview::OnScrollEvent(ui::ScrollEvent* event) {
 270   // Set the handled flag to prevent delivering scroll events to the window but
 271   // still allowing other pretarget handlers to process the scroll event.
 272   if (GetTargetedWindow(static_cast<aura::Window*>(event->target())))
 273     event->SetHandled();
 274 }
 275
 276 void WindowOverview::OnTouchEvent(ui::TouchEvent* event) {
 277   // Existing touches should be allowed to continue. This prevents getting
 278   // stuck in a gesture or with pressed fingers being tracked elsewhere.
 279   if (event->type() != ui::ET_TOUCH_PRESSED)
 280     return;
 281
 282   aura::Window* target = GetEventTarget(event);
 283   if (!target)
 284     return;
 285
 286   // TODO(flackr): StopPropogation prevents generation of gesture events.
 287   // We should find a better way to prevent events from being delivered to
 288   // the window, perhaps a transparent window in front of the target window
 289   // or using EventClientImpl::CanProcessEventsWithinSubtree and then a tap
 290   // gesture could be used to activate the window.
 291   event->SetHandled();
 292   window_selector_->SelectWindow(target);
 293 }
 294
 295 aura::Window* WindowOverview::GetEventTarget(ui::LocatedEvent* event) {
 296   aura::Window* target = static_cast<aura::Window*>(event->target());
 297   // If the target window doesn't actually contain the event location (i.e.
 298   // mouse down over the window and mouse up elsewhere) then do not select the
 299   // window.
 300   if (!target->HitTest(event->location()))
 301     return NULL;
 302
 303   return GetTargetedWindow(target);
 304 }
 305
 306 aura::Window* WindowOverview::GetTargetedWindow(aura::Window* window) {
 307   for (WindowSelectorItemList::iterator iter = windows_->begin();
 308        iter != windows_->end(); ++iter) {
 309     aura::Window* selected = (*iter)->TargetedWindow(window);
 310     if (selected)
 311       return selected;
 312   }
 313   return NULL;
 314 }
 315
 316 void WindowOverview::HideAndTrackNonOverviewWindows() {
 317   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
 318   for (Shell::RootWindowList::const_iterator root_iter = root_windows.begin();
 319        root_iter != root_windows.end(); ++root_iter) {
 320     for (size_t i = 0; i < kSwitchableWindowContainerIdsLength; ++i) {
 321       aura::Window* container = Shell::GetContainer(*root_iter,
 322           kSwitchableWindowContainerIds[i]);
 323       // Copy the children list as it can change during iteration.
 324       aura::Window::Windows children(container->children());
 325       for (aura::Window::Windows::const_iterator iter = children.begin();
 326            iter != children.end(); ++iter) {
 327         if (GetTargetedWindow(*iter) || !(*iter)->IsVisible())
 328           continue;
 329         ui::ScopedLayerAnimationSettings settings(
 330             (*iter)->layer()->GetAnimator());
 331         settings.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
 332             ScopedTransformOverviewWindow::kTransitionMilliseconds));
 333         settings.SetPreemptionStrategy(
 334             ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 335         (*iter)->Hide();
 336         (*iter)->layer()->SetOpacity(0);
 337         hidden_windows_.Add(*iter);
 338       }
 339     }
 340   }
 341 }
 342
 343 void WindowOverview::PositionWindows() {
 344   if (single_root_window_) {
 345     std::vector<WindowSelectorItem*> windows;
 346     for (WindowSelectorItemList::iterator iter = windows_->begin();
 347          iter != windows_->end(); ++iter) {
 348       windows.push_back(*iter);
 349     }
 350     PositionWindowsOnRoot(single_root_window_, windows);
 351   } else {
 352     Shell::RootWindowList root_window_list = Shell::GetAllRootWindows();
 353     for (size_t i = 0; i < root_window_list.size(); ++i)
 354       PositionWindowsFromRoot(root_window_list[i]);
 355   }
 356 }
 357
 358 void WindowOverview::PositionWindowsFromRoot(aura::Window* root_window) {
 359   std::vector<WindowSelectorItem*> windows;
 360   for (WindowSelectorItemList::iterator iter = windows_->begin();
 361        iter != windows_->end(); ++iter) {
 362     if ((*iter)->GetRootWindow() == root_window)
 363       windows.push_back(*iter);
 364   }
 365   PositionWindowsOnRoot(root_window, windows);
 366 }
 367
 368 void WindowOverview::PositionWindowsOnRoot(
 369     aura::Window* root_window,
 370     const std::vector<WindowSelectorItem*>& windows) {
 371   if (windows.empty())
 372     return;
 373
 374   gfx::Size window_size;
 375   gfx::Rect total_bounds = ScreenAsh::ConvertRectToScreen(root_window,
 376       ScreenAsh::GetDisplayWorkAreaBoundsInParent(
 377       Shell::GetContainer(root_window,
 378                           internal::kShellWindowId_DefaultContainer)));
 379
 380   // Find the minimum number of windows per row that will fit all of the
 381   // windows on screen.
 382   size_t columns = std::max(
 383       total_bounds.width() > total_bounds.height() ? kMinCardsMajor : 1,
 384       static_cast<int>(ceil(sqrt(total_bounds.width() * windows.size() /
 385                                  (kCardAspectRatio * total_bounds.height())))));
 386   size_t rows = ((windows.size() + columns - 1) / columns);
 387   window_size.set_width(std::min(
 388       static_cast<int>(total_bounds.width() / columns),
 389       static_cast<int>(total_bounds.height() * kCardAspectRatio / rows)));
 390   window_size.set_height(window_size.width() / kCardAspectRatio);
 391
 392   // Calculate the X and Y offsets necessary to center the grid.
 393   int x_offset = total_bounds.x() + ((windows.size() >= columns ? 0 :
 394       (columns - windows.size()) * window_size.width()) +
 395       (total_bounds.width() - columns * window_size.width())) / 2;
 396   int y_offset = total_bounds.y() + (total_bounds.height() -
 397       rows * window_size.height()) / 2;
 398   for (size_t i = 0; i < windows.size(); ++i) {
 399     gfx::Transform transform;
 400     int column = i % columns;
 401     int row = i / columns;
 402     gfx::Rect target_bounds(window_size.width() * column + x_offset,
 403                             window_size.height() * row + y_offset,
 404                             window_size.width(),
 405                             window_size.height());
 406     target_bounds.Inset(kWindowMargin, kWindowMargin);
 407     windows[i]->SetBounds(root_window, target_bounds);
 408   }
 409 }
 410
 411 void WindowOverview::InitializeSelectionWidget() {
 412   selection_widget_.reset(new views::Widget);
 413   views::Widget::InitParams params;
 414   params.type = views::Widget::InitParams::TYPE_POPUP;
 415   params.can_activate = false;
 416   params.keep_on_top = false;
 417   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
 418   params.opacity = views::Widget::InitParams::OPAQUE_WINDOW;
 419   params.parent = Shell::GetContainer(
 420       single_root_window_ ? single_root_window_ :
 421                             windows_->front()->GetRootWindow(),
 422       internal::kShellWindowId_DefaultContainer);
 423   params.accept_events = false;
 424   selection_widget_->set_focus_on_creation(false);
 425   selection_widget_->Init(params);
 426   views::View* content_view = new views::View;
 427   content_view->set_background(
 428       views::Background::CreateSolidBackground(kWindowOverviewSelectionColor));
 429   selection_widget_->SetContentsView(content_view);
 430   selection_widget_->Show();
 431   selection_widget_->GetNativeWindow()->parent()->StackChildAtBottom(
 432       selection_widget_->GetNativeWindow());
 433   selection_widget_->GetNativeWindow()->layer()->SetOpacity(0);
 434 }
 435
 436 gfx::Rect WindowOverview::GetSelectionBounds(size_t index) {
 437   gfx::Rect bounds((*windows_)[index]->bounds());
 438   bounds.Inset(-kWindowOverviewSelectionPadding,
 439                -kWindowOverviewSelectionPadding);
 440   return bounds;
 441 }
 442
 443 }  // namespace ash