ash/wm/window_animations.cc

   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 #include "ash/wm/window_animations.h"
   6
   7 #include <math.h>
   8
   9 #include <algorithm>
  10 #include <vector>
  11
  12 #include "ash/launcher/launcher.h"
  13 #include "ash/screen_ash.h"
  14 #include "ash/shelf/shelf_layout_manager.h"
  15 #include "ash/shelf/shelf_widget.h"
  16 #include "ash/shell.h"
  17 #include "ash/wm/window_util.h"
  18 #include "ash/wm/workspace_controller.h"
  19 #include "base/command_line.h"
  20 #include "base/compiler_specific.h"
  21 #include "base/logging.h"
  22 #include "base/message_loop/message_loop.h"
  23 #include "base/stl_util.h"
  24 #include "base/time/time.h"
  25 #include "ui/aura/client/aura_constants.h"
  26 #include "ui/aura/window.h"
  27 #include "ui/aura/window_observer.h"
  28 #include "ui/aura/window_property.h"
  29 #include "ui/compositor/compositor_observer.h"
  30 #include "ui/compositor/layer.h"
  31 #include "ui/compositor/layer_animation_observer.h"
  32 #include "ui/compositor/layer_animation_sequence.h"
  33 #include "ui/compositor/layer_animator.h"
  34 #include "ui/compositor/scoped_layer_animation_settings.h"
  35 #include "ui/gfx/interpolated_transform.h"
  36 #include "ui/gfx/screen.h"
  37 #include "ui/gfx/vector3d_f.h"
  38 #include "ui/views/corewm/window_util.h"
  39 #include "ui/views/view.h"
  40 #include "ui/views/widget/widget.h"
  41
  42 namespace ash {
  43 namespace {
  44 const int kLayerAnimationsForMinimizeDurationMS = 200;
  45
  46 // Durations for the cross-fade animation, in milliseconds.
  47 const float kCrossFadeDurationMinMs = 200.f;
  48 const float kCrossFadeDurationMaxMs = 400.f;
  49
  50 // Durations for the brightness/grayscale fade animation, in milliseconds.
  51 const int kBrightnessGrayscaleFadeDurationMs = 1000;
  52
  53 // Brightness/grayscale values for hide/show window animations.
  54 const float kWindowAnimation_HideBrightnessGrayscale = 1.f;
  55 const float kWindowAnimation_ShowBrightnessGrayscale = 0.f;
  56
  57 const float kWindowAnimation_HideOpacity = 0.f;
  58 const float kWindowAnimation_ShowOpacity = 1.f;
  59 // TODO(sky): if we end up sticking with 0, nuke the code doing the rotation.
  60 const float kWindowAnimation_MinimizeRotate = 0.f;
  61
  62 // Tween type when cross fading a workspace window.
  63 const gfx::Tween::Type kCrossFadeTweenType = gfx::Tween::EASE_IN_OUT;
  64
  65 // Scales for AshWindow above/below current workspace.
  66 const float kLayerScaleAboveSize = 1.1f;
  67 const float kLayerScaleBelowSize = .9f;
  68
  69 int64 Round64(float f) {
  70   return static_cast<int64>(f + 0.5f);
  71 }
  72
  73 }  // namespace
  74
  75 const int kCrossFadeDurationMS = 200;
  76
  77 void AddLayerAnimationsForMinimize(aura::Window* window, bool show) {
  78   // Recalculate the transform at restore time since the launcher item may have
  79   // moved while the window was minimized.
  80   gfx::Rect bounds = window->bounds();
  81   gfx::Rect target_bounds = GetMinimizeAnimationTargetBoundsInScreen(window);
  82   target_bounds =
  83       ScreenAsh::ConvertRectFromScreen(window->parent(), target_bounds);
  84
  85   float scale_x = static_cast<float>(target_bounds.width()) / bounds.width();
  86   float scale_y = static_cast<float>(target_bounds.height()) / bounds.height();
  87
  88   scoped_ptr<ui::InterpolatedTransform> scale(
  89       new ui::InterpolatedScale(gfx::Point3F(1, 1, 1),
  90                                 gfx::Point3F(scale_x, scale_y, 1)));
  91
  92   scoped_ptr<ui::InterpolatedTransform> translation(
  93       new ui::InterpolatedTranslation(
  94           gfx::Point(),
  95           gfx::Point(target_bounds.x() - bounds.x(),
  96                      target_bounds.y() - bounds.y())));
  97
  98   scoped_ptr<ui::InterpolatedTransform> rotation(
  99       new ui::InterpolatedRotation(0, kWindowAnimation_MinimizeRotate));
 100
 101   scoped_ptr<ui::InterpolatedTransform> rotation_about_pivot(
 102       new ui::InterpolatedTransformAboutPivot(
 103           gfx::Point(bounds.width() * 0.5, bounds.height() * 0.5),
 104           rotation.release()));
 105
 106   scale->SetChild(translation.release());
 107   rotation_about_pivot->SetChild(scale.release());
 108
 109   rotation_about_pivot->SetReversed(show);
 110
 111   base::TimeDelta duration = base::TimeDelta::FromMilliseconds(
 112       kLayerAnimationsForMinimizeDurationMS);
 113
 114   scoped_ptr<ui::LayerAnimationElement> transition(
 115       ui::LayerAnimationElement::CreateInterpolatedTransformElement(
 116           rotation_about_pivot.release(), duration));
 117
 118   transition->set_tween_type(
 119       show ? gfx::Tween::EASE_IN : gfx::Tween::EASE_IN_OUT);
 120
 121   window->layer()->GetAnimator()->ScheduleAnimation(
 122       new ui::LayerAnimationSequence(transition.release()));
 123
 124   // When hiding a window, turn off blending until the animation is 3 / 4 done
 125   // to save bandwidth and reduce jank.
 126   if (!show) {
 127     window->layer()->GetAnimator()->SchedulePauseForProperties(
 128         (duration * 3) / 4, ui::LayerAnimationElement::OPACITY, -1);
 129   }
 130
 131   // Fade in and out quickly when the window is small to reduce jank.
 132   float opacity = show ? 1.0f : 0.0f;
 133   window->layer()->GetAnimator()->ScheduleAnimation(
 134       new ui::LayerAnimationSequence(
 135           ui::LayerAnimationElement::CreateOpacityElement(
 136               opacity, duration / 4)));
 137 }
 138
 139 void AnimateShowWindow_Minimize(aura::Window* window) {
 140   window->layer()->set_delegate(window);
 141   window->layer()->SetOpacity(kWindowAnimation_HideOpacity);
 142   AddLayerAnimationsForMinimize(window, true);
 143
 144   // Now that the window has been restored, we need to clear its animation style
 145   // to default so that normal animation applies.
 146   views::corewm::SetWindowVisibilityAnimationType(
 147       window, views::corewm::WINDOW_VISIBILITY_ANIMATION_TYPE_DEFAULT);
 148 }
 149
 150 void AnimateHideWindow_Minimize(aura::Window* window) {
 151   window->layer()->set_delegate(NULL);
 152
 153   // Property sets within this scope will be implicitly animated.
 154   ui::ScopedLayerAnimationSettings settings(window->layer()->GetAnimator());
 155   base::TimeDelta duration = base::TimeDelta::FromMilliseconds(
 156       kLayerAnimationsForMinimizeDurationMS);
 157   settings.SetTransitionDuration(duration);
 158   settings.AddObserver(
 159       views::corewm::CreateHidingWindowAnimationObserver(window));
 160   window->layer()->SetVisible(false);
 161
 162   AddLayerAnimationsForMinimize(window, false);
 163 }
 164
 165 void AnimateShowHideWindowCommon_BrightnessGrayscale(aura::Window* window,
 166                                                      bool show) {
 167   window->layer()->set_delegate(window);
 168
 169   float start_value, end_value;
 170   if (show) {
 171     start_value = kWindowAnimation_HideBrightnessGrayscale;
 172     end_value = kWindowAnimation_ShowBrightnessGrayscale;
 173   } else {
 174     start_value = kWindowAnimation_ShowBrightnessGrayscale;
 175     end_value = kWindowAnimation_HideBrightnessGrayscale;
 176   }
 177
 178   window->layer()->SetLayerBrightness(start_value);
 179   window->layer()->SetLayerGrayscale(start_value);
 180   if (show) {
 181     window->layer()->SetOpacity(kWindowAnimation_ShowOpacity);
 182     window->layer()->SetVisible(true);
 183   }
 184
 185   base::TimeDelta duration =
 186       base::TimeDelta::FromMilliseconds(kBrightnessGrayscaleFadeDurationMs);
 187
 188   ui::ScopedLayerAnimationSettings settings(window->layer()->GetAnimator());
 189   settings.SetTransitionDuration(duration);
 190   if (!show) {
 191     settings.AddObserver(
 192         views::corewm::CreateHidingWindowAnimationObserver(window));
 193   }
 194
 195   window->layer()->GetAnimator()->
 196       ScheduleTogether(
 197           CreateBrightnessGrayscaleAnimationSequence(end_value, duration));
 198   if (!show) {
 199     window->layer()->SetOpacity(kWindowAnimation_HideOpacity);
 200     window->layer()->SetVisible(false);
 201   }
 202 }
 203
 204 void AnimateShowWindow_BrightnessGrayscale(aura::Window* window) {
 205   AnimateShowHideWindowCommon_BrightnessGrayscale(window, true);
 206 }
 207
 208 void AnimateHideWindow_BrightnessGrayscale(aura::Window* window) {
 209   AnimateShowHideWindowCommon_BrightnessGrayscale(window, false);
 210 }
 211
 212 bool AnimateShowWindow(aura::Window* window) {
 213   if (!views::corewm::HasWindowVisibilityAnimationTransition(
 214           window, views::corewm::ANIMATE_SHOW)) {
 215     return false;
 216   }
 217
 218   switch (views::corewm::GetWindowVisibilityAnimationType(window)) {
 219     case WINDOW_VISIBILITY_ANIMATION_TYPE_MINIMIZE:
 220       AnimateShowWindow_Minimize(window);
 221       return true;
 222     case WINDOW_VISIBILITY_ANIMATION_TYPE_BRIGHTNESS_GRAYSCALE:
 223       AnimateShowWindow_BrightnessGrayscale(window);
 224       return true;
 225     default:
 226       NOTREACHED();
 227       return false;
 228   }
 229 }
 230
 231 bool AnimateHideWindow(aura::Window* window) {
 232   if (!views::corewm::HasWindowVisibilityAnimationTransition(
 233           window, views::corewm::ANIMATE_HIDE)) {
 234     return false;
 235   }
 236
 237   switch (views::corewm::GetWindowVisibilityAnimationType(window)) {
 238     case WINDOW_VISIBILITY_ANIMATION_TYPE_MINIMIZE:
 239       AnimateHideWindow_Minimize(window);
 240       return true;
 241     case WINDOW_VISIBILITY_ANIMATION_TYPE_BRIGHTNESS_GRAYSCALE:
 242       AnimateHideWindow_BrightnessGrayscale(window);
 243       return true;
 244     default:
 245       NOTREACHED();
 246       return false;
 247   }
 248 }
 249
 250 // Observer for a window cross-fade animation. If either the window closes or
 251 // the layer's animation completes or compositing is aborted due to GPU crash,
 252 // it deletes the layer and removes itself as an observer.
 253 class CrossFadeObserver : public ui::CompositorObserver,
 254                           public aura::WindowObserver,
 255                           public ui::ImplicitAnimationObserver {
 256  public:
 257   // Observes |window| for destruction, but does not take ownership.
 258   // Takes ownership of |layer| and its child layers.
 259   CrossFadeObserver(aura::Window* window, ui::Layer* layer)
 260       : window_(window),
 261         layer_(layer) {
 262     window_->AddObserver(this);
 263     layer_->GetCompositor()->AddObserver(this);
 264   }
 265   virtual ~CrossFadeObserver() {
 266     window_->RemoveObserver(this);
 267     window_ = NULL;
 268     layer_->GetCompositor()->RemoveObserver(this);
 269     views::corewm::DeepDeleteLayers(layer_);
 270     layer_ = NULL;
 271   }
 272
 273   // ui::CompositorObserver overrides:
 274   virtual void OnCompositingDidCommit(ui::Compositor* compositor) OVERRIDE {
 275   }
 276   virtual void OnCompositingStarted(ui::Compositor* compositor,
 277                                     base::TimeTicks start_time) OVERRIDE {
 278   }
 279   virtual void OnCompositingEnded(ui::Compositor* compositor) OVERRIDE {
 280   }
 281   virtual void OnCompositingAborted(ui::Compositor* compositor) OVERRIDE {
 282     // Triggers OnImplicitAnimationsCompleted() to be called and deletes us.
 283     layer_->GetAnimator()->StopAnimating();
 284   }
 285   virtual void OnCompositingLockStateChanged(
 286       ui::Compositor* compositor) OVERRIDE {
 287   }
 288   virtual void OnUpdateVSyncParameters(ui::Compositor* compositor,
 289                                        base::TimeTicks timebase,
 290                                        base::TimeDelta interval) OVERRIDE {
 291   }
 292
 293   // aura::WindowObserver overrides:
 294   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE {
 295     // Triggers OnImplicitAnimationsCompleted() to be called and deletes us.
 296     layer_->GetAnimator()->StopAnimating();
 297   }
 298   virtual void OnWindowRemovingFromRootWindow(aura::Window* window) OVERRIDE {
 299     layer_->GetAnimator()->StopAnimating();
 300   }
 301
 302   // ui::ImplicitAnimationObserver overrides:
 303   virtual void OnImplicitAnimationsCompleted() OVERRIDE {
 304     delete this;
 305   }
 306
 307  private:
 308   aura::Window* window_;  // not owned
 309   ui::Layer* layer_;  // owned
 310
 311   DISALLOW_COPY_AND_ASSIGN(CrossFadeObserver);
 312 };
 313
 314 // Implementation of cross fading. Window is the window being cross faded. It
 315 // should be at the target bounds. |old_layer| the previous layer from |window|.
 316 // This takes ownership of |old_layer| and deletes when the animation is done.
 317 // |pause_duration| is the duration to pause at the current bounds before
 318 // animating. Returns the duration of the fade.
 319 base::TimeDelta CrossFadeImpl(aura::Window* window,
 320                               ui::Layer* old_layer,
 321                               gfx::Tween::Type tween_type) {
 322   const gfx::Rect old_bounds(old_layer->bounds());
 323   const gfx::Rect new_bounds(window->bounds());
 324   const bool old_on_top = (old_bounds.width() > new_bounds.width());
 325
 326   // Shorten the animation if there's not much visual movement.
 327   const base::TimeDelta duration = GetCrossFadeDuration(old_bounds, new_bounds);
 328
 329   // Scale up the old layer while translating to new position.
 330   {
 331     old_layer->GetAnimator()->StopAnimating();
 332     ui::ScopedLayerAnimationSettings settings(old_layer->GetAnimator());
 333
 334     // Animation observer owns the old layer and deletes itself.
 335     settings.AddObserver(new CrossFadeObserver(window, old_layer));
 336     settings.SetTransitionDuration(duration);
 337     settings.SetTweenType(tween_type);
 338     gfx::Transform out_transform;
 339     float scale_x = static_cast<float>(new_bounds.width()) /
 340         static_cast<float>(old_bounds.width());
 341     float scale_y = static_cast<float>(new_bounds.height()) /
 342         static_cast<float>(old_bounds.height());
 343     out_transform.Translate(new_bounds.x() - old_bounds.x(),
 344                             new_bounds.y() - old_bounds.y());
 345     out_transform.Scale(scale_x, scale_y);
 346     old_layer->SetTransform(out_transform);
 347     if (old_on_top) {
 348       // The old layer is on top, and should fade out.  The new layer below will
 349       // stay opaque to block the desktop.
 350       old_layer->SetOpacity(kWindowAnimation_HideOpacity);
 351     }
 352     // In tests |old_layer| is deleted here, as animations have zero duration.
 353     old_layer = NULL;
 354   }
 355
 356   // Set the new layer's current transform, such that the user sees a scaled
 357   // version of the window with the original bounds at the original position.
 358   gfx::Transform in_transform;
 359   const float scale_x = static_cast<float>(old_bounds.width()) /
 360       static_cast<float>(new_bounds.width());
 361   const float scale_y = static_cast<float>(old_bounds.height()) /
 362       static_cast<float>(new_bounds.height());
 363   in_transform.Translate(old_bounds.x() - new_bounds.x(),
 364                                old_bounds.y() - new_bounds.y());
 365   in_transform.Scale(scale_x, scale_y);
 366   window->layer()->SetTransform(in_transform);
 367   if (!old_on_top) {
 368     // The new layer is on top and should fade in.  The old layer below will
 369     // stay opaque and block the desktop.
 370     window->layer()->SetOpacity(kWindowAnimation_HideOpacity);
 371   }
 372   {
 373     // Animate the new layer to the identity transform, so the window goes to
 374     // its newly set bounds.
 375     ui::ScopedLayerAnimationSettings settings(window->layer()->GetAnimator());
 376     settings.SetTransitionDuration(duration);
 377     settings.SetTweenType(tween_type);
 378     window->layer()->SetTransform(gfx::Transform());
 379     if (!old_on_top) {
 380       // New layer is on top, fade it in.
 381       window->layer()->SetOpacity(kWindowAnimation_ShowOpacity);
 382     }
 383   }
 384   return duration;
 385 }
 386
 387 void CrossFadeToBounds(aura::Window* window, const gfx::Rect& new_bounds) {
 388   // Some test results in invoking CrossFadeToBounds when window is not visible.
 389   // No animation is necessary in that case, thus just change the bounds and
 390   // quit.
 391   if (!window->TargetVisibility()) {
 392     window->SetBounds(new_bounds);
 393     return;
 394   }
 395
 396   const gfx::Rect old_bounds = window->bounds();
 397
 398   // Create fresh layers for the window and all its children to paint into.
 399   // Takes ownership of the old layer and all its children, which will be
 400   // cleaned up after the animation completes.
 401   // Specify |set_bounds| to true here to keep the old bounds in the child
 402   // windows of |window|.
 403   ui::Layer* old_layer = views::corewm::RecreateWindowLayers(window, true);
 404   ui::Layer* new_layer = window->layer();
 405
 406   // Resize the window to the new size, which will force a layout and paint.
 407   window->SetBounds(new_bounds);
 408
 409   // Ensure the higher-resolution layer is on top.
 410   bool old_on_top = (old_bounds.width() > new_bounds.width());
 411   if (old_on_top)
 412     old_layer->parent()->StackBelow(new_layer, old_layer);
 413   else
 414     old_layer->parent()->StackAbove(new_layer, old_layer);
 415
 416   CrossFadeImpl(window, old_layer, gfx::Tween::EASE_OUT);
 417 }
 418
 419 void CrossFadeWindowBetweenWorkspaces(aura::Window* new_workspace,
 420                                       aura::Window* window,
 421                                       ui::Layer* old_layer) {
 422   ui::Layer* layer_parent = new_workspace->layer()->parent();
 423   layer_parent->Add(old_layer);
 424   const bool restoring = old_layer->bounds().width() > window->bounds().width();
 425   if (restoring)
 426     layer_parent->StackAbove(old_layer, new_workspace->layer());
 427   else
 428     layer_parent->StackBelow(old_layer, new_workspace->layer());
 429
 430   CrossFadeImpl(window, old_layer, kCrossFadeTweenType);
 431 }
 432
 433 base::TimeDelta GetCrossFadeDuration(const gfx::Rect& old_bounds,
 434                                      const gfx::Rect& new_bounds) {
 435   if (views::corewm::WindowAnimationsDisabled(NULL))
 436     return base::TimeDelta();
 437
 438   int old_area = old_bounds.width() * old_bounds.height();
 439   int new_area = new_bounds.width() * new_bounds.height();
 440   int max_area = std::max(old_area, new_area);
 441   // Avoid divide by zero.
 442   if (max_area == 0)
 443     return base::TimeDelta::FromMilliseconds(kCrossFadeDurationMS);
 444
 445   int delta_area = std::abs(old_area - new_area);
 446   // If the area didn't change, the animation is instantaneous.
 447   if (delta_area == 0)
 448     return base::TimeDelta::FromMilliseconds(kCrossFadeDurationMS);
 449
 450   float factor =
 451       static_cast<float>(delta_area) / static_cast<float>(max_area);
 452   const float kRange = kCrossFadeDurationMaxMs - kCrossFadeDurationMinMs;
 453   return base::TimeDelta::FromMilliseconds(
 454       Round64(kCrossFadeDurationMinMs + (factor * kRange)));
 455 }
 456
 457 bool AnimateOnChildWindowVisibilityChanged(aura::Window* window, bool visible) {
 458   if (views::corewm::WindowAnimationsDisabled(window))
 459     return false;
 460
 461   // Attempt to run CoreWm supplied animation types.
 462   if (views::corewm::AnimateOnChildWindowVisibilityChanged(window, visible))
 463     return true;
 464
 465   // Otherwise try to run an Ash-specific animation.
 466   if (visible)
 467     return AnimateShowWindow(window);
 468   // Don't start hiding the window again if it's already being hidden.
 469   return window->layer()->GetTargetOpacity() != 0.0f &&
 470       AnimateHideWindow(window);
 471 }
 472
 473 std::vector<ui::LayerAnimationSequence*>
 474 CreateBrightnessGrayscaleAnimationSequence(float target_value,
 475                                            base::TimeDelta duration) {
 476   gfx::Tween::Type animation_type = gfx::Tween::EASE_OUT;
 477   scoped_ptr<ui::LayerAnimationSequence> brightness_sequence(
 478       new ui::LayerAnimationSequence());
 479   scoped_ptr<ui::LayerAnimationSequence> grayscale_sequence(
 480       new ui::LayerAnimationSequence());
 481
 482   scoped_ptr<ui::LayerAnimationElement> brightness_element(
 483       ui::LayerAnimationElement::CreateBrightnessElement(
 484           target_value, duration));
 485   brightness_element->set_tween_type(animation_type);
 486   brightness_sequence->AddElement(brightness_element.release());
 487
 488   scoped_ptr<ui::LayerAnimationElement> grayscale_element(
 489       ui::LayerAnimationElement::CreateGrayscaleElement(
 490           target_value, duration));
 491   grayscale_element->set_tween_type(animation_type);
 492   grayscale_sequence->AddElement(grayscale_element.release());
 493
 494   std::vector<ui::LayerAnimationSequence*> animations;
 495   animations.push_back(brightness_sequence.release());
 496   animations.push_back(grayscale_sequence.release());
 497
 498   return animations;
 499 }
 500
 501 // Returns scale related to the specified AshWindowScaleType.
 502 void SetTransformForScaleAnimation(ui::Layer* layer,
 503                                    LayerScaleAnimationDirection type) {
 504   const float scale =
 505       type == LAYER_SCALE_ANIMATION_ABOVE ? kLayerScaleAboveSize :
 506           kLayerScaleBelowSize;
 507   gfx::Transform transform;
 508   transform.Translate(-layer->bounds().width() * (scale - 1.0f) / 2,
 509                       -layer->bounds().height() * (scale - 1.0f) / 2);
 510   transform.Scale(scale, scale);
 511   layer->SetTransform(transform);
 512 }
 513
 514 gfx::Rect GetMinimizeAnimationTargetBoundsInScreen(aura::Window* window) {
 515   Launcher* launcher = Launcher::ForWindow(window);
 516   // Launcher is created lazily and can be NULL.
 517   if (!launcher)
 518     return gfx::Rect();
 519   gfx::Rect item_rect = launcher->
 520       GetScreenBoundsOfItemIconForWindow(window);
 521
 522   // The launcher item is visible and has an icon.
 523   if (!item_rect.IsEmpty())
 524     return item_rect;
 525
 526   // If both the icon width and height are 0, then there is no icon in the
 527   // launcher for |window| or the icon is hidden in the overflow menu. If the
 528   // launcher is auto hidden, one of the height or width will be 0 but the
 529   // position in the launcher and the major dimension are still reported
 530   // correctly and the window can be animated to the launcher item's light
 531   // bar.
 532   if (item_rect.width() != 0 || item_rect.height() != 0) {
 533     internal::ShelfLayoutManager* layout_manager =
 534         internal::ShelfLayoutManager::ForLauncher(window);
 535     if (layout_manager->visibility_state() == SHELF_AUTO_HIDE) {
 536       gfx::Rect shelf_bounds =
 537           launcher->shelf_widget()->GetWindowBoundsInScreen();
 538       switch (layout_manager->GetAlignment()) {
 539         case SHELF_ALIGNMENT_BOTTOM:
 540           item_rect.set_y(shelf_bounds.y());
 541           break;
 542         case SHELF_ALIGNMENT_LEFT:
 543           item_rect.set_x(shelf_bounds.right());
 544           break;
 545         case SHELF_ALIGNMENT_RIGHT:
 546           item_rect.set_x(shelf_bounds.x());
 547           break;
 548         case SHELF_ALIGNMENT_TOP:
 549           item_rect.set_y(shelf_bounds.bottom());
 550           break;
 551       }
 552       return item_rect;
 553     }
 554   }
 555
 556   // Assume the launcher is overflowed, zoom off to the bottom right of the
 557   // work area.
 558   gfx::Rect work_area =
 559       Shell::GetScreen()->GetDisplayNearestWindow(window).work_area();
 560   return gfx::Rect(work_area.right(), work_area.bottom(), 0, 0);
 561 }
 562
 563 }  // namespace ash