src/ash/wm/toplevel_window_event_handler.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/toplevel_window_event_handler.h"
   6
   7 #include "ash/shell.h"
   8 #include "ash/wm/resize_shadow_controller.h"
   9 #include "ash/wm/window_resizer.h"
  10 #include "ash/wm/window_state.h"
  11 #include "ash/wm/window_state_observer.h"
  12 #include "ash/wm/window_util.h"
  13 #include "ash/wm/wm_event.h"
  14 #include "base/message_loop/message_loop.h"
  15 #include "base/run_loop.h"
  16 #include "ui/aura/client/cursor_client.h"
  17 #include "ui/aura/env.h"
  18 #include "ui/aura/window.h"
  19 #include "ui/aura/window_delegate.h"
  20 #include "ui/aura/window_event_dispatcher.h"
  21 #include "ui/aura/window_observer.h"
  22 #include "ui/aura/window_tree_host.h"
  23 #include "ui/base/cursor/cursor.h"
  24 #include "ui/base/hit_test.h"
  25 #include "ui/base/ui_base_types.h"
  26 #include "ui/events/event.h"
  27 #include "ui/events/event_utils.h"
  28 #include "ui/events/gestures/gesture_recognizer.h"
  29 #include "ui/gfx/geometry/point_conversions.h"
  30 #include "ui/gfx/screen.h"
  31
  32 namespace {
  33 const double kMinHorizVelocityForWindowSwipe = 1100;
  34 const double kMinVertVelocityForWindowMinimize = 1000;
  35 }
  36
  37 namespace ash {
  38
  39 namespace {
  40
  41 // Returns whether |window| can be moved via a two finger drag given
  42 // the hittest results of the two fingers.
  43 bool CanStartTwoFingerMove(aura::Window* window,
  44                            int window_component1,
  45                            int window_component2) {
  46   // We allow moving a window via two fingers when the hittest components are
  47   // HTCLIENT. This is done so that a window can be dragged via two fingers when
  48   // the tab strip is full and hitting the caption area is difficult. We check
  49   // the window type and the state type so that we do not steal touches from the
  50   // web contents.
  51   if (!wm::GetWindowState(window)->IsNormalOrSnapped() ||
  52       window->type() != ui::wm::WINDOW_TYPE_NORMAL) {
  53     return false;
  54   }
  55   int component1_behavior =
  56       WindowResizer::GetBoundsChangeForWindowComponent(window_component1);
  57   int component2_behavior =
  58       WindowResizer::GetBoundsChangeForWindowComponent(window_component2);
  59   return (component1_behavior & WindowResizer::kBoundsChange_Resizes) == 0 &&
  60       (component2_behavior & WindowResizer::kBoundsChange_Resizes) == 0;
  61 }
  62
  63 // Returns whether |window| can be moved or resized via one finger given
  64 // |window_component|.
  65 bool CanStartOneFingerDrag(int window_component) {
  66   return WindowResizer::GetBoundsChangeForWindowComponent(
  67       window_component) != 0;
  68 }
  69
  70 gfx::Point ConvertPointToParent(aura::Window* window,
  71                                 const gfx::Point& point) {
  72   gfx::Point result(point);
  73   aura::Window::ConvertPointToTarget(window, window->parent(), &result);
  74   return result;
  75 }
  76
  77 // Returns the window component containing |event|'s location.
  78 int GetWindowComponent(aura::Window* window, const ui::LocatedEvent& event) {
  79   return window->delegate()->GetNonClientComponent(event.location());
  80 }
  81
  82 }  // namespace
  83
  84 // ScopedWindowResizer ---------------------------------------------------------
  85
  86 // Wraps a WindowResizer and installs an observer on its target window.  When
  87 // the window is destroyed ResizerWindowDestroyed() is invoked back on the
  88 // ToplevelWindowEventHandler to clean up.
  89 class ToplevelWindowEventHandler::ScopedWindowResizer
  90     : public aura::WindowObserver,
  91       public wm::WindowStateObserver {
  92  public:
  93   ScopedWindowResizer(ToplevelWindowEventHandler* handler,
  94                       WindowResizer* resizer);
  95   ~ScopedWindowResizer() override;
  96
  97   // Returns true if the drag moves the window and does not resize.
  98   bool IsMove() const;
  99
 100   WindowResizer* resizer() { return resizer_.get(); }
 101
 102   // WindowObserver overrides:
 103   void OnWindowDestroying(aura::Window* window) override;
 104
 105   // WindowStateObserver overrides:
 106   void OnPreWindowStateTypeChange(wm::WindowState* window_state,
 107                                   wm::WindowStateType type) override;
 108
 109  private:
 110   ToplevelWindowEventHandler* handler_;
 111   scoped_ptr<WindowResizer> resizer_;
 112
 113   DISALLOW_COPY_AND_ASSIGN(ScopedWindowResizer);
 114 };
 115
 116 ToplevelWindowEventHandler::ScopedWindowResizer::ScopedWindowResizer(
 117     ToplevelWindowEventHandler* handler,
 118     WindowResizer* resizer)
 119     : handler_(handler),
 120       resizer_(resizer) {
 121   resizer_->GetTarget()->AddObserver(this);
 122   wm::GetWindowState(resizer_->GetTarget())->AddObserver(this);
 123 }
 124
 125 ToplevelWindowEventHandler::ScopedWindowResizer::~ScopedWindowResizer() {
 126   resizer_->GetTarget()->RemoveObserver(this);
 127   wm::GetWindowState(resizer_->GetTarget())->RemoveObserver(this);
 128 }
 129
 130 bool ToplevelWindowEventHandler::ScopedWindowResizer::IsMove() const {
 131   return resizer_->details().bounds_change ==
 132       WindowResizer::kBoundsChange_Repositions;
 133 }
 134
 135 void
 136 ToplevelWindowEventHandler::ScopedWindowResizer::OnPreWindowStateTypeChange(
 137     wm::WindowState* window_state,
 138     wm::WindowStateType old) {
 139   handler_->CompleteDrag(DRAG_COMPLETE);
 140 }
 141
 142 void ToplevelWindowEventHandler::ScopedWindowResizer::OnWindowDestroying(
 143     aura::Window* window) {
 144   DCHECK_EQ(resizer_->GetTarget(), window);
 145   handler_->ResizerWindowDestroyed();
 146 }
 147
 148 // ToplevelWindowEventHandler --------------------------------------------------
 149
 150 ToplevelWindowEventHandler::ToplevelWindowEventHandler()
 151     : first_finger_hittest_(HTNOWHERE),
 152       in_move_loop_(false),
 153       in_gesture_drag_(false),
 154       drag_reverted_(false),
 155       destroyed_(NULL) {
 156   Shell::GetInstance()->display_controller()->AddObserver(this);
 157 }
 158
 159 ToplevelWindowEventHandler::~ToplevelWindowEventHandler() {
 160   Shell::GetInstance()->display_controller()->RemoveObserver(this);
 161   if (destroyed_)
 162     *destroyed_ = true;
 163 }
 164
 165 void ToplevelWindowEventHandler::OnKeyEvent(ui::KeyEvent* event) {
 166   if (window_resizer_.get() && event->type() == ui::ET_KEY_PRESSED &&
 167       event->key_code() == ui::VKEY_ESCAPE) {
 168     CompleteDrag(DRAG_REVERT);
 169   }
 170 }
 171
 172 void ToplevelWindowEventHandler::OnMouseEvent(
 173     ui::MouseEvent* event) {
 174   if (event->handled())
 175     return;
 176   if ((event->flags() &
 177       (ui::EF_MIDDLE_MOUSE_BUTTON | ui::EF_RIGHT_MOUSE_BUTTON)) != 0)
 178     return;
 179
 180   if (in_gesture_drag_)
 181     return;
 182
 183   aura::Window* target = static_cast<aura::Window*>(event->target());
 184   switch (event->type()) {
 185     case ui::ET_MOUSE_PRESSED:
 186       HandleMousePressed(target, event);
 187       break;
 188     case ui::ET_MOUSE_DRAGGED:
 189       HandleDrag(target, event);
 190       break;
 191     case ui::ET_MOUSE_CAPTURE_CHANGED:
 192     case ui::ET_MOUSE_RELEASED:
 193       HandleMouseReleased(target, event);
 194       break;
 195     case ui::ET_MOUSE_MOVED:
 196       HandleMouseMoved(target, event);
 197       break;
 198     case ui::ET_MOUSE_EXITED:
 199       HandleMouseExited(target, event);
 200       break;
 201     default:
 202       break;
 203   }
 204 }
 205
 206 void ToplevelWindowEventHandler::OnGestureEvent(ui::GestureEvent* event) {
 207   if (event->handled())
 208     return;
 209   aura::Window* target = static_cast<aura::Window*>(event->target());
 210   if (!target->delegate())
 211     return;
 212
 213   if (window_resizer_.get() && !in_gesture_drag_)
 214     return;
 215
 216   if (window_resizer_.get() &&
 217       window_resizer_->resizer()->GetTarget() != target) {
 218     return;
 219   }
 220
 221   if (event->details().touch_points() > 2) {
 222     if (CompleteDrag(DRAG_COMPLETE))
 223       event->StopPropagation();
 224     return;
 225   }
 226
 227   switch (event->type()) {
 228     case ui::ET_GESTURE_TAP_DOWN: {
 229       int component = GetWindowComponent(target, *event);
 230       if (!(WindowResizer::GetBoundsChangeForWindowComponent(component) &
 231             WindowResizer::kBoundsChange_Resizes))
 232         return;
 233       ResizeShadowController* controller =
 234           Shell::GetInstance()->resize_shadow_controller();
 235       if (controller)
 236         controller->ShowShadow(target, component);
 237       return;
 238     }
 239     case ui::ET_GESTURE_END: {
 240       ResizeShadowController* controller =
 241           Shell::GetInstance()->resize_shadow_controller();
 242       if (controller)
 243         controller->HideShadow(target);
 244
 245       if (window_resizer_.get() &&
 246           (event->details().touch_points() == 1 ||
 247            !CanStartOneFingerDrag(first_finger_hittest_))) {
 248         CompleteDrag(DRAG_COMPLETE);
 249         event->StopPropagation();
 250       }
 251       return;
 252     }
 253     case ui::ET_GESTURE_BEGIN: {
 254       if (event->details().touch_points() == 1) {
 255         first_finger_hittest_ = GetWindowComponent(target, *event);
 256       } else if (window_resizer_.get()) {
 257         if (!window_resizer_->IsMove()) {
 258           // The transition from resizing with one finger to resizing with two
 259           // fingers causes unintended resizing because the location of
 260           // ET_GESTURE_SCROLL_UPDATE jumps from the position of the first
 261           // finger to the position in the middle of the two fingers. For this
 262           // reason two finger resizing is not supported.
 263           CompleteDrag(DRAG_COMPLETE);
 264           event->StopPropagation();
 265         }
 266       } else {
 267         int second_finger_hittest = GetWindowComponent(target, *event);
 268         if (CanStartTwoFingerMove(
 269                 target, first_finger_hittest_, second_finger_hittest)) {
 270           gfx::Point location_in_parent =
 271               event->details().bounding_box().CenterPoint();
 272           AttemptToStartDrag(target, location_in_parent, HTCAPTION,
 273                              aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 274           event->StopPropagation();
 275         }
 276       }
 277       return;
 278     }
 279     case ui::ET_GESTURE_SCROLL_BEGIN: {
 280       // The one finger drag is not started in ET_GESTURE_BEGIN to avoid the
 281       // window jumping upon initiating a two finger drag. When a one finger
 282       // drag is converted to a two finger drag, a jump occurs because the
 283       // location of the ET_GESTURE_SCROLL_UPDATE event switches from the single
 284       // finger's position to the position in the middle of the two fingers.
 285       if (window_resizer_.get())
 286         return;
 287       int component = GetWindowComponent(target, *event);
 288       if (!CanStartOneFingerDrag(component))
 289         return;
 290       gfx::Point location_in_parent(
 291           ConvertPointToParent(target, event->location()));
 292       AttemptToStartDrag(target, location_in_parent, component,
 293                          aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 294       event->StopPropagation();
 295       return;
 296     }
 297     default:
 298       break;
 299   }
 300
 301   if (!window_resizer_.get())
 302     return;
 303
 304   switch (event->type()) {
 305     case ui::ET_GESTURE_SCROLL_UPDATE:
 306       HandleDrag(target, event);
 307       event->StopPropagation();
 308       return;
 309     case ui::ET_GESTURE_SCROLL_END:
 310       // We must complete the drag here instead of as a result of ET_GESTURE_END
 311       // because otherwise the drag will be reverted when EndMoveLoop() is
 312       // called.
 313       // TODO(pkotwicz): Pass drag completion status to
 314       // WindowMoveClient::EndMoveLoop().
 315       CompleteDrag(DRAG_COMPLETE);
 316       event->StopPropagation();
 317       return;
 318     case ui::ET_SCROLL_FLING_START:
 319       CompleteDrag(DRAG_COMPLETE);
 320
 321       // TODO(pkotwicz): Fix tests which inadvertantly start flings and check
 322       // window_resizer_->IsMove() instead of the hittest component at |event|'s
 323       // location.
 324       if (GetWindowComponent(target, *event) != HTCAPTION ||
 325           !wm::GetWindowState(target)->IsNormalOrSnapped()) {
 326         return;
 327       }
 328
 329       if (event->details().velocity_y() > kMinVertVelocityForWindowMinimize) {
 330         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MINIMIZED);
 331       } else if (event->details().velocity_y() <
 332                  -kMinVertVelocityForWindowMinimize) {
 333         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MAXIMIZED);
 334       } else if (event->details().velocity_x() >
 335                  kMinHorizVelocityForWindowSwipe) {
 336         SetWindowStateTypeFromGesture(target,
 337                                       wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED);
 338       } else if (event->details().velocity_x() <
 339                  -kMinHorizVelocityForWindowSwipe) {
 340         SetWindowStateTypeFromGesture(target,
 341                                       wm::WINDOW_STATE_TYPE_LEFT_SNAPPED);
 342       }
 343       event->StopPropagation();
 344       return;
 345     case ui::ET_GESTURE_SWIPE:
 346       DCHECK_GT(event->details().touch_points(), 0);
 347       if (event->details().touch_points() == 1)
 348         return;
 349       if (!wm::GetWindowState(target)->IsNormalOrSnapped())
 350         return;
 351
 352       CompleteDrag(DRAG_COMPLETE);
 353
 354       if (event->details().swipe_down()) {
 355         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MINIMIZED);
 356       } else if (event->details().swipe_up()) {
 357         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MAXIMIZED);
 358       } else if (event->details().swipe_right()) {
 359         SetWindowStateTypeFromGesture(target,
 360                                       wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED);
 361       } else {
 362         SetWindowStateTypeFromGesture(target,
 363                                       wm::WINDOW_STATE_TYPE_LEFT_SNAPPED);
 364       }
 365       event->StopPropagation();
 366       return;
 367     default:
 368       return;
 369   }
 370 }
 371
 372 aura::client::WindowMoveResult ToplevelWindowEventHandler::RunMoveLoop(
 373     aura::Window* source,
 374     const gfx::Vector2d& drag_offset,
 375     aura::client::WindowMoveSource move_source) {
 376   DCHECK(!in_move_loop_);  // Can only handle one nested loop at a time.
 377   aura::Window* root_window = source->GetRootWindow();
 378   DCHECK(root_window);
 379   // TODO(tdresser): Use gfx::PointF. See crbug.com/337824.
 380   gfx::Point drag_location;
 381   if (move_source == aura::client::WINDOW_MOVE_SOURCE_TOUCH &&
 382       aura::Env::GetInstance()->is_touch_down()) {
 383     gfx::PointF drag_location_f;
 384     bool has_point = ui::GestureRecognizer::Get()->
 385         GetLastTouchPointForTarget(source, &drag_location_f);
 386     drag_location = gfx::ToFlooredPoint(drag_location_f);
 387     DCHECK(has_point);
 388   } else {
 389     drag_location =
 390         root_window->GetHost()->dispatcher()->GetLastMouseLocationInRoot();
 391     aura::Window::ConvertPointToTarget(
 392         root_window, source->parent(), &drag_location);
 393   }
 394   // Set the cursor before calling AttemptToStartDrag(), as that will
 395   // eventually call LockCursor() and prevent the cursor from changing.
 396   aura::client::CursorClient* cursor_client =
 397       aura::client::GetCursorClient(root_window);
 398   if (cursor_client)
 399     cursor_client->SetCursor(ui::kCursorPointer);
 400   if (!AttemptToStartDrag(source, drag_location, HTCAPTION, move_source))
 401     return aura::client::MOVE_CANCELED;
 402
 403   in_move_loop_ = true;
 404   bool destroyed = false;
 405   destroyed_ = &destroyed;
 406   base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
 407   base::MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
 408   base::RunLoop run_loop;
 409   quit_closure_ = run_loop.QuitClosure();
 410   run_loop.Run();
 411   if (destroyed)
 412     return aura::client::MOVE_CANCELED;
 413   destroyed_ = NULL;
 414   in_move_loop_ = false;
 415   return drag_reverted_ ? aura::client::MOVE_CANCELED :
 416       aura::client::MOVE_SUCCESSFUL;
 417 }
 418
 419 void ToplevelWindowEventHandler::EndMoveLoop() {
 420   if (in_move_loop_)
 421     CompleteDrag(DRAG_REVERT);
 422 }
 423
 424 void ToplevelWindowEventHandler::OnDisplayConfigurationChanging() {
 425   CompleteDrag(DRAG_REVERT);
 426 }
 427
 428 bool ToplevelWindowEventHandler::AttemptToStartDrag(
 429     aura::Window* window,
 430     const gfx::Point& point_in_parent,
 431     int window_component,
 432     aura::client::WindowMoveSource source) {
 433   if (window_resizer_.get())
 434     return false;
 435   WindowResizer* resizer = CreateWindowResizer(window, point_in_parent,
 436       window_component, source).release();
 437   if (!resizer)
 438     return false;
 439
 440   window_resizer_.reset(new ScopedWindowResizer(this, resizer));
 441
 442   pre_drag_window_bounds_ = window->bounds();
 443   in_gesture_drag_ = (source == aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 444   return true;
 445 }
 446
 447 bool ToplevelWindowEventHandler::CompleteDrag(DragCompletionStatus status) {
 448   if (!window_resizer_)
 449     return false;
 450
 451   scoped_ptr<ScopedWindowResizer> resizer(window_resizer_.release());
 452   switch (status) {
 453     case DRAG_COMPLETE:
 454       resizer->resizer()->CompleteDrag();
 455       break;
 456     case DRAG_REVERT:
 457       resizer->resizer()->RevertDrag();
 458       break;
 459     case DRAG_RESIZER_WINDOW_DESTROYED:
 460       // We explicitly do not invoke RevertDrag() since that may do things to
 461       // WindowResizer::GetTarget() which was destroyed.
 462       break;
 463   }
 464   drag_reverted_ = (status != DRAG_COMPLETE);
 465
 466   first_finger_hittest_ = HTNOWHERE;
 467   in_gesture_drag_ = false;
 468   if (in_move_loop_)
 469     quit_closure_.Run();
 470   return true;
 471 }
 472
 473 void ToplevelWindowEventHandler::HandleMousePressed(
 474     aura::Window* target,
 475     ui::MouseEvent* event) {
 476   if (event->phase() != ui::EP_PRETARGET || !target->delegate())
 477     return;
 478
 479   // We also update the current window component here because for the
 480   // mouse-drag-release-press case, where the mouse is released and
 481   // pressed without mouse move event.
 482   int component = GetWindowComponent(target, *event);
 483   if ((event->flags() &
 484         (ui::EF_IS_DOUBLE_CLICK | ui::EF_IS_TRIPLE_CLICK)) == 0 &&
 485       WindowResizer::GetBoundsChangeForWindowComponent(component)) {
 486     gfx::Point location_in_parent(
 487         ConvertPointToParent(target, event->location()));
 488     AttemptToStartDrag(target, location_in_parent, component,
 489                        aura::client::WINDOW_MOVE_SOURCE_MOUSE);
 490     // Set as handled so that other event handlers do no act upon the event
 491     // but still receive it so that they receive both parts of each pressed/
 492     // released pair.
 493     event->SetHandled();
 494   } else {
 495     CompleteDrag(DRAG_COMPLETE);
 496   }
 497 }
 498
 499 void ToplevelWindowEventHandler::HandleMouseReleased(
 500     aura::Window* target,
 501     ui::MouseEvent* event) {
 502   if (event->phase() != ui::EP_PRETARGET)
 503     return;
 504
 505   CompleteDrag(event->type() == ui::ET_MOUSE_RELEASED ?
 506                    DRAG_COMPLETE : DRAG_REVERT);
 507 }
 508
 509 void ToplevelWindowEventHandler::HandleDrag(
 510     aura::Window* target,
 511     ui::LocatedEvent* event) {
 512   // This function only be triggered to move window
 513   // by mouse drag or touch move event.
 514   DCHECK(event->type() == ui::ET_MOUSE_DRAGGED ||
 515          event->type() == ui::ET_TOUCH_MOVED ||
 516          event->type() == ui::ET_GESTURE_SCROLL_UPDATE);
 517
 518   // Drag actions are performed pre-target handling to prevent spurious mouse
 519   // moves from the move/size operation from being sent to the target.
 520   if (event->phase() != ui::EP_PRETARGET)
 521     return;
 522
 523   if (!window_resizer_)
 524     return;
 525   window_resizer_->resizer()->Drag(
 526       ConvertPointToParent(target, event->location()), event->flags());
 527   event->StopPropagation();
 528 }
 529
 530 void ToplevelWindowEventHandler::HandleMouseMoved(
 531     aura::Window* target,
 532     ui::LocatedEvent* event) {
 533   // Shadow effects are applied after target handling. Note that we don't
 534   // respect ER_HANDLED here right now since we have not had a reason to allow
 535   // the target to cancel shadow rendering.
 536   if (event->phase() != ui::EP_POSTTARGET || !target->delegate())
 537     return;
 538
 539   // TODO(jamescook): Move the resize cursor update code into here from
 540   // CompoundEventFilter?
 541   ResizeShadowController* controller =
 542       Shell::GetInstance()->resize_shadow_controller();
 543   if (controller) {
 544     if (event->flags() & ui::EF_IS_NON_CLIENT) {
 545       int component =
 546           target->delegate()->GetNonClientComponent(event->location());
 547       controller->ShowShadow(target, component);
 548     } else {
 549       controller->HideShadow(target);
 550     }
 551   }
 552 }
 553
 554 void ToplevelWindowEventHandler::HandleMouseExited(
 555     aura::Window* target,
 556     ui::LocatedEvent* event) {
 557   // Shadow effects are applied after target handling. Note that we don't
 558   // respect ER_HANDLED here right now since we have not had a reason to allow
 559   // the target to cancel shadow rendering.
 560   if (event->phase() != ui::EP_POSTTARGET)
 561     return;
 562
 563   ResizeShadowController* controller =
 564       Shell::GetInstance()->resize_shadow_controller();
 565   if (controller)
 566     controller->HideShadow(target);
 567 }
 568
 569 void ToplevelWindowEventHandler::SetWindowStateTypeFromGesture(
 570     aura::Window* window,
 571     wm::WindowStateType new_state_type) {
 572   wm::WindowState* window_state = ash::wm::GetWindowState(window);
 573   // TODO(oshima): Move extra logic (set_unminimize_to_restore_bounds,
 574   // SetRestoreBoundsInParent) that modifies the window state
 575   // into WindowState.
 576   switch (new_state_type) {
 577     case wm::WINDOW_STATE_TYPE_MINIMIZED:
 578       if (window_state->CanMinimize()) {
 579         window_state->Minimize();
 580         window_state->set_unminimize_to_restore_bounds(true);
 581         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 582       }
 583       break;
 584     case wm::WINDOW_STATE_TYPE_MAXIMIZED:
 585       if (window_state->CanMaximize()) {
 586         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 587         window_state->Maximize();
 588       }
 589       break;
 590     case wm::WINDOW_STATE_TYPE_LEFT_SNAPPED:
 591       if (window_state->CanSnap()) {
 592         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 593         const wm::WMEvent event(wm::WM_EVENT_SNAP_LEFT);
 594         window_state->OnWMEvent(&event);
 595       }
 596       break;
 597     case wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED:
 598       if (window_state->CanSnap()) {
 599         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 600         const wm::WMEvent event(wm::WM_EVENT_SNAP_RIGHT);
 601         window_state->OnWMEvent(&event);
 602       }
 603       break;
 604     default:
 605       NOTREACHED();
 606   }
 607 }
 608
 609 void ToplevelWindowEventHandler::ResizerWindowDestroyed() {
 610   CompleteDrag(DRAG_RESIZER_WINDOW_DESTROYED);
 611 }
 612
 613 }  // namespace ash