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   // Whether ScopedWindowResizer grabbed capture.
 114   bool grabbed_capture_;
 115
 116   DISALLOW_COPY_AND_ASSIGN(ScopedWindowResizer);
 117 };
 118
 119 ToplevelWindowEventHandler::ScopedWindowResizer::ScopedWindowResizer(
 120     ToplevelWindowEventHandler* handler,
 121     WindowResizer* resizer)
 122     : handler_(handler),
 123       resizer_(resizer),
 124       grabbed_capture_(false) {
 125   aura::Window* target = resizer_->GetTarget();
 126   target->AddObserver(this);
 127   wm::GetWindowState(target)->AddObserver(this);
 128
 129   if (!target->HasCapture()) {
 130     grabbed_capture_ = true;
 131     target->SetCapture();
 132   }
 133 }
 134
 135 ToplevelWindowEventHandler::ScopedWindowResizer::~ScopedWindowResizer() {
 136   aura::Window* target = resizer_->GetTarget();
 137   target->RemoveObserver(this);
 138   wm::GetWindowState(target)->RemoveObserver(this);
 139   if (grabbed_capture_)
 140     target->ReleaseCapture();
 141 }
 142
 143 bool ToplevelWindowEventHandler::ScopedWindowResizer::IsMove() const {
 144   return resizer_->details().bounds_change ==
 145       WindowResizer::kBoundsChange_Repositions;
 146 }
 147
 148 void
 149 ToplevelWindowEventHandler::ScopedWindowResizer::OnPreWindowStateTypeChange(
 150     wm::WindowState* window_state,
 151     wm::WindowStateType old) {
 152   handler_->CompleteDrag(DRAG_COMPLETE);
 153 }
 154
 155 void ToplevelWindowEventHandler::ScopedWindowResizer::OnWindowDestroying(
 156     aura::Window* window) {
 157   DCHECK_EQ(resizer_->GetTarget(), window);
 158   handler_->ResizerWindowDestroyed();
 159 }
 160
 161 // ToplevelWindowEventHandler --------------------------------------------------
 162
 163 ToplevelWindowEventHandler::ToplevelWindowEventHandler()
 164     : first_finger_hittest_(HTNOWHERE),
 165       in_move_loop_(false),
 166       in_gesture_drag_(false),
 167       drag_reverted_(false),
 168       destroyed_(NULL) {
 169   Shell::GetInstance()->display_controller()->AddObserver(this);
 170 }
 171
 172 ToplevelWindowEventHandler::~ToplevelWindowEventHandler() {
 173   Shell::GetInstance()->display_controller()->RemoveObserver(this);
 174   if (destroyed_)
 175     *destroyed_ = true;
 176 }
 177
 178 void ToplevelWindowEventHandler::OnKeyEvent(ui::KeyEvent* event) {
 179   if (window_resizer_.get() && event->type() == ui::ET_KEY_PRESSED &&
 180       event->key_code() == ui::VKEY_ESCAPE) {
 181     CompleteDrag(DRAG_REVERT);
 182   }
 183 }
 184
 185 void ToplevelWindowEventHandler::OnMouseEvent(
 186     ui::MouseEvent* event) {
 187   if (event->handled())
 188     return;
 189   if ((event->flags() &
 190       (ui::EF_MIDDLE_MOUSE_BUTTON | ui::EF_RIGHT_MOUSE_BUTTON)) != 0)
 191     return;
 192
 193   if (in_gesture_drag_)
 194     return;
 195
 196   aura::Window* target = static_cast<aura::Window*>(event->target());
 197   switch (event->type()) {
 198     case ui::ET_MOUSE_PRESSED:
 199       HandleMousePressed(target, event);
 200       break;
 201     case ui::ET_MOUSE_DRAGGED:
 202       HandleDrag(target, event);
 203       break;
 204     case ui::ET_MOUSE_CAPTURE_CHANGED:
 205     case ui::ET_MOUSE_RELEASED:
 206       HandleMouseReleased(target, event);
 207       break;
 208     case ui::ET_MOUSE_MOVED:
 209       HandleMouseMoved(target, event);
 210       break;
 211     case ui::ET_MOUSE_EXITED:
 212       HandleMouseExited(target, event);
 213       break;
 214     default:
 215       break;
 216   }
 217 }
 218
 219 void ToplevelWindowEventHandler::OnGestureEvent(ui::GestureEvent* event) {
 220   if (event->handled())
 221     return;
 222   aura::Window* target = static_cast<aura::Window*>(event->target());
 223   if (!target->delegate())
 224     return;
 225
 226   if (window_resizer_.get() && !in_gesture_drag_)
 227     return;
 228
 229   if (window_resizer_.get() &&
 230       window_resizer_->resizer()->GetTarget() != target) {
 231     return;
 232   }
 233
 234   if (event->details().touch_points() > 2) {
 235     if (CompleteDrag(DRAG_COMPLETE))
 236       event->StopPropagation();
 237     return;
 238   }
 239
 240   switch (event->type()) {
 241     case ui::ET_GESTURE_TAP_DOWN: {
 242       int component = GetWindowComponent(target, *event);
 243       if (!(WindowResizer::GetBoundsChangeForWindowComponent(component) &
 244             WindowResizer::kBoundsChange_Resizes))
 245         return;
 246       ResizeShadowController* controller =
 247           Shell::GetInstance()->resize_shadow_controller();
 248       if (controller)
 249         controller->ShowShadow(target, component);
 250       return;
 251     }
 252     case ui::ET_GESTURE_END: {
 253       ResizeShadowController* controller =
 254           Shell::GetInstance()->resize_shadow_controller();
 255       if (controller)
 256         controller->HideShadow(target);
 257
 258       if (window_resizer_.get() &&
 259           (event->details().touch_points() == 1 ||
 260            !CanStartOneFingerDrag(first_finger_hittest_))) {
 261         CompleteDrag(DRAG_COMPLETE);
 262         event->StopPropagation();
 263       }
 264       return;
 265     }
 266     case ui::ET_GESTURE_BEGIN: {
 267       if (event->details().touch_points() == 1) {
 268         first_finger_hittest_ = GetWindowComponent(target, *event);
 269       } else if (window_resizer_.get()) {
 270         if (!window_resizer_->IsMove()) {
 271           // The transition from resizing with one finger to resizing with two
 272           // fingers causes unintended resizing because the location of
 273           // ET_GESTURE_SCROLL_UPDATE jumps from the position of the first
 274           // finger to the position in the middle of the two fingers. For this
 275           // reason two finger resizing is not supported.
 276           CompleteDrag(DRAG_COMPLETE);
 277           event->StopPropagation();
 278         }
 279       } else {
 280         int second_finger_hittest = GetWindowComponent(target, *event);
 281         if (CanStartTwoFingerMove(
 282                 target, first_finger_hittest_, second_finger_hittest)) {
 283           gfx::Point location_in_parent =
 284               event->details().bounding_box().CenterPoint();
 285           AttemptToStartDrag(target, location_in_parent, HTCAPTION,
 286                              aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 287           event->StopPropagation();
 288         }
 289       }
 290       return;
 291     }
 292     case ui::ET_GESTURE_SCROLL_BEGIN: {
 293       // The one finger drag is not started in ET_GESTURE_BEGIN to avoid the
 294       // window jumping upon initiating a two finger drag. When a one finger
 295       // drag is converted to a two finger drag, a jump occurs because the
 296       // location of the ET_GESTURE_SCROLL_UPDATE event switches from the single
 297       // finger's position to the position in the middle of the two fingers.
 298       if (window_resizer_.get())
 299         return;
 300       int component = GetWindowComponent(target, *event);
 301       if (!CanStartOneFingerDrag(component))
 302         return;
 303       gfx::Point location_in_parent(
 304           ConvertPointToParent(target, event->location()));
 305       AttemptToStartDrag(target, location_in_parent, component,
 306                          aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 307       event->StopPropagation();
 308       return;
 309     }
 310     default:
 311       break;
 312   }
 313
 314   if (!window_resizer_.get())
 315     return;
 316
 317   switch (event->type()) {
 318     case ui::ET_GESTURE_SCROLL_UPDATE:
 319       HandleDrag(target, event);
 320       event->StopPropagation();
 321       return;
 322     case ui::ET_GESTURE_SCROLL_END:
 323       // We must complete the drag here instead of as a result of ET_GESTURE_END
 324       // because otherwise the drag will be reverted when EndMoveLoop() is
 325       // called.
 326       // TODO(pkotwicz): Pass drag completion status to
 327       // WindowMoveClient::EndMoveLoop().
 328       CompleteDrag(DRAG_COMPLETE);
 329       event->StopPropagation();
 330       return;
 331     case ui::ET_SCROLL_FLING_START:
 332       CompleteDrag(DRAG_COMPLETE);
 333
 334       // TODO(pkotwicz): Fix tests which inadvertantly start flings and check
 335       // window_resizer_->IsMove() instead of the hittest component at |event|'s
 336       // location.
 337       if (GetWindowComponent(target, *event) != HTCAPTION ||
 338           !wm::GetWindowState(target)->IsNormalOrSnapped()) {
 339         return;
 340       }
 341
 342       if (event->details().velocity_y() > kMinVertVelocityForWindowMinimize) {
 343         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MINIMIZED);
 344       } else if (event->details().velocity_y() <
 345                  -kMinVertVelocityForWindowMinimize) {
 346         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MAXIMIZED);
 347       } else if (event->details().velocity_x() >
 348                  kMinHorizVelocityForWindowSwipe) {
 349         SetWindowStateTypeFromGesture(target,
 350                                       wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED);
 351       } else if (event->details().velocity_x() <
 352                  -kMinHorizVelocityForWindowSwipe) {
 353         SetWindowStateTypeFromGesture(target,
 354                                       wm::WINDOW_STATE_TYPE_LEFT_SNAPPED);
 355       }
 356       event->StopPropagation();
 357       return;
 358     case ui::ET_GESTURE_SWIPE:
 359       DCHECK_GT(event->details().touch_points(), 0);
 360       if (event->details().touch_points() == 1)
 361         return;
 362       if (!wm::GetWindowState(target)->IsNormalOrSnapped())
 363         return;
 364
 365       CompleteDrag(DRAG_COMPLETE);
 366
 367       if (event->details().swipe_down()) {
 368         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MINIMIZED);
 369       } else if (event->details().swipe_up()) {
 370         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MAXIMIZED);
 371       } else if (event->details().swipe_right()) {
 372         SetWindowStateTypeFromGesture(target,
 373                                       wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED);
 374       } else {
 375         SetWindowStateTypeFromGesture(target,
 376                                       wm::WINDOW_STATE_TYPE_LEFT_SNAPPED);
 377       }
 378       event->StopPropagation();
 379       return;
 380     default:
 381       return;
 382   }
 383 }
 384
 385 aura::client::WindowMoveResult ToplevelWindowEventHandler::RunMoveLoop(
 386     aura::Window* source,
 387     const gfx::Vector2d& drag_offset,
 388     aura::client::WindowMoveSource move_source) {
 389   DCHECK(!in_move_loop_);  // Can only handle one nested loop at a time.
 390   aura::Window* root_window = source->GetRootWindow();
 391   DCHECK(root_window);
 392   // TODO(tdresser): Use gfx::PointF. See crbug.com/337824.
 393   gfx::Point drag_location;
 394   if (move_source == aura::client::WINDOW_MOVE_SOURCE_TOUCH &&
 395       aura::Env::GetInstance()->is_touch_down()) {
 396     gfx::PointF drag_location_f;
 397     bool has_point = ui::GestureRecognizer::Get()->
 398         GetLastTouchPointForTarget(source, &drag_location_f);
 399     drag_location = gfx::ToFlooredPoint(drag_location_f);
 400     DCHECK(has_point);
 401   } else {
 402     drag_location =
 403         root_window->GetHost()->dispatcher()->GetLastMouseLocationInRoot();
 404     aura::Window::ConvertPointToTarget(
 405         root_window, source->parent(), &drag_location);
 406   }
 407   // Set the cursor before calling AttemptToStartDrag(), as that will
 408   // eventually call LockCursor() and prevent the cursor from changing.
 409   aura::client::CursorClient* cursor_client =
 410       aura::client::GetCursorClient(root_window);
 411   if (cursor_client)
 412     cursor_client->SetCursor(ui::kCursorPointer);
 413   if (!AttemptToStartDrag(source, drag_location, HTCAPTION, move_source))
 414     return aura::client::MOVE_CANCELED;
 415
 416   in_move_loop_ = true;
 417   bool destroyed = false;
 418   destroyed_ = &destroyed;
 419   base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
 420   base::MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
 421   base::RunLoop run_loop;
 422   quit_closure_ = run_loop.QuitClosure();
 423   run_loop.Run();
 424   if (destroyed)
 425     return aura::client::MOVE_CANCELED;
 426   destroyed_ = NULL;
 427   in_move_loop_ = false;
 428   return drag_reverted_ ? aura::client::MOVE_CANCELED :
 429       aura::client::MOVE_SUCCESSFUL;
 430 }
 431
 432 void ToplevelWindowEventHandler::EndMoveLoop() {
 433   if (in_move_loop_)
 434     CompleteDrag(DRAG_REVERT);
 435 }
 436
 437 void ToplevelWindowEventHandler::OnDisplayConfigurationChanging() {
 438   CompleteDrag(DRAG_REVERT);
 439 }
 440
 441 bool ToplevelWindowEventHandler::AttemptToStartDrag(
 442     aura::Window* window,
 443     const gfx::Point& point_in_parent,
 444     int window_component,
 445     aura::client::WindowMoveSource source) {
 446   if (window_resizer_.get())
 447     return false;
 448   WindowResizer* resizer = CreateWindowResizer(window, point_in_parent,
 449       window_component, source).release();
 450   if (!resizer)
 451     return false;
 452
 453   window_resizer_.reset(new ScopedWindowResizer(this, resizer));
 454
 455   pre_drag_window_bounds_ = window->bounds();
 456   in_gesture_drag_ = (source == aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 457   return true;
 458 }
 459
 460 bool ToplevelWindowEventHandler::CompleteDrag(DragCompletionStatus status) {
 461   if (!window_resizer_)
 462     return false;
 463
 464   scoped_ptr<ScopedWindowResizer> resizer(window_resizer_.release());
 465   switch (status) {
 466     case DRAG_COMPLETE:
 467       resizer->resizer()->CompleteDrag();
 468       break;
 469     case DRAG_REVERT:
 470       resizer->resizer()->RevertDrag();
 471       break;
 472     case DRAG_RESIZER_WINDOW_DESTROYED:
 473       // We explicitly do not invoke RevertDrag() since that may do things to
 474       // WindowResizer::GetTarget() which was destroyed.
 475       break;
 476   }
 477   drag_reverted_ = (status != DRAG_COMPLETE);
 478
 479   first_finger_hittest_ = HTNOWHERE;
 480   in_gesture_drag_ = false;
 481   if (in_move_loop_)
 482     quit_closure_.Run();
 483   return true;
 484 }
 485
 486 void ToplevelWindowEventHandler::HandleMousePressed(
 487     aura::Window* target,
 488     ui::MouseEvent* event) {
 489   if (event->phase() != ui::EP_PRETARGET || !target->delegate())
 490     return;
 491
 492   // We also update the current window component here because for the
 493   // mouse-drag-release-press case, where the mouse is released and
 494   // pressed without mouse move event.
 495   int component = GetWindowComponent(target, *event);
 496   if ((event->flags() &
 497         (ui::EF_IS_DOUBLE_CLICK | ui::EF_IS_TRIPLE_CLICK)) == 0 &&
 498       WindowResizer::GetBoundsChangeForWindowComponent(component)) {
 499     gfx::Point location_in_parent(
 500         ConvertPointToParent(target, event->location()));
 501     AttemptToStartDrag(target, location_in_parent, component,
 502                        aura::client::WINDOW_MOVE_SOURCE_MOUSE);
 503     // Set as handled so that other event handlers do no act upon the event
 504     // but still receive it so that they receive both parts of each pressed/
 505     // released pair.
 506     event->SetHandled();
 507   } else {
 508     CompleteDrag(DRAG_COMPLETE);
 509   }
 510 }
 511
 512 void ToplevelWindowEventHandler::HandleMouseReleased(
 513     aura::Window* target,
 514     ui::MouseEvent* event) {
 515   if (event->phase() != ui::EP_PRETARGET)
 516     return;
 517
 518   CompleteDrag(event->type() == ui::ET_MOUSE_RELEASED ?
 519                    DRAG_COMPLETE : DRAG_REVERT);
 520 }
 521
 522 void ToplevelWindowEventHandler::HandleDrag(
 523     aura::Window* target,
 524     ui::LocatedEvent* event) {
 525   // This function only be triggered to move window
 526   // by mouse drag or touch move event.
 527   DCHECK(event->type() == ui::ET_MOUSE_DRAGGED ||
 528          event->type() == ui::ET_TOUCH_MOVED ||
 529          event->type() == ui::ET_GESTURE_SCROLL_UPDATE);
 530
 531   // Drag actions are performed pre-target handling to prevent spurious mouse
 532   // moves from the move/size operation from being sent to the target.
 533   if (event->phase() != ui::EP_PRETARGET)
 534     return;
 535
 536   if (!window_resizer_)
 537     return;
 538   window_resizer_->resizer()->Drag(
 539       ConvertPointToParent(target, event->location()), event->flags());
 540   event->StopPropagation();
 541 }
 542
 543 void ToplevelWindowEventHandler::HandleMouseMoved(
 544     aura::Window* target,
 545     ui::LocatedEvent* event) {
 546   // Shadow effects are applied after target handling. Note that we don't
 547   // respect ER_HANDLED here right now since we have not had a reason to allow
 548   // the target to cancel shadow rendering.
 549   if (event->phase() != ui::EP_POSTTARGET || !target->delegate())
 550     return;
 551
 552   // TODO(jamescook): Move the resize cursor update code into here from
 553   // CompoundEventFilter?
 554   ResizeShadowController* controller =
 555       Shell::GetInstance()->resize_shadow_controller();
 556   if (controller) {
 557     if (event->flags() & ui::EF_IS_NON_CLIENT) {
 558       int component =
 559           target->delegate()->GetNonClientComponent(event->location());
 560       controller->ShowShadow(target, component);
 561     } else {
 562       controller->HideShadow(target);
 563     }
 564   }
 565 }
 566
 567 void ToplevelWindowEventHandler::HandleMouseExited(
 568     aura::Window* target,
 569     ui::LocatedEvent* event) {
 570   // Shadow effects are applied after target handling. Note that we don't
 571   // respect ER_HANDLED here right now since we have not had a reason to allow
 572   // the target to cancel shadow rendering.
 573   if (event->phase() != ui::EP_POSTTARGET)
 574     return;
 575
 576   ResizeShadowController* controller =
 577       Shell::GetInstance()->resize_shadow_controller();
 578   if (controller)
 579     controller->HideShadow(target);
 580 }
 581
 582 void ToplevelWindowEventHandler::SetWindowStateTypeFromGesture(
 583     aura::Window* window,
 584     wm::WindowStateType new_state_type) {
 585   wm::WindowState* window_state = ash::wm::GetWindowState(window);
 586   // TODO(oshima): Move extra logic (set_unminimize_to_restore_bounds,
 587   // SetRestoreBoundsInParent) that modifies the window state
 588   // into WindowState.
 589   switch (new_state_type) {
 590     case wm::WINDOW_STATE_TYPE_MINIMIZED:
 591       if (window_state->CanMinimize()) {
 592         window_state->Minimize();
 593         window_state->set_unminimize_to_restore_bounds(true);
 594         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 595       }
 596       break;
 597     case wm::WINDOW_STATE_TYPE_MAXIMIZED:
 598       if (window_state->CanMaximize()) {
 599         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 600         window_state->Maximize();
 601       }
 602       break;
 603     case wm::WINDOW_STATE_TYPE_LEFT_SNAPPED:
 604       if (window_state->CanSnap()) {
 605         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 606         const wm::WMEvent event(wm::WM_EVENT_SNAP_LEFT);
 607         window_state->OnWMEvent(&event);
 608       }
 609       break;
 610     case wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED:
 611       if (window_state->CanSnap()) {
 612         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 613         const wm::WMEvent event(wm::WM_EVENT_SNAP_RIGHT);
 614         window_state->OnWMEvent(&event);
 615       }
 616       break;
 617     default:
 618       NOTREACHED();
 619   }
 620 }
 621
 622 void ToplevelWindowEventHandler::ResizerWindowDestroyed() {
 623   CompleteDrag(DRAG_RESIZER_WINDOW_DESTROYED);
 624 }
 625
 626 }  // namespace ash