Home | History | Annotate | Download | only in wm 
      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   virtual ~ScopedWindowResizer();
     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   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
    104 
    105   // WindowStateObserver overrides:
    106   virtual 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
    614