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()->window_tree_host_manager()->AddObserver(this);
 170 }
 171
 172 ToplevelWindowEventHandler::~ToplevelWindowEventHandler() {
 173   Shell::GetInstance()->window_tree_host_manager()->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 (event->type() == ui::ET_MOUSE_CAPTURE_CHANGED) {
 194     // Capture is grabbed when both gesture and mouse drags start. Handle
 195     // capture loss regardless of which type of drag is in progress.
 196     HandleCaptureLost(event);
 197     return;
 198   }
 199
 200   if (in_gesture_drag_)
 201     return;
 202
 203   aura::Window* target = static_cast<aura::Window*>(event->target());
 204   switch (event->type()) {
 205     case ui::ET_MOUSE_PRESSED:
 206       HandleMousePressed(target, event);
 207       break;
 208     case ui::ET_MOUSE_DRAGGED:
 209       HandleDrag(target, event);
 210       break;
 211     case ui::ET_MOUSE_RELEASED:
 212       HandleMouseReleased(target, event);
 213       break;
 214     case ui::ET_MOUSE_MOVED:
 215       HandleMouseMoved(target, event);
 216       break;
 217     case ui::ET_MOUSE_EXITED:
 218       HandleMouseExited(target, event);
 219       break;
 220     default:
 221       break;
 222   }
 223 }
 224
 225 void ToplevelWindowEventHandler::OnGestureEvent(ui::GestureEvent* event) {
 226   if (event->handled())
 227     return;
 228   aura::Window* target = static_cast<aura::Window*>(event->target());
 229   if (!target->delegate())
 230     return;
 231
 232   if (window_resizer_.get() && !in_gesture_drag_)
 233     return;
 234
 235   if (window_resizer_.get() &&
 236       window_resizer_->resizer()->GetTarget() != target) {
 237     return;
 238   }
 239
 240   if (event->details().touch_points() > 2) {
 241     if (CompleteDrag(DRAG_COMPLETE))
 242       event->StopPropagation();
 243     return;
 244   }
 245
 246   switch (event->type()) {
 247     case ui::ET_GESTURE_TAP_DOWN: {
 248       int component = GetWindowComponent(target, *event);
 249       if (!(WindowResizer::GetBoundsChangeForWindowComponent(component) &
 250             WindowResizer::kBoundsChange_Resizes))
 251         return;
 252       ResizeShadowController* controller =
 253           Shell::GetInstance()->resize_shadow_controller();
 254       if (controller)
 255         controller->ShowShadow(target, component);
 256       return;
 257     }
 258     case ui::ET_GESTURE_END: {
 259       ResizeShadowController* controller =
 260           Shell::GetInstance()->resize_shadow_controller();
 261       if (controller)
 262         controller->HideShadow(target);
 263
 264       if (window_resizer_.get() &&
 265           (event->details().touch_points() == 1 ||
 266            !CanStartOneFingerDrag(first_finger_hittest_))) {
 267         CompleteDrag(DRAG_COMPLETE);
 268         event->StopPropagation();
 269       }
 270       return;
 271     }
 272     case ui::ET_GESTURE_BEGIN: {
 273       if (event->details().touch_points() == 1) {
 274         first_finger_hittest_ = GetWindowComponent(target, *event);
 275       } else if (window_resizer_.get()) {
 276         if (!window_resizer_->IsMove()) {
 277           // The transition from resizing with one finger to resizing with two
 278           // fingers causes unintended resizing because the location of
 279           // ET_GESTURE_SCROLL_UPDATE jumps from the position of the first
 280           // finger to the position in the middle of the two fingers. For this
 281           // reason two finger resizing is not supported.
 282           CompleteDrag(DRAG_COMPLETE);
 283           event->StopPropagation();
 284         }
 285       } else {
 286         int second_finger_hittest = GetWindowComponent(target, *event);
 287         if (CanStartTwoFingerMove(
 288                 target, first_finger_hittest_, second_finger_hittest)) {
 289           gfx::Point location_in_parent =
 290               event->details().bounding_box().CenterPoint();
 291           AttemptToStartDrag(target, location_in_parent, HTCAPTION,
 292                              aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 293           event->StopPropagation();
 294         }
 295       }
 296       return;
 297     }
 298     case ui::ET_GESTURE_SCROLL_BEGIN: {
 299       // The one finger drag is not started in ET_GESTURE_BEGIN to avoid the
 300       // window jumping upon initiating a two finger drag. When a one finger
 301       // drag is converted to a two finger drag, a jump occurs because the
 302       // location of the ET_GESTURE_SCROLL_UPDATE event switches from the single
 303       // finger's position to the position in the middle of the two fingers.
 304       if (window_resizer_.get())
 305         return;
 306       int component = GetWindowComponent(target, *event);
 307       if (!CanStartOneFingerDrag(component))
 308         return;
 309       gfx::Point location_in_parent(
 310           ConvertPointToParent(target, event->location()));
 311       AttemptToStartDrag(target, location_in_parent, component,
 312                          aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 313       event->StopPropagation();
 314       return;
 315     }
 316     default:
 317       break;
 318   }
 319
 320   if (!window_resizer_.get())
 321     return;
 322
 323   switch (event->type()) {
 324     case ui::ET_GESTURE_SCROLL_UPDATE:
 325       HandleDrag(target, event);
 326       event->StopPropagation();
 327       return;
 328     case ui::ET_GESTURE_SCROLL_END:
 329       // We must complete the drag here instead of as a result of ET_GESTURE_END
 330       // because otherwise the drag will be reverted when EndMoveLoop() is
 331       // called.
 332       // TODO(pkotwicz): Pass drag completion status to
 333       // WindowMoveClient::EndMoveLoop().
 334       CompleteDrag(DRAG_COMPLETE);
 335       event->StopPropagation();
 336       return;
 337     case ui::ET_SCROLL_FLING_START:
 338       CompleteDrag(DRAG_COMPLETE);
 339
 340       // TODO(pkotwicz): Fix tests which inadvertantly start flings and check
 341       // window_resizer_->IsMove() instead of the hittest component at |event|'s
 342       // location.
 343       if (GetWindowComponent(target, *event) != HTCAPTION ||
 344           !wm::GetWindowState(target)->IsNormalOrSnapped()) {
 345         return;
 346       }
 347
 348       if (event->details().velocity_y() > kMinVertVelocityForWindowMinimize) {
 349         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MINIMIZED);
 350       } else if (event->details().velocity_y() <
 351                  -kMinVertVelocityForWindowMinimize) {
 352         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MAXIMIZED);
 353       } else if (event->details().velocity_x() >
 354                  kMinHorizVelocityForWindowSwipe) {
 355         SetWindowStateTypeFromGesture(target,
 356                                       wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED);
 357       } else if (event->details().velocity_x() <
 358                  -kMinHorizVelocityForWindowSwipe) {
 359         SetWindowStateTypeFromGesture(target,
 360                                       wm::WINDOW_STATE_TYPE_LEFT_SNAPPED);
 361       }
 362       event->StopPropagation();
 363       return;
 364     case ui::ET_GESTURE_SWIPE:
 365       DCHECK_GT(event->details().touch_points(), 0);
 366       if (event->details().touch_points() == 1)
 367         return;
 368       if (!wm::GetWindowState(target)->IsNormalOrSnapped())
 369         return;
 370
 371       CompleteDrag(DRAG_COMPLETE);
 372
 373       if (event->details().swipe_down()) {
 374         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MINIMIZED);
 375       } else if (event->details().swipe_up()) {
 376         SetWindowStateTypeFromGesture(target, wm::WINDOW_STATE_TYPE_MAXIMIZED);
 377       } else if (event->details().swipe_right()) {
 378         SetWindowStateTypeFromGesture(target,
 379                                       wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED);
 380       } else {
 381         SetWindowStateTypeFromGesture(target,
 382                                       wm::WINDOW_STATE_TYPE_LEFT_SNAPPED);
 383       }
 384       event->StopPropagation();
 385       return;
 386     default:
 387       return;
 388   }
 389 }
 390
 391 aura::client::WindowMoveResult ToplevelWindowEventHandler::RunMoveLoop(
 392     aura::Window* source,
 393     const gfx::Vector2d& drag_offset,
 394     aura::client::WindowMoveSource move_source) {
 395   DCHECK(!in_move_loop_);  // Can only handle one nested loop at a time.
 396   aura::Window* root_window = source->GetRootWindow();
 397   DCHECK(root_window);
 398   // TODO(tdresser): Use gfx::PointF. See crbug.com/337824.
 399   gfx::Point drag_location;
 400   if (move_source == aura::client::WINDOW_MOVE_SOURCE_TOUCH &&
 401       aura::Env::GetInstance()->is_touch_down()) {
 402     gfx::PointF drag_location_f;
 403     bool has_point = ui::GestureRecognizer::Get()->
 404         GetLastTouchPointForTarget(source, &drag_location_f);
 405     drag_location = gfx::ToFlooredPoint(drag_location_f);
 406     DCHECK(has_point);
 407   } else {
 408     drag_location =
 409         root_window->GetHost()->dispatcher()->GetLastMouseLocationInRoot();
 410     aura::Window::ConvertPointToTarget(
 411         root_window, source->parent(), &drag_location);
 412   }
 413   // Set the cursor before calling AttemptToStartDrag(), as that will
 414   // eventually call LockCursor() and prevent the cursor from changing.
 415   aura::client::CursorClient* cursor_client =
 416       aura::client::GetCursorClient(root_window);
 417   if (cursor_client)
 418     cursor_client->SetCursor(ui::kCursorPointer);
 419   if (!AttemptToStartDrag(source, drag_location, HTCAPTION, move_source))
 420     return aura::client::MOVE_CANCELED;
 421
 422   in_move_loop_ = true;
 423   bool destroyed = false;
 424   destroyed_ = &destroyed;
 425   base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
 426   base::MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
 427   base::RunLoop run_loop;
 428   quit_closure_ = run_loop.QuitClosure();
 429   run_loop.Run();
 430   if (destroyed)
 431     return aura::client::MOVE_CANCELED;
 432   destroyed_ = NULL;
 433   in_move_loop_ = false;
 434   return drag_reverted_ ? aura::client::MOVE_CANCELED :
 435       aura::client::MOVE_SUCCESSFUL;
 436 }
 437
 438 void ToplevelWindowEventHandler::EndMoveLoop() {
 439   if (in_move_loop_)
 440     CompleteDrag(DRAG_REVERT);
 441 }
 442
 443 void ToplevelWindowEventHandler::OnDisplayConfigurationChanging() {
 444   CompleteDrag(DRAG_REVERT);
 445 }
 446
 447 bool ToplevelWindowEventHandler::AttemptToStartDrag(
 448     aura::Window* window,
 449     const gfx::Point& point_in_parent,
 450     int window_component,
 451     aura::client::WindowMoveSource source) {
 452   if (window_resizer_.get())
 453     return false;
 454   WindowResizer* resizer = CreateWindowResizer(window, point_in_parent,
 455       window_component, source).release();
 456   if (!resizer)
 457     return false;
 458
 459   window_resizer_.reset(new ScopedWindowResizer(this, resizer));
 460
 461   pre_drag_window_bounds_ = window->bounds();
 462   in_gesture_drag_ = (source == aura::client::WINDOW_MOVE_SOURCE_TOUCH);
 463   return true;
 464 }
 465
 466 bool ToplevelWindowEventHandler::CompleteDrag(DragCompletionStatus status) {
 467   if (!window_resizer_)
 468     return false;
 469
 470   scoped_ptr<ScopedWindowResizer> resizer(window_resizer_.release());
 471   switch (status) {
 472     case DRAG_COMPLETE:
 473       resizer->resizer()->CompleteDrag();
 474       break;
 475     case DRAG_REVERT:
 476       resizer->resizer()->RevertDrag();
 477       break;
 478     case DRAG_RESIZER_WINDOW_DESTROYED:
 479       // We explicitly do not invoke RevertDrag() since that may do things to
 480       // WindowResizer::GetTarget() which was destroyed.
 481       break;
 482   }
 483   drag_reverted_ = (status != DRAG_COMPLETE);
 484
 485   first_finger_hittest_ = HTNOWHERE;
 486   in_gesture_drag_ = false;
 487   if (in_move_loop_)
 488     quit_closure_.Run();
 489   return true;
 490 }
 491
 492 void ToplevelWindowEventHandler::HandleMousePressed(
 493     aura::Window* target,
 494     ui::MouseEvent* event) {
 495   if (event->phase() != ui::EP_PRETARGET || !target->delegate())
 496     return;
 497
 498   // We also update the current window component here because for the
 499   // mouse-drag-release-press case, where the mouse is released and
 500   // pressed without mouse move event.
 501   int component = GetWindowComponent(target, *event);
 502   if ((event->flags() &
 503         (ui::EF_IS_DOUBLE_CLICK | ui::EF_IS_TRIPLE_CLICK)) == 0 &&
 504       WindowResizer::GetBoundsChangeForWindowComponent(component)) {
 505     gfx::Point location_in_parent(
 506         ConvertPointToParent(target, event->location()));
 507     AttemptToStartDrag(target, location_in_parent, component,
 508                        aura::client::WINDOW_MOVE_SOURCE_MOUSE);
 509     // Set as handled so that other event handlers do no act upon the event
 510     // but still receive it so that they receive both parts of each pressed/
 511     // released pair.
 512     event->SetHandled();
 513   } else {
 514     CompleteDrag(DRAG_COMPLETE);
 515   }
 516 }
 517
 518 void ToplevelWindowEventHandler::HandleMouseReleased(
 519     aura::Window* target,
 520     ui::MouseEvent* event) {
 521   if (event->phase() == ui::EP_PRETARGET)
 522     CompleteDrag(DRAG_COMPLETE);
 523 }
 524
 525 void ToplevelWindowEventHandler::HandleDrag(
 526     aura::Window* target,
 527     ui::LocatedEvent* event) {
 528   // This function only be triggered to move window
 529   // by mouse drag or touch move event.
 530   DCHECK(event->type() == ui::ET_MOUSE_DRAGGED ||
 531          event->type() == ui::ET_TOUCH_MOVED ||
 532          event->type() == ui::ET_GESTURE_SCROLL_UPDATE);
 533
 534   // Drag actions are performed pre-target handling to prevent spurious mouse
 535   // moves from the move/size operation from being sent to the target.
 536   if (event->phase() != ui::EP_PRETARGET)
 537     return;
 538
 539   if (!window_resizer_)
 540     return;
 541   window_resizer_->resizer()->Drag(
 542       ConvertPointToParent(target, event->location()), event->flags());
 543   event->StopPropagation();
 544 }
 545
 546 void ToplevelWindowEventHandler::HandleMouseMoved(
 547     aura::Window* target,
 548     ui::LocatedEvent* event) {
 549   // Shadow effects are applied after target handling. Note that we don't
 550   // respect ER_HANDLED here right now since we have not had a reason to allow
 551   // the target to cancel shadow rendering.
 552   if (event->phase() != ui::EP_POSTTARGET || !target->delegate())
 553     return;
 554
 555   // TODO(jamescook): Move the resize cursor update code into here from
 556   // CompoundEventFilter?
 557   ResizeShadowController* controller =
 558       Shell::GetInstance()->resize_shadow_controller();
 559   if (controller) {
 560     if (event->flags() & ui::EF_IS_NON_CLIENT) {
 561       int component =
 562           target->delegate()->GetNonClientComponent(event->location());
 563       controller->ShowShadow(target, component);
 564     } else {
 565       controller->HideShadow(target);
 566     }
 567   }
 568 }
 569
 570 void ToplevelWindowEventHandler::HandleMouseExited(
 571     aura::Window* target,
 572     ui::LocatedEvent* event) {
 573   // Shadow effects are applied after target handling. Note that we don't
 574   // respect ER_HANDLED here right now since we have not had a reason to allow
 575   // the target to cancel shadow rendering.
 576   if (event->phase() != ui::EP_POSTTARGET)
 577     return;
 578
 579   ResizeShadowController* controller =
 580       Shell::GetInstance()->resize_shadow_controller();
 581   if (controller)
 582     controller->HideShadow(target);
 583 }
 584
 585 void ToplevelWindowEventHandler::HandleCaptureLost(ui::LocatedEvent* event) {
 586   if (event->phase() == ui::EP_PRETARGET)
 587     CompleteDrag(DRAG_REVERT);
 588 }
 589
 590 void ToplevelWindowEventHandler::SetWindowStateTypeFromGesture(
 591     aura::Window* window,
 592     wm::WindowStateType new_state_type) {
 593   wm::WindowState* window_state = ash::wm::GetWindowState(window);
 594   // TODO(oshima): Move extra logic (set_unminimize_to_restore_bounds,
 595   // SetRestoreBoundsInParent) that modifies the window state
 596   // into WindowState.
 597   switch (new_state_type) {
 598     case wm::WINDOW_STATE_TYPE_MINIMIZED:
 599       if (window_state->CanMinimize()) {
 600         window_state->Minimize();
 601         window_state->set_unminimize_to_restore_bounds(true);
 602         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 603       }
 604       break;
 605     case wm::WINDOW_STATE_TYPE_MAXIMIZED:
 606       if (window_state->CanMaximize()) {
 607         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 608         window_state->Maximize();
 609       }
 610       break;
 611     case wm::WINDOW_STATE_TYPE_LEFT_SNAPPED:
 612       if (window_state->CanSnap()) {
 613         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 614         const wm::WMEvent event(wm::WM_EVENT_SNAP_LEFT);
 615         window_state->OnWMEvent(&event);
 616       }
 617       break;
 618     case wm::WINDOW_STATE_TYPE_RIGHT_SNAPPED:
 619       if (window_state->CanSnap()) {
 620         window_state->SetRestoreBoundsInParent(pre_drag_window_bounds_);
 621         const wm::WMEvent event(wm::WM_EVENT_SNAP_RIGHT);
 622         window_state->OnWMEvent(&event);
 623       }
 624       break;
 625     default:
 626       NOTREACHED();
 627   }
 628 }
 629
 630 void ToplevelWindowEventHandler::ResizerWindowDestroyed() {
 631   CompleteDrag(DRAG_RESIZER_WINDOW_DESTROYED);
 632 }
 633
 634 }  // namespace ash