src/ash/drag_drop/drag_drop_controller.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/drag_drop/drag_drop_controller.h"
   6
   7 #include "ash/drag_drop/drag_drop_tracker.h"
   8 #include "ash/drag_drop/drag_image_view.h"
   9 #include "ash/shell.h"
  10 #include "base/bind.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/run_loop.h"
  13 #include "ui/aura/client/capture_client.h"
  14 #include "ui/aura/env.h"
  15 #include "ui/aura/window.h"
  16 #include "ui/aura/window_delegate.h"
  17 #include "ui/aura/window_event_dispatcher.h"
  18 #include "ui/base/dragdrop/drag_drop_types.h"
  19 #include "ui/base/dragdrop/os_exchange_data.h"
  20 #include "ui/base/hit_test.h"
  21 #include "ui/events/event.h"
  22 #include "ui/events/event_utils.h"
  23 #include "ui/gfx/animation/linear_animation.h"
  24 #include "ui/gfx/path.h"
  25 #include "ui/gfx/point.h"
  26 #include "ui/gfx/rect.h"
  27 #include "ui/gfx/rect_conversions.h"
  28 #include "ui/views/views_delegate.h"
  29 #include "ui/views/widget/native_widget_aura.h"
  30 #include "ui/wm/core/coordinate_conversion.h"
  31 #include "ui/wm/public/drag_drop_delegate.h"
  32
  33 namespace ash {
  34 namespace {
  35
  36 // The duration of the drag cancel animation in millisecond.
  37 const int kCancelAnimationDuration = 250;
  38 const int kTouchCancelAnimationDuration = 20;
  39 // The frame rate of the drag cancel animation in hertz.
  40 const int kCancelAnimationFrameRate = 60;
  41
  42 // For touch initiated dragging, we scale and shift drag image by the following:
  43 static const float kTouchDragImageScale = 1.2f;
  44 static const int kTouchDragImageVerticalOffset = -25;
  45
  46 // Adjusts the drag image bounds such that the new bounds are scaled by |scale|
  47 // and translated by the |drag_image_offset| and and additional
  48 // |vertical_offset|.
  49 gfx::Rect AdjustDragImageBoundsForScaleAndOffset(
  50     const gfx::Rect& drag_image_bounds,
  51     int vertical_offset,
  52     float scale,
  53     gfx::Vector2d* drag_image_offset) {
  54   gfx::PointF final_origin = drag_image_bounds.origin();
  55   gfx::SizeF final_size = drag_image_bounds.size();
  56   final_size.Scale(scale);
  57   drag_image_offset->set_x(drag_image_offset->x() * scale);
  58   drag_image_offset->set_y(drag_image_offset->y() * scale);
  59   float total_x_offset = drag_image_offset->x();
  60   float total_y_offset = drag_image_offset->y() - vertical_offset;
  61   final_origin.Offset(-total_x_offset, -total_y_offset);
  62   return gfx::ToEnclosingRect(gfx::RectF(final_origin, final_size));
  63 }
  64
  65 void DispatchGestureEndToWindow(aura::Window* window) {
  66   if (window && window->delegate()) {
  67     ui::GestureEvent gesture_end(
  68         0,
  69         0,
  70         0,
  71         ui::EventTimeForNow(),
  72         ui::GestureEventDetails(ui::ET_GESTURE_END, 0, 0));
  73     window->delegate()->OnGestureEvent(&gesture_end);
  74   }
  75 }
  76 }  // namespace
  77
  78 class DragDropTrackerDelegate : public aura::WindowDelegate {
  79  public:
  80   explicit DragDropTrackerDelegate(DragDropController* controller)
  81       : drag_drop_controller_(controller) {}
  82   virtual ~DragDropTrackerDelegate() {}
  83
  84   // Overridden from WindowDelegate:
  85   virtual gfx::Size GetMinimumSize() const OVERRIDE {
  86     return gfx::Size();
  87   }
  88
  89   virtual gfx::Size GetMaximumSize() const OVERRIDE {
  90     return gfx::Size();
  91   }
  92
  93   virtual void OnBoundsChanged(const gfx::Rect& old_bounds,
  94                                const gfx::Rect& new_bounds) OVERRIDE {}
  95   virtual gfx::NativeCursor GetCursor(const gfx::Point& point) OVERRIDE {
  96     return gfx::kNullCursor;
  97   }
  98   virtual int GetNonClientComponent(const gfx::Point& point) const OVERRIDE {
  99     return HTCAPTION;
 100   }
 101   virtual bool ShouldDescendIntoChildForEventHandling(
 102       aura::Window* child,
 103       const gfx::Point& location) OVERRIDE {
 104     return true;
 105   }
 106   virtual bool CanFocus() OVERRIDE { return true; }
 107   virtual void OnCaptureLost() OVERRIDE {
 108     if (drag_drop_controller_->IsDragDropInProgress())
 109       drag_drop_controller_->DragCancel();
 110   }
 111   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
 112   }
 113   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {}
 114   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE {}
 115   virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE {}
 116   virtual void OnWindowTargetVisibilityChanged(bool visible) OVERRIDE {}
 117   virtual bool HasHitTestMask() const OVERRIDE {
 118     return true;
 119   }
 120   virtual void GetHitTestMask(gfx::Path* mask) const OVERRIDE {
 121     DCHECK(mask->isEmpty());
 122   }
 123
 124  private:
 125   DragDropController* drag_drop_controller_;
 126
 127   DISALLOW_COPY_AND_ASSIGN(DragDropTrackerDelegate);
 128 };
 129
 130 ////////////////////////////////////////////////////////////////////////////////
 131 // DragDropController, public:
 132
 133 DragDropController::DragDropController()
 134     : drag_data_(NULL),
 135       drag_operation_(0),
 136       drag_window_(NULL),
 137       drag_source_window_(NULL),
 138       should_block_during_drag_drop_(true),
 139       drag_drop_window_delegate_(new DragDropTrackerDelegate(this)),
 140       current_drag_event_source_(ui::DragDropTypes::DRAG_EVENT_SOURCE_MOUSE),
 141       weak_factory_(this) {
 142   Shell::GetInstance()->PrependPreTargetHandler(this);
 143 }
 144
 145 DragDropController::~DragDropController() {
 146   Shell::GetInstance()->RemovePreTargetHandler(this);
 147   Cleanup();
 148   if (cancel_animation_)
 149     cancel_animation_->End();
 150   if (drag_image_)
 151     drag_image_.reset();
 152 }
 153
 154 int DragDropController::StartDragAndDrop(
 155     const ui::OSExchangeData& data,
 156     aura::Window* root_window,
 157     aura::Window* source_window,
 158     const gfx::Point& root_location,
 159     int operation,
 160     ui::DragDropTypes::DragEventSource source) {
 161   if (IsDragDropInProgress())
 162     return 0;
 163
 164   const ui::OSExchangeData::Provider* provider = &data.provider();
 165   // We do not support touch drag/drop without a drag image.
 166   if (source == ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH &&
 167       provider->GetDragImage().size().IsEmpty())
 168     return 0;
 169
 170   current_drag_event_source_ = source;
 171   DragDropTracker* tracker =
 172       new DragDropTracker(root_window, drag_drop_window_delegate_.get());
 173   if (source == ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH) {
 174     // We need to transfer the current gesture sequence and the GR's touch event
 175     // queue to the |drag_drop_tracker_|'s capture window so that when it takes
 176     // capture, it still gets a valid gesture state.
 177     ui::GestureRecognizer::Get()->TransferEventsTo(source_window,
 178         tracker->capture_window());
 179     // We also send a gesture end to the source window so it can clear state.
 180     // TODO(varunjain): Remove this whole block when gesture sequence
 181     // transferring is properly done in the GR (http://crbug.com/160558)
 182     DispatchGestureEndToWindow(source_window);
 183   }
 184   tracker->TakeCapture();
 185   drag_drop_tracker_.reset(tracker);
 186   drag_source_window_ = source_window;
 187   if (drag_source_window_)
 188     drag_source_window_->AddObserver(this);
 189   pending_long_tap_.reset();
 190
 191   drag_data_ = &data;
 192   drag_operation_ = operation;
 193
 194   float drag_image_scale = 1;
 195   int drag_image_vertical_offset = 0;
 196   if (source == ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH) {
 197     drag_image_scale = kTouchDragImageScale;
 198     drag_image_vertical_offset = kTouchDragImageVerticalOffset;
 199   }
 200   gfx::Point start_location = root_location;
 201   ::wm::ConvertPointToScreen(root_window, &start_location);
 202   drag_image_final_bounds_for_cancel_animation_ = gfx::Rect(
 203       start_location - provider->GetDragImageOffset(),
 204       provider->GetDragImage().size());
 205   drag_image_.reset(new DragImageView(source_window->GetRootWindow(), source));
 206   drag_image_->SetImage(provider->GetDragImage());
 207   drag_image_offset_ = provider->GetDragImageOffset();
 208   gfx::Rect drag_image_bounds(start_location, drag_image_->GetPreferredSize());
 209   drag_image_bounds = AdjustDragImageBoundsForScaleAndOffset(drag_image_bounds,
 210       drag_image_vertical_offset, drag_image_scale, &drag_image_offset_);
 211   drag_image_->SetBoundsInScreen(drag_image_bounds);
 212   drag_image_->SetWidgetVisible(true);
 213   if (source == ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH) {
 214     drag_image_->SetTouchDragOperationHintPosition(gfx::Point(
 215         drag_image_offset_.x(),
 216         drag_image_offset_.y() + drag_image_vertical_offset));
 217   }
 218
 219   drag_window_ = NULL;
 220
 221   // Ends cancel animation if it's in progress.
 222   if (cancel_animation_)
 223     cancel_animation_->End();
 224
 225   if (should_block_during_drag_drop_) {
 226     base::RunLoop run_loop;
 227     quit_closure_ = run_loop.QuitClosure();
 228     base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
 229     base::MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
 230     run_loop.Run();
 231   }
 232
 233   if (!cancel_animation_.get() || !cancel_animation_->is_animating() ||
 234       !pending_long_tap_.get()) {
 235     // If drag cancel animation is running, this cleanup is done when the
 236     // animation completes.
 237     if (drag_source_window_)
 238       drag_source_window_->RemoveObserver(this);
 239     drag_source_window_ = NULL;
 240   }
 241
 242   return drag_operation_;
 243 }
 244
 245 void DragDropController::DragUpdate(aura::Window* target,
 246                                     const ui::LocatedEvent& event) {
 247   int op = ui::DragDropTypes::DRAG_NONE;
 248   if (target != drag_window_) {
 249     if (drag_window_) {
 250       aura::client::DragDropDelegate* delegate =
 251           aura::client::GetDragDropDelegate(drag_window_);
 252       if (delegate)
 253         delegate->OnDragExited();
 254       if (drag_window_ != drag_source_window_)
 255         drag_window_->RemoveObserver(this);
 256     }
 257     drag_window_ = target;
 258     // We are already an observer of |drag_source_window_| so no need to add.
 259     if (drag_window_ != drag_source_window_)
 260       drag_window_->AddObserver(this);
 261     aura::client::DragDropDelegate* delegate =
 262         aura::client::GetDragDropDelegate(drag_window_);
 263     if (delegate) {
 264       ui::DropTargetEvent e(*drag_data_,
 265                             event.location(),
 266                             event.root_location(),
 267                             drag_operation_);
 268       e.set_flags(event.flags());
 269       delegate->OnDragEntered(e);
 270     }
 271   } else {
 272     aura::client::DragDropDelegate* delegate =
 273         aura::client::GetDragDropDelegate(drag_window_);
 274     if (delegate) {
 275       ui::DropTargetEvent e(*drag_data_,
 276                             event.location(),
 277                             event.root_location(),
 278                             drag_operation_);
 279       e.set_flags(event.flags());
 280       op = delegate->OnDragUpdated(e);
 281       gfx::NativeCursor cursor = ui::kCursorNoDrop;
 282       if (op & ui::DragDropTypes::DRAG_COPY)
 283         cursor = ui::kCursorCopy;
 284       else if (op & ui::DragDropTypes::DRAG_LINK)
 285         cursor = ui::kCursorAlias;
 286       else if (op & ui::DragDropTypes::DRAG_MOVE)
 287         cursor = ui::kCursorGrabbing;
 288       ash::Shell::GetInstance()->cursor_manager()->SetCursor(cursor);
 289     }
 290   }
 291
 292   DCHECK(drag_image_.get());
 293   if (drag_image_->visible()) {
 294     gfx::Point root_location_in_screen = event.root_location();
 295     ::wm::ConvertPointToScreen(target->GetRootWindow(),
 296                                &root_location_in_screen);
 297     drag_image_->SetScreenPosition(
 298         root_location_in_screen - drag_image_offset_);
 299     drag_image_->SetTouchDragOperation(op);
 300   }
 301 }
 302
 303 void DragDropController::Drop(aura::Window* target,
 304                               const ui::LocatedEvent& event) {
 305   ash::Shell::GetInstance()->cursor_manager()->SetCursor(ui::kCursorPointer);
 306
 307   // We must guarantee that a target gets a OnDragEntered before Drop. WebKit
 308   // depends on not getting a Drop without DragEnter. This behavior is
 309   // consistent with drag/drop on other platforms.
 310   if (target != drag_window_)
 311     DragUpdate(target, event);
 312   DCHECK(target == drag_window_);
 313
 314   aura::client::DragDropDelegate* delegate =
 315       aura::client::GetDragDropDelegate(target);
 316   if (delegate) {
 317     ui::DropTargetEvent e(
 318         *drag_data_, event.location(), event.root_location(), drag_operation_);
 319     e.set_flags(event.flags());
 320     drag_operation_ = delegate->OnPerformDrop(e);
 321     if (drag_operation_ == 0)
 322       StartCanceledAnimation(kCancelAnimationDuration);
 323     else
 324       drag_image_.reset();
 325   } else {
 326     drag_image_.reset();
 327   }
 328
 329   Cleanup();
 330   if (should_block_during_drag_drop_)
 331     quit_closure_.Run();
 332 }
 333
 334 void DragDropController::DragCancel() {
 335   DoDragCancel(kCancelAnimationDuration);
 336 }
 337
 338 bool DragDropController::IsDragDropInProgress() {
 339   return !!drag_drop_tracker_.get();
 340 }
 341
 342 void DragDropController::OnKeyEvent(ui::KeyEvent* event) {
 343   if (IsDragDropInProgress() && event->key_code() == ui::VKEY_ESCAPE) {
 344     DragCancel();
 345     event->StopPropagation();
 346   }
 347 }
 348
 349 void DragDropController::OnMouseEvent(ui::MouseEvent* event) {
 350   if (!IsDragDropInProgress())
 351     return;
 352
 353   // If current drag session was not started by mouse, dont process this mouse
 354   // event, but consume it so it does not interfere with current drag session.
 355   if (current_drag_event_source_ !=
 356       ui::DragDropTypes::DRAG_EVENT_SOURCE_MOUSE) {
 357     event->StopPropagation();
 358     return;
 359   }
 360
 361   aura::Window* translated_target = drag_drop_tracker_->GetTarget(*event);
 362   if (!translated_target) {
 363     DragCancel();
 364     event->StopPropagation();
 365     return;
 366   }
 367   scoped_ptr<ui::LocatedEvent> translated_event(
 368       drag_drop_tracker_->ConvertEvent(translated_target, *event));
 369   switch (translated_event->type()) {
 370     case ui::ET_MOUSE_DRAGGED:
 371       DragUpdate(translated_target, *translated_event.get());
 372       break;
 373     case ui::ET_MOUSE_RELEASED:
 374       Drop(translated_target, *translated_event.get());
 375       break;
 376     default:
 377       // We could also reach here because RootWindow may sometimes generate a
 378       // bunch of fake mouse events
 379       // (aura::RootWindow::PostMouseMoveEventAfterWindowChange).
 380       break;
 381   }
 382   event->StopPropagation();
 383 }
 384
 385 void DragDropController::OnTouchEvent(ui::TouchEvent* event) {
 386   if (!IsDragDropInProgress())
 387     return;
 388
 389   // If current drag session was not started by touch, dont process this touch
 390   // event, but consume it so it does not interfere with current drag session.
 391   if (current_drag_event_source_ != ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH)
 392     event->StopPropagation();
 393
 394   if (event->handled())
 395     return;
 396
 397   if (event->type() == ui::ET_TOUCH_CANCELLED)
 398     DragCancel();
 399 }
 400
 401 void DragDropController::OnGestureEvent(ui::GestureEvent* event) {
 402   if (!IsDragDropInProgress())
 403     return;
 404
 405   // No one else should handle gesture events when in drag drop. Note that it is
 406   // not enough to just set ER_HANDLED because the dispatcher only stops
 407   // dispatching when the event has ER_CONSUMED. If we just set ER_HANDLED, the
 408   // event will still be dispatched to other handlers and we depend on
 409   // individual handlers' kindness to not touch events marked ER_HANDLED (not
 410   // all handlers are so kind and may cause bugs like crbug.com/236493).
 411   event->StopPropagation();
 412
 413   // If current drag session was not started by touch, dont process this event.
 414   if (current_drag_event_source_ != ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH)
 415     return;
 416
 417   // Apply kTouchDragImageVerticalOffset to the location.
 418   ui::GestureEvent touch_offset_event(*event,
 419                                       static_cast<aura::Window*>(NULL),
 420                                       static_cast<aura::Window*>(NULL));
 421   gfx::Point touch_offset_location = touch_offset_event.location();
 422   gfx::Point touch_offset_root_location = touch_offset_event.root_location();
 423   touch_offset_location.Offset(0, kTouchDragImageVerticalOffset);
 424   touch_offset_root_location.Offset(0, kTouchDragImageVerticalOffset);
 425   touch_offset_event.set_location(touch_offset_location);
 426   touch_offset_event.set_root_location(touch_offset_root_location);
 427
 428   aura::Window* translated_target =
 429       drag_drop_tracker_->GetTarget(touch_offset_event);
 430   if (!translated_target) {
 431     DragCancel();
 432     event->SetHandled();
 433     return;
 434   }
 435   scoped_ptr<ui::LocatedEvent> translated_event(
 436       drag_drop_tracker_->ConvertEvent(translated_target, touch_offset_event));
 437
 438   switch (event->type()) {
 439     case ui::ET_GESTURE_SCROLL_UPDATE:
 440       DragUpdate(translated_target, *translated_event.get());
 441       break;
 442     case ui::ET_GESTURE_SCROLL_END:
 443       Drop(translated_target, *translated_event.get());
 444       break;
 445     case ui::ET_SCROLL_FLING_START:
 446     case ui::ET_GESTURE_LONG_TAP:
 447       // Ideally we would want to just forward this long tap event to the
 448       // |drag_source_window_|. However, webkit does not accept events while a
 449       // drag drop is still in progress. The drag drop ends only when the nested
 450       // message loop ends. Due to this stupidity, we have to defer forwarding
 451       // the long tap.
 452       pending_long_tap_.reset(
 453           new ui::GestureEvent(*event,
 454               static_cast<aura::Window*>(drag_drop_tracker_->capture_window()),
 455               static_cast<aura::Window*>(drag_source_window_)));
 456       DoDragCancel(kTouchCancelAnimationDuration);
 457       break;
 458     default:
 459       break;
 460   }
 461   event->SetHandled();
 462 }
 463
 464 void DragDropController::OnWindowDestroyed(aura::Window* window) {
 465   if (drag_window_ == window)
 466     drag_window_ = NULL;
 467   if (drag_source_window_ == window)
 468     drag_source_window_ = NULL;
 469 }
 470
 471 ////////////////////////////////////////////////////////////////////////////////
 472 // DragDropController, protected:
 473
 474 gfx::LinearAnimation* DragDropController::CreateCancelAnimation(
 475     int duration,
 476     int frame_rate,
 477     gfx::AnimationDelegate* delegate) {
 478   return new gfx::LinearAnimation(duration, frame_rate, delegate);
 479 }
 480
 481 ////////////////////////////////////////////////////////////////////////////////
 482 // DragDropController, private:
 483
 484 void DragDropController::AnimationEnded(const gfx::Animation* animation) {
 485   cancel_animation_.reset();
 486
 487   // By the time we finish animation, another drag/drop session may have
 488   // started. We do not want to destroy the drag image in that case.
 489   if (!IsDragDropInProgress())
 490     drag_image_.reset();
 491   if (pending_long_tap_) {
 492     // If not in a nested message loop, we can forward the long tap right now.
 493     if (!should_block_during_drag_drop_)
 494       ForwardPendingLongTap();
 495     else {
 496       // See comment about this in OnGestureEvent().
 497       base::MessageLoopForUI::current()->PostTask(
 498           FROM_HERE,
 499           base::Bind(&DragDropController::ForwardPendingLongTap,
 500                      weak_factory_.GetWeakPtr()));
 501     }
 502   }
 503 }
 504
 505 void DragDropController::DoDragCancel(int drag_cancel_animation_duration_ms) {
 506   ash::Shell::GetInstance()->cursor_manager()->SetCursor(ui::kCursorPointer);
 507
 508   // |drag_window_| can be NULL if we have just started the drag and have not
 509   // received any DragUpdates, or, if the |drag_window_| gets destroyed during
 510   // a drag/drop.
 511   aura::client::DragDropDelegate* delegate = drag_window_?
 512       aura::client::GetDragDropDelegate(drag_window_) : NULL;
 513   if (delegate)
 514     delegate->OnDragExited();
 515
 516   Cleanup();
 517   drag_operation_ = 0;
 518   StartCanceledAnimation(drag_cancel_animation_duration_ms);
 519   if (should_block_during_drag_drop_)
 520     quit_closure_.Run();
 521 }
 522
 523 void DragDropController::AnimationProgressed(const gfx::Animation* animation) {
 524   gfx::Rect current_bounds = animation->CurrentValueBetween(
 525       drag_image_initial_bounds_for_cancel_animation_,
 526       drag_image_final_bounds_for_cancel_animation_);
 527   drag_image_->SetBoundsInScreen(current_bounds);
 528 }
 529
 530 void DragDropController::AnimationCanceled(const gfx::Animation* animation) {
 531   AnimationEnded(animation);
 532 }
 533
 534 void DragDropController::StartCanceledAnimation(int animation_duration_ms) {
 535   DCHECK(drag_image_.get());
 536   drag_image_->SetTouchDragOperationHintOff();
 537   drag_image_initial_bounds_for_cancel_animation_ =
 538       drag_image_->GetBoundsInScreen();
 539   cancel_animation_.reset(CreateCancelAnimation(animation_duration_ms,
 540                                                 kCancelAnimationFrameRate,
 541                                                 this));
 542   cancel_animation_->Start();
 543 }
 544
 545 void DragDropController::ForwardPendingLongTap() {
 546   if (drag_source_window_ && drag_source_window_->delegate()) {
 547     drag_source_window_->delegate()->OnGestureEvent(pending_long_tap_.get());
 548     DispatchGestureEndToWindow(drag_source_window_);
 549   }
 550   pending_long_tap_.reset();
 551   if (drag_source_window_)
 552     drag_source_window_->RemoveObserver(this);
 553   drag_source_window_ = NULL;
 554 }
 555
 556 void DragDropController::Cleanup() {
 557   if (drag_window_)
 558     drag_window_->RemoveObserver(this);
 559   drag_window_ = NULL;
 560   drag_data_ = NULL;
 561   // Cleanup can be called again while deleting DragDropTracker, so use Pass
 562   // instead of reset to avoid double free.
 563   drag_drop_tracker_.Pass();
 564 }
 565
 566 }  // namespace ash