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