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