dom/events/DragEvent.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/dom/DragEvent.h"
   8 #include "mozilla/dom/MouseEventBinding.h"
   9 #include "mozilla/MouseEvents.h"
  10 #include "nsContentUtils.h"
  11 #include "prtime.h"
  12
  13 namespace mozilla::dom {
  14
  15 DragEvent::DragEvent(EventTarget* aOwner, nsPresContext* aPresContext,
  16                      WidgetDragEvent* aEvent)
  17     : MouseEvent(
  18           aOwner, aPresContext,
  19           aEvent ? aEvent : new WidgetDragEvent(false, eVoidEvent, nullptr)) {
  20   if (aEvent) {
  21     mEventIsInternal = false;
  22   } else {
  23     mEventIsInternal = true;
  24     mEvent->mRefPoint = LayoutDeviceIntPoint(0, 0);
  25     mEvent->AsMouseEvent()->mInputSource =
  26         MouseEvent_Binding::MOZ_SOURCE_UNKNOWN;
  27   }
  28 }
  29
  30 void DragEvent::InitDragEvent(const nsAString& aType, bool aCanBubble,
  31                               bool aCancelable, nsGlobalWindowInner* aView,
  32                               int32_t aDetail, int32_t aScreenX,
  33                               int32_t aScreenY, int32_t aClientX,
  34                               int32_t aClientY, bool aCtrlKey, bool aAltKey,
  35                               bool aShiftKey, bool aMetaKey, uint16_t aButton,
  36                               EventTarget* aRelatedTarget,
  37                               DataTransfer* aDataTransfer) {
  38   NS_ENSURE_TRUE_VOID(!mEvent->mFlags.mIsBeingDispatched);
  39
  40   MouseEvent::InitMouseEvent(aType, aCanBubble, aCancelable, aView, aDetail,
  41                              aScreenX, aScreenY, aClientX, aClientY, aCtrlKey,
  42                              aAltKey, aShiftKey, aMetaKey, aButton,
  43                              aRelatedTarget);
  44   if (mEventIsInternal) {
  45     mEvent->AsDragEvent()->mDataTransfer = aDataTransfer;
  46   }
  47 }
  48
  49 DataTransfer* DragEvent::GetDataTransfer() {
  50   // the dataTransfer field of the event caches the DataTransfer associated
  51   // with the drag. It is initialized when an attempt is made to retrieve it
  52   // rather that when the event is created to avoid duplicating the data when
  53   // no listener ever uses it.
  54   if (!mEvent || mEvent->mClass != eDragEventClass) {
  55     NS_WARNING("Tried to get dataTransfer from non-drag event!");
  56     return nullptr;
  57   }
  58
  59   WidgetDragEvent* dragEvent = mEvent->AsDragEvent();
  60   // for synthetic events, just use the supplied data transfer object even if
  61   // null
  62   if (!mEventIsInternal) {
  63     nsresult rv = nsContentUtils::SetDataTransferInEvent(dragEvent);
  64     NS_ENSURE_SUCCESS(rv, nullptr);
  65   }
  66
  67   return dragEvent->mDataTransfer;
  68 }
  69
  70 // static
  71 already_AddRefed<DragEvent> DragEvent::Constructor(
  72     const GlobalObject& aGlobal, const nsAString& aType,
  73     const DragEventInit& aParam) {
  74   nsCOMPtr<EventTarget> t = do_QueryInterface(aGlobal.GetAsSupports());
  75   RefPtr<DragEvent> e = new DragEvent(t, nullptr, nullptr);
  76   bool trusted = e->Init(t);
  77   e->InitDragEvent(aType, aParam.mBubbles, aParam.mCancelable, aParam.mView,
  78                    aParam.mDetail, aParam.mScreenX, aParam.mScreenY,
  79                    aParam.mClientX, aParam.mClientY, aParam.mCtrlKey,
  80                    aParam.mAltKey, aParam.mShiftKey, aParam.mMetaKey,
  81                    aParam.mButton, aParam.mRelatedTarget, aParam.mDataTransfer);
  82   e->InitializeExtraMouseEventDictionaryMembers(aParam);
  83   e->SetTrusted(trusted);
  84   e->SetComposed(aParam.mComposed);
  85   return e.forget();
  86 }
  87
  88 }  // namespace mozilla::dom
  89
  90 using namespace mozilla;
  91 using namespace mozilla::dom;
  92
  93 already_AddRefed<DragEvent> NS_NewDOMDragEvent(EventTarget* aOwner,
  94                                                nsPresContext* aPresContext,
  95                                                WidgetDragEvent* aEvent) {
  96   RefPtr<DragEvent> event = new DragEvent(aOwner, aPresContext, aEvent);
  97   return event.forget();
  98 }