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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at */
#include "mozilla/dom/DragEvent.h"
#include "mozilla/dom/MouseEventBinding.h"
#include "mozilla/MouseEvents.h"
#include "nsContentUtils.h"
#include "prtime.h"
namespace mozilla::dom {
DragEvent::DragEvent(EventTarget* aOwner, nsPresContext* aPresContext,
WidgetDragEvent* aEvent)
: MouseEvent(
aOwner, aPresContext,
aEvent ? aEvent : new WidgetDragEvent(false, eVoidEvent, nullptr)) {
if (aEvent) {
mEventIsInternal = false;
} else {
mEventIsInternal = true;
mEvent->mRefPoint = LayoutDeviceIntPoint(0, 0);
mEvent->AsMouseEvent()->mInputSource =
void DragEvent::InitDragEvent(const nsAString& aType, bool aCanBubble,
bool aCancelable, nsGlobalWindowInner* aView,
int32_t aDetail, int32_t aScreenX,
int32_t aScreenY, int32_t aClientX,
int32_t aClientY, bool aCtrlKey, bool aAltKey,
bool aShiftKey, bool aMetaKey, uint16_t aButton,
EventTarget* aRelatedTarget,
DataTransfer* aDataTransfer) {
MouseEvent::InitMouseEvent(aType, aCanBubble, aCancelable, aView, aDetail,
aScreenX, aScreenY, aClientX, aClientY, aCtrlKey,
aAltKey, aShiftKey, aMetaKey, aButton,
if (mEventIsInternal) {
mEvent->AsDragEvent()->mDataTransfer = aDataTransfer;
DataTransfer* DragEvent::GetDataTransfer() {
// the dataTransfer field of the event caches the DataTransfer associated
// with the drag. It is initialized when an attempt is made to retrieve it
// rather that when the event is created to avoid duplicating the data when
// no listener ever uses it.
if (!mEvent || mEvent->mClass != eDragEventClass) {
NS_WARNING("Tried to get dataTransfer from non-drag event!");
return nullptr;
WidgetDragEvent* dragEvent = mEvent->AsDragEvent();
// for synthetic events, just use the supplied data transfer object even if
// null
if (!mEventIsInternal) {
nsresult rv = nsContentUtils::SetDataTransferInEvent(dragEvent);
NS_ENSURE_SUCCESS(rv, nullptr);
return dragEvent->mDataTransfer;
// static
already_AddRefed<DragEvent> DragEvent::Constructor(
const GlobalObject& aGlobal, const nsAString& aType,
const DragEventInit& aParam) {
nsCOMPtr<EventTarget> t = do_QueryInterface(aGlobal.GetAsSupports());
RefPtr<DragEvent> e = new DragEvent(t, nullptr, nullptr);
bool trusted = e->Init(t);
e->InitDragEvent(aType, aParam.mBubbles, aParam.mCancelable, aParam.mView,
aParam.mDetail, aParam.mScreenX, aParam.mScreenY,
aParam.mClientX, aParam.mClientY, aParam.mCtrlKey,
aParam.mAltKey, aParam.mShiftKey, aParam.mMetaKey,
aParam.mButton, aParam.mRelatedTarget, aParam.mDataTransfer);
return e.forget();
} // namespace mozilla::dom
using namespace mozilla;
using namespace mozilla::dom;
already_AddRefed<DragEvent> NS_NewDOMDragEvent(EventTarget* aOwner,
nsPresContext* aPresContext,
WidgetDragEvent* aEvent) {
RefPtr<DragEvent> event = new DragEvent(aOwner, aPresContext, aEvent);
return event.forget();