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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 */
#ifndef nsBaseDragService_h__
#define nsBaseDragService_h__
#include "nsIDragService.h"
#include "nsIDragSession.h"
#include "nsCOMPtr.h"
#include "nsRect.h"
#include "nsPoint.h"
#include "nsString.h"
#include "mozilla/RefPtr.h"
#include "mozilla/dom/ContentParent.h"
#include "mozilla/dom/HTMLCanvasElement.h"
#include "mozilla/dom/RemoteDragStartData.h"
#include "mozilla/Logging.h"
#include "nsTArray.h"
#include "nsRegion.h"
#include "Units.h"
extern mozilla::LazyLogModule sWidgetDragServiceLog;
#define MOZ_DRAGSERVICE_LOG(...) \
MOZ_LOG(sWidgetDragServiceLog, mozilla::LogLevel::Debug, (__VA_ARGS__))
MOZ_LOG_TEST(sWidgetDragServiceLog, mozilla::LogLevel::Debug)
// translucency level for drag images
class nsIContent;
class nsINode;
class nsPresContext;
class nsIImageLoadingContent;
namespace mozilla {
namespace gfx {
class SourceSurface;
} // namespace gfx
namespace dom {
class DataTransfer;
class Selection;
} // namespace dom
} // namespace mozilla
* XP DragService wrapper base class
class nsBaseDragService : public nsIDragService, public nsIDragSession {
typedef mozilla::gfx::SourceSurface SourceSurface;
// nsISupports
// nsIDragSession and nsIDragService
void SetDragEndPoint(nsIntPoint aEndDragPoint) {
mEndDragPoint =
void SetDragEndPoint(mozilla::LayoutDeviceIntPoint aEndDragPoint) {
mEndDragPoint = aEndDragPoint;
uint16_t GetInputSource() { return mInputSource; }
int32_t TakeChildProcessDragAction();
virtual ~nsBaseDragService();
* Called from nsBaseDragService to initiate a platform drag from a source
* in this process. This is expected to ensure that StartDragSession() and
* EndDragSession() get called if the platform drag is successfully invoked.
MOZ_CAN_RUN_SCRIPT virtual nsresult InvokeDragSessionImpl(
nsIArray* aTransferableArray,
const mozilla::Maybe<mozilla::CSSIntRegion>& aRegion,
uint32_t aActionType) = 0;
* Draw the drag image, if any, to a surface and return it. The drag image
* is constructed from mImage if specified, or aDOMNode if mImage is null.
* aRegion may be used to draw only a subset of the element. This region
* should be supplied using x and y coordinates measured in css pixels
* that are relative to the upper-left corner of the window.
* aScreenPosition should be the screen coordinates of the mouse click
* for the drag. These are in CSS pixels.
* On return, aScreenDragRect will contain the screen coordinates of the
* area being dragged. This is used by the platform-specific part of the
* drag service to determine the drag feedback. This rect will be in the
* device pixels of the presContext.
* If there is no drag image, the returned surface will be null, but
* aScreenDragRect will still be set to the drag area.
* aPresContext will be set to the nsPresContext used determined from
* whichever of mImage or aDOMNode is used.
nsresult DrawDrag(nsINode* aDOMNode,
const mozilla::Maybe<mozilla::CSSIntRegion>& aRegion,
mozilla::CSSIntPoint aScreenPosition,
mozilla::LayoutDeviceIntRect* aScreenDragRect,
RefPtr<SourceSurface>* aSurface,
nsPresContext** aPresContext);
* Draw a drag image for an image node specified by aImageLoader or aCanvas.
* This is called by DrawDrag.
nsresult DrawDragForImage(nsPresContext* aPresContext,
nsIImageLoadingContent* aImageLoader,
mozilla::dom::HTMLCanvasElement* aCanvas,
mozilla::LayoutDeviceIntRect* aScreenDragRect,
RefPtr<SourceSurface>* aSurface);
* If the drag image is a popup, open the popup when the drag begins.
void OpenDragPopup();
* Free resources contained in DataTransferItems that aren't needed by JS.
void DiscardInternalTransferData();
// Returns true if a drag event was dispatched to a child process after
// the previous TakeDragEventDispatchedToChildProcess() call.
bool TakeDragEventDispatchedToChildProcess() {
bool retval = mDragEventDispatchedToChildProcess;
mDragEventDispatchedToChildProcess = false;
return retval;
bool mCanDrop;
bool mOnlyChromeDrop;
bool mDoingDrag;
bool mSessionIsSynthesizedForTests;
bool mIsDraggingTextInTextControl;
// true if in EndDragSession
bool mEndingSession;
// true if mImage should be used to set a drag image
bool mHasImage;
// true if the user cancelled the drag operation
bool mUserCancelled;
bool mDragEventDispatchedToChildProcess;
uint32_t mDragAction;
uint32_t mDragActionFromChildProcess;
// mEffectAllowedForTests stores allowed effects at invoking the drag
// for tests.
uint32_t mEffectAllowedForTests;
nsCOMPtr<nsINode> mSourceNode;
nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
nsCOMPtr<nsIContentSecurityPolicy> mCsp;
// the document at the drag source. will be null if it came from outside the
// app.
RefPtr<mozilla::dom::Document> mSourceDocument;
RefPtr<mozilla::dom::WindowContext> mSourceWindowContext;
RefPtr<mozilla::dom::WindowContext> mSourceTopWindowContext;
// the contentpolicy type passed to the channel when initiating the drag
// session
nsContentPolicyType mContentPolicyType;
RefPtr<mozilla::dom::DataTransfer> mDataTransfer;
// used to determine the image to appear on the cursor while dragging
nsCOMPtr<nsINode> mImage;
// offset of cursor within the image
mozilla::CSSIntPoint mImageOffset;
// set if a selection is being dragged
RefPtr<mozilla::dom::Selection> mSelection;
// remote drag data
RefPtr<mozilla::dom::RemoteDragStartData> mDragStartData;
// set if the image in mImage is a popup. If this case, the popup will be
// opened and moved instead of using a drag image.
nsCOMPtr<mozilla::dom::Element> mDragPopup;
// the screen position where drag gesture occurred, used for positioning the
// drag image.
mozilla::CSSIntPoint mScreenPosition;
// The position relative to the top level widget where the drag ended.
mozilla::LayoutDeviceIntPoint mEndDragPoint;
uint32_t mSuppressLevel;
// The input source of the drag event. Possible values are from MouseEvent.
uint16_t mInputSource;
nsTArray<RefPtr<mozilla::dom::ContentParent>> mChildProcesses;
// Sub-region for tree-selections.
mozilla::Maybe<mozilla::CSSIntRegion> mRegion;
#endif // nsBaseDragService_h__