gecko-dev/widget/xpwidgets/nsBaseDragService.h
2012-05-21 12:12:37 +01:00

150 lines
4.7 KiB
C++

/* -*- 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 http://mozilla.org/MPL/2.0/. */
#ifndef nsBaseDragService_h__
#define nsBaseDragService_h__
#include "nsIDragService.h"
#include "nsIDragSession.h"
#include "nsITransferable.h"
#include "nsISupportsArray.h"
#include "nsIDOMDocument.h"
#include "nsIDOMDataTransfer.h"
#include "nsIContent.h"
#include "nsCOMPtr.h"
#include "nsPoint.h"
#include "gfxImageSurface.h"
// translucency level for drag images
#define DRAG_TRANSLUCENCY 0.65
class nsIDOMNode;
class nsIFrame;
class nsPresContext;
class nsIImageLoadingContent;
class nsICanvasElementExternal;
/**
* XP DragService wrapper base class
*/
class nsBaseDragService : public nsIDragService,
public nsIDragSession
{
public:
nsBaseDragService();
virtual ~nsBaseDragService();
//nsISupports
NS_DECL_ISUPPORTS
//nsIDragSession and nsIDragService
NS_DECL_NSIDRAGSERVICE
NS_DECL_NSIDRAGSESSION
void SetDragEndPoint(nsIntPoint aEndDragPoint) { mEndDragPoint = aEndDragPoint; }
PRUint16 GetInputSource() { return mInputSource; }
protected:
/**
* 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.
*
* aScreenX and aScreenY should be the screen coordinates of the mouse click
* for the drag.
*
* 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.
*
* 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(nsIDOMNode* aDOMNode,
nsIScriptableRegion* aRegion,
PRInt32 aScreenX, PRInt32 aScreenY,
nsIntRect* aScreenDragRect,
gfxASurface** 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,
nsICanvasElementExternal* aCanvas,
PRInt32 aScreenX, PRInt32 aScreenY,
nsIntRect* aScreenDragRect,
gfxASurface** aSurface);
/**
* Convert aScreenX and aScreenY from CSS pixels into unscaled device pixels.
*/
void
ConvertToUnscaledDevPixels(nsPresContext* aPresContext,
PRInt32* aScreenX, PRInt32* aScreenY);
/**
* If the drag image is a popup, open the popup when the drag begins.
*/
void OpenDragPopup();
bool mCanDrop;
bool mOnlyChromeDrop;
bool mDoingDrag;
// true if mImage should be used to set a drag image
bool mHasImage;
// true if the user cancelled the drag operation
bool mUserCancelled;
PRUint32 mDragAction;
nsSize mTargetSize;
nsCOMPtr<nsIDOMNode> mSourceNode;
nsCOMPtr<nsIDOMDocument> mSourceDocument; // the document at the drag source. will be null
// if it came from outside the app.
nsCOMPtr<nsIDOMDataTransfer> mDataTransfer;
// used to determine the image to appear on the cursor while dragging
nsCOMPtr<nsIDOMNode> mImage;
// offset of cursor within the image
PRInt32 mImageX;
PRInt32 mImageY;
// set if a selection is being dragged
nsCOMPtr<nsISelection> mSelection;
// 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<nsIContent> mDragPopup;
// the screen position where drag gesture occurred, used for positioning the
// drag image when no image is specified. If a value is -1, no event was
// supplied so the screen position is not known
PRInt32 mScreenX;
PRInt32 mScreenY;
// the screen position where the drag ended
nsIntPoint mEndDragPoint;
PRUint32 mSuppressLevel;
// The input source of the drag event. Possible values are from nsIDOMMouseEvent.
PRUint16 mInputSource;
};
#endif // nsBaseDragService_h__