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nsIDragService

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nsIDragService is defined in widget/public/nsIDragService.idl. It is scriptable and unfrozen (hasn't changed since Mozilla1.9).

Inherits from: nsISupports

[edit] Method overview

void invokeDragSession(in nsIDOMNode aDOMNode, in nsISupportsArray aTransferables, in nsIScriptableRegion aRegion, in unsigned long aActionType);
void invokeDragSessionWithImage(in nsIDOMNode aDOMNode, in nsISupportsArray aTransferableArray, in nsIScriptableRegion aRegion, in unsigned long aActionType,in nsIDOMNode aImage, in long aImageX, in long aImageY, in nsIDOMMouseEvent aDragEvent);
void invokeDragSessionWithSelection(in nsISelection aSelection, in nsISupportsArray aTransferableArray, in unsigned long aActionType, in nsIDOMMouseEvent aDragEvent);
nsIDragSession getCurrentSession();
voidstartDragSession();
void endDragSession(in PRBool aDoneDrag);
void fireDragEventAtSource(in unsigned long aMsg); New in Firefox 3

[edit] Constants

Constant Value Description
DRAGDROP_ACTION_NONE 0 LONG data type.
DRAGDROP_ACTION_COPY 1 LONG data type.
DRAGDROP_ACTION_MOVE 2 LONG data type.
DRAGDROP_ACTION_LINK 3 LONG data type.

[edit] Methods

[edit] invokeDragSession()

Starts a modal drag session with an array of transaferables 

  void invokeDragSession ( 
   in nsIDOMNode aDOMNode, 
   in nsISupportsArray aTransferables, 
   in nsIScriptableRegion aRegion, 
   in unsigned long aActionType 
 );
[edit] Parameters
aDOMNode
aTransferables
an array of transferables to be dragged
aRegion
a region containing rectangles for cursor feedback, in window coordinates.
aActionType
specified which of copy/move/link are allowed

[edit] invokeDragSessionWithImage()

Starts a modal drag session using an image. The first four arguments are the same as invokeDragSession.

A custom image may be specified using the aImage argument. If this is supplied, the aImageX and aImageY arguments specify the offset within the image where the cursor would be positioned. That is, when the image is drawn, it is offset up and left the amount so that the cursor appears at that location within the image. If aImage is null, aImageX and aImageY are not used and the image is instead determined from the source node aDOMNode, and the offset calculated so that the initial location for the image appears in the same screen position as where the element is located. The node must be within a document.

Currently, supported images are all DOM nodes. If this is an HTML <image> or <canvas> element, the drag image is taken from the image data. If the element is in a document, it will be rendered at its displayed size, otherwise, it will be rendered at its real size. For other types of elements, the element is rendered into an offscreen buffer in the same manner as it is currently displayed. The document selection is hidden while drawing. The aDragEvent must be supplied as the current screen coordinates of the event are needed to calculate the image location. 

  void invokeDragSessionWithImage(in nsIDOMNode aDOMNode,
                                  in nsISupportsArray aTransferableArray,
                                  in nsIScriptableRegion aRegion,
                                  in unsigned long aActionType,
                                  in nsIDOMNode aImage,
                                  in long aImageX,
                                  in long aImageY,
                                  in nsIDOMMouseEvent aDragEvent
  );
[edit] Parameters
aImage
Image object
aImageX
X position of image
aImageY
Y position of image
aDragEvent

[edit] invokeDragSessionWithSelection()

Start a modal drag session using the selection as the drag image. The aDragEvent must be supplied as the current screen coordinates of the event are needed to calculate the image location. 

  void invokeDragSessionWithSelection(
     in nsISelection aSelection,
     in nsISupportsArray aTransferableArray,
     in unsigned long aActionType,
     in nsIDOMMouseEvent aDragEvent
  );
[edit] Parameters
aSelection
aTransferableArray
aActionType
specified which of copy/move/link are allowed
aDragEvent

[edit] getCurrentSession()

Returns the current Drag Session 

  nsIDragSession getCurrentSession ( ) ;

[edit] startDragSession()

Tells the Drag Service to start a drag session. This is called when an external drag occurs 

  void startDragSession ( ) ;

[edit] endDragSession()

Tells the Drag Service to end a drag session. This is called when an external drag occurs 

  void endDragSession ( 
     in PRBool aDoneDrag New in Firefox 3
  ) ;
[edit] Parameters
aDoneDrag New in Firefox 3
If aDoneDrag is true, the drag has finished, otherwise the drag has just left the window. This parameter does not exist in versions of Firefox prior to Firefox 3.

[edit] fireDragEventAtSource()

Fire a drag event at the source of the drag. This method only exists in Firefox 3 and later. 

  void fireDragEventAtSource ( New in Firefox 3
     in unsigned long aMsg 
  );
[edit] Parameters
aMsg
Retrieved from "http://developer.mozilla.org/en/docs/nsIDragService"