SetDragCallback()

Syntax

SetDragCallback(@DragCallback())

Specifies a callback function to be called during a Drag & Drop operation initiated from this application. The callback allows to modify the Drag & Drop process provided by PureBasic, for example by providing a custom cursor through the API of the Operating system. The form and function of the callback is dependant on the OS and described below:

Windows:

  Procedure DragCallback(Action)
  
    ProcedureReturn #True
  EndProcedure

The callback is called during the Drag & Drop operation. Action specifies the action that would be taken if the user released the mouse at this point. It can be one of these values:

  #PB_Drag_None: The data will not be accepted if dropped here
  #PB_Drag_Copy: The data will be copied
  #PB_Drag_Move: The data will be moved
  #PB_Drag_Link: The data will be linked

The callback can provide a custom cursor or drag image. If it does so, it should return #False. Returning #True will cause the default cursor to be used.

Linux:

  Procedure DragCallback(*Context.GdkDragContext, isStart)
  
  EndProcedure

The callback is only called at the start and the end of a Drag & Drop operation. The '*Context' parameter specifies the gdk drag context of this operation, 'isStart' specifies wether this is the start or the end of the operation. The returnvalue of the callback is ignored.

Gtk functions like gtk_drag_set_icon_pixbuf_() can be used in the callback to set a different drag image for the operation.

MacOSX:

  Procedure DragCallback(DragReference, isStart)
  
  EndProcedure

The callback is only called at the start and the end of a Drag & Drop operation. The 'DragReference' parameter specifies the Carbon drag context of this operation in form of a 'DragRef' value, 'isStart' specifies wether this is the start or the end of the operation. The returnvalue of the callback is ignored.

All functions of the Carbon Drag Manager can be used to influence the drag operation before it starts (adding more flavors/items for example) and to get more information about the operation after it completed.

Supported OS

All

<- EventDropY() - DragDrop Index - SetDropCallback() ->