GUIBaseContext :: doBeforeDrop - Pre-event handler for Drop events

The pre-event handler for drop events ( GEV_BeginDrop ) is called before the drop action will be executed. The handler may access information in the drop object using functions as dropText() or dropProperty() . propPosition() and GetHorizontalDropPosition () will return the position where the object is going to be dropped. The handler allows canceling the drop action by returning 1 .

The handler should return one of the following values:

• -1 (not handled) - the event handler will be removed from the handler list and is not called anymore.
• 1 (refuse) - Requested action will not be executed.
• 0 (ok) - Action is permitted to be executed.