DragSource.connectPrepare

gulong connectPrepare(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T :  gdk.content_provider.ContentProvider)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0]  ==  double)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1]  ==  double)))
   && (Parameters!T.length <  3 || (ParameterStorageClassTuple!T[2]  ==  ParameterStorageClass.none &&  is(Parameters!T[2] :  gtk.drag_source.DragSource)))
   &&  Parameters!T.length <  4)

Connect to Prepare signal.

Emitted when a drag is about to be initiated.

It returns the [gdk.content_provider.ContentProvider] to use for the drag that is about to start. The default handler for this signal returns the value of the [gtk.drag_source.DragSource.content] property, so if you set up that property ahead of time, you don't need to connect to this signal.

Parameters

`callback`	signal callback delegate or function to connect `gdk.content_provider.ContentProvider callback(double x, double y, gtk.drag_source.DragSource dragSource)` `x` the X coordinate of the drag starting point (optional) `y` the Y coordinate of the drag starting point (optional) `dragSource` the instance the signal is connected to (optional) `Returns` a [gdk.content_provider.ContentProvider]
`after`	Yes.After to execute callback after default handler, No.After to execute before (default)

Returns

Signal ID