Sets whether tool_item has a drag window. When TRUE the
toolitem can be used as a drag source through gtk_drag_source_set().
When tool_item has a drag window it will intercept all events,
even those that would otherwise be sent to a child of tool_item.
Sets whether tool_item has a drag window. When TRUE the toolitem can be used as a drag source through gtk_drag_source_set(). When tool_item has a drag window it will intercept all events, even those that would otherwise be sent to a child of tool_item.