how to make drag and drop possible in custom widget

i have a table view and i have created my own custom widget and I inserted the widget in a row of table view using setIndexWidget()
i want to do drag and drop those widget in a table view.

To be more clear, If i drag the last widget and drop it in the first position, then the first widget has to move to the second position and the last widget (which is dragged) has to move to first position. (same like drag and drop of the items in the List view). Can anyone suggest me a way to drag and drop of the custom widgets.