How to move the plot legend item around by mouse?

[Nicho]

Hi,
I want to move the plot legend items on the plot by mouse events:
To select a legend item by press event and then move it around.
When the mouse button is released, the legend item will be displayed at the position of the mouse.
I have coded sth. according to the example 'itemeditor'.
But it doesn't work.
I guess the reason is:
I have reimplemented the QwtPlotLegendItem::draw().
Just add a judgement about whether the item is visible.
But the QwtPlotLegendItem::geometry() is not a virtual one.
I can not calculate the new geometry of the item which is used by draw() function.

IN conclusion,
FOR the QwtPlotLegendItem,it can be aligned by 8 types .
My question is how to display a legend item at any position.
How could I do?

Thanks .

Nicho