Thanks for the super quick response and the idea about the resize . I am trying to achieve exactly like the following link.
where I wana resize and drag and drop shapes as well.
I am working on creating a portal just like MS Paint where user can click on some objects in a panel and can resize , drag and drop it, on the fly. I thought of having a panel plugin which contains all the basic shapes like circle, rectangle,triangle etc. So if the user clicks on the circle icon in the panel a circle will be drawn on the canvas. Then the user can resize that circle like the link I pasted above. This is the big picture of my current work. Let me know if I need to start a new topic about this in HOW DO I.