Mouse selection handler ?

[Being friendzoned sucks]

Is there a way to get the coordinates of a mouse selection ?

I want to create something like a selecting in desktop/files , when you go to your desktop and click left button and drag it you can see a blue selecting " in windows at least " that you can select things using it..

I want something like that , when the user clicks a button the mouse acts like it acts in files and select things and then return the coordinates or a graph view.

Basically you know the tool called snipping tool in windows ? you know when you click the button it renders a thing that lets you select what you want ? that's what I want.

can you direct me to a class or something that gives function that does the same job ?

---

Added after 1 57 minutes:

I followed this:

http://qt-project.org/doc/qt-4.8/qrubberband.html

and it's working great except I want it to get the coordinates outside of my program not just inside it.