use custom mimedata between two windows

[prasad_N]

I asked you twice(!) if it worked for an empty QMimeData.
Twice(!) you wrote that, yes, that was the case.
So, why are you posting questions if you ignore any attempt in helping you?_

I think you misunderstood, It worked in my project where I have huge code & I can n't put all that code here so, I just created simplified version from simple tree model example just to check & I realized its not working in this simplified version.
When you stress on that particular statement I got you point & I double checked it in my project .

Anyway, the problem is obviously not your subclass._

then where is the problem, exactly this is what i am asking.. can't I pass customized mimedata OR is there a problem with my mimedata subclass OR do I need to re implement any other functions in subclass/model/view when I subclass mimedata ?