thank you jpn,

my problem is solved ( except that my program crashes on clicking any items of context menu, i will solve that ).

I am also having one more problem, i had assigned shortcutkeys to these actions via

Qt Code: 
  1. cutAct->setShortcut(tr("Ctrl+X"));
To copy to clipboard, switch view to plain text mode 

But this doesn't seem to work. is there some mistake in that ?