title: Qt KeyPress Event on QlineEdit
body: <p>i searched over the net on how to capture a key press event only on a specific QWidget ( a QlineEdit ) 
  one way to do is to inherit from that class and over ride the virtual keyPress function , 
  but i cant do that since i'm using QtDesigner ( is it possible to do it with QtDesigner ? ) </p>
  
  <p>i also tried to over ride the KeyPress Event on the entire windows but i need to filter only the the events when a specific lineEdit is active which i could not find a way to do so ( but there must be a way ) </p>
  
  <p>over all what is the best way to sole this problem ? thanks :) </p>