[Qt-interest] Intercept Esc and Return/Enter keys in a QComboBox line edit

[Luper Rouch]

I would like to make a QComboBox that acts like this :
  * if the last item is selected:
    * make the combo box editable,
    * select the text in the combo box line edit then,
    * if the user presses Esc: return the combo box to its initial state
    * if the user presses Return, Enter or the focus leaves the combo
      box:
      * insert the edited text as a new item in the combo box
      * return the combo box to its initial, non editable state

What I have done is almost working, except that when Esc or Return is 
pressed, the key press is also passed to the parent dialog, which closes 
it. How could I "trap" the key press in the line edit while it's being 
edited ?

Thanks,
Luper