Pre-process keypress event:
        return True if event is accepted, false otherwise

def preprocess_keyevent(self, event):
        """Pre-process keypress event:
        return True if event is accepted, false otherwise"""
        # Copy must be done first to be able to copy read-only text parts
        # (otherwise, right below, we would remove selection
        #  if not on current line)
        ctrl = event.modifiers() & Qt.ControlModifier
        meta = event.modifiers() & Qt.MetaModifier    # meta=ctrl in OSX
        if event.key() == Qt.Key_C and \
          ((Qt.MetaModifier | Qt.ControlModifier) & event.modifiers()):
            if meta and sys.platform == 'darwin':
                self.interrupt()
            elif ctrl:
                self.copy()
            event.accept()
            return True
        
        if self.new_input_line and ( len(event.text()) or event.key() in \
           (Qt.Key_Up, Qt.Key_Down, Qt.Key_Left, Qt.Key_Right) ):
            self.on_new_line()
        
        return False