Rejects the current edit and shows the parts widget.

def cancelEdit( self ):
        """
        Rejects the current edit and shows the parts widget.
        """
        
        if ( self._partsWidget.isVisible() ):
            return False
            
        self._completerTree.hide()
        self.completer().popup().hide()
        
        self.setText(self._originalText)
        return True