Centers the view on a given datetime for the gantt widget.
        
        :param      dtime | <QDateTime>

def centerOnDateTime(self, dtime):
        """
        Centers the view on a given datetime for the gantt widget.
        
        :param      dtime | <QDateTime>
        """
        view = self.uiGanttVIEW
        scene = view.scene()
        point = view.mapToScene(0, 0)
        x = scene.datetimeXPos(dtime)
        y = point.y()
        view.centerOn(x, y)