问Qt工具提示如何防止文本在内置延迟后消失？

EN

class Node(QGraphicsRectItem):
    def __init__(self, x, y, w, h, qpen, qbrush, text):
        QGraphicsRectItem.__init__(self)

        self.setRect(x, y, w, h)
        self.setBrush(qbrush)
        self.setPen(qpen)

        self.setAcceptHoverEvents(True)
        self.text = text

        #self.setFlag(QGraphicsItem.ItemIsMovable)
        #self.toolkit = QToolTip()
        #self.setToolTip(text)
        #self.setWhatsThis(self.text)

    def hoverEnterEvent(self, event):
        QToolTip.showText(event.screenPos(),self.text)

        #print("hoverEnterEvent : {}".format(event))
        #print(type(self.toolTip))
        #self.QToolTip.showText(event.pos(),text)
        #event.ToolTip.showText(text)

        #QWhatsThis.showText(event.screenPos(),self.text)
        #self.enterWhatsThisMode()

    def hoverLeaveEvent(self, event):
        QToolTip.hideText()

        #print("hoverLeaveEvent : {}".format(event))
        #self.QToolTip.hideText()
        #event.ToolTip.hideText()

        #QWhatsThis.hideText()
        #self.leaveWhatsThisMode()