PyQ中的悬停点击事件

Question

在我的应用程序中，我有一个qgraphicscene，用户应该能够通过点击鼠标键并将鼠标悬停在项目上来更改项目的颜色。在

下面是我从另一个问题中借用的示例代码：

PyQt: hover and click events for graphicscene ellipse

from PyQt5 import QtGui, QtCore, QtWidgets

class MyFrame(QtWidgets.QGraphicsView):
    def __init__( self, parent = None ):
        super(MyFrame, self).__init__(parent)

        self.setScene(QtWidgets.QGraphicsScene())

        # add some items
        x = 0
        y = 0
        w = 15
        h = 15
        pen = QtGui.QPen(QtGui.QColor(QtCore.Qt.green))
        brush = QtGui.QBrush(pen.color().darker(150))

        # i want a mouse over and mouse click event for this ellipse
        for xi in range(3):
            for yi in range(3):
                item = callbackRect(x+xi*30, y+yi*30, w, h)
                item.setAcceptHoverEvents(True)
                item.setPen(pen)
                item.setBrush(brush)
                self.scene().addItem(item)
                item.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable)

class callbackRect(QtWidgets.QGraphicsRectItem):
    '''
    Rectangle call-back class.
    '''

    def mouseReleaseEvent(self, event):
        # recolor on click
        color = QtGui.QColor(180, 174, 185)
        brush = QtGui.QBrush(color)
        QtWidgets.QGraphicsRectItem.setBrush(self, brush)

        return QtWidgets.QGraphicsRectItem.mouseReleaseEvent(self, event)

    def hoverMoveEvent(self, event):
        # Do your stuff here.
        pass

    def hoverEnterEvent(self, event):
        color = QtGui.QColor(0, 174, 185)
        brush = QtGui.QBrush(color)
        QtWidgets.QGraphicsRectItem.setBrush(self, brush)

    def hoverLeaveEvent(self, event):
        color = QtGui.QColor(QtCore.Qt.green)
        brush = QtGui.QBrush(color.darker(150))
        QtWidgets.QGraphicsRectItem.setBrush(self, brush)

if ( __name__ == '__main__' ):
    app = QtWidgets.QApplication([])
    f = MyFrame()
    f.show()
    app.exec_()

因此，在这段代码中，悬停方法只在没有按下鼠标键的情况下调用。如文档中所述（对于PySide），mousePressEvent“决定哪个图形项接收鼠标事件”，这在某种程度上阻止了其他项的鼠标事件。在

https://deptinfo-ensip.univ-poitiers.fr/ENS/pyside-docs/PySide/QtGui/QGraphicsItem.html?highlight=graphicsitem#PySide.QtGui.PySide.QtGui.QGraphicsItem.mouseMoveEvent

但是，有没有一种方法可以同时按住鼠标键并调用不同项目的悬停事件？在

Answer 1

问题是事件的组合使任务变得复杂，您可以传播mouseMoveEvent事件，但不能用悬停事件来传播。一个简单的解决方案是在QGraphicsView的方法mouseMoveEvent中实现逻辑，如下所示：

class MyFrame(QtWidgets.QGraphicsView):
    def __init__( self, parent = None ):
        super(MyFrame, self).__init__(parent)    
        self.setScene(QtWidgets.QGraphicsScene())
        [...]

    itemsSelected = []
    def mouseMoveEvent(self, event):
        QtWidgets.QGraphicsView.mouseMoveEvent(self, event)
        items = self.items(event.pos())#, QtGui.QTransform())
        for item in self.itemsSelected:
            if item in items:
                item.enterColor()
            else:
                item.leaveColor()
        self.itemsSelected = items

class callbackRect(QtWidgets.QGraphicsRectItem):
    '''
    Rectangle call-back class.
    '''
    def enterColor(self):
        color = QtGui.QColor(0, 174, 185)
        brush = QtGui.QBrush(color)
        QtWidgets.QGraphicsRectItem.setBrush(self, brush)

    def leaveColor(self):
        color = QtGui.QColor(QtCore.Qt.green)
        brush = QtGui.QBrush(color.darker(150))
        QtWidgets.QGraphicsRectItem.setBrush(self, brush)

    def hoverEnterEvent(self, event):
        self.enterColor()

    def hoverLeaveEvent(self, event):
        self.leaveColor()