PyQt:图形场景椭圆的悬停和单击事件 [英] PyQt: hover and click events for graphicscene ellipse

问题描述

我想知道用户是否将鼠标悬停在或单击 GraphicsScene 形状对象(例如，我在下面评论的椭圆对象).我是 PyQt 的新手，C++ 的文档比 Python 好得多，所以我在弄清楚这个问题时遇到了一些麻烦.

I'd like to find out if a user hovers over or clicks a GraphicsScene shape object (for example, the ellipse object I commented below). I'm new to PyQt and the documentation is much better for C++ than Python, so I'm having a bit of trouble figuring this one out.

from PyQt4 import QtGui, QtCore

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

        self.setScene(QtGui.QGraphicsScene())

        # add some items
        x = 0
        y = 0
        w = 45
        h = 45
        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
        item = self.scene().addEllipse(x, y, w, h, pen, brush)


        item.setFlag(QtGui.QGraphicsItem.ItemIsMovable)

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

更新！！！

现在我可以根据释放鼠标单击来触发事件.不幸的是，只有我创建的最后一个项目可以响应事件.这是怎么回事?

Now I can get an event to take place based on a mouse click release. Unfortunately, only the last item I create can respond to events. What's going on here?

from PyQt4 import QtGui, QtCore

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

        self.setScene(QtGui.QGraphicsScene())

        # add some items
        x = 0
        y = 0
        w = 20
        h = 20
        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(10):
            for yi in range(10):
                item = callbackRect(x+xi*30, y+yi*30, w, h)
                item.setAcceptHoverEvents(True)
                item.setPen(pen)
                item.setBrush(brush)
                self.scene().addItem(item)

        # item = self.scene().addEllipse(x, y, w, h, pen, brush)


        item.setFlag(QtGui.QGraphicsItem.ItemIsMovable)

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

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

        return QtGui.QGraphicsRectItem.mouseReleaseEvent(self, event)

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

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

推荐答案

您可以定义自己的椭圆类并替换单击和悬停事件:

You can define your own ellipse class and replace both click and hover events:

class MyEllipse(QtGui.QGraphicsEllipseItem):

    def mouseReleaseEvent(self, event):
        # Do your stuff here.
        return QtGui.QGraphicsEllipseItem.mouseReleaseEvent(self, event)

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

用法:

item = MyEllipse(x, y, w, h)
item.setAcceptHoverEvents(True)
item.setPen(pen)
item.setBrush(brush)
self.scene().addItem(item)

希望有帮助！

这篇关于PyQt:图形场景椭圆的悬停和单击事件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！