将 QSlider 移动到鼠标点击位置 [英] Moving QSlider to Mouse Click Position

问题描述

我有一个 QSlider，当用户按下鼠标左键时，我想将其移动到鼠标光标的位置.我一直在四处寻找，但找不到任何最近解决了我的问题的东西.

I have a QSlider that I want to move to the position of the mouse cursor when the user presses the left mouse button. I've been hunting around and couldn't find anything that was recent and solved my problem.

这是我拥有的滑块.我希望能够点击让滑块跳转到鼠标点击的位置.我可以拖动滑块，但我希望能够点击.我测试了单击 Dolphin 文件管理器中的滑块.它增加而不是跳转到鼠标的确切位置.

This is the slider I have. I want to be able to click to have the slider jump to the position where the mouse clicks. I can drag the slider, but I want to be able to click. I tested out clicking on the slider in the Dolphin file manager. It incremented rather than jumping to the exact position of the mouse.

查看 Qt5 文档

QSlider 很少有自己的功能 [...]

QSlider has very few of its own functions [...]

这表明没有内置的方法可以做到这一点.有没有办法获得鼠标点击的位置并将滑块移动到该点?

This would indicate that there is no built-in way to do this. Is there no way to get where the mouse clicked and move the slider to that point?

推荐答案

解决方案是计算位置并设置在 mousePressEvent 中，计算并不像算术计算那样容易，因为它取决于样式每个操作系统和样式表，所以我们必须使用 QStyle，如下所示:

The solution is to make a calculation of the position and set it in the mousePressEvent, the calculation is not easy as an arithmetic calculation since it depends on the style of each OS and the stylesheet so we must use QStyle as shown below:

from PyQt5 import QtCore, QtWidgets


class Slider(QtWidgets.QSlider):
    def mousePressEvent(self, event):
        super(Slider, self).mousePressEvent(event)
        if event.button() == QtCore.Qt.LeftButton:
            val = self.pixelPosToRangeValue(event.pos())
            self.setValue(val)

    def pixelPosToRangeValue(self, pos):
        opt = QtWidgets.QStyleOptionSlider()
        self.initStyleOption(opt)
        gr = self.style().subControlRect(QtWidgets.QStyle.CC_Slider, opt, QtWidgets.QStyle.SC_SliderGroove, self)
        sr = self.style().subControlRect(QtWidgets.QStyle.CC_Slider, opt, QtWidgets.QStyle.SC_SliderHandle, self)

        if self.orientation() == QtCore.Qt.Horizontal:
            sliderLength = sr.width()
            sliderMin = gr.x()
            sliderMax = gr.right() - sliderLength + 1
        else:
            sliderLength = sr.height()
            sliderMin = gr.y()
            sliderMax = gr.bottom() - sliderLength + 1;
        pr = pos - sr.center() + sr.topLeft()
        p = pr.x() if self.orientation() == QtCore.Qt.Horizontal else pr.y()
        return QtWidgets.QStyle.sliderValueFromPosition(self.minimum(), self.maximum(), p - sliderMin,
                                               sliderMax - sliderMin, opt.upsideDown)


if __name__ == '__main__':
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = QtWidgets.QWidget()
    flay = QtWidgets.QFormLayout(w)
    w1 = QtWidgets.QSlider(QtCore.Qt.Horizontal)
    w2 = Slider(QtCore.Qt.Horizontal)
    flay.addRow("default: ", w1)
    flay.addRow("modified: ", w2)
    w.show()
    sys.exit(app.exec_())

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