Use float for QSlider

Question

I have a QLineEdit and a QSlider in which it interacts with each other.

Eg. If I set a value in the QLineEdit, the slider will be updated, or if I slide the slider a

Answer 1

@dissidia's answer is good. But if you have a lot of sliders in your app or if you need several different scale factors, it pays to subclass QSlider to make your own QDoubleSlider.

The class below is based on the work of others, but has an extra feature you'll want if you link to a QLineEdit or QDoubleSpinBox: a new signal for valueChanged called doubleValueChanged.

class DoubleSlider(QSlider):

    # create our our signal that we can connect to if necessary
    doubleValueChanged = pyqtSignal(float)

    def __init__(self, decimals=3, *args, **kargs):
        super(DoubleSlider, self).__init__( *args, **kargs)
        self._multi = 10 ** decimals

        self.valueChanged.connect(self.emitDoubleValueChanged)

    def emitDoubleValueChanged(self):
        value = float(super(DoubleSlider, self).value())/self._multi
        self.doubleValueChanged.emit(value)

    def value(self):
        return float(super(DoubleSlider, self).value()) / self._multi

    def setMinimum(self, value):
        return super(DoubleSlider, self).setMinimum(value * self._multi)

    def setMaximum(self, value):
        return super(DoubleSlider, self).setMaximum(value * self._multi)

    def setSingleStep(self, value):
        return super(DoubleSlider, self).setSingleStep(value * self._multi)

    def singleStep(self):
        return float(super(DoubleSlider, self).singleStep()) / self._multi

    def setValue(self, value):
        super(DoubleSlider, self).setValue(int(value * self._multi))