pyqt example sliders (snippet)

Python pyqt (gui) example 'sliders'

sliders

Python pyqt example: sliders

#!/usr/bin/env python


#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
##
## "Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are
## met:
##   * Redistributions of source code must retain the above copyright
##     notice, this list of conditions and the following disclaimer.
##   * Redistributions in binary form must reproduce the above copyright
##     notice, this list of conditions and the following disclaimer in
##     the documentation and/or other materials provided with the
##     distribution.
##   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
##     the names of its contributors may be used to endorse or promote
##     products derived from this software without specific prior written
##     permission.
##
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
## $QT_END_LICENSE$
##
#############################################################################


from PyQt5.QtCore import pyqtSignal, Qt
from PyQt5.QtWidgets import (QApplication, QBoxLayout, QCheckBox, QComboBox,
        QDial, QGridLayout, QGroupBox, QHBoxLayout, QLabel, QScrollBar,
        QSlider, QSpinBox, QStackedWidget, QWidget)


class SlidersGroup(QGroupBox):

    valueChanged = pyqtSignal(int)

    def __init__(self, orientation, title, parent=None):
        super(SlidersGroup, self).__init__(title, parent)

        self.slider = QSlider(orientation)
        self.slider.setFocusPolicy(Qt.StrongFocus)
        self.slider.setTickPosition(QSlider.TicksBothSides)
        self.slider.setTickInterval(10)
        self.slider.setSingleStep(1)

        self.scrollBar = QScrollBar(orientation)
        self.scrollBar.setFocusPolicy(Qt.StrongFocus)

        self.dial = QDial()
        self.dial.setFocusPolicy(Qt.StrongFocus)

        self.slider.valueChanged.connect(self.scrollBar.setValue)
        self.scrollBar.valueChanged.connect(self.dial.setValue)
        self.dial.valueChanged.connect(self.slider.setValue)
        self.dial.valueChanged.connect(self.valueChanged)

        if orientation == Qt.Horizontal:
            direction = QBoxLayout.TopToBottom
        else:
            direction = QBoxLayout.LeftToRight

        slidersLayout = QBoxLayout(direction)
        slidersLayout.addWidget(self.slider)
        slidersLayout.addWidget(self.scrollBar)
        slidersLayout.addWidget(self.dial)
        self.setLayout(slidersLayout)    

    def setValue(self, value):    
        self.slider.setValue(value)    

    def setMinimum(self, value):    
        self.slider.setMinimum(value)
        self.scrollBar.setMinimum(value)
        self.dial.setMinimum(value)    

    def setMaximum(self, value):    
        self.slider.setMaximum(value)
        self.scrollBar.setMaximum(value)
        self.dial.setMaximum(value)    

    def invertAppearance(self, invert):
        self.slider.setInvertedAppearance(invert)
        self.scrollBar.setInvertedAppearance(invert)
        self.dial.setInvertedAppearance(invert)    

    def invertKeyBindings(self, invert):
        self.slider.setInvertedControls(invert)
        self.scrollBar.setInvertedControls(invert)
        self.dial.setInvertedControls(invert)


class Window(QWidget):
    def __init__(self):
        super(Window, self).__init__()

        self.horizontalSliders = SlidersGroup(Qt.Horizontal,
                "Horizontal")
        self.verticalSliders = SlidersGroup(Qt.Vertical, "Vertical")

        self.stackedWidget = QStackedWidget()
        self.stackedWidget.addWidget(self.horizontalSliders)
        self.stackedWidget.addWidget(self.verticalSliders)

        self.createControls("Controls")

        self.horizontalSliders.valueChanged.connect(self.verticalSliders.setValue)
        self.verticalSliders.valueChanged.connect(self.valueSpinBox.setValue)
        self.valueSpinBox.valueChanged.connect(self.horizontalSliders.setValue)

        layout = QHBoxLayout()
        layout.addWidget(self.controlsGroup)
        layout.addWidget(self.stackedWidget)
        self.setLayout(layout)

        self.minimumSpinBox.setValue(0)
        self.maximumSpinBox.setValue(20)
        self.valueSpinBox.setValue(5)

        self.setWindowTitle("Sliders")

    def createControls(self, title):
        self.controlsGroup = QGroupBox(title)

        minimumLabel = QLabel("Minimum value:")
        maximumLabel = QLabel("Maximum value:")
        valueLabel = QLabel("Current value:")

        invertedAppearance = QCheckBox("Inverted appearance")
        invertedKeyBindings = QCheckBox("Inverted key bindings")

        self.minimumSpinBox = QSpinBox()
        self.minimumSpinBox.setRange(-100, 100)
        self.minimumSpinBox.setSingleStep(1)

        self.maximumSpinBox = QSpinBox()
        self.maximumSpinBox.setRange(-100, 100)
        self.maximumSpinBox.setSingleStep(1)

        self.valueSpinBox = QSpinBox()
        self.valueSpinBox.setRange(-100, 100)
        self.valueSpinBox.setSingleStep(1)

        orientationCombo = QComboBox()
        orientationCombo.addItem("Horizontal slider-like widgets")
        orientationCombo.addItem("Vertical slider-like widgets")

        orientationCombo.activated.connect(self.stackedWidget.setCurrentIndex)
        self.minimumSpinBox.valueChanged.connect(self.horizontalSliders.setMinimum)
        self.minimumSpinBox.valueChanged.connect(self.verticalSliders.setMinimum)
        self.maximumSpinBox.valueChanged.connect(self.horizontalSliders.setMaximum)
        self.maximumSpinBox.valueChanged.connect(self.verticalSliders.setMaximum)
        invertedAppearance.toggled.connect(self.horizontalSliders.invertAppearance)
        invertedAppearance.toggled.connect(self.verticalSliders.invertAppearance)
        invertedKeyBindings.toggled.connect(self.horizontalSliders.invertKeyBindings)
        invertedKeyBindings.toggled.connect(self.verticalSliders.invertKeyBindings)

        controlsLayout = QGridLayout()
        controlsLayout.addWidget(minimumLabel, 0, 0)
        controlsLayout.addWidget(maximumLabel, 1, 0)
        controlsLayout.addWidget(valueLabel, 2, 0)
        controlsLayout.addWidget(self.minimumSpinBox, 0, 1)
        controlsLayout.addWidget(self.maximumSpinBox, 1, 1)
        controlsLayout.addWidget(self.valueSpinBox, 2, 1)
        controlsLayout.addWidget(invertedAppearance, 0, 2)
        controlsLayout.addWidget(invertedKeyBindings, 1, 2)
        controlsLayout.addWidget(orientationCombo, 3, 0, 1, 3)
        self.controlsGroup.setLayout(controlsLayout)


if __name__ == '__main__':

    import sys

    app = QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec_())

Useful links

• Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
• Install PyQt: https://pythonbasics.org/install-pyqt/