PyQt5 QScrollBar – Setting Inverted Control Property

Last Updated : 01 Dec, 2022

In this article we will see how we can set inverted control property of QScrollBar. QScrollBar is a control that enables the user to access parts of a document that is larger than the widget used to display it. Slider is the scroll-able object inside the bar. This property holds whether or not the slider inverts its wheel and key events. If this property is false, scrolling the mouse wheel "up" and using keys like page up will increase the slider's value towards its maximum. Otherwise pressing page up will move value towards the slider's minimum.

In order to do this we will use setInvertedControls method with the scroll bar object. Syntax : scroll.setInvertedControls(True) Argument : It takes bool as argument Return : It returns None

Below is the implementation

Python3

# importing libraries
from PyQt5.QtWidgets import * 
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import * 
from PyQt5.QtCore import * 
import sys


class Window(QMainWindow):

    def __init__(self):
        super().__init__()

        # setting title
        self.setWindowTitle("Python ")

        # setting geometry
        self.setGeometry(100, 100, 500, 400)

        # calling method
        self.UiComponents()

        # showing all the widgets
        self.show()



    # method for components
    def UiComponents(self):

        scroll = QScrollBar(self)

        # setting geometry of the scroll bar
        scroll.setGeometry(100, 50, 30, 200)

        # making its background color to green
        scroll.setStyleSheet("background : lightgrey;")

        # setting inverted appearance
        scroll.setInvertedAppearance(True)

        # setting inverted control
        scroll.setInvertedControls(True)

        # creating a label
        label = QLabel("GeeksforGeeks", self)

        # setting geometry to the label
        label.setGeometry(200, 100, 300, 80)

        # making label multi line
        label.setWordWrap(True)

        # getting value changed signal
        scroll.valueChanged.connect(lambda: do_action())

        # method called when signal is emitted
        def do_action():
            
            # setting text to the label
            label.setText("Current Value : " + str(scroll.value()))




# create pyqt5 app
App = QApplication(sys.argv)

# create the instance of our Window
window = Window()

# start the app
sys.exit(App.exec())