PyQt5 QScrollBar – Setting Window Opacity property

Last Updated : 31 Jul, 2020

In this article we will see how we can set window opacity property to the 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 the level of opacity for the window. The valid range of opacity is from 1.0 (completely opaque) to 0.0 (completely transparent). Note : On X11 you need to have a composite manager running, and the X11 specific _NET_WM_WINDOW_OPACITY atom needs to be supported by the window manager you are using.

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

Below is the implementation

Python3 1==

# 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 window opacity property
        scroll.setWindowOpacity(1.0)

        # creating a label
        label = QLabel("GeesforGeeks", 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())