PyQt5 – Translucent Bar of Progress Bar

In this article we will see how to make the bar translucent i.e in between opaque and transparent. The progress bar have two components one is the background which is visible when bar is not at 100% other is the bar which tells the progress, when we make bar translucent the background will be visible.

In order to do this we have to change the alpha level i.e transparency level of bar, below is normal progress bar vs translucent progress bar, background color is set to red and bar color is set to green.

In order to change the alpha level we have to change the CSS style sheet, below is the style sheet code for bar.

QProgressBar::chunk
{
background : rgba(0, 255, 0, 100);
}

This sheet is used which setStyleSheet method, below is the implementation

# 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 background color to window
        # self.setStyleSheet("background-color : yellow")

        # setting geometry
        self.setGeometry(100, 100, 600, 400)

        # calling method
        self.UiComponents()

        # showing all the widgets
        self.show()

    # method for widgets
    def UiComponents(self):
        # creating progress bar
        bar = QProgressBar(self)

        # setting geometry to progress bar
        bar.setGeometry(200, 100, 200, 30)

        # setting the value
        bar.setValue(80)

        # setting alignment to center
        bar.setAlignment(Qt.AlignCenter)

        # setting background to color
        # and bar color with alpha factor
        bar.setStyleSheet("QProgressBar"
                          "{"
                            "background-color : rgba(255, 0, 0, 255);"
                            "border : 1px"
                          "}"

                          "QProgressBar::chunk"
                          "{"
                            "background : rgba(0, 255, 0, 100);"
                          "}"
                          )


App = QApplication(sys.argv)

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

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

Output :