PyQt - QScrollBar Widget

A scrollbar control enables the user to access parts of the document i.e. outside the viewable area. It provides visual indicator to the current position. It has a slider by which a value between a preset range is set in analogous fashion. This value is usually correlated to bring a hidden data inside the viewport.

The Scroll bars are necessary for navigating the large document, lengthy content, web pages, and lists.

There are four types of control in scrollbar −

A slider Two Scroll arrows Page control

QScrollBar widget provides a vertical or horizontal scroll bar. If developer need to display another widget with scrollable content, it's easier to use the QScrollArea class. It provides a viewport widget and scroll bars, making the implementation of scrolling functionality simpler. However, if they need to implement scrolling functionality for specialized widgets using QAbstractScrollArea, QScrollBar can be useful.

Following signals of QScrollBar class are frequently used −

Example

In the following example, three scroll bars are placed to control RGB values of font color for the text displayed in a label. The complete code is as follows −

# importing libraries
import sys
from PyQt6.QtWidgets import *
from PyQt6 import QtCore, QtGui
from PyQt6.QtGui import *
from PyQt6.QtCore import *

class Window(QMainWindow):
   def __init__(self):
      super().__init__()

      # setting title
      self.setWindowTitle("PyQt")
      # setting geometry
      self.setGeometry(100, 100, 500, 400)

      # calling method
      self.UiComponents()

      # showing widgets
      self.show()
   # method for components
   def UiComponents(self):
      # creating a QListWidget
      list_widget = QListWidget(self)

      # setting geometry to it
      list_widget.setGeometry(50, 70, 150, 80)

      # list widget items
      item1 = QListWidgetItem("Tutorialspoint")
      item2 = QListWidgetItem("BOX 1")
      item3 = QListWidgetItem("BOX 2")
      item4 = QListWidgetItem("BOX 3")
      item5 = QListWidgetItem("BOX 4")
      item6 = QListWidgetItem("BOX 5")
      item7 = QListWidgetItem("BOX 6")
      item8 = QListWidgetItem("BOX 7")
      item9 = QListWidgetItem("BOX 8")
      item10 = QListWidgetItem("BOX 9")
      # adding items to the list widget
      list_widget.addItem(item1)
      list_widget.addItem(item2)
      list_widget.addItem(item3)
      list_widget.addItem(item4)
      list_widget.addItem(item5)
      list_widget.addItem(item6)
      list_widget.addItem(item7)
      list_widget.addItem(item8)
      list_widget.addItem(item9)
      list_widget.addItem(item10)

      # scroll bar
      scroll_bar = QScrollBar(self)
      # setting style sheet to the scroll bar
      scroll_bar.setStyleSheet("background : gray;")
      # setting vertical scroll bar to it
      list_widget.setVerticalScrollBar(scroll_bar)

      # creating a label
      label = QLabel("Tutorialspoint", self)
      # setting geometry to the label
      label.setGeometry(230, 100, 280, 100)
      # making label multi line
      label.setWordWrap(True)

App = QApplication(sys.argv)
# create the instance of our Window
window = Window()
# start the app
sys.exit(App.exec())

Output

The above code produces the following output −