QMenuBar, QMenu & QAction Widgets

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The QMenuBar is, like a menu strip at the top of an app window where you can find menus to access features and choices, in the application.

The QMenu is, like a menu that pops up when you do something on the screen by clicking on a button or something else, in the interface. It can have options, submenus and lines to separate them.

QMenu class provides a widget which can be added to menu bar. It is also used to create context menu and popup menu. Each QMenu object may contain one or more QAction objects or cascaded QMenu objects.

To create a popup menu, PyQt API provides createPopupMenu() function. menuBar() function returns main windows QMenuBar object. addMenu() function lets addition of menu to the bar. In turn, actions are added in the menu by addAction() method.

Methods used in designing a Menu System

Following table lists some of the important methods used in designing a menu system.

Given below are the most commonly used methods of QMenu.

QMenu object emits triggered() signal whenever any QAction button is clicked. Reference to the clicked QAction object is passed on to the connected slot function.

Example 1: QMenuBar

In this example, we create a simple PyQt application with a QMainWindow containing a QMenuBar. We add a "File" menu to the menu bar, along with an "Exit" action that closes the application when triggered.

import sys
from PyQt6.QtWidgets import QApplication, QMainWindow
from PyQt6.QtGui import QAction

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

      self.initUI()

   def initUI(self):
      menubar = self.menuBar()
      file_menu = menubar.addMenu('File')

      exit_action = QAction('Exit', self)
      exit_action.triggered.connect(self.close)
      file_menu.addAction(exit_action)

      self.setWindowTitle('QMenuBar Example')
      self.setGeometry(300, 300, 400, 300)

if __name__ == '__main__':
   app = QApplication(sys.argv)
   window = MainWindow()
   window.show()
   sys.exit(app.exec())

Output

The above code produces the following result −

Example 2: QMenu

In this example, we add an "Edit" menu to the menu bar, along with a submenu titled "Submenu." This submenu is created using QMenu and added to the "Edit" menu.

import sys
from PyQt6.QtWidgets import QApplication, QMainWindow, QMenu
from PyQt6.QtGui import QAction

class MainWindow(QMainWindow):
   def __init__(self):
      super().__init__()
      self.initUI()

   def initUI(self):
      menubar = self.menuBar()
      file_menu = menubar.addMenu('File')

      edit_menu = menubar.addMenu('Edit')
      edit_submenu = QMenu('Submenu', self)
      edit_menu.addMenu(edit_submenu)

      exit_action = QAction('Exit', self)
      exit_action.triggered.connect(self.close)
      file_menu.addAction(exit_action)

      self.setWindowTitle('QMenu Example')
      self.setGeometry(300, 300, 400, 300)

if __name__ == '__main__':
   app = QApplication(sys.argv)
   window = MainWindow()
   window.show()
   sys.exit(app.exec())

Output

The above code produces the following result −

Example 3: QAction

An QAction signifies a user triggered action commonly linked to menu options, toolbar icons or keyboard shortcuts.

In this example, we add "Copy" and "Paste" actions to the submenu. These actions can be triggered by the user and perform specific tasks when activated.

import sys
from PyQt6.QtWidgets import QApplication, QMainWindow, QMenu
from PyQt6.QtGui import QAction

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

      self.initUI()
        
   def initUI(self):
      menubar = self.menuBar()
      file_menu = menubar.addMenu('File')

      edit_menu = menubar.addMenu('Edit')
      edit_submenu = QMenu('Submenu', self)
      edit_menu.addMenu(edit_submenu)

      exit_action = QAction('Exit', self)
      exit_action.triggered.connect(self.close)
      file_menu.addAction(exit_action)

      copy_action = QAction('Copy', self)
      paste_action = QAction('Paste', self)
      edit_submenu.addAction(copy_action)
      edit_submenu.addAction(paste_action)

      self.setWindowTitle('QAction Example')
      self.setGeometry(300, 300, 400, 300)

if __name__ == '__main__':
   app = QApplication(sys.argv)
   window = MainWindow()
   window.show()
   sys.exit(app.exec())

Output

The above code produces the following result −