PySide6 QMainWindow Menus Example

QMainWindow menus

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# The QMenu class provides a menu widget for use 
# in menu bars, context menus, and other popup menus. 

# The QAction class provides an abstraction for user commands
# Same action objects can be added to 
# menus, toolbars and keyboard shortcuts.

import sys

from PySide6.QtGui import QAction
from PySide6.QtWidgets import (QApplication, QMainWindow,
    QTextEdit, QLabel, QMessageBox)


class Editor(QMainWindow):
    
    def __init__(self):

        super().__init__()

        self.text_edit = QTextEdit()        
        self.setCentralWidget(self.text_edit)

        self.label = QLabel()
        self.statusBar().addWidget(self.label)
        
        self.text_edit.textChanged.connect(self.on_text_changed)
        
        # You can access the main window QMenuBar
        # using QMainWindow.menuBar()
        
        menu_bar = self.menuBar()
        
        # 1 - Create a QMenu instance using QMenuBar.addMenu() 
        #     Use the ampersand to make keyboard shortcuts work.
        
        file_menu = menu_bar.addMenu('&File')
        
        # 2 - Create a QAction instance.
        #     Connect a slot to its triggered signal.
        #     Set Editor as QAction's parent.
        
        exit_action = QAction(self)
        exit_action.setText('Exit')
        exit_action.setShortcut('Alt+X')
        exit_action.triggered.connect(QApplication.quit)
        
        # 3 - Add action to the menu.
        
        file_menu.addAction(exit_action)
        
        
        # Repeat the steps for each menu item
        
        help_menu = menu_bar.addMenu('&Help')
        
        about_action = QAction(self)
        about_action.setText('About')
        about_action.triggered.connect(self.show_messagebox)
        
        help_menu.addAction(about_action)
    
    def on_text_changed(self):
        
        cursor = self.text_edit.textCursor()
        
        size = len(self.text_edit.toPlainText())
        x = str(cursor.blockNumber() + 1)
        y = str(cursor.columnNumber() + 1)
        
        self.label.setText('Chars: {}, Ln: {}, Col: {}'.format(size, x, y))
        
    def show_messagebox(self):
        
        messagebox = QMessageBox()
        messagebox.setText('PySide6 menu example')
        messagebox.exec()


if __name__ == '__main__':

    app = QApplication(sys.argv)

    editor = Editor()
    editor.show()

    sys.exit(app.exec())

The QMenuBar class represents a horizontal menu bar, the QMenu class represents a menu widget and the QAction class represents user commands. To add drop-down menus to your main window

  1. Get the reference to the main window menu bar using QMainWindow.menuBar() and add the menu to it using QMenuBar.addMenu().

  2. Create a QAction object and connect a slot to its triggered signal. The QAction needs to live for the entire Editor lifetime so set it as its member variable.

  3. Add the action to the menu using the QMenu.addAction() method.

Optionally you can assign keyboard shortcuts to menus (accelerators) adding ampersand characters to their text. For instance, &File will open the File menu. Adding an ampersand does not work for QAction objects so you need to add keyboard shortcuts to them using QAction.setShortcut()