MotionBuilder - Custom Menu

mobu_qt_menu.py

# Creates a new QMenu and attaches to main MotionBuilder menu bar

try:
    from PySide2.QtWidgets import QApplication, QMenuBar, QMenu, QAction
except ImportError:
    from PySide.QtGui import QApplication, QMenuBar, QMenu, QAction
    
def get_main_qt_window():
    parent = QApplication.activeWindow()
    grand_parent = parent
    while grand_parent is not None:
        parent = grand_parent
        grand_parent = parent.parent()

    return parent

main_widget = get_main_qt_window()
menubar =  main_widget.findChild(QMenuBar)
custom_menu = QMenu('Custom Menu')
action = QAction('Hello World', custom_menu)
custom_menu.addAction(action)
menubar.addMenu(custom_menu)