PyQt QMenu dropdown direction

Question

I'm looking for a way to control the direction that sub-menus are opened from in a QMenu. The default behavior is to open to the right, unless there isn't enough screen real estate, then open to the left.

If you have a menu that's on the far right of the screen, (example: chrome's settings wrench), if you have several nested menus, the default behavior causes them to ping back and forth between opening from the left and opening from the right, which is a maddening user experience .

What I'd like is a way to tell QMenu to always open submenus to the LEFT; there is definitely not a direct control for this in QMenu, but Qt often has a lot of magical 'application' or 'global' settings for platform-specific behavior. I was wondering if anyone knew!

I have done this before in C# using ToolStripMenu, so I know that some toolkits have this ability.

Answer 1

There is one option I can think of. You can set a particular menu's direction via setLayoutDirection(QtCore.Qt.RightToLeft) and it will always expand to left if there is space.

Though, I must say, it doesn't look pretty when the top level menus aligned left to right, where as sub-menus are right to left. At least, not on my Windows 7:

import sys
from PyQt4 import QtGui, QtCore

app = QtGui.QApplication(sys.argv)
main = QtGui.QMainWindow()
menubar = QtGui.QMenuBar()

menus = []
submenus = {}
for x in range(10):
    # top menus
    menu = QtGui.QMenu('Top %d' % x)
    menus.append(menu)

    # set direction
    menu.setLayoutDirection(QtCore.Qt.RightToLeft)

    # add to menubar
    menubar.addMenu(menu)

    for y in range(5):
        # a sub-menu
        submenu = QtGui.QMenu('Level 1 - %d' % y)

        # some dummy actions
        submenu.addAction('Level 2 - 1')
        submenu.addAction('Level 2 - 2')

        # keep reference
        submenus[(x,y)] = submenu
        # add to the top menu
        menu.addMenu(submenu)

main.setMenuBar(menubar)
main.show()

sys.exit(app.exec_())