Hotkey overlay to toggle modes in Maya,

toolToggle.py

import pymel.core as pm

from functools import partial
from maya import OpenMayaUI as omui

try:
    from PySide2.QtCore import *
    from PySide2.QtGui import *
    from PySide2.QtWidgets import *
    from shiboken2 import wrapInstance
except ImportError:
    from PySide.QtCore import *
    from PySide.QtGui import *
    from shiboken import wrapInstance

# TODO Fix shortcut ambiguity issue


def _getMainMayaWindow():
    mayaMainWindowPtr = omui.MQtUtil.mainWindow()
    mayaMainWindow = wrapInstance(long(mayaMainWindowPtr), QWidget)
    return mayaMainWindow


def toggleMoveMode(currentMode):
    toggleModes = {0:'Object', 2:'World', 10:'Component'}
    if currentMode == 0:
        pm.manipMoveContext('Move', e=True, m=2)    # Object->World
    elif currentMode == 2:
        pm.manipMoveContext('Move', e=True, m=10)   # World->Component
    elif currentMode == 10:
        pm.manipMoveContext('Move', e=True, m=0)    # Component->Object

    else:
        pm.manipMoveContext('Move', e=True, m=2)    # World is default, so from any other mode go back world.

    pm.inViewMessage(
        amg=toggleModes[pm.manipMoveContext('Move', q=True, m=True)],
        pos='topCenter',
        fade=True,
    )

    return True


def toggleRotateMode(currentMode):

    toggleModes = {0:'Object', 1:'World', 2:'Gimbal'}

    if currentMode == 0:
        pm.manipRotateContext('Rotate', e=True, m=1)
    elif currentMode == 1:
        pm.manipRotateContext('Rotate', e=True, m=2)
    elif currentMode == 2:
        pm.manipRotateContext('Rotate', e=True, m=0)

    else:
        pm.manipRotateContext('Rotate', e=True, m=0)

    pm.inViewMessage(
        amg=toggleModes[pm.manipRotateContext('Rotate', q=True, m=True)],
        pos='topCenter',
        fade=True,
    )
    return True


def toggleScaleMode(currentMode):
    toggleModes = {0:'Object', 2:'World', 10:'Component'}

    if currentMode == 0:
        pm.manipScaleContext('Scale', e=True, m=2)
    elif currentMode == 2:
        pm.manipScaleContext('Scale', e=True, m=10)
    elif currentMode == 10:
        pm.manipScaleContext('Scale', e=True, m=0)

    else:
        pm.manipScaleContext('Scale', e=True, m=0)

    pm.inViewMessage(
        amg=toggleModes[pm.manipScaleContext('Scale', q=True, m=True)],
        pos='topCenter',
        fade=True,
    )

    return True


def moveToolShortcutActivated(shortcut):
    """ Hotkey overlay for Move Tool Context, """
    if 'moveSuperContext' == pm.currentCtx():
        toggleMoveMode(pm.manipMoveContext('Move', q=True, mode=True))

    else:
        shortcut.setEnabled(0)
        e = QKeyEvent(QEvent.KeyPress, Qt.Key_W, Qt.NoModifier)
        QCoreApplication.postEvent(_getMainMayaWindow(), e)
        pm.evalDeferred(partial(shortcut.setEnabled, 1))


def rotateToolShortcutActivated(shortcut):
    """ Hotkey overlay for Rotate Tool Context, """
    if 'RotateSuperContext' == pm.currentCtx():
        toggleRotateMode(pm.manipRotateContext('Rotate', q=True, mode=True))

    else:
        shortcut.setEnabled(0)
        e = QKeyEvent(QEvent.KeyPress, Qt.Key_E, Qt.NoModifier)
        QCoreApplication.postEvent(_getMainMayaWindow(), e)
        pm.evalDeferred(partial(shortcut.setEnabled, 1))


def scaleToolShortcutActivated(shortcut):
    """ Hotkey overlay for Scale Tool Context, """
    if 'scaleSuperContext' == pm.currentCtx():  # breaking from the previous naming standard starting with lowercase...
        toggleScaleMode(pm.manipScaleContext('Scale', q=True, mode=True))

    else:
        shortcut.setEnabled(0)
        e = QKeyEvent(QEvent.KeyPress, Qt.Key_R, Qt.NoModifier)
        QCoreApplication.postEvent(_getMainMayaWindow(), e)
        pm.evalDeferred(partial(shortcut.setEnabled, 1))


def initShortcuts():
    moveModeShortcut = QShortcut(QKeySequence(Qt.Key_W), _getMainMayaWindow())
    moveModeShortcut.setContext(Qt.ApplicationShortcut)
    moveModeShortcut.activated.connect(partial(moveToolShortcutActivated, moveModeShortcut))

    rotateModeShortcut = QShortcut(QKeySequence(Qt.Key_E), _getMainMayaWindow())
    rotateModeShortcut.setContext(Qt.ApplicationShortcut)
    rotateModeShortcut.activated.connect(partial(rotateToolShortcutActivated, rotateModeShortcut))

    scaleModeShortcut = QShortcut(QKeySequence(Qt.Key_R), _getMainMayaWindow())
    scaleModeShortcut.setContext(Qt.ApplicationShortcut)
    scaleModeShortcut.activated.connect(partial(scaleToolShortcutActivated, scaleModeShortcut))


# Do not call more than once per session, will cause shortcuts to signal ambiguously
initShortcuts()