I understand that is not controller, but it's something related to modifier. Is that possible to add a new menu item or add new toolbar option using pywinauto? The reason that I am asking it's because I would like to add some extra options (as addons) on some running apps.
This is interesting topic, but currently the answer is "no". We've never investigated such possibilities. Some programs like explorer.exe have configurable menus through Windows registry. But I've never seen general purpose modifications. If you know some examples, it would be interesting to learn.
Technically it's possible to create some control in target application process using injected DLL (see pywinauto/injected but this is the very first prototype targeted for another purpose: "record-replay" script recorder for "win32" backend). I think we can keep your idea in mind, but it's low priority for now.
Maybe the easiest way for now is using pywinauto.win32_hooks module. It allows assigning callbacks on key combinations. Example is here: https://github.com/pywinauto/pywinauto/blob/master/examples/hook_and_listen.py
Thanks. I'm already using win32_hooks module (binding FnKeys). Having custom menus/toolbars would be a plus, and perhaps a new way to create custom automations on stacked applications.