macOS Rework Umbrella #32176

This is an umbrella issue to keep track of the macOS Rework PRs and outstanding issues.

Pull Requests

Each phase depends on the previous phase's pull requests.

Phase 1

Phase 2

Phase 3

Remaining Issues (no PR planned yet)

#32041 - This involves a simple compatibility shim, deprecation warning, and notifying other projects. Likely not applicable if we keep "macosx" in 3.12 and deprecate the whole backend.

Remaining work without issues or PRs:

• Research IPython and the mapping between "macosx"/"macos"/"osx" in _fix_ipython_backend2gui.
• "test_backend_macosx.py" should probably become "test_backend_macos.py", and a new "test_backend_macosx.py" goes in to test deprecation notices and/or the compatibility shim.
• Only install PyOS_InputHook when we also install our app delegate (see [Doc]: PyOS_InputHook documentation is incorrect #32314). Add API to manually install our input hook, if desired. Adjust app delegate instantiation - should it only occur if we enter _macos__init with no NSApp?
• Per Phase 1 review: tweak the _mpl_button and _mpl_buttons logic.
• Per Phase 1 review: the macosx.window_mode rcParams should be aliased to macos.window_mode and the documentation section for macosx removed. We will need to resuscitate the rcParam aliasing code that was removed in Remove now-unused rcParams _deprecated entries. #21004.
• Documentation changes / API Notes / Release Notes
• Change "GUI: MacOSX" label to "GUI: macOS".
• Actual switchover from macosx to macos as default