Jeffrey Bergier<p>All right, I got undo working in [Not]Soulver for <a href="https://jeffburg.social/tags/OpenStep" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>OpenStep</span></a>. It turns out that I was right... NSDocument automatically handles undo and redo for you AND actually it was working in 10.2, 10.4, 10.6, and 10.8.... but I just never tried.</p><p>But in 10.10 Yosemite, Apple improved how the responder chain works to automatically include NSViewController in the responder chain. And because I was overriding things to manually add it, it broke undo support in 10.10 and later.</p><p>But I worked around this (by not working around this 🙄) and now its working everywhere (except OpenStep which does not have NSDocument or NSUndoManager). </p><p>Please enjoy the new builds 🙇♂️<br>I recommend the X15 build as it runs natively on Apple Silicon.</p><p><a href="https://github.com/jeffreybergier/NotSoulver/commit/987226c5e178b8f46e2983457c66dd4a2ed465e3" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://</span><span class="ellipsis">github.com/jeffreybergier/NotS</span><span class="invisible">oulver/commit/987226c5e178b8f46e2983457c66dd4a2ed465e3</span></a></p>