Comment by tylerhall

2 days ago

Developer of the app here. You’re correct. Accessibility APIs + timer + transparent top-level NSWindow that ignores input and draws a border.

Fwiw I think this is the right approach. The trade-off between stability across OS updates vs tracking performance is a no-brainer for me - the absolute last thing that I would want is a deluge of bug reports with no other information than "it stopped working" when Apple pushes out an update

  • As a developer I would interpret that as "try it in the new OS and you will immediately see what is wrong so there is no reason for me to write a tedious and unnecessary message to you".

Very nice idea, thank you for developing it. With an M1 iMac, though the window border lags the position of the window quite a lot if you drag it around, so probably not usable for me.

  • Some lag is probably going to be unavoidable with a third-party app. The only way to have perfect synchronization of window dragging/resizing and the border is for macOS to implement this as a first-party feature.