Slow progress: My hex editor now has an info panel that shows what’s under the cursor. https://movq.de/v/f9586ec65c/s.png

I’m inclined to remove all mouse support, except for moving windows. 🤔 I originally wanted this to emulate the behavior of DOS programs, but a) mouse support is a lot of code, b) using the mouse is cumbersome anyway and I would rarely do it.