Re: Mouse-hovering over 'mouse-face' overlays/regions on a TTY Emacs

[Eli Zaretskii]

> From: João Távora <joaotavora@gmail.com>
> Cc: jared@finder.org,  emacs-devel@gnu.org
> Date: Mon, 30 Nov 2020 18:05:07 +0000
> 
> I think I figured it out.  draw_row_with_mouse_face() is eventually
> called by show_mouse_face(), but it is a noop on my system.  Easy to
> see:
> 
> static void
> draw_row_with_mouse_face (struct window *w, int start_x, struct glyph_row 
> *row,
>                         int start_hpos, int end_hpos,
>                         enum draw_glyphs_face draw)
> {
> #ifdef HAVE_WINDOW_SYSTEM
>    ...
> #endif
> #if defined (HAVE_GPM) || defined (MSDOS) || defined (WINDOWSNT)
>   tty_draw_row_with_mouse_face (w, row, start_hpos, end_hpos, draw);
> #endif
> }
> 
> 
> I'm currently using Mac OS.  Most of the TTY things work here, and I
> would expect drawing some face on a part of the screen to work too.  I
> can certainly show and hide faces programatically.
> 
> I've tried uncommenting that, but it fails during linking.

You need to implement tty_draw_row_with_mouse_face for macOS terminal.
Look at the other implementations, it should be easy.