Re: [RFA] Console based mouse face highlighting.

[Eli Zaretskii]

> Cc: Eli Zaretskii <address@hidden>,  address@hidden
> From: Stefan Monnier <address@hidden>
> Date: Thu, 17 May 2007 10:59:36 -0400
> 
> > Well it means changes to write_glyphs and rif->write_glyphs in a dozen or so
> > places in dispnew.c, and a change to x_write_glyph in xdisp.c at least (and
> > perhaps w32con_write_glyphs).  If you're comfortable with those changes and
> > still think it's the right approach, I'll do that.
> 
> It doesn't seem like it'd be a big problem as such.  But I do wonder why
> this is necessary now, even though it hasn't been necessary until now for
> all other places where we support mouse highlighting.

Actually, you will see that xdisp.c:draw_glyphs _does_ accept an
argument HL which tells it to use the mouse highlight face when
appropriate.  So at least on X and w32 this was always necessary.

msdos.c doesn't need this because it actually cheats: instead of
redrawing the glyphs with the mouse face, it pokes the video memory
with the attribute byte that changes the text colors, but leaves the
characters themselves intact (to avoid encoding them).  msdos.c can do
that because, unlike on X, it knows that the mouse face can only
change the text _colors_, so the characters themselves don't need to
be redrawn.