Re: Overlay behavior change

[Gregory Heytings]

> > Indeed I "really" need that, or at least that's what I'm used to: I use 
> > (show-paren-mode) with (setq show-paren-style 'expression), and during 
> > the last twenty years or so it has implicitly used ":extend t".
>
> My suggestion is to try the new display first, you might like it after 
> some time.  There's no need to paint the entire line with the background 
> color, just the text should be enough.  That it looks strange at first 
> is just a (bad) habit we all have.

In fact, I very much like the fact that a block (of code) is displayed on 
my screen as a (visual) block.  And I don't like the staircase aspect of 
the current default.  But I promise I'll give it another try ;-)

What I would have liked to see is something that is neither the previous 
nor the current default behavior.  This idea will probably not be 
considered (let's name it the attribute ":visualblock t"), but here it is:

1. calculate the overlay as it would have been displayed by Emacs 21 to 
26.

2. remove all pixel columns on the right *and on the left* of the overlay 
which have no "content" (that is, no characters on the right, whitespace 
characters on the left).

This way the block (of code) would really be displayed on the screen as a 
block, even a deeply nested one.  The above "algorithm" would work with 
fixed and variable-width fonts, but could of course be made more efficient 
for fixed-width fonts.

Gregory