Re: Fill column indicator functionality

[Ergus]

On Fri, Mar 15, 2019 at 09:52:53AM +0200, Eli Zaretskii wrote:

> Can you solve this problem by using the :height attribute whose value
> is 1.0 (a floating-point number) for the face of the character?  If
> that doesn't work, we might introduce a special feature for this use
> case.

Hi:

I tried that solution (setting the :height attribute to 1.0 in the face
declaration) and it didn't work.

```
(defface fill-column-face
'((t :inherit (shadow default) :height 1.0))
"Face for displaying fill column indicator line.
This face is used when `display-fill-column-indicator-mode' is
non-nil.

If you customize the font of this face, make sure it is a
monospaced font, otherwise the line's characters will not line
up horizontally."
:version "27.1"
:group 'basic-faces
:group 'display-fill-column-indicator)
```

There is still a small space and for rows with different size fonts it
keeps always the same size.

I see that there is a calc_line_height_property; can we use that to
change the glyph. Maybe it is possible to implement a setter (equivalent
to get_it_property?

We can compare the line height with the it height and change it
temporarily to print the indicator?

Does it makes sense?