Re: [Manuel Serrano <address@hidden>] Re: flyspell before and after-string

[Stefan Monnier]

> > I don't know what happens in XEmacs--I only work on Emacs.
> > 
> > The code you sent creates overlays.  They would continue to exist and
> > be displayed until something removes them with delete-overlay.  There
> > seems to be code in flyspell.el that tries to delete them, so the
> > question is why it does not delete these overlays.
> > 
> > Manuel, could you debug it?
> I still think the problem is in Emacs or in the documentation about
> overlay. In the section "Overlays properties" it is said:
> 
> -----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----
> `before-string'
>      This property's value is a string to add to the display at the
>      beginning of the overlay.  The string does not appear in the
>      buffer in any sense--only on the screen.
> 
> `after-string'
>      This property's value is a string to add to the display at the end
>      of the overlay.  The string does not appear in the buffer in any
>      sense--only on the screen.
> -----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----
> 
> So, I would have guessed that when a region using an overlay with
> a before-string and an after-string properties is deleted, the before-string
> and after-string disappear of the screen. That is, I have tried:
> 
> -----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----
> (require 'flyspell)
> 
> (defvar ov nil)
> 
> (defun add-ov (beg end)
>   (setq ov (make-overlay beg end nil t nil))
>   (overlay-put ov 'face 'flyspell-incorrect-face)
>   (overlay-put ov 'mouse-face 'highlight)
>   (overlay-put ov 'before-string "->")
>   (overlay-put ov 'after-string "<-"))
> 
> (defun del-ov ()
>   (delete-overlay ov))
> -----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----
> 
> Then, on a random buffer:
> 
> -----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----
> (add-ov 1 4)
> (delete-region 1 4)
> -----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----
> 
> The strings "->" and "<-" are still on the screen. Is this really normal?

Check out the `evaporate' property of overlays.
You could set it to t so that your overlays get automatically
deleted when their size gets down to 0.


        Stefan