Hi Carsten, Carsten Dominik wrote: > On 10.4.2013, at 18:21, Eli Zaretskii <e...@gnu.org> wrote: >>> From: Carsten Dominik <carsten.domi...@gmail.com> >>> On 10 apr. 2013, at 11:54, Suvayu Ali <fatkasuvayu+li...@gmail.com> wrote: >>>> This request is common enough; every time it comes up overlays are >>>> proposed as a solution. It would be good if this is available even as a >>>> library outside of Org. >>> >>> Yes, overlays are better. >> >> I beg the Org developers to please be very careful when introducing >> expensive display features such as overlays into Org. Org already >> puts the Emacs display engine to its limits in many of its popular >> features; > > this is interesting input, I was not aware of this. Has this been discussed > before, can you point me to relevant threads, and what are the symptoms of the > display engine being at its limits? > >> adding overlays to this mess might be too much.
I guess Eli simply means, in a general way, that overlays do negatively impact display performance, as you said as well a couple of times: ╭──── │ From: Carsten Dominik <carsten.domi...@gmail.com> │ Subject: Re: performance problems with drawers │ Newsgroups: gmane.emacs.orgmode │ To: Al <gman...@wilec.net> │ Cc: emacs-orgmode@gnu.org │ Date: Wed, 8 Jul 2009 07:05:53 +0200 (3 years, 39 weeks, 3 days ago) │ │ Hi Al, │ │ first of all, I cannot reproduce the fact that drawers have such │ a major influence on time, wit a test file that I created to │ be similar to what you describe. │ │ There is a way to speed up drawer handling, by using text properties │ instead of overlays. How have some vague plans to do this, but nothing │ concrete or soon. │ │ - Carsten ╰──── and ╭──── │ From: Carsten Dominik <carsten.domi...@gmail.com> │ Subject: Re: fontification and icon issues │ Newsgroups: gmane.emacs.orgmode │ To: David O'Toole <dto1...@gmail.com> │ Cc: emacs-orgmode@gnu.org │ Date: Thu, 24 Sep 2009 10:46:24 +0100 (3 years, 28 weeks, 2 days ago) │ │ On Sep 22, 2009, at 4:11 PM, David O'Toole wrote: │ > [...] │ > │ > 2. using add-text-properties to specify a display property (or even just │ > a face) for any part of an org headline text kills the fontification of │ > the rest of the text (TODO keyword and leading stars unaffected.) I'm │ > trying to use font-lock-add-keywords to display the images. │ │ Can you make an example file, and maybe a small function that does set these │ properties, so that I can see what you mean? │ │ - Carsten │ │ > Maybe I should use overlays instead? │ │ This can be done, but if every line in a very large file gets │ an overlay, performance is severely degraded. │ │ - Carsten ╰──── >> I don't know enough about Org to understand why overlays are being >> considered instead of text properties, but feel free to describe the >> issues (preferably on emacs-devel) and start a discussion about the >> possible alternatives. Best regards, Seb -- Sebastien Vauban