Re: Support paragraph-local tab stops

[Yuan Fu]

> On May 27, 2020, at 11:29 AM, Eli Zaretskii <address@hidden> wrote:
> 
>> From: Yuan Fu <address@hidden>
>> Date: Tue, 26 May 2020 19:26:01 -0400
>> 
>> As show above, the second table has longer tab stops since they have longer 
>> headers.
>> 
>> In Emacs, both table would have to use long tab stops, and the first table 
>> with short headers would waste a lot of space. In order to set proper tab 
>> stops, you have to go through the whole buffer and use the longest header 
>> for each column.
>> 
>> Word processors doesn’t have this problem because they have paragraph-local 
>> tab stops, so each table can have their own tabs stops. I wonder if Emacs 
>> can do the same. Can we add a text property that points to a list that 
>> specifies the tabs stops to use? Is that possible?
> 
> IMO, TAB stops are not the right tool for the job here.  You need to
> use the :align-to display property, which allows to align text with
> pixel granularity.

I think both approach are equally appropriate. And the tab-based one aligns 
more closely to word processors. If we want to gradually add WYSIWYG editor 
features, and enable Emacs to edit rich text, this is an unavoidable feature.

I just wrote a (very rough) proof-of-concept patch—it’s much easier than I 
thought. With the patch you can do something like

(put-text-property (region-beginning) (region-end)
                   'pixel-tab-stop-list '(70 140 210 280 350 420))


Yuan

tab-stop.patch
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