bug#50067: Context menus

[Dmitry Gutov <dgutov@yandex.ru>]

On 26.08.2021 16:01, Eli Zaretskii wrote:
>> Cc: alan@idiocy.org, mattiase@acm.org, homeros.misasa@gmail.com,
>>   tkk@misasa.okayama-u.ac.jp, larsi@gnus.org, 50067@debbugs.gnu.org
>> From: Dmitry Gutov <dgutov@yandex.ru>
>> Date: Tue, 24 Aug 2021 20:59:40 +0300
>>
>>>> An option to display the first match right away will be most
>>>> appreciated, thanks.
>>> Like compilation-auto-jump-to-first-error.
>>
>> So we even have a precedent, very good.
>>
>> Could you both check out the attached patch?
>>
>> Together with (setq xref-auto-jump-to-first-definition t)
> 
> Thanks, this looks very handy, I will definitely use it.

Very good. Let's now discuss a couple of minor alterations. We can 
always go back to this patch if we don't decide on anything better.

I think I remember now why it didn't make sense to me to have this 
behavior OOTB: I think the main goal of the user who calls 
xref-find-definitions is, usually, to pick one definition they wanted to 
visit. Which also means having the xref buffer dismissed at the end.

With the patch under discussion we automatically jump to the first 
location. We can even iterate through locations with 
next-error/previous-error (M-g M-n/M-g M-p). But to close 
(quit/kill/etc) the list of locations, you have to switch back to its 
window and press 'q'. Didn't that look like a bother to you?

Here's how it could look instead:

1. When you press M-., the first location is "shown", but not jumped to. 
The focus remains on the Xref window, with point on its first item (the 
arrow beside it is visible, like you wanted). Location is visible in the 
other window, and we can either visit it and dismiss the Xref buffer 
(with 'C-u RET'), simply visit it with 'RET', or look at the other 
locations with 'n'/'p'.

For this to work, the patch will need to change xref--auto-jump-first, 
swapping

+  (xref-next-line-no-show)
+  (xref-goto-xref))

for

+  (xref-next-line)

The new option's name would probably be different too.

And you could also use a "transient" show-definitions-function like:

(setq xref-show-definitions-function
       #'xref-show-definitions-buffer-at-bottom)

Then you'd only need to press RET in the results buffer to jump and 
dismiss the results buffer.

2. Simply have point move to the first location in the list (rather than 
remain on the group name). From there, the user can press 'C-o' to show 
the location without visiting, or 'RET', or 'C-u RET' like described 
above. I understand this does not fit your prior workflows, but it does 
require the least number of button presses in the scenario "go to the 
first location and dismiss the Xref buffer", especially in combination 
with the (setq xref-show-definitions-function ...) form above.

>> Questions for feedback:
>>
>> 1. Does the new behavior work okay window management-wise (it does
>> occupy +1 window, after all)?
> 
> Not sure I understand the question: we pop up an additional window
> when there are more than one candidate even without this option, so
> why do you say "+1 window"?  Maybe you had some recipe in mind that I
> didn't try?

It's "+1 window" compared to how 'find-tag' worked/works, which I assume 
is the target.

So it's still not the same behavior.

>> 2. Should this setting also extend to other commands like
>> xref-find-references?
> 
> Not necessarily.  Perhaps xref-auto-jump-to-first-definition should be
> tri-state, to allow users to request the same with
> xref-find-references as well?

Sure. Or we can have two variables, especially if we end up cramming 
different variations of behavior into them.

We can do a lot of things. What would help, is better knowledge about 
what people *want* to do.