Re: master 6e5d79c048: Display show-paren-context-when-offscreen in child frame

[Tassilo Horn <tsdh@gnu.org>]

Po Lu <luangruo@yahoo.com> writes:

>>>     Display show-paren-context-when-offscreen in child frame
>>
>> This leads to:
>>
>> In show-paren--context-child-frame-redirect-focus:
>> paren.el:279:18: Warning: reference to free variable `corfu--frame'
>>
>> Leftover debugging code?
>
> That code was probably copied from Corfu, another package that uses
> child frames.

Indeed, now fixed.

> But I gave it a try, and I don't know why the header line, or perhaps
> an overlay, can't be used for that job instead:

Daniel Martín said that he might want to give a header-line approach a
try.  The problem with that is that the context to be displayed could be
more than a line.

But you are right that an overlay could do the job, too.  I'll give that
a try.

> child frames are slow on some systems, and very slow on the PGTK port.

I'm actually using pgtk on a 7 years old laptop and it doesn't feel
slow.  The reason why I started with the child-frame approach is that
the child-frame can be positioned precisely at the top-left of the
current window.  Since emacs now supports pixel-wise scrolling, it can
happen that only the lower half of the line at `window-start' is
visible which would be bad if an overlay was placed there.  Is there a
way to test if some position is completely visible?

Bye,
Tassilo