Making `xwidget-event' a special event

Making `xwidget-event' a special event

[Po Lu]

I would like to make `xwidget-event' and `xwidget-display-event' special
events.

This is because `xwidget-event' should never be grouped into key
sequences or echo, or the xwidget.el machinery could be confused.

For instance, if the user hits `C-x' and then immediately afterwards a
"load-finished" xwidget event is sent, xwidget-webkit will not receive
the "load-finished" xwidget event, which causes it to keep displaying a
loading indicator regardless of whether or not the load has actually
completed.

Users are supposed to use the `callback' property of the xwidget to
handle xwidget events anyway.  This hasn't been documented though, and
this deficiency in the documentation also exists in Emacs 28, so perhaps
the documentation there needs to be updated as well?

It also doesn't make sense to put an xwidget-event in a keyboard macro
or in unread-command-events.

Does this look OK?  If so, I'll make this change ASAP.

(Also, where would this change be best documented?)

Thanks.

Re: Making `xwidget-event' a special event

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Date: Fri, 19 Nov 2021 20:15:51 +0800
> 
> I would like to make `xwidget-event' and `xwidget-display-event' special
> events.
> 
> This is because `xwidget-event' should never be grouped into key
> sequences or echo, or the xwidget.el machinery could be confused.
> 
> For instance, if the user hits `C-x' and then immediately afterwards a
> "load-finished" xwidget event is sent, xwidget-webkit will not receive
> the "load-finished" xwidget event, which causes it to keep displaying a
> loading indicator regardless of whether or not the load has actually
> completed.

Are we sure all the idiosyncrasies of processing special events will
never run afoul of what Lisp programs and users want to do with the
xwidget events?

Re: Making `xwidget-event' a special event

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

>> This is because `xwidget-event' should never be grouped into key
>> sequences or echo, or the xwidget.el machinery could be confused.
>> 
>> For instance, if the user hits `C-x' and then immediately afterwards a
>> "load-finished" xwidget event is sent, xwidget-webkit will not receive
>> the "load-finished" xwidget event, which causes it to keep displaying a
>> loading indicator regardless of whether or not the load has actually
>> completed.

> Are we sure all the idiosyncrasies of processing special events will
> never run afoul of what Lisp programs and users want to do with the
> xwidget events?

Could you please explain the important idiosyncrasies, so I can
determine if that is the case?

Thanks in advance!

Re: Making `xwidget-event' a special event

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org
> Date: Fri, 19 Nov 2021 21:06:34 +0800
> 
> > Are we sure all the idiosyncrasies of processing special events will
> > never run afoul of what Lisp programs and users want to do with the
> > xwidget events?
> 
> Could you please explain the important idiosyncrasies, so I can
> determine if that is the case?

They are documented in "Special Events" in the ELisp manual.  Maybe
Stefan could add to that if the manual isn't comprehensive enough.

Re: Making `xwidget-event' a special event

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

> They are documented in "Special Events" in the ELisp manual.  Maybe
> Stefan could add to that if the manual isn't comprehensive enough.

They seem fine, so if Stefan doesn't have anything to add I'll make the
change.  Thanks.