bug#4394: 23.1; flashing when overlapping face and mouse-face properties

bug#4394: 23.1; flashing when overlapping face and mouse-face properties

[Drew Adams]

emacs -Q
 
In *scratch*, type this:
(accessible-keymaps (current-global-map))
 
Put point somewhere after the sexp and hit `C-u C-x C-e'.
 
The result sexp inserted is large, and it has a mouse-face property
over it all. Double-click a left paren somewhere inside the sexp, to
select a sublist.
 
The display flashes spasmodically. Very annoying. And you can hardly
see the region highlight at all.
 

In GNU Emacs 23.1.1 (i386-mingw-nt5.1.2600)
 of 2009-07-29 on SOFT-MJASON
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.4)'
 

bug#4394: 23.1; flashing when overlapping face and mouse-face properties

[Lars Magne Ingebrigtsen]

"Drew Adams" <drew.adams@oracle.com> writes:

> In *scratch*, type this:
> (accessible-keymaps (current-global-map))
>
> Put point somewhere after the sexp and hit `C-u C-x C-e'.
>
> The result sexp inserted is large, and it has a mouse-face property
> over it all. Double-click a left paren somewhere inside the sexp, to
> select a sublist.
>
> The display flashes spasmodically. Very annoying. And you can hardly
> see the region highlight at all.

Yes, that's annoying.  Perhaps `C-u C-x C-e' shouldn't put the
mouse-face property on the entire list, but only on the bits it's
interesting to actually click?

-- 
(domestic pets only, the antidote for overdose, milk.)
  bloggy blog http://lars.ingebrigtsen.no/

bug#4394: 23.1; flashing when overlapping face and mouse-face properties

[Lars Ingebrigtsen]

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"Drew Adams" <drew.adams@oracle.com> writes:

> In *scratch*, type this:
> (accessible-keymaps (current-global-map))
>
> Put point somewhere after the sexp and hit `C-u C-x C-e'.
>
> The result sexp inserted is large, and it has a mouse-face property
> over it all. Double-click a left paren somewhere inside the sexp, to
> select a sublist.
>
> The display flashes spasmodically. Very annoying. And you can hardly
> see the region highlight at all.

A more manageable example is:

(number-sequence 1 20)
=> (1 2 3 4 5 6 7 8 9 10 11 12 ...)

Which is displayed this way:


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[-- Attachment #3: Type: text/plain, Size: 721 bytes --]


The point of the mouse face is to tell the user that they can mouse-2 on
the region to expand the abbreviated bits.  (This is done in
`last-sexp-setup-props'.)

However, when the sexp is large, the mouse face is indeed very annoying.
Would it make sense to shorten it somehow?  For instance, only display
it over the "..." to indicate that it's the abbreviation that the mouse
face is trying to draw attention to?  Or...  something else?

Like...  er...  adding underlines or something to the dots and not using
a mouse face at all?  Or underlines and a mouse face, but just for the
dots...

Anybody got an opinion?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#4394: 23.1; flashing when overlapping face and mouse-face properties

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Sun, 18 Jul 2021 21:06:57 +0200
> Cc: Stefan Monnier <monnier@iro.umontreal.ca>, 4394@debbugs.gnu.org
> 
> The point of the mouse face is to tell the user that they can mouse-2 on
> the region to expand the abbreviated bits.  (This is done in
> `last-sexp-setup-props'.)
> 
> However, when the sexp is large, the mouse face is indeed very annoying.
> Would it make sense to shorten it somehow?  For instance, only display
> it over the "..." to indicate that it's the abbreviation that the mouse
> face is trying to draw attention to?  Or...  something else?
> 
> Like...  er...  adding underlines or something to the dots and not using
> a mouse face at all?  Or underlines and a mouse face, but just for the
> dots...
> 
> Anybody got an opinion?

My opinion is that we should leave this alone.

bug#4394: 23.1; flashing when overlapping face and mouse-face properties

[Eli Zaretskii]

> Date: Sun, 18 Jul 2021 22:11:29 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: monnier@iro.umontreal.ca, 4394@debbugs.gnu.org
> 
> > From: Lars Ingebrigtsen <larsi@gnus.org>
> > Date: Sun, 18 Jul 2021 21:06:57 +0200
> > Cc: Stefan Monnier <monnier@iro.umontreal.ca>, 4394@debbugs.gnu.org
> > 
> > The point of the mouse face is to tell the user that they can mouse-2 on
> > the region to expand the abbreviated bits.  (This is done in
> > `last-sexp-setup-props'.)
> > 
> > However, when the sexp is large, the mouse face is indeed very annoying.
> > Would it make sense to shorten it somehow?  For instance, only display
> > it over the "..." to indicate that it's the abbreviation that the mouse
> > face is trying to draw attention to?  Or...  something else?
> > 
> > Like...  er...  adding underlines or something to the dots and not using
> > a mouse face at all?  Or underlines and a mouse face, but just for the
> > dots...
> > 
> > Anybody got an opinion?
> 
> My opinion is that we should leave this alone.

Btw, here the highlight stops at the right parentheses, it doesn't go
to the right edge of the window.

bug#4394: 23.1; flashing when overlapping face and mouse-face properties

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

>> Anybody got an opinion?
>
> My opinion is that we should leave this alone.

OK; closing this bug report, then.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no