bug#35492: 27.0.50; set-mouse-color nop

bug#35492: 27.0.50; set-mouse-color nop

[Devon Sean McCullough]

The following have no effect:
	(set-mouse-color "red")
	(set-mouse-color “yellow")
	(set-mouse-color "windowBackgroundColor")
The mouse color should change.

		Peace
			—Devon

P.S. Have you discontinued MacOSX 10.11.6 El Capitan support?
Emacs-26.2 and later constantly glitch my screen with spurious clearing and redrawing.
My colleagues report no such aggravation under MacOSX 10.14 Mojave.
I s’poze I could revert to Emacs-26.1-2 as a workaround.

This build is from https://EmacsForMacOSX.com
and was certainly not built on my machine,
contrary to the automated report below.

In GNU Emacs 27.0.50 (build 1, x86_64-apple-darwin14.5.0, NS appkit-1404.47 Version 10.11.6 (Build 15G22010))
 of 2019-04-29 built on Devons-Air.fios-router.home
Windowing system distributor 'Apple', version 10.3.1404
System Description:  Mac OS X 10.11.6

Recent messages:
Loading uniquify...done
Loading electric...done
Loading emacs-lisp/eldoc...done
Loading cus-start...done
Loading tooltip...done
Loading /Applications/Emacs-27.0.50.app/Contents/Resources/lisp/leim/leim-list.el (source)...done
Finding pointers to doc strings...done
For information about GNU Emacs and the GNU system, type C-h C-a.
Loading loadup.el (source)...done
nil
nil
Configured using:
 'configure --with-ns '--enable-locallisppath=/Library/Application
 Support/Emacs/${version}/site-lisp:/Library/Application
 Support/Emacs/site-lisp' --with-modules'

Configured features:
NOTIFY KQUEUE ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS MODULES
THREADS PDUMPER

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny seq byte-opt gv
bytecomp byte-compile cconv dired dired-loaddefs format-spec rfc822 mml
easymenu mml-sec password-cache epa derived epg epg-config gnus-util
rmail rmail-loaddefs text-property-search mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs cl-lib
sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
time-date elec-pair tooltip cus-start eldoc electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel term/ns-win ns-win ucs-normalize
mule-util term/common-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow isearch timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932
hebrew greek romanian slovak czech european ethiopic indian cyrillic
chinese composite charscript charprop case-table epa-hook jka-cmpr-hook
help simple abbrev obarray minibuffer cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads kqueue cocoa ns multi-tty make-network-process emacs)

Memory information:
((conses 16 264989 15806)
 (symbols 48 20142 6)
 (strings 32 54280 2357)
 (string-bytes 1 2299535)
 (vectors 16 49211)
 (vector-slots 8 1381781 77348)
 (floats 8 184 74)
 (intervals 56 210 0)
 (buffers 992 12))

bug#35492: 27.0.50; set-mouse-color nop

[Eli Zaretskii]

> From: Devon Sean McCullough <Emacs-Hacker2018@jovi.net>
> Date: Mon, 29 Apr 2019 14:18:42 -0400
> 
> The following have no effect:
> 	(set-mouse-color "red")
> 	(set-mouse-color “yellow")
> 	(set-mouse-color "windowBackgroundColor")
> The mouse color should change.

AFAIK, this is currently not supported on MacOS.

bug#35492: 27.0.50; set-mouse-color nop

[Alan Third]

On Mon, Apr 29, 2019 at 02:18:42PM -0400, Devon Sean McCullough wrote:
> The following have no effect:
> 	(set-mouse-color "red")
> 	(set-mouse-color “yellow")
> 	(set-mouse-color "windowBackgroundColor")
> The mouse color should change.

Hi Devon,

I don’t think the NS port supports modifying the mouse pointer. It
looks like it could probably be handled with custom NSCursors.

> P.S. Have you discontinued MacOSX 10.11.6 El Capitan support?
> Emacs-26.2 and later constantly glitch my screen with spurious clearing and redrawing.
> My colleagues report no such aggravation under MacOSX 10.14 Mojave.
> I s’poze I could revert to Emacs-26.1-2 as a workaround.

If your colleagues aren’t seeing any issues with 10.14, it’s probably
a fluke. Either that or you’re doing something, or running something,
which is prodding the bugs in the display system directly.

In macOS 10.14 Apple dropped the drawing mechanism we used, and I’ve
been unable to come up with a suitable alternative.
-- 
Alan Third

bug#35492: 27.0.50; set-mouse-color nop

[Devon Sean McCullough]

> 	On Apr 30, 2019, at 4:22 PM, Alan Third <alan@idiocy.org> wrote:
> On Mon, Apr 29, 2019 at 02:18:42PM -0400, Devon Sean McCullough wrote:
>> The following have no effect:
>> 	(set-mouse-color "red")
>> 	(set-mouse-color “yellow")
>> 	(set-mouse-color "windowBackgroundColor")
>> The mouse color should change.

> I don’t think the NS port supports modifying the mouse pointer. It
> looks like it could probably be handled with custom NSCursors.

I see NS allows us to both read and write cursor images
so a possible solution might involve (mouse-cursor-image nil)
to get the current cursor image and (mouse-cursor-image nil image)
to set it, either as a new primitive or an existing one I’m ignorant of.
Lisp code thus replaces the cursor colors according to some heuristic;
this notion struck me after giving image.c & image.el a cursory glance.

	Peace
		--Devon

>> P.S. Have you discontinued MacOSX 10.11.6 El Capitan support?
>> Emacs-26.2 and later constantly glitch my screen with spurious clearing and redrawing.
>> My colleagues report no such aggravation under MacOSX 10.14 Mojave.
>> I s’poze I could revert to Emacs-26.1-2 as a workaround.
> 
> If your colleagues aren’t seeing any issues with 10.14, it’s probably
> a fluke. Either that or you’re doing something, or running something,
> which is prodding the bugs in the display system directly.
> 
> In macOS 10.14 Apple dropped the drawing mechanism we used, and I’ve
> been unable to come up with a suitable alternative.

Perhaps their displays are faster, rendering the needless redisplay imperceptible.

bug#35492: 27.0.50; set-mouse-color nop

[Alan Third]

On Wed, May 01, 2019 at 07:07:53AM -0400, Devon Sean McCullough wrote:
> > 	On Apr 30, 2019, at 4:22 PM, Alan Third <alan@idiocy.org> wrote:
> > On Mon, Apr 29, 2019 at 02:18:42PM -0400, Devon Sean McCullough wrote:
> >> The following have no effect:
> >> 	(set-mouse-color "red")
> >> 	(set-mouse-color “yellow")
> >> 	(set-mouse-color "windowBackgroundColor")
> >> The mouse color should change.
> 
> > I don’t think the NS port supports modifying the mouse pointer. It
> > looks like it could probably be handled with custom NSCursors.
> 
> I see NS allows us to both read and write cursor images
> so a possible solution might involve (mouse-cursor-image nil)
> to get the current cursor image and (mouse-cursor-image nil image)
> to set it, either as a new primitive or an existing one I’m ignorant of.
> Lisp code thus replaces the cursor colors according to some heuristic;
> this notion struck me after giving image.c & image.el a cursory glance.

It looks like it’s possible to get a copy of the image for the current
cursor, so it’s possible we could just modify that.
-- 
Alan Third

bug#35492: 27.0.50; set-mouse-color nop

[Devon Sean McCullough]

> On May 1, 2019, at 5:11 PM, Alan Third <alan@idiocy.org> wrote:
> 
> On Wed, May 01, 2019 at 07:07:53AM -0400, Devon Sean McCullough wrote:
>>> 	On Apr 30, 2019, at 4:22 PM, Alan Third <alan@idiocy.org> wrote:
>>> On Mon, Apr 29, 2019 at 02:18:42PM -0400, Devon Sean McCullough wrote:
>>>> The following have no effect:
>>>> 	(set-mouse-color "red")
>>>> 	(set-mouse-color “yellow")
>>>> 	(set-mouse-color "windowBackgroundColor")
>>>> The mouse color should change.
>> 
>>> I don’t think the NS port supports modifying the mouse pointer. It
>>> looks like it could probably be handled with custom NSCursors.
>> 
>> I see NS allows us to both read and write cursor images
>> so a possible solution might involve (mouse-cursor-image nil)
>> to get the current cursor image and (mouse-cursor-image nil image)
>> to set it, either as a new primitive or an existing one I’m ignorant of.
>> Lisp code thus replaces the cursor colors according to some heuristic;
>> this notion struck me after giving image.c & image.el a cursory glance.
> 
> It looks like it’s possible to get a copy of the image for the current
> cursor, so it’s possible we could just modify that.

Yes, that’s what I said.

		Peace
			—Devon

P.S. I would be foolish to do in C
and it would be wise to allow Lisp
to generate custom cursors too.

bug#35492: 27.0.50; set-mouse-color nop

[Alan Third]

On Wed, May 01, 2019 at 05:49:16PM -0400, Devon Sean McCullough wrote:
> 
> > On May 1, 2019, at 5:11 PM, Alan Third <alan@idiocy.org> wrote:
> > 
> > On Wed, May 01, 2019 at 07:07:53AM -0400, Devon Sean McCullough wrote:
> >>> 	On Apr 30, 2019, at 4:22 PM, Alan Third <alan@idiocy.org> wrote:
> >>> On Mon, Apr 29, 2019 at 02:18:42PM -0400, Devon Sean McCullough wrote:
> >>>> The following have no effect:
> >>>> 	(set-mouse-color "red")
> >>>> 	(set-mouse-color “yellow")
> >>>> 	(set-mouse-color "windowBackgroundColor")
> >>>> The mouse color should change.
> >> 
> >>> I don’t think the NS port supports modifying the mouse pointer. It
> >>> looks like it could probably be handled with custom NSCursors.
> >> 
> >> I see NS allows us to both read and write cursor images
> >> so a possible solution might involve (mouse-cursor-image nil)
> >> to get the current cursor image and (mouse-cursor-image nil image)
> >> to set it, either as a new primitive or an existing one I’m ignorant of.
> >> Lisp code thus replaces the cursor colors according to some heuristic;
> >> this notion struck me after giving image.c & image.el a cursory glance.
> > 
> > It looks like it’s possible to get a copy of the image for the current
> > cursor, so it’s possible we could just modify that.
> 
> Yes, that’s what I said.

Sorry, I misunderstood you.

The biggest stumbling block I can see is that we don’t have any way to
convert from an NSImage, which is what NSCursor returns, to something
we can edit from lisp (XPM, I assume?). So we’d have to implement
that.

The alternative, I suppose, would be to provide a custom set of
cursors that we can edit before using them.

> P.S. I would be foolish to do in C
> and it would be wise to allow Lisp
> to generate custom cursors too.

-- 
Alan Third