Systray should support transparency on 32-bit Emacs (Was: No systray with emacs v29.0.50)

[danrobi11]

I compiled v29.0.50 today and the exwm systray is not working. Was working fine with 27.1

[Stebalien]

See https://lists.gnu.org/archive/html/emacs-devel/2022-02/msg00104.html for context.

[danrobi11]

@Stebalien Hi. Thank's for the support. It works but the tray is now top left corner :/ Its better than nothing tho.

[Stebalien]

Hm. Odd. It's in the bottom-right corner on my machine with the latest Emacs master and that fix. It might depend on startup order? Maybe enable the systemtray later?

[danrobi11]

Hm. Odd. It's in the bottom-right corner on my machine

@Stebalien Ya its weird. Not a deal breaker tho so I might try to debug that later on. I'll close the issue for now. Thank's again for the support, much appreciated.

[Stebalien]

I'd reopen it. This is just a workaround, the bug is still there.

[danrobi11]

I'd reopen it. This is just a workaround, the bug is still there

Ok

[medranocalvo]

@danrobi11, thank you for reporting this issue.

I've linked a similar report by @jaor on #858.

I think the issue is either with exwm--color->pixel or the combination of the systray being reparented on the Emacs' frame X window (https://github.com/ch11ng/exwm/blob/master/exwm-systemtray.el#L367), the background-pixmap being set to ParentRelative (https://github.com/ch11ng/exwm/blob/master/exwm-systemtray.el#L512) and that both X windows have different visuals.

@Stebalien, I appreciate your help in the issue tracker and elsewhere.

[jaor]

i've been trying to fix the problem by assigning a correct visual to
the systray embedder without success, so i must be missing something
(unsurprisingly, since i don't know much about xcb, i'm afraid). as
an observation, what seems to be going on with the current code plus
the transparency for workspaces patch (which is working like a charm
for me, btw) is that when a new icon pops up and the embedder tries to
reparent it (that callback gets effectively called), the icon ends up
as a workspace (or root) child (my guess is that the reparenting
simply fails, but i haven't been able to make it work).

[jaor]

for reference jaor@dfd2b4d is my latest failed attempt at fixing the systemtray problem by adjusting visuals and the like (mimicking what's being doing in exwm-workspace).

[medranocalvo]

Please test proposed fix: #867.

[jaor]

yes, i can confirm the systray is back to working well for me in a very recent emacs 29. many thanks!

[medranocalvo]

Happy to hear it. Please test customizing colors, etc. @jaor, I’d like to assemble a team to help testing, especially due to the different configurations. May I contact you ***@***.***) when I need testing changes related to the systemtray? Also, may I contact you to ask you to try the `master` branch before releasing?

…

Am 21.03.2022 um 02:27 schrieb jao ***@***.***>:  yes, i can confirm the systray is back to working well for me in a very recent emacs 29. many thanks! — Reply to this email directly, view it on GitHub, or unsubscribe. Triage notifications on the go with GitHub Mobile for iOS or Android. You are receiving this because you commented.

[medranocalvo]

Sorry, the ask for help in testing is meant for everyone, especially all involved in this ticket!

…

Am 21.03.2022 um 07:22 schrieb medranocalvo ***@***.***>:  Happy to hear it. Please test customizing colors, etc. @jaor, I’d like to assemble a team to help testing, especially due to the different configurations. May I contact you ***@***.***) when I need testing changes related to the systemtray? Also, may I contact you to ask you to try the `master` branch before releasing? > Am 21.03.2022 um 02:27 schrieb jao ***@***.***>: > >  > > yes, i can confirm the systray is back to working well for me in a very > recent emacs 29. many thanks! > — > Reply to this email directly, view it on GitHub, or unsubscribe. > Triage notifications on the go with GitHub Mobile for iOS or Android. > You are receiving this because you commented. — Reply to this email directly, view it on GitHub, or unsubscribe. Triage notifications on the go with GitHub Mobile for iOS or Android. You are receiving this because you are subscribed to this thread.

[jaor]

a little detail, though: while the systray is there and takes icons just fine, it's not exactly respecting the set alpha-background... it's a bit difficult to tell, but i'd say the first icon added to the tray has an opaque background, while subsequent ones get the correct alpha.

[jaor]

hi @medranocalvo. yes, feel free to contact me for helping in testing, no problem. and thanks for your work on exwm! jao -- Omnia disce, videbus postea nihil esse superfluum - Hugh of St Victor

[medranocalvo]

Thank you for accepting. I'll note it down in the Wiki.

a little detail, though: while the systray is there and takes icons just
fine, it's not exactly respecting the set alpha-background... it's a bit
difficult to tell, but i'd say the first icon added to the tray has an
opaque background, while subsequent ones get the correct alpha.

Hmm, you are right.

What was the previous behaviour, though? As far as I can see, it seems to inherit the frame's background; there was no transparency. This is what I see on Emacs 27 and EXWM without #867:

Previous code used a xcb:BackPixmap:ParentRelative :background-pixmap, where the parent was the Emacs frame [1]. https://x.org/releases/X11R7.7/doc/xproto/x11protocol.html#requests:CreateWindow says:

If background ParentRelative is specified, the parent's background is used, but the window must have the same depth as the parent (or a Match error results)

#867 changes the embedder window to use the root window's depth and visual, but the parent is the Emacs' frame with the 32bit depth, so we can no longer use ParentRelative, and use None instead.

If the background is None, the previous screen contents from other windows of the same depth as the window are simply left in place if the contents come from the parent of the window or an inferior of the parent; otherwise, the initial contents of the exposed regions are undefined.

I guess we are seen the contents become "undefined".

I'm not sure what the right fix is. We can create the embedder window with 32bit depth, but the spec says that we must be prepared to support icons in other depths. And that we "must use the Composite extension to composite the icon against the background". See https://specifications.freedesktop.org/systemtray-spec/systemtray-spec-latest.html#visuals and https://specifications.freedesktop.org/systemtray-spec/systemtray-spec-latest.html#idm45080845287296. I don't have de bandwidth to do that. (Would you be interested in trying?)

Meanwhile, please test the new commit in #867, which creates a 32bit embedder window, and let me know how it works for you.

---

[1]: Though, if I understand correctly, xcb:BackPixmap:None was effectively used unless customized, as no xcb:CW:BackPixmap was included in :value-mask; see https://github.com/ch11ng/exwm/pull/867/files#diff-fb276d4e1c34c3538814bf2e1f91532cbbf064326920d214655c6252b2d83316R514. Unless the :set form of the exwm-systemtray-background-color defcustom ran inconditionally.

[jaor]

On Thu, Mar 24 2022, medranocalvo wrote: Meanwhile, please test the new commit in #867, which creates a 32bit embedder window, and let me know how it works for you.

i am using it in combination with the one to enable 32 bit visual in workspaces and it's working well, modulo the little problem with the background. (i used to use :alpha previously, although almost always with emacs compiled from its git master branch, and i'd say the systemtray was respecting that alpha background.)

[Stebalien]

It's working well for me as well.

[Stebalien]

Ok, so, one bug: if I start nm-applet before starting Emacs, it'll display as a window. Interestingly: 1. Restarting nm-applet doesn't help. 2. Restarting Emacs, then re-starting nm-applet doesn't help. The only thing that fixes this is: 1. Stopping nm-applet. 2. Re-starting emacs. 3. Starting nm-applet.

[medranocalvo]

@Stebalien: the issue with nm-applet seems to be the following:

1. when it starts it does not know that EXWM will make a fancy 32-bit depth systray, so it makes a regular systray icon. EXWM's 32-bit systray (as in #867) does not support those.
2. I don't know. It's possible that the systray agent is not restarted?

When starting it after EXWM is up, nm-applet notices that we support 32-bit and makes such an icon.

I decided I'll disable systray transparency when using 32-bit depth emacs, reason in #867. This ticket will be turned into a feature request. Opinions?

[Stebalien]

when it starts it does not know that EXWM will make a fancy 32-bit depth systray, so it makes a regular systray icon.

Makes sense, although I'm still confused why restarting nm-applet doesn't fix it (I'm definitely restarting it).

I decided I'll disable systray transparency when using 32-bit depth emacs, reason in #867. This ticket will be turned into a feature request. Opinions?

That seems reasonable for most EXWM users. It also reduces the need for #879.

[Stebalien]

So, reverting that commit works but only if a background color is explicitly set with exwm-systemtray-background-color. We'd probably want a theme hook to set the background color when the theme background is toggled.

If it isn't set, the "background" defaults to "whatever was drawn before", so any changing/animated icon quickly becomes a mess.

[medranocalvo]

@danrobi11, @Stebalien, @jaor: please test the latest version: #867 (comment).

@Stebalien:

when it starts it does not know that EXWM will make a fancy 32-bit depth systray, so it makes a regular systray icon.

Makes sense, although I'm still confused why restarting nm-applet doesn't fix it (I'm definitely restarting it).

I don't know either...

[jaor]

On Fri, Nov 04 2022, medranocalvo wrote: @danrobi11, @Stebalien, @jaor: please test the latest version: #867 (comment).

if the latest version means the current master, for me it's not working in emacs 29: i need 32 bit depth for frame alpha-transparency (which is working fine with that same version), and with that depth the systray is not working: applets are open in a regular (empty) window, instead of a systray.

[Stebalien]

It means the latest version of #867.

[jaor]

On Sat, Nov 05 2022, Steven Allen wrote: It means the latest version of #867.

Thanks. In that branch, when i `(require 'exwm-systemtray)` i get the error: ```elisp Debugger entered--Lisp error: (void-function exwm-systemtray--transparency-supported-p) (exwm-systemtray--transparency-supported-p) (if (exwm-systemtray--transparency-supported-p) 'workspace-background 'transparent) (closure (t) nil "" (if (exwm-systemtray--transparency-supported-p) 'workspace-background 'transparent))() funcall((closure (t) nil "" (if (exwm-systemtray--transparency-supported-p) 'workspace-background 'transparent))) eval((funcall #'(closure (t) nil "" (if (exwm-systemtray--transparency-supported-p) 'workspace-background 'transparent))) t) custom-initialize-default(exwm-systemtray-background-color (funcall #'(closure (t) nil "" (if (exwm-systemtray--transparency-supported-p) 'workspace-background 'transparent)))) custom-declare-variable(exwm-systemtray-background-color (funcall #'(closure (t) nil "" (if (exwm-systemtray--transparency-supported-p) 'workspace-background 'transparent))) "Background color of systemtray.\nThis should be a c..." :type (choice (const :tag "Transparent" 'transparent) (const :tag "Frame background" 'workspace-background) (color)) :initialize custom-initialize-default :set (closure (t) (symbol value) (if (and (eq value 'transparent) (not (exwm-systemtray--transparency-supported-p))) (progn (display-warning 'exwm-systemtray "Transparent background is not supported yet when u...") (setq value 'workspace-background))) (set-default symbol value) (if (and exwm-systemtray--connection exwm-systemtray--embedder-window) (progn (exwm-systemtray--set-background-color) (xcb:-+request exwm-systemtray--connection (make-instance 'xcb:UnmapWindow :window exwm-systemtray--embedder-window)) (xcb:-+request exwm-systemtray--connection (make-instance 'xcb:MapWindow :window exwm-systemtray--embedder-window)) (xcb:flush exwm-systemtray--connection))))) eval-buffer(#<buffer *load*> nil "/home/jao/lib/elisp/exwm/exwm-systemtray.el" nil t) ; Reading at buffer position 4175 load-with-code-conversion("/home/jao/lib/elisp/exwm/exwm-systemtray.el" "/home/jao/lib/elisp/exwm/exwm-systemtray.el" nil t) require(exwm-systemtray) ``` so probably that function needs to be defined before using it in custom. Anyway, i can workaround that problem (defining the function before the defcustom), and emacs/exwm starts and works, etc. But of course, the tray doesn't work at all with 32bit depth. I understand this is deliberate, so well, that's it (as mentioned, it doesn't solve the issue for me, because i want alpha-background, but that's just me). Thanks, jao

[medranocalvo]

@jaor: please test again the latest version of #867. I solved the initialization issue by setting the default to 'workspace-background, as it's supported by all configuration. I have to say that I think, though am not sure, that there is no difference between 'transparent and 'workspace-background in 24-bit configurations: 'transparent makes the systemtray use the same background-pixmap as Emacs' frames; I'd guess that the background pixmap is exactly the frame background color. In your experience, did 'transparent offer actual transparency?

But of course, the tray doesn't work at all with 32bit depth. I understand this is deliberate, so well, that's it (as mentioned, it doesn't solve the issue for me, because i want alpha-background, but that's just me).

Do I understand correctly that you'd like the systemtray to be 32-bit and support alpha-background?

[jaor]

On Wed, Nov 09 2022, medranocalvo wrote: @jaor: please test again the latest version of #867. I solved the initialization issue by setting the default to 'workspace-background, as it's supported by all configuration. I have to say that I think, though am not sure, that there is no difference between 'transparent and 'workspace-background in 24-bit configurations: 'transparent makes the systemtray use the same background-pixmap as Emacs' frames; I'd guess that the background pixmap is exactly the frame background color. In your experience, did 'transparent offer actual transparency?

the difference is that the 24 bit option applies transparency also for the foreground text.

> But of course, the tray doesn't work at all with 32bit depth. I > understand this is deliberate, so well, that's it (as mentioned, it > doesn't solve the issue for me, because i want alpha-background, but > that's just me). Do I understand correctly that you'd like the systemtray to be 32-bit and support alpha-background?

yes, exactly. if i am not mistaken, one needs 32 bit for the `alpha-background` frame parameter to work, and the latter (as opposed to the "old" `alpha` one uses in emacs 28 and before which also makes transparent the foreground) is needed to have background-only transparency. many thanks for looking at this! jao -- A bug report without a patch is like a bike without a cake. - Stefan Monnier

[jaor]

@jaor: please test again the latest version of #867.

just restarted in that version and yes, it's working well for me now, thanks! (modulo the absence of transparency, but i think that's expected).

[medranocalvo]

0.27 has been released, which includes the fixes in #867. Transparency is not supported in 32-bit visual Emacs.