spaceline flicker with 2 or more windows

[mpanarin]

Thanks for the awesome package!

I encountered an issue: on emacs27, and spacemacs on develop branch. When more than one window is open with tabs on, spaceline starts to flicker with every line change. Can be connected to the similar issue that existed in helm with focus? https://github.com/emacs-helm/helm/issues/1593

[ema2159]

Hi, It may have to do with both packages using powerline. I personally use doom-modeline so I haven't encountered this issue, but it most likely has to do with that. I'll try to investigate, and if you find a solution don't be afraid of submitting a PR!

[ema2159]

Please show me your centaur-tabs config! What I think may be causing the problem is the header-line face.

[mpanarin]

Just tried switching to doom modeline, just to check. Still have similar issue with modeline not being highlighted and cursor flashing sometimes in second window. This definitely looks like focus switching. Maybe its not centaur-tabs directly though :\

my config:

(use-package centaur-tabs
    :demand
    :config
    (centaur-tabs-mode t)
    (setq centaur-tabs-style "bar")
    (setq centaur-tabs-height 32)
    (setq centaur-tabs-set-icons t)
    (setq centaur-tabs-set-bar 'over)
    (setq centaur-tabs-set-close-button nil)
    (setq centaur-tabs-cycle-scope 'tabs)
    (centaur-tabs-group-by-projectile-project)
    (centaur-tabs-mode t)
    (defun centaur-tabs-hide-tab (x)
      (let ((name (format "%s" x)))
          (or
         (window-dedicated-p (selected-window))
           (string-prefix-p "*epc" name)
           (string-prefix-p "*helm" name)
           (string-prefix-p "*Helm" name)
           (string-prefix-p "*spacemacs*" name)
           (string-prefix-p "*Messages*" name)
           (string-prefix-p "*Compile-Log*" name)
           (string-prefix-p "*which-key*" name)
           (string-prefix-p "*lsp" name)
           (string-prefix-p "magit" name)
           )))
    :hook (
     (dashboard-mode . centaur-tabs-local-mode)
     (treemacs-mode . centaur-tabs-local-mode)
     (spacemacs-buffer-mode . centaur-tabs-local-mode)
     (term-mode . centaur-tabs-local-mode)
     (calendar-mode . centaur-tabs-local-mode)
     (org-agenda-mode . centaur-tabs-local-mode)
     (helpful-mode . centaur-tabs-local-mode)
     (dired-mode . centaur-tabs-local-mode)
     (zone-mode . centaur-tabs-local-mode)
     (helm-mode . centaur-tabs-local-mode))
    :bind
    ("C-<prior>" . centaur-tabs-backward)
    ("C-<next>" . centaur-tabs-forward)
    ("C-c t" . centaur-tabs-counsel-switch-group)
    (:map evil-normal-state-map
            ("g l" . centaur-tabs-forward)
            ("g h" . centaur-tabs-backward)
            ("SPC b n" . centaur-tabs-forward)
            ("SPC b p" . centaur-tabs-backward))
    )

[ema2159]

Dammit! I thought the (centaur-tabs-headline-match) function was the culprit, it seems its some other problem. I don't use Spacemacs so it would be hard to solve. You could ask them to try to check what's going on

[ema2159]

Please keep me updated with this and let me know how I can help!

[mpanarin]

Yep, sure. Will do some more testing on coming days.

Another thing I noticed, is that it doesn't flicker when tabs from two different groups are present. ex. In window 1 tabs from project1 (projectile) and in window 2 tabs from project2. Maybe this will give you some hint. I'll also try to check on the out-of-the box spacemacs config to rule out some of mine configurations. Maybe, if it is still flickering, you could try check it?

Because I am very-very limited in my elisp knowledge :\

Thanks in advance!

[mpanarin]

Aaand yes. Issue is reproducable on basic spacemacs install. If you have time, can you please check?

Here is the minimal spacemacs config https://gist.github.com/mpanarin/f6cacb692b422c8427ed17d14ad0b163

[ema2159]

Do you know other people that use spacemacs and centaur-tabs too? This in order to see if the problem is with spacemacs compatibility so I can open an issue there

[mpanarin]

Yep, have a friend with the exact same issues as me In this situation the right window has spaceline grayed out all the time (like when the window is not focused) and on the left side spaceline will flicker when moving cursor between lines (and especially on the empty lines).

[cburroughs]

I at least one of the behaviors described in the linked spacemacs ticket -- pressing the up key with a vertical split causes the modeline to appear unfocused -- also happens with doom-modeline.

Steps:

• emacs -Q

• (progn
  (require 'package)
  (package-initialize)
  (require 'doom-modeline)
  (doom-modeline-mode 1)
  (require 'centaur-tabs)
  (centaur-tabs-mode 1))
  ;; ^^ evaluate the above

• open buffers foo and bar
• vertically split
• arrange it such that foo is on the left and bar on the right
• switch to the right window
• type some text
• press "up" or C-p on the top line
• modeline now has the unfocused face

[ema2159]

Sorry for the incredibly long delay, I think I found a decent solution for this problem, although I would like you to test it when you can (if you still use this package). I used a rather simple solution. I added a run-idle-timer to the function that's hooked to the after-changes-function to prevent the tabs from being recalculated each time the user types, undos or anything. The changes will be merged on master soon.

[ema2159]

Fixed in 3658efc.

[mpanarin]

@ema2159
Hi, thanks for spending more time on this. Your fix didn't help though :\

Some time ago I was debugging the issue and the problem seems that functions like with-temp-buffer for some reason trigger the buffer-list-update-hook(but it actually shouldn't) that triggers (force-mode-line-update). Never had the time to dig further into this though. Maybe I'll try to check it this weekends.

[ema2159]

Hmmmm, that info actually helps me to solve this and #83. I'll try to fix it as soon as possible. I'm trying to fix as much as possible from the package before starting to support Emacs 27 which will come with a bunch of nice features.

[mpanarin]

Just for the info, I am on emacs 28. Though I had this issue with emacs 26 and 27 as well.

[ema2159]

@mpanarin now, finally, it should be solved. The solution wasn't trivial and I needed the help of @hlissner to solve it. Please test it in the Spacemacs environment and tell me if it works! In Vanilla Emacs it's fixed.

[mpanarin]

@ema2159 Oh my god, yes! This fixed the issue completely )

Thanks! Guess I'll start my slow transition back from tab-line-mode )

[ema2159]

Awesome! Soon I'll try to support Emacs's 27 tab-line and some of its functionalities like window based tab groups soon.