Bar flickering in vertical mode

The issue:

Qtile version: 0.21.0

My qtile bar flickers in vertical mode. This might be related to #3062, but the bar behaves normally in horizontal mode for me. Also the fixes in that issue have already been applied to my relatively recent build of Qtile.

https://user-images.githubusercontent.com/8607532/174957846-5fe9465c-e184-4287-a113-264c7bba453e.mp4

There are actually two behaviors here:

1. The bottom segment(s) of the bar (the clock and battery widgets in my case) simply vanish. This is persistent. They reappear for a couple of seconds when I switch desktops but then disappear again. This happens no matter what the bottom widget is.

2. The entire bar flickers whenever something visual happens in an application (such as opening a new tab in a browser, or when changing desktops).

I’ve tried the following things without success:

1. Ensure that all widgets in the bar support a vertical bar orientation (no groupbox etc)
2. Remove all the multibyte fontawesome icons from the bar, as well as the image widget, leaving only text.
3. Try different monospaced fonts
4. Disable each widget in turn (assuming some misbehaving widget is responsible for this)
5. Initialize the bar with no margin, no border_width
6. Reverse the order of the bar widgets

Here is a simplified version of my bar config that displays the flickering behavior:

colors = [["#172030", "#172030"], # panel background
          ["#273a43", "#273a43"], # background for current screen tab
          ["#e8e9eb", "#e8e9eb"], # font color for group names
          ["#db6e8f", "#db6e8f"], # border line color for current tab
          ["#1f2a3f", "#1f2a3f"], # border line color for 'other tabs' and color for 'odd widgets'
          ["#0e131d", "#0e131d"], # for the 'even widgets'
          ["#b16e75", "#1f2a3f"], # window name
          # ["#0e131d", "#c6797e"], #
          ["#34262D", "#c6797e"], #
          ["#7d7f7b", "#7d7f7b"]] # background for inactive screens

terminal = "st"

def sep(cf,cb):
    __box = widget.Sep(
        linewidth = 0,
        padding = 4,
        foreground = colors[cf],
        background = colors[cb],
    )
    return __box

widget_defaults = dict(
    font='Monospace Extrabold',
    fontsize=22,
    background=colors[2][0],
    padding=12,
)

extension_defaults = widget_defaults.copy()
tasklist_focused_markup = "<span weight=\"bold\">{}</span>"

def init_widgets_list():
    widgets_list = [
        widget.Sep(
            linewidth = 0,
            padding = 6,
            foreground = colors[2],
            background = colors[0]
        ),
        widget.Sep(
            linewidth = 0,
            padding = 6,
            foreground = colors[2],
            background = colors[0]
        ),
        widget.Prompt(
            prompt = prompt,
            padding = 10,
            foreground = colors[3],
            background = colors[1]
        ),
        widget.Sep(
            linewidth = 0,
            padding = 40,
            foreground = colors[2],
            background = colors[0]
        ),
        widget.WindowTabs(
            fontsize = 20,
            foreground = colors[6][0],
            background = colors[0],
            border = colors[6][::-1], # was colors[1]
            highlight_method = 'block',
            markup_focused = tasklist_focused_markup,
            max_title_width = 150,
            margin = 1,
            padding = 5,
        ),
        widget.Systray(
            background = colors[0],
            padding = 5
        ),
        sep(0,4),
        widget.Bluetooth(
            foreground = colors[2],
            background = colors[5],
            fmt = '{}',
            padding = 5, max_chars = 9,
            hci = '/dev_88_D0_39_F9_15_0A',
            mouse_callbacks = {'Button1': lambda: qtile.cmd_spawn('dmenu-bluetooth')}
        ),
        sep(5,4),
        widget.Backlight(
            foreground = colors[2],
            background = colors[4],
            padding = 2,
            step = 4,
            update_interval = 1.0,
            backlight_name = "amdgpu_bl0"
        ),
        sep(4,5),
        widget.CPU(
            foreground = colors[2],
            background = colors[5],
            padding = 2,
            format = "{load_percent:2.0f}%",
            update_interval = 2.0,
            mouse_callbacks = {'Button1': lambda: qtile.cmd_spawn(terminal + ' -t dropdown_cpu -e btm')},
        ),
        sep(5,4),
        widget.Battery(
            foreground = colors[2],
            background = colors[4],
            padding = 3,
            low_percentage=0.20,
            low_foreground=colors[3],
            update_delay=15,
            format='{percent:.0%}', # '{watt:.1f}W'
        ),
        widget.Clock(
            foreground = colors[2],
            background = colors[5],
            format =  "%a %d/%m %R", #"%A, %B %d - %H:%M ",
            mouse_callbacks = {'Button1': lambda: send_notification('calendar',' "$(cal -3)"')},
        ),
            ]
    return list(widgets_list)

def init_screens():
    return [Screen(left=bar.Bar(widgets=init_widgets_list(), opacity=1.0, size=40, margin=[0,5,0,0])),
            Screen(left=bar.Bar(widgets=init_widgets_list(), opacity=1.0, size=40, margin=[0,5,0,0]))]

There’s nothing in my qtile log except some restart messages:

2022-06-22 11:59:07,922 WARNING libqtile lifecycle.py:_atexit():L33 Restarting Qtile with os.execv(...)
2022-06-22 11:59:34,592 WARNING libqtile lifecycle.py:_atexit():L33 Restarting Qtile with os.execv(...)
2022-06-22 12:09:48,848 WARNING libqtile lifecycle.py:_atexit():L33 Restarting Qtile with os.execv(...)

(I don’t know what hook to subscribe to with what function to get relevant messages in the log for this bug.)

Required:

• I have searched past issues to see if this bug has already been reported.

[karthink]

I still observe flickering in vertical qtile bars in both a regular session and in Xephyr. I haven’t had time to create a minimal config to reproduce this yet, please leave this issue open for a bit longer.

elParaguayo @.***> writes:

@karthink any update on this?

– Reply to this email directly or view it on GitHub: https://github.com/qtile/qtile/issues/3652#issuecomment-1186153319 You are receiving this because you were mentioned.

Message ID: @.***>

[elParaguayo]

@karthink any update on this?