#844 Playlist & equalizer and showing in taskbar

[Palo Kisa]

Hi, we've got following problem reported https://github.com/lxde/lxqt/issues/937

Please, have a look in there and say your opinion...

Should the playlist & equalizer window appear in taskbar if the main window is minimized?
If not, will you try make suggested changes on your side?

thanks

palo

[trialuser02]

I've tested cinnamon, lxde (gtk-based), kde and xfce. Most panels use _NET_WM_STATE_SKIP_TASKBAR atom and do not show playlist and equalizer.

Qt sends event type QEvent::WinIdChange when window id is changed. I added extra event type (QEvent::WindowActivate, etc) due to Qt5 bug. Sometimes windows id changes without QEvent::WinIdChange event.

Also I tried to set Qt::WA_X11NetWmWindowTypeToolBar without any success. Most panels ignore this attribute.

[Palo Kisa]

Most panels use _NET_WM_STATE_SKIP_TASKBAR atom and do not show playlist and equalizer.

We use/check that atom too, but that atom is not set when the main window si minimized. Have a look on this:

$ xwininfo | egrep 'Window id:'
xwininfo: Window id: 0x440000b "Playlist"

...now if qmmp isn't minimised (the *SKIP* atoms are set):

$ xprop -id 0x440000b | egrep -i skip
_NET_WM_STATE(ATOM) = _NET_WM_STATE_SKIP_TASKBAR, _NET_WM_STATE_SKIP_PAGER

, but when minized (no *SKIP* atoms):

$ xprop -id 0x440000b | egrep -i skip
$

Also the default openbox window switcher (alt+tab) shows all three windows no matter if minimized or not.

[Palo Kisa]

... or even better "greps", so you believe that the window id isn't changed:

• normal:

$ xprop -id 0x440000b | egrep '^(WM_NAME|_NET_WM_STATE)'
_NET_WM_STATE(ATOM) = _NET_WM_STATE_SKIP_TASKBAR, _NET_WM_STATE_SKIP_PAGER
WM_NAME(STRING) = "Playlist"

• minimized:

$ xprop -id 0x440000b | egrep '^(WM_NAME|_NET_WM_STATE)'
_NET_WM_STATE(ATOM) = _NET_WM_STATE_HIDDEN
WM_NAME(STRING) = "Playlist"

[trialuser02]

I have Qt4 version:

normal:
user@testhost:~$ xprop -id 0x2a00029 | egrep '^(WM_NAME|_NET_WM_STATE)'
_NET_WM_STATE(ATOM) = _NET_WM_STATE_SKIP_TASKBAR, _NET_WM_STATE_SKIP_PAGER
WM_NAME(COMPOUND_TEXT) = "Список"

minimized:
xprop -id 0x2a00029 | egrep '^(WM_NAME|_NET_WM_STATE)'
_NET_WM_STATE(ATOM) = _NET_WM_STATE_HIDDEN, _NET_WM_STATE_SKIP_TASKBAR, _NET_WM_STATE_SKIP_PAGER
WM_NAME(COMPOUND_TEXT) = "Список"

So, try to check Qt4-based version. May be Qt5 clears all atoms on minimaze.

[Palo Kisa]

So, try to check Qt4-based version. May be Qt5 clears all atoms on minimaze.

Indeed. With the Qt4 build (debian's qmmp v0.9.1), the _NET_WM_STATE_SKIP_* atoms are preserved also in minimized state.

So now as I see it, you can:

• add the QEvent::Hide to your workarounds in bool *::event (QEvent *event)
• report this "atom clearing" to Qt and wait for the fix on their side
• add the Qt::WA_X11NetWmWindowTypeToolBar flag to playlist&equalizer windows, which will fix "not showing" in LXQt's taskbar
• use other technique for "not showing" playlist&equalizer windows (check if there is any other (better) way of doing it)
• do nothing and ignore this :)

[trialuser02]

This patch works for me: https://codereview.qt-project.org/#/c/149013/1
Please, test.

[Palo Kisa]

This patch works for me: https://codereview.qt-project.org/#/c/149013/1
Please, test.

This realy seems to be it, but I can't test it -> compiling the whole Qt from source is out of my scope.

I will post a notice into our tracker.

Thanks for your time.