xfce-panel shown during fullscreen

[Ius]

Hi,

I've recently run into some issues running VLC in fullscreen (on Arch Linux/Xfce). Whenever the VLC window is maximized prior to switching to fullscreen, the Xfce panel is still shown in full screen mode. Interestingly, when VLC is not maximized, fullscreen works fine and the Xfce panel is hidden.

This seems to only affect the Xfce/VLC combo - eg. mplayer switches to fullscreen without any problems, regardless of the window state.

Relevant version info:
vlc 1.1.13
xfwm 4.8.3
xfce-panel 4.8.6

I've initially posted this issue on the Arch Linux forums [1] and have found a somewhat relevant looking bug on the Ubuntu bugtracker [2] (marked as resolved).

My main question is: is VLC to blame, or Xfce? (ie. what bug tracker should I post it to?)

[1] https://bbs.archlinux.org/viewtopic.php?id=135096
[2] https://bugs.launchpad.net/ubuntu/+sour ... bug/453173

[Rémi Denis-Courmont]

It is most likely either a bug in Qt4's QtGui or in XFCE.
If it works fine with 'vlc --no-embedded.video', then the bug is probably in Qt4. If it still does not work, then it is probably in XFCE, or maybe in VLC.

Until someone finds out what the bug is, it is impossible to say for sure where that is.

[Ius]

If it works fine with 'vlc --no-embedded.video', then the bug is probably in Qt4.

Ah, hadn't thought of disabling the GUI. For the record, yes, it works fine this way.

[Rémi Denis-Courmont]

So while it could still be a VLC bug, this hints very strongly at a disagreement between QtGui and XFCE...

VLC is not much involved in fullscreening the Qt4-embedded video window.

[Ius]

I hadn't even taken Qt into account. Looks like Qt might be to blame indeed, but I haven't been able to produce a standalone testcase yet.

Two interesting obervations:
- Manually switching to minimal view (CTRL+H) before going fullscreen makes it work without issue
- MainInterface::setVideoFullScreen() calls MainInterface::setMinimalView() in the same way

Yet in the second case the WindowFullScreen state doesn't yield the expected result. And I'm not sure what's so special about the Xfce panel.

EDIT: Managed to (trivially) reproduce it, so it's an issue with Qt or Xfce. This [1] appears to be related. Thanks for pointing me to Qt.

[1] http://developer.qt.nokia.com/doc/qt-4. ... FullScreen

[Jean-Baptiste Kempf]

Please try VLC 2.0

[Cobinja]

Hi

I'm experiencing the exact same problem.

My system:
Xubuntu 12.04
VLC 2.0.1-4 (the one from Ubuntu repos)
xfce panel 4.8.6
xfwm 4.8.3

I also tried the VLC-version from the stable-daily ppa (version 2.0.1+git20120424+r88-0~r36~precise1). Same problem.

//edit:
This is definitely not a VLC problem. This is what I did:
1. Install Xubuntu 11.10 and its latest updates
2. Install VLC 2.0.1 from stable-daily ppa. With this, libs of QT 4.7 are installed as dependencies
Problem does not occur
3. Install Qt 4.8 libs from ppa:/kubuntu/backports
Problem does occur, although neither VLC nor xfce changed.

So this is not a VLC or xfce problem, but a Qt problem (at least with the 4.8 libs from (K)ubuntu-repos)

[Cobinja]

Hi

I did some code diving into both vlc and qt. Though I still think that this is (at least partially) a Qt issue, there is a way for vlc to work around it.

This is what happens:
VLC uses the Qt window state to save the state that was active prior to switching to fullscreen. When coming from a maximized window, this results in a window that is both maximized and in fullscreen. The Qt window state for a normal, non-maximized, non-minimized window is 0 (zero), that's why fullscreen mode works flawlessly when coming from such a window.
When a QWidget in a maximized fullscreen window is changed via signals and slots, a repaint is requested, which eventually can result in a re-layout of the window.
Before switching to fullscreen, VLC goes to minimal view. This seems to be not finished when the fullscreen mode request is handled by Qt, so the visibilty change for minimal view actually happens afterwards (I can't tell why, but it's the only explanation I can come up with).
When a user manually switches to minimal mode, this is completed before the user can switch to fullscreen. Humans are just too slow for computers
When a window with both the window states "maximized" and "fullscreen" is re-layouted, the result is a window with the geometry of a maximized window and the (non-visible) decoration of a fullscreen window. That's why the xfce panel is visible.

I'm linking two things:
[1]
Two Qt creator projects for testing fullscreen mode in xfce. One breaks it, one doesn't. Both have the same UI. The button "Toggle Fullscreen" does as captioned, the button "Set label" shows the current window state in the label below the buttons (name and integer code).
How to break the fullscreen:
a) maximize the window
b) toggle fullscreen (fullscreen mode works at that moment)
c) click "Set label" (fullscreen mode breaks, xfce panel appears)
If you rid the MainWindow class of the layout, you can test that the fullscreen mode doesn't break anymore (although the window still gets both maximized and fullscreen modes).
The second project has a working fullscreen switcher, which does the state saving on client side, not in Qt window state.

[2]
Diffs with a (possible) solution on VLC side. Feel free to use it if suitable.

[1] http://www.cobinja.de/FullScreenTest.tar.gz
[2] http://www.cobinja.de/main_interface.diff.tar.gz

[Jean-Baptiste Kempf]

Send the patch to vlc-devel

[Cobinja]

Send the patch to vlc-devel

Done

[swiftgeek]

Version 2.0.3, archlinux
It's happening again

[cyclopropene]

I am using vlc version 1.1.13 on Fedora 16 with xfce. This happens to me but only if the vlc window is maximized when I try to enter fullscreen. The easy fix for me is to make sure the window is not maximized before going into fullscreen mode then it works fine.

[voddan]

I think, the problem is in VLC itself - Parole MP works fine.

My solution:
I created a small and invisible panel on my desktop (xfce settings manager -> Panel -> '+' ) and set its setting 'don't reserve space on borders'.
After that all other panels work fine with VLC.

Good hack!