[AppImage] Move lmms wrapper script into AppRun

[ghost]

In the AppImage building process, there is originally a wrapper shell script named lmms, used to start the real LMMS executable lmms.real. This wrapper script is unused in the RC5 AppImage build. Instead, the AppRun script is used directly to start the LMMS executable. Code responsible for setting some environment variables, is not present in the AppRun script, which leads to issues like the GUI not scaling properly.

user@user-pc:~$ ps -aux
user      7579  0.0  0.0  15304  3020 pts/1    S+   14:17   0:00 bash /tmp/.mount_lmms-1PHiOKW/AppRun
user      7582  0.3  0.0  22340  2724 ?        Ssl  14:17   0:00 ./lmms-1.2.0-rc5-linux-x86_64.AppImage
user      7593 41.8  2.7 2023764 220588 pts/1  Sl+  14:17   1:10 /tmp/.mount_lmms-1PHiOKW/usr/bin/lmms.real

user@user-pc:~$ cat /tmp/.mount_lmms-1PHiOKW/AppRun
#!/usr/bin/env bash
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
if which carla > /dev/null 2>&1; then
   CARLAPATH="/usr/bin/carla"
   CARLAPREFIX="${CARLAPATH%/bin*}"
   echo "Carla appears to be installed on this system at $CARLAPREFIX/lib[64]/carla so we'll use it."
   export LD_LIBRARY_PATH=$CARLAPREFIX/lib/carla:$CARLAPREFIX/lib64/carla:$LD_LIBRARY_PATH
else
   echo "Carla does not appear to be installed.  That's OK, please ignore any related library errors."
fi
export LD_LIBRARY_PATH=$DIR/usr/lib/:$DIR/usr/lib/lmms:$LD_LIBRARY_PATH
# Prevent segfault on VirualBox
if lsmod |grep vboxguest > /dev/null 2>&1; then
   echo "VirtualBox detected.  Forcing libgl software rendering."
   export LIBGL_ALWAYS_SOFTWARE=1;
fi
if ldconfig -p | grep libjack.so.0 > /dev/null 2>&1; then
   echo "Jack appears to be installed on this system, so we'll use it."
else
   echo "Jack does not appear to be installed.  That's OK, we'll use a dummy version instead."
   export LD_LIBRARY_PATH=$DIR/usr/lib/lmms/optional:$LD_LIBRARY_PATH
fi
QT_X11_NO_NATIVE_MENUBAR=1 $DIR/usr/bin/lmms.real "$@"

user@user-pc:~$ env QT_AUTO_SCREEN_SCALE_FACTOR=1 ./lmms-1.2.0-rc5-linux-x86_64.AppImage
# Scales perfectly

[tresf]

What makes you think this script is not being executed?

[ghost]

May be related 8bc9e9d#commitcomment-25979076 HiDPI scaling is intentionally unset due to, Qt issues?

We'll turn off QT_AUTO_SCREEN_SCALE_FACTOR then for now. People can

always flag it back on manually. I'll add this to the Carla PR and upload a new AppImage. This issue can be closed.

[tresf]

@flynn16 yes, we had to turn it off. You should be able to turn it back on with QT_AUTO_SCREEN_SCALE_FACTOR=1 ./lmms-1.2.0-rc5-linux-x86_64.AppImage. If that doesn't work, you can export it in a separate variable. When this behavior becomes more reliable in Qt, we'll happily turn it back on.

[tresf]

FYI, @flynn16, it appearslinuxdeployqt will eventually be succeeded by linuxdeploy, which allows a custom AppRun to be specified.

I think this is the best approach long-term.

Reference: probonopd/linuxdeployqt#289 (comment)

For the short-term we will continue to use linuxdeployqt with the lmms.real workaround.