set-gdm-wallpaper

#!/usr/bin/sh

set -e

if ! hash gresource 2>/dev/null; then
  echo "gresource binary not found. "
  echo " "
  echo "Please install glib2 or glib2-devel"
  echo " "
  echo "Fedora:"
  echo "# dnf install glib2-devel"
  exit 1
fi

if [ ! -n "$1" ]
then
  echo 'Usage:';
  echo '  set-gdm-wallpaper /path/to/image';
  echo '  set-gdm-wallpaper --uninstall';
  exit 1
fi

if [ "$1" == "--uninstall" ]
then
  if grep -q "macOS_mojave_wallpaper_mid-day.png" /usr/share/gnome-shell/gnome-shell-theme.gresource; then
    cp -f /usr/share/gnome-shell/gnome-shell-theme.gresource.backup /usr/share/gnome-shell/gnome-shell-theme.gresource

    echo 'gnome-shell-theme.gresource recovered';
  fi

  exit
fi

workdir="/usr/share/gnome-shell/wallpaper"

if [ "$1" == "--rpm" ]
then
  image="$workdir/macOS_mojave_wallpaper_mid-day.png"
else
  image="$1"
fi

if [ ! -f $image ]
then
  echo "File not found: \"$image\" "
  exit 1
fi

echo "Updating wallpaper..."

mkdir -p $workdir/theme

echo '<?xml version="1.0" encoding="UTF-8"?>' > $workdir/gnome-shell-theme.gresource.xml
echo '<gresources><gresource prefix="/org/gnome/shell/theme">' >> $workdir/gnome-shell-theme.gresource.xml

for r in `gresource list /usr/share/gnome-shell/gnome-shell-theme.gresource`; do
  gfile="${r#\/org\/gnome\/shell\/theme/}";
  mkdir -p "$(dirname $workdir/theme/$gfile)"

  if [ "$gfile" != "wallpaper-gdm.png" ]; then
    gresource extract /usr/share/gnome-shell/gnome-shell-theme.gresource $r >$workdir/theme/$gfile
    echo "<file>$gfile</file>" >> $workdir/gnome-shell-theme.gresource.xml
  fi
done

echo "<file>wallpaper-gdm.png</file>" >> $workdir/gnome-shell-theme.gresource.xml
cp -f $image $workdir/theme/wallpaper-gdm.png

echo '</gresource></gresources>' >> $workdir/gnome-shell-theme.gresource.xml

sed -i -e 's/background: #2e3436 url(resource:\/\/\/org\/gnome\/shell\/theme\/noise-texture.png);/background: #2e3436 url(resource:\/\/\/org\/gnome\/shell\/theme\/wallpaper-gdm.png);background-size: cover;/g' $workdir/theme/gnome-shell.css

cd $workdir/theme
glib-compile-resources $workdir/gnome-shell-theme.gresource.xml

if ! grep -q "wallpaper-gdm.png" /usr/share/gnome-shell/gnome-shell-theme.gresource; then
  cp -f /usr/share/gnome-shell/gnome-shell-theme.gresource /usr/share/gnome-shell/gnome-shell-theme.gresource.backup
  echo "Backup"
fi

cp -f $workdir/gnome-shell-theme.gresource /usr/share/gnome-shell/

rm -rf $workdir/theme
rm -f $workdir/gnome-shell-theme.gresource.xml
rm -f $workdir/gnome-shell-theme.gresource

echo "Done!"