Change GDM Background

Question

I'm using Archlinux (Antergos) with GDM and Gnome installed. Is there any way to change the GDM background ?

By setting the Lock Screen background in Gnome Settings, it only changes the GDM background when the computer is locked, not when logging in.

Solution 1

I found this solution here and wrote a script to automate it. Woo!

Create an xml file from this paste called ~/chgdm-bg-tmp/theme/gnome-shell-theme.gresource.xml if you get an error saying Could not find file gnome-shell-theme.gresource.xml.

Edit: this broke when I upgraded from gnome-shell 3.16 to 3.26. The reason was that there are resources that are no longer being used, so the glib-compile-resources command fails. If you're having an error, I suggest removing the line:<file>more-results.svg</file> and then it should compile fine.

#!/bin/bash

if [ -z "$1" ]; then
  echo "Usage: ./chgdm-bg <path/to/picture.png> [y/n]"
  exit 1
fi

echo MAKE SURE YOUR PICTURE IS THE SAME RESOLUTION AS YOUR SCREEN.
echo If you dont you will likely regret it.
sleep 3

if [ ! -f $1 ]; then
  echo Error: could not find file $1
  exit 1
fi

PIC=$1
WORKDIR=${HOME}/chgdm-bg-tmp
DATE=$(date +"%Y-%m-%d_%T")

if [ ! -d $WORKDIR ]; then
  mkdir -p $WORKDIR/theme
fi

cd "${WORKDIR}/theme"
mkdir -p backups

IFS='/' read -r -a array <<< "$PIC"
cp $PIC .
PIC=${array[-1]}
echo "Target picture: ${PIC}"
chmod 777 $PIC

SHARE=/usr/share/gnome-shell/
GRESOURCE=gnome-shell-theme.gresource
CSS=gnome-shell.css
XMLRES=gnome-shell-theme.gresource.xml

if [ -f ${SHARE}${GRESOURCE} ]; then
  echo Backing up ${SHARE}${GRESOURCE}...
  cp ${SHARE}${GRESOURCE} "backups/${GRESOURCE}.bak.${DATE}"
  cp ${SHARE}${GRESOURCE} $GRESOURCE
  printf "Unpacking binary resource..."
  for r in `gresource list $GRESOURCE`; do
    printf "."
    gresource extract $GRESOURCE $r >$WORKDIR/${r#\/org\/gnome\/shell/}
  done
  echo
  WORKDIR="${WORKDIR}/theme/"


  if [ -f ${XMLRES} ]; then
    echo Backing up ${XMLRES}...
    cp "${XMLRES}" "backups/${XMLRES}.bak.${DATE}"
    if [ -f "tmp" ]; then
      rm -f tmp
    fi
    touch tmp
    awk -v var="$PIC" '/gresource prefix="\/org\/gnome\/shell\/theme">/ { print; printf "    <file>"; printf var; print "<\/file>"; next }1' $XMLRES > tmp && mv tmp $XMLRES
    #sed -n -i "/\ \ \ \ <file>$PIC<\/file>/d" $XMLRES
    #sed -n -i "/gresource prefix=\"\/org\/gnome\/shell\/theme\">/a \ \ \ \ <file>$PIC<\/file>" $XMLRES
  else
    echo Error: could not find file ${XMLRES}
    exit 1
  fi

  if [ -f $CSS ]; then
    echo Backing up $CSS...
    cp $CSS "backups/${CSS}.bak.${DATE}"
    sed -i 's/#lockDialogGroup/#lockDialogGroup-old/' $CSS
    printf "#lockDialogGroup {\n    background: #2e3436 url(${PIC});\n    background-repeat: no-repeat;\n    background-size: cover; }\n" >> $CSS
  else
    echo Error: could not find file $CSS
    exit 1
  fi

  echo Compiling binary resources...
  glib-compile-resources $XMLRES
  echo Copying binary resources over to ${SHARE}...
  sudo cp $GRESOURCE "${SHARE}${GRESOURCE}"
  sudo cp $CSS "${SHARE}${CSS}"

  if [ -z $2 ]; then
    echo "Restart now? (y/n)"
    read ans
  fi

  if [ "$2" = "y" ] || [ "$ans" = "y" ]; then
    echo Restarting...
    for i in {1..5}; do
      echo $((6-i))
      sleep 1
    done
    #/usr/bin/gnome-session-quit --no-prompt
    #sudo pkill -u $USER
    sudo shutdown -r now
  else
    echo Restart to load your changes.
  fi
else
  echo Error: could not find file ${SHARE}${GRESOURCE}
  exit 1
fi

Solution 2

GDM is using gresource, wich means we can't change the background directly, we have to rebuild the .geresource file.

The fastest way to do this is to use an utility called archibold.

To install it :

curl -L -O http://archibold.io/sh/archibold
chmod +x archibold
sudo mv archibold /usr/bin/

To use it :

sudo archibold login-background background.png

Just replace background.png with your new background's path. You'll then need to restart GDM (for instance by rebooting).

Comments

[Zach]

Came here to say that archibold is deprecated. Currently hanging at boot on f27.