_gtk4_demo()
{
    local cur prev opts
    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"
    prev="${COMP_WORDS[COMP_CWORD-1]}"
    opts="--gapplication-service \
          --help \
          --help-all \
          --help-gapplication \
          --list \
          --run \
          --autoquit \
          --version"

    case "${prev}" in
        --run)
            local demos=$(gtk4-demo --list 2>/dev/null | tr '\n' ' ')
            COMPREPLY=( $(compgen -W "${demos}" -- ${cur}) )
            return 0
            ;;
        *)
        ;;
    esac

    if [[ ${cur} == -* ]] ; then
        COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
        return 0
    fi
}
complete -F _gtk4_demo gtk4-demo