GNOME prototype: detect GNOME/GDM, GDM autologin and session switching

lib/desktop.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+# Which desktop Steamify is running on (KDE Plasma or GNOME), and the
+# session the login manager has to start for it. GNOME (GDM) is a prototype.
+# Sourced by steamify.sh; not meant to be run on its own.
+
+desktop_kind() {
+    # gnome or kde: the running session first, else what the login manager
+    # is (GDM means GNOME), else KDE, which Steamify was made for.
+    case ":${STEAMIFY_DESKTOP:-${XDG_CURRENT_DESKTOP:-}}:" in
+        *:GNOME:*|*:gnome:*) echo gnome; return ;;
+        *:KDE:*|*:kde:*) echo kde; return ;;
+    esac
+    [[ "$(current_display_manager)" == gdm ]] && { echo gnome; return; }
+    echo kde
+}
+
+desktop_session_file() {
+    # The login manager's session entry for the desktop: plasma.desktop, or
+    # whichever GNOME one is installed (gnome.desktop, gnome-xorg.desktop).
+    local f
+    if [[ "$(desktop_kind)" == gnome ]]; then
+        for f in /usr/share/wayland-sessions/gnome*.desktop /usr/share/xsessions/gnome*.desktop; do
+            [[ -f "$f" ]] && { basename "$f"; return; }
+        done
+        echo gnome.desktop
+    else
+        echo plasma.desktop
+    fi
+}
+
+choose_login_manager() {
+    # LOGIN_MANAGER for gaming_enable: gdm on GNOME, else sddm with single
+    # user mode and plasmalogin without.
+    if [[ "$(desktop_kind)" == gnome ]]; then LOGIN_MANAGER=gdm
+    elif [[ "${WANTED[single]:-0}" == 1 ]]; then LOGIN_MANAGER=sddm
+    else LOGIN_MANAGER=plasmalogin; fi
+}