Initial commit. Add poc hack script

proof-of-concept.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+set -euo pipefail
+LOCK=/tmp/after-lock.lock
+INITIAL_DELAY=3
+LOOP_DELAY=17
+
+if ! mkdir "${LOCK}" &> /dev/null; then
+    exit 0
+fi
+cleanup() {
+    rmdir "${LOCK}"
+}
+trap cleanup INT TERM EXIT
+
+screensaver_isactive() {
+    [[ $(qdbus org.kde.screensaver /ScreenSaver org.freedesktop.ScreenSaver.GetActive) = "true" ]]
+}
+
+display_shouldsleep() {
+    if ! xset q | grep -q Monitor; then
+        return 0
+    elif [[ "$(xset q | grep -oP '(?<=Monitor is )\w+')" = 'On' ]]; then
+        return 0
+    fi
+    return 1
+}
+
+sleep "${INITIAL_DELAY}"
+while screensaver_isactive; do
+    if display_shouldsleep; then
+        xset dpms force suspend
+    fi
+    sleep "${LOOP_DELAY}"
+done