add xscreensaver kiosk blog post

input/blog/2022/2022_01_17_xscreensaver_kiosk.md

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+title: Blog
+post: XScreenSaver as TV decoration
+description: Script for placing fullscreen windows
+date: 2022-01-17
+---
+
+I got a new TV connected to my PC.
+Using xrandr, I made some simple scripts to switch between stand-alone or mirrored mode.
+To control media playback comfortably from the desktop monitor, I'm using the nifty little tool [squint](https://github.com/a-ba/squint/), auto-starting and killing it as needed from my aforementioned scripts.
+
+To show some pretty pictures on the TV, I also created the following (pretty hacky) script for moving [XScreenSaver](https://www.jwz.org/xscreensaver/) hacks fullscreen'ed to the TV.
+
+Maybe it helps someone else.
+
+<pre class="sh_sh">
+#!/bin/bash
+
+# tv-screen-saver
+#
+# Show random animations on only one monitor.
+#
+# Dependencies:
+#   - XScreenSaver
+#   - wmctrl
+#   - xdotool
+#
+# This script randomly selects a screensaver (hack) from XScreenSaver,
+# runs it, moves it to a specific location on the desktop,
+# fullscreens it, waits for 5mins, then kills the hack.
+# This process is repeated endlessly.
+#
+# Control the position where the window will be placed by editing the
+# MONITOR_PLACE below. The parameters are X-Pos,Y-Pos,Width,Height.
+# Use -1 to keep existing values.
+#
+# Hacks that should be skipped are listed in HACK_BLACKLIST below.
+#
+# The window focus will be saved and restored when opening a new hack.
+#
+# Bugs:
+# In the timespan of opening a new hack, some keypresses may go to the new
+# hack window, if you are currently typing.
+
+TIMEOUT=300
+MONITOR_PLACE="3000,-1,-1,-1"
+HACKS_DIR=/usr/lib/xscreensaver
+
+HACK_BLACKLIST=("xscreensaver-auth" "xscreensaver-getimage" "xscreensaver-getimage-file" "xscreensaver-getimage-video" "xscreensaver-gfx" "xscreensaver-gl-visual" "xscreensaver-systemd" "xscreensaver-text" "webcollage" "webcollage-helper" "vidwhacker")
+
+HACK_PID=0
+FOCUS_WIN=0
+
+# kill running screensaver when user exits with Ctrl+C
+trap graceful_exit INT
+
+# make sure screensavers can find required xscreensaver-text and other helpers
+PATH=$PATH:$HACKS_DIR
+
+get_random_hack() {
+    HACK_NAME=$(ls $HACKS_DIR | shuf -n 1)
+
+    # skip if on blacklist
+    for i in ${!HACK_BLACKLIST[@]};
+    do
+        if [ "$HACK_NAME" == "${HACK_BLACKLIST[$i]}" ]
+        then
+            get_random_hack
+            exit 0
+        fi
+    done
+
+    echo $HACK_NAME
+}
+
+put_on_tv() {
+    wmctrl -r 'from the XScreenSaver' -e 0,$MONITOR_PLACE
+    wmctrl -r 'from the XScreenSaver' -b toggle,fullscreen
+}
+
+save_window_focus() {
+    FOCUS_WIN=$(xdotool getactivewindow)
+}
+
+restore_window_focus() {
+    xdotool windowactivate $FOCUS_WIN
+}
+
+graceful_exit() {
+    if [ "$HACK_PID" -ne "0" ]
+    then
+        kill $HACK_PID
+    fi
+    exit 0
+}
+
+while true
+do
+    save_window_focus
+
+    # run new hack
+    HACK=$(get_random_hack)
+    echo "Running $HACK for $TIMEOUT seconds"
+    $HACKS_DIR/$HACK &
+    HACK_PID=$!
+
+    # wait for window to appear
+    sleep 0.2
+    put_on_tv
+
+    restore_window_focus
+
+    sleep $TIMEOUT
+    kill $HACK_PID
+
+    # wait a bit before starting next one
+    sleep 0.2
+done
+</pre>