arch_wayland_window_reopen_pos.sh

#!/usr/bin/env bash

set -e
KWINRULES=~/.config/kwinrulesrc

echo "Focus the window now. Capturing in 3 seconds..."
sleep 3

RAW=$(gdbus call --session --dest org.kde.KWin --object-path /KWin --method org.kde.KWin.queryWindowInfo 2>/dev/null) || {
  echo "Error: could not get window info from KWin. Is the window focused?"
  exit 1
}

parse_num() { echo "$RAW" | sed -n "s/.*'$1': <\([0-9.]*\).*/\1/p" | head -1; }
WMCLASS=$(echo "$RAW" | sed -n "s/.*'resourceClass': <'\([^']*\)'.*/\1/p" | head -1)

POS_X=$(parse_num x | cut -d. -f1)
POS_Y=$(parse_num y | cut -d. -f1)
WIDTH=$(parse_num width | cut -d. -f1)
HEIGHT=$(parse_num height | cut -d. -f1)

[[ -z "$POS_X" ]] && POS_X=0
[[ -z "$POS_Y" ]] && POS_Y=0
[[ -z "$WIDTH" || -z "$HEIGHT" ]] && { echo "Could not parse geometry. KWin output was:"; echo "$RAW"; exit 1; }
[[ -z "$WMCLASS" ]] && WMCLASS="google-chrome"

POS="${POS_X},${POS_Y}"
SIZE="${WIDTH},${HEIGHT}"

echo "Detected window class: $WMCLASS"
echo "Position: $POS  Size: $SIZE"

UUID=$(uuidgen 2>/dev/null | tr -d '-' || echo "$(cat /proc/sys/kernel/random/uuid 2>/dev/null | tr -d '-' || echo "chrome-$(date +%s)")")

RULE="[${UUID}]
Description=Window position and size (forced)
position=$POS
positionrule=4
size=$SIZE
sizerule=4
types=1
wmclass=$WMCLASS
wmclassmatch=1
wmclasscomplete=true

"

cp "$KWINRULES" "${KWINRULES}.bak"

current_rules=$(awk '/^rules=/ { print $0; exit }' "$KWINRULES")
new_rules="rules=${UUID},${current_rules#rules=}"
sed -i "s/^rules=.*/$new_rules/" "$KWINRULES"

old_count=$(grep '^count=' "$KWINRULES" | head -1)
new_count=$(( ${old_count#count=} + 1 ))
sed -i "s/^count=.*/count=$new_count/" "$KWINRULES"

printf '%s' "$RULE" > /tmp/kwinrule.txt
python3 - "$KWINRULES" /tmp/kwinrule.txt << 'PY'
import sys
path = sys.argv[1]
rule_path = sys.argv[2]
p = open(path).read()
rule = open(rule_path).read()
marker = "[General]"
if marker not in p:
    raise SystemExit("Could not find [General] in kwinrulesrc")
idx = p.index(marker)
new_content = p[:idx] + rule + p[idx:]
open(path, "w").write(new_content)
PY
rm -f /tmp/kwinrule.txt

echo "Done. Rule added for $WMCLASS: position $POS, size $SIZE (forced)."
echo "Close the window and open it again for the rule to apply. New windows will open at that position and size."