[polybar] Fix pomo timer notification updating

Fixed notifications following outdated pomo timers if the timer was ever
paused or restarted. Will now limit the pomo timer to a single 'running'
instance containing the notification function.

polybar/.config/polybar/config

@@ -57,7 +57,7 @@ padding-left = 0
 padding-right = 0
 module-margin-left = 2
 
-modules-left = workspaces
+modules-left = workspaces pomo
 modules-center = music date papersdue
 modules-right = networkspeed archupdates cpu temp backlight volume battery
 ; do not use offsets for the bar, would only work with override-redirect
@@ -235,6 +235,17 @@ click-right = exist rofi-bib-due normal "opening due papers" && rofi-bib-due -p3
 format-prefix = " "
 interval = 120
 
+; displays a small pomodoro timer
+[module/pomo]
+type = custom/script
+exec = $XDG_CONFIG_HOME/polybar/scripts/poly-pomo
+exec-if = exist pomo normal "pomodoro timer"
+; pause timer
+click-left = $XDG_CONFIG_HOME/polybar/scripts/poly-pomo toggle
+; restart timer
+click-right = $XDG_CONFIG_HOME/polybar/scripts/poly-pomo restart
+tail = true
+
 ; display unified available packages for update on arch from repos/aur
 ; uses pacman-contrib/checkupdates if available to avoid partial arch upgrades
 [module/archupdates]

polybar/.config/polybar/scripts/poly-pomo

@@ -0,0 +1,35 @@
+#!/usr/bin/env sh
+
+run_notify() {
+  pomo notify &
+  PID_NOTIFY="$!"
+  echo "$PID_NOTIFY" >"${XDG_RUNTIME_DIR:-$HOME}"/.running-pomo.lock
+}
+
+# create background notify process; close it when this process  is killed
+close_notify() {
+  lockfile="${XDG_RUNTIME_DIR:-$HOME}"/.running-pomo.lock
+  [ -f "$lockfile" ] && kill "$(cat "$lockfile")"
+  kill "$PID_NOTIFY"
+  rm "${XDG_RUNTIME_DIR:-$HOME}"/.running-pomo.lock
+}
+trap close_notify EXIT
+
+restart_notify() {
+  close_notify
+  run_notify
+}
+
+if [ -z "$1" ]; then
+  run_notify
+  while true; do
+    pomo clock
+    sleep 1
+  done
+elif [ "$1" = "toggle" ]; then
+  pomo pause
+  restart_notify
+elif [ "$1" = "restart" ]; then
+  pomo stop && pomo start
+  restart_notify
+fi

polybar/.local/bin/pomo

@@ -0,0 +1 @@
+../share/pomo/pomo.sh