listener update

code/game/machinery/computer/station_alert.dm

@@ -4,16 +4,17 @@
 	icon_screen = "alert:0"
 	icon_keyboard = "atmos_key"
 	circuit = /obj/item/circuitboard/computer/stationalert
-	var/alarms = list("Fire" = list(), "Atmosphere" = list(), "Power" = list())
+	///Listens for alarms, provides the alarms list for our ui
+	var/datum/alarm_listener/listener
 
 	light_color = LIGHT_COLOR_CYAN
 
 /obj/machinery/computer/station_alert/Initialize(mapload)
-	. = ..()
-	GLOB.alert_consoles += src
+	listener = new(list(ALARM_ATMOS, ALARM_FIRE, ALARM_POWER), list(z))
+	return ..()
 
 /obj/machinery/computer/station_alert/Destroy()
-	GLOB.alert_consoles -= src
+	QDEL_NULL(listener)
 	return ..()
 
 /obj/machinery/computer/station_alert/ui_interact(mob/user, datum/tgui/ui)
@@ -26,69 +27,19 @@
 	var/list/data = list()
 
 	data["alarms"] = list()
-	for(var/class in alarms)
-		data["alarms"][class] = list()
-		for(var/area in alarms[class])
-			data["alarms"][class] += area
+	var/list/alarms = listener.alarms
+	for(var/alarm_type in alarms)
+		data["alarms"][alarm_type] = list()
+		for(var/area_name in alarms[alarm_type])
+			data["alarms"][alarm_type] += area_name
 
 	return data
 
-/obj/machinery/computer/station_alert/proc/triggerAlarm(class, area/home, cameras, obj/source)
-	if(source.z != z)
-		return
-	if(stat & (BROKEN))
-		return
-
-	var/list/our_sort = alarms[class]
-	for(var/areaname in our_sort)
-		if (areaname == home.name)
-			var/list/alarm = our_sort[areaname]
-			var/list/sources = alarm[3]
-			if (!(source in sources))
-				sources += source
-			return TRUE
-
-	var/obj/machinery/camera/cam = null
-	var/list/our_cams = null
-	if(cameras && islist(cameras))
-		our_cams = cameras
-		if (our_cams.len == 1)
-			cam = our_cams[1]
-	else if(cameras && istype(cameras, /obj/machinery/camera))
-		cam = cameras
-	our_sort[home.name] = list(home, (cam ? cam : cameras), list(source))
-	return TRUE
-
-/obj/machinery/computer/station_alert/proc/freeCamera(area/home, obj/machinery/camera/cam)
-	for(var/class in alarms)
-		var/our_area = alarms[class][home.name]
-		if(!our_area)
-			continue
-		var/cams = our_area[2] //Get the cameras
-		if(!cams)
-			continue
-		if(islist(cams))
-			cams -= cam
-			if(length(cams) == 1)
-				our_area[2] = cams[1]
-		else
-			our_area[2] = null
-
-/obj/machinery/computer/station_alert/proc/cancelAlarm(class, area/A, obj/origin)
-	if(stat & (BROKEN))
-		return
-	var/list/L = alarms[class]
-	var/cleared = 0
-	for (var/I in L)
-		if (I == A.name)
-			var/list/alarm = L[I]
-			var/list/srcs  = alarm[3]
-			if (origin in srcs)
-				srcs -= origin
-			if (srcs.len == 0)
-				cleared = 1
-				L -= I
-	return !cleared
+/obj/machinery/computer/station_alert/on_machine_stat_update(stat)
+	if(stat & BROKEN)
+		listener.prevent_alarm_changes()
+	else
+		listener.allow_alarm_changes()
 
 /obj/machinery/computer/station_alert/update_overlays()
 	. = ..()
@@ -98,12 +49,7 @@
 		. |= "[icon_keyboard]_off"
 		return
 	. |= icon_keyboard
-	var/active_alarms = FALSE
-	for(var/cat in alarms)
-		if(length(alarms[cat]))
-			active_alarms = TRUE
-			break
-	if(active_alarms)
+	if(length(listener.alarms))
 		overlay_state = "alert:2"
 	else
 		overlay_state = "alert:0"