Proximity sensing refactor (#425)

code/game/machinery/camera/camera.dm

@@ -46,7 +46,8 @@
 	assembly.state = 4
 	GLOB.cameranet.cameras += src
 	GLOB.cameranet.addCamera(src)
-	add_to_proximity_list(src, 1) //1 was default of everything
+	proximity_monitor = new(src, 1)
+
 	/* // Use this to look for cameras that have the same c_tag.
 	for(var/obj/machinery/camera/C in cameranet.cameras)
 		var/list/tempnetwork = C.network&src.network
@@ -59,13 +60,8 @@
 	if(mapload && z == 1 && prob(3) && !start_active)
 		toggle_cam()
 
-/obj/machinery/camera/Move()
-	remove_from_proximity_list(src, 1)
-	return ..()
-
 /obj/machinery/camera/Destroy()
 	toggle_cam(null, 0) //kick anyone viewing out
-	remove_from_proximity_list(src, 1)
 	if(assembly)
 		qdel(assembly)
 		assembly = null

code/game/machinery/flasher.dm

@@ -154,6 +154,10 @@
 			new /obj/item/stack/sheet/metal (loc, 2)
 	qdel(src)
 
+/obj/machinery/flasher/portable/Initialize()
+	. = ..()
+	proximity_monitor = new(src, 0)
+
 /obj/machinery/flasher/portable/HasProximity(atom/movable/AM)
 	if (last_flash && world.time < last_flash + 150)
 		return
@@ -172,25 +176,17 @@
 			add_overlay("[base_state]-s")
 			anchored = 1
 			power_change()
-			add_to_proximity_list(src, range)
+			proximity_monitor.SetRange(range)
 		else
 			to_chat(user, "<span class='notice'>[src] can now be moved.</span>")
 			cut_overlays()
 			anchored = 0
 			power_change()
-			remove_from_proximity_list(src, range)
+			proximity_monitor.SetRange(0)
 
 	else
 		return ..()
 
-/obj/machinery/flasher/portable/Destroy()
-	remove_from_proximity_list(src, range)
-	return ..()
-
-/obj/machinery/flasher/portable/Moved(oldloc)
-	remove_from_proximity_list(oldloc, range)
-	return ..()
-
 /obj/item/wallframe/flasher
 	name = "mounted flash frame"
 	desc = "Used for building wall-mounted flashers."