Proximity sensing refactor (#425)

code/modules/mining/machine_stacking.dm

@@ -10,14 +10,13 @@
 	var/machinedir = SOUTHEAST
 	speed_process = 1
 
-/obj/machinery/mineral/stacking_unit_console/New()
-	..()
-	spawn(7)
-		src.machine = locate(/obj/machinery/mineral/stacking_machine, get_step(src, machinedir))
-		if (machine)
-			machine.CONSOLE = src
-		else
-			qdel(src)
+/obj/machinery/mineral/stacking_unit_console/Initialize()
+	. = ..()
+	machine = locate(/obj/machinery/mineral/stacking_machine, get_step(src, machinedir))
+	if (machine)
+		machine.CONSOLE = src
+	else
+		qdel(src)
 
 /obj/machinery/mineral/stacking_unit_console/attack_hand(mob/user)
 
@@ -70,6 +69,14 @@
 	var/stack_amt = 50; //ammount to stack before releassing
 	input_dir = EAST
 	output_dir = WEST
+
+/obj/machinery/mineral/stacking_machine/Initialize()
+	. = ..()
+	proximity_monitor = new(src, 1)
+
+/obj/machinery/mineral/stacking_machine/HasProximity(atom/movable/AM)
+	if(istype(AM, /obj/item/stack/sheet) && AM.loc == get_step(src, input_dir))
+		process_sheet(AM)
 
 /obj/machinery/mineral/stacking_machine/proc/process_sheet(obj/item/stack/sheet/inp)
 	if(!(inp.type in stack_list)) //It's the first of this sheet added
@@ -83,10 +90,4 @@
 		var/obj/item/stack/sheet/out = new inp.type()
 		out.amount = stack_amt
 		unload_mineral(out)
-		storage.amount -= stack_amt
-
-/obj/machinery/mineral/stacking_machine/process()
-	var/turf/T = get_step(src, input_dir)
-	if(T)
-		for(var/obj/item/stack/sheet/S in T)
-			process_sheet(S)
+		storage.amount -= stack_amt