Adds Radio Jammers to Traitor Uplink

Subspace Jammers can be bought in the traitor uplink for 25 TC.  They are already in the code, but this PR adds them to the uplink.

This PR also adds a power meter to the sprite, as a small QoL change.

They run off of weapon cells and one cell will last for about a minute.

code/datums/uplink/tools.dm

@@ -74,6 +74,13 @@
 	watched, by changing color and beeping.  It is able to detect both AI visual surveillance and security camera utilization from terminals, and \
 	will give different warnings by beeping and changing colors based on what it detects.  Only the holder can hear the warnings."
 
+/datum/uplink_item/item/tools/radio_jammer
+	name = "Subspace Jammer"
+	item_cost = 25
+	path = /obj/item/device/radio_jammer
+	desc = "A device which is capable of disrupting subspace communications, preventing the use of headsets, PDAs, and communicators within \
+	a radius of seven meters.  It runs off weapon cells, which can be replaced as needed.  One cell will last for approximately a minute."
+
 /datum/uplink_item/item/tools/emag
 	name = "Cryptographic Sequencer"
 	item_cost = 30

code/game/objects/items/devices/radio/jammer.dm

@@ -19,16 +19,18 @@ var/global/list/active_radio_jammers = list()
 	icon = 'icons/obj/device.dmi'
 	icon_state = "jammer0"
 	var/active_state = "jammer1"
+	var/last_overlay_percent = null // Stores overlay icon_state to avoid excessive recreation of overlays.
 
 	var/on = 0
 	var/jam_range = 7
 	var/obj/item/weapon/cell/device/weapon/power_source
-	var/tick_cost = 80
+	var/tick_cost = 80 // Will last for roughly one minute, as process() ticks every 2 seconds.
 
 	origin_tech = list(TECH_ILLEGAL = 7, TECH_BLUESPACE = 5) //Such technology! Subspace jamming!
 
 /obj/item/device/radio_jammer/New()
 	power_source = new(src)
+	update_icon() // So it starts with the full overlay.
 
 /obj/item/device/radio_jammer/Destroy()
 	if(on)
@@ -42,7 +44,7 @@ var/global/list/active_radio_jammers = list()
 	processing_objects.Remove(src)
 	active_radio_jammers -= src
 	on = FALSE
-	icon_state = initial(icon_state)
+	update_icon()
 
 /obj/item/device/radio_jammer/proc/turn_on(mob/user)
 	if(user)
@@ -50,7 +52,7 @@ var/global/list/active_radio_jammers = list()
 	processing_objects.Add(src)
 	active_radio_jammers += src
 	on = TRUE
-	icon_state = active_state
+	update_icon()
 
 /obj/item/device/radio_jammer/process()
 	if(!power_source || !power_source.check_charge(tick_cost))
@@ -60,6 +62,7 @@ var/global/list/active_radio_jammers = list()
 		turn_off(notify)
 	else
 		power_source.use(tick_cost)
+		update_icon()
 
 
 /obj/item/device/radio_jammer/attack_hand(mob/user)
@@ -86,4 +89,25 @@ var/global/list/active_radio_jammers = list()
 		power_source.update_icon() //Why doesn't a cell do this already? :|
 		user.unEquip(power_source)
 		power_source.forceMove(src)
+		update_icon()
 		to_chat(user,"<span class='notice'>You insert \the [power_source] into \the [src].</span>")
+
+/obj/item/device/radio_jammer/update_icon()
+	if(on)
+		icon_state = active_state
+	else
+		icon_state = initial(icon_state)
+
+	var/overlay_percent = 0
+	if(power_source)
+		overlay_percent = between(0, round( power_source.percent() , 25), 100)
+	else
+		overlay_percent = 0
+
+	// Only Cut() if we need to.
+	if(overlay_percent != last_overlay_percent)
+		overlays.Cut()
+		var/image/I = image(src.icon, src, "jammer_overlay_[overlay_percent]")
+		overlays += I
+		last_overlay_percent = overlay_percent
+