The final action buttons PR (#16514)

* Make action button target datum

* Initial working action palette

* Action related refactors

* tgstation/tgstation/pull/71339

code/game/objects/items.dm

@@ -115,8 +115,10 @@
 
 /obj/item/New()
 	..()
+
 	for(var/path in actions_types)
-		new path(src)
+		add_item_action(path)
+
 	if(embed_chance < 0)
 		if(sharp)
 			embed_chance = max(5, round(force/w_class))
@@ -137,10 +139,55 @@
 		m.update_inv_r_hand()
 		m.update_inv_l_hand()
 		src.loc = null
-	for(var/X in actions)
-		qdel(X)
+
+	// Handle celaning up our actions list
+	for(var/datum/action/action as anything in actions)
+		remove_item_action(action)
+
 	return ..()
 
+
+/// Called when an action associated with our item is deleted
+/obj/item/proc/on_action_deleted(datum/source)
+	SIGNAL_HANDLER
+
+	if(!(source in actions))
+		CRASH("An action ([source.type]) was deleted that was associated with an item ([src]), but was not found in the item's actions list.")
+
+	LAZYREMOVE(actions, source)
+
+/// Adds an item action to our list of item actions.
+/// Item actions are actions linked to our item, that are granted to mobs who equip us.
+/// This also ensures that the actions are properly tracked in the actions list and removed if they're deleted.
+/// Can be be passed a typepath of an action or an instance of an action.
+/obj/item/proc/add_item_action(action_or_action_type)
+	var/datum/action/action
+	if(ispath(action_or_action_type, /datum/action))
+		action = new action_or_action_type(src)
+	else if(istype(action_or_action_type, /datum/action))
+		action = action_or_action_type
+	else
+		CRASH("item add_item_action got a type or instance of something that wasn't an action.")
+
+	LAZYADD(actions, action)
+	RegisterSignal(action, COMSIG_PARENT_QDELETING, PROC_REF(on_action_deleted))
+	if(ismob(loc))
+		// We're being held or are equipped by someone while adding an action?
+		// Then they should also probably be granted the action, given it's in a correct slot
+		var/mob/holder = loc
+		give_item_action(action, holder, holder.get_inventory_slot(src))
+
+	return action
+
+/// Removes an instance of an action from our list of item actions.
+/obj/item/proc/remove_item_action(datum/action/action)
+	if(!action)
+		return
+
+	UnregisterSignal(action, COMSIG_PARENT_QDELETING)
+	LAZYREMOVE(actions, action)
+	qdel(action)
+
 // Check if target is reasonable for us to operate on.
 /obj/item/proc/check_allowed_items(atom/target, not_inside, target_self)
 	if(((src in target) && !target_self) || ((!istype(target.loc, /turf)) && (!istype(target, /turf)) && (not_inside)))
@@ -335,8 +382,9 @@
 	if(zoom)
 		zoom() //binoculars, scope, etc
 	appearance_flags &= ~NO_CLIENT_COLOR
-	for(var/datum/action/A as anything in actions)
-		A.Remove(user)
+	// Remove any item actions we temporary gave out.
+	for(var/datum/action/action_item_has as anything in actions)
+		action_item_has.Remove(user)
 
 // called just as an item is picked up (loc is not yet changed)
 /obj/item/proc/pickup(mob/user)
@@ -362,10 +410,9 @@
 // for items that can be placed in multiple slots
 // note this isn't called during the initial dressing of a player
 /obj/item/proc/equipped(var/mob/user, var/slot)
-	for(var/X in actions)
-		var/datum/action/A = X
-		if(item_action_slot_check(slot, user)) //some items only give their actions buttons when in a specific slot.
-			A.Grant(user)
+	// Give out actions our item has to people who equip it.
+	for(var/datum/action/action as anything in actions)
+		give_item_action(action, user, slot)
 	hud_layerise()
 	user.position_hud_item(src,slot)
 	if(user.client)	user.client.screen |= src
@@ -379,6 +426,18 @@
 		playsound(src, pickup_sound, 20, preference = /datum/preference/toggle/pickup_sounds)
 	return
 
+/// Gives one of our item actions to a mob, when equipped to a certain slot
+/obj/item/proc/give_item_action(datum/action/action, mob/to_who, slot)
+	// Some items only give their actions buttons when in a specific slot.
+	if(!item_action_slot_check(slot, to_who))
+		// There is a chance we still have our item action currently,
+		// and are moving it from a "valid slot" to an "invalid slot".
+		// So call Remove() here regardless, even if excessive.
+		action.Remove(to_who)
+		return
+
+	action.Grant(to_who)
+
 //sometimes we only want to grant the item's action if it's equipped in a specific slot.
 /obj/item/proc/item_action_slot_check(slot, mob/user)
 	if(slot == SLOT_BACK || slot == LEGS) //these aren't true slots, so avoid granting actions there

code/game/objects/items/devices/flashlight.dm

@@ -102,7 +102,7 @@
 		STOP_PROCESSING(SSobj, src)
 	playsound(src, 'sound/weapons/empty.ogg', 15, 1, -3) // VOREStation Edit
 	update_brightness()
-	user.update_action_buttons_icon()
+	user.update_mob_action_buttons()
 	return 1
 
 /obj/item/flashlight/emp_act(severity)

code/game/objects/items/weapons/shields_vr.dm

@@ -64,7 +64,7 @@
 		set_light(0)
 		light_applied = 0
 	update_icon(user)
-	user.update_action_buttons_icon()
+	user.update_mob_action_buttons()
 	playsound(src, 'sound/weapons/empty.ogg', 15, 1, -3)
 
 /obj/item/shield/riot/explorer/update_icon()

code/game/objects/items/weapons/tanks/jetpack.dm

@@ -55,7 +55,7 @@
 	if (ismob(usr))
 		var/mob/M = usr
 		M.update_inv_back()
-		M.update_action_buttons_icon()
+		M.update_mob_action_buttons()
 
 	to_chat(usr, "You toggle the thrusters [on? "on":"off"].")