Screentips for anomaly neutralizer / null rod (and other effect removers) (#65221)

code/datums/components/effect_remover.dm

@@ -8,6 +8,8 @@
 	var/success_feedback
 	/// Line forcesaid by the user on successful removal.
 	var/success_forcesay
+	/// The text used in the screentip when our parent is hovering over an item we can clear. Ex "Destroy rune"
+	var/tip_text
 	/// Callback invoked with removal is done.
 	var/datum/callback/on_clear_callback
 	/// A typecache of all effects we can clear with our item.
@@ -16,6 +18,7 @@
 /datum/component/effect_remover/Initialize(
 	success_forcesay,
 	success_feedback,
+	tip_text,
 	on_clear_callback,
 	effects_we_clear,
 	)
@@ -30,14 +33,24 @@
 
 	src.success_feedback = success_feedback
 	src.success_forcesay = success_forcesay
+	src.tip_text = tip_text
 	src.on_clear_callback = on_clear_callback
 	src.effects_we_clear = typecacheof(effects_we_clear)
 
+/datum/component/effect_remover/Destroy(force, silent)
+	QDEL_NULL(on_clear_callback)
+	return ..()
+
 /datum/component/effect_remover/RegisterWithParent()
 	RegisterSignal(parent, COMSIG_ITEM_ATTACK_EFFECT, .proc/try_remove_effect)
 
+	if(tip_text)
+		var/obj/item/item_parent = parent
+		item_parent.item_flags |= ITEM_HAS_CONTEXTUAL_SCREENTIPS
+		RegisterSignal(parent, COMSIG_ITEM_REQUESTING_CONTEXT_FOR_TARGET, .proc/add_item_context)
+
 /datum/component/effect_remover/UnregisterFromParent()
-	UnregisterSignal(parent, COMSIG_ITEM_ATTACK_EFFECT)
+	UnregisterSignal(parent, list(COMSIG_ITEM_ATTACK_EFFECT, COMSIG_ITEM_REQUESTING_CONTEXT_FOR_TARGET))
 
 /*
  * Signal proc for [COMSIG_ITEM_ATTACK_EFFECT].
@@ -67,3 +80,17 @@
 
 	if(!QDELETED(target))
 		qdel(target)
+
+/*
+ * Signal proc for [COMSIG_ITEM_REQUESTING_CONTEXT_FOR_TARGET].
+ *
+ * Adds some context for the target, if we have one set and it's a valid target.
+ */
+/datum/component/effect_remover/proc/add_item_context(obj/item/source, list/context, atom/target, mob/living/user)
+	SIGNAL_HANDLER
+
+	if(effects_we_clear[target.type])
+		context[SCREENTIP_CONTEXT_LMB] = tip_text
+		return CONTEXTUAL_SCREENTIP_SET
+
+	return NONE