Refactors NanoUI interaction (again)

Takes NanoUI interaction code and splits it into more manageable modules.

The default handler that checks distances, camera coverage, etc., etc.
Admin NanoUI windows now only check for admin rights, ignoring sight, distance, and anything else.
ERT/mercenary appearance changer now remains open for as long as the mob remains on the admin Z-level.
PDAs and uplinks now require that you keep the item somewhere in your main inventory (or contents to be precise). Hands or ears are fine, inside bags are not.
Rig suits also check that they are in the operator's inventory or that the synthetic operator is somewhere within the suit's contents (recursively).

code/modules/nano/interaction/admin.dm

@@ -0,0 +1,7 @@
+/*
+	This state checks that the user is an admin, end of story
+*/
+/var/global/datum/topic_state/admin_state/admin_state = new()
+
+/datum/topic_state/admin_state/can_use_topic(var/src_object, var/mob/user)
+	return check_rights(R_ADMIN, 0, user) ? STATUS_INTERACTIVE : STATUS_CLOSE

code/modules/nano/interaction/base.dm

@@ -0,0 +1,19 @@
+/atom/proc/nano_host()
+	return src
+
+/atom/proc/CanUseTopic(var/mob/user, var/datum/topic_state/state)
+	var/src_object = nano_host()
+	return state.can_use_topic(src_object, user)
+
+/datum/topic_state/proc/href_list(var/mob/user)
+	return list()
+
+/datum/topic_state/proc/can_use_topic(var/src_object, var/mob/user)
+	return STATUS_INTERACTIVE
+
+/mob/proc/shared_nano_interaction()
+	if (src.stat || !client)
+		return STATUS_CLOSE						// no updates, close the interface
+	else if (restrained() || lying || stat || stunned || weakened)
+		return STATUS_UPDATE					// update only (orange visibility)
+	return STATUS_INTERACTIVE

code/modules/nano/interaction/contained.dm

@@ -0,0 +1,18 @@
+/*
+	This state checks if user is somewhere within src_object, as well as the default NanoUI interaction.
+*/
+/var/global/datum/topic_state/contained_state/contained_state = new()
+
+/datum/topic_state/contained_state/can_use_topic(var/atom/src_object, var/mob/user)
+	if(!src_object.contains(src))
+		return STATUS_CLOSE
+
+	return user.shared_nano_interaction()
+
+/atom/proc/contains(var/atom/location)
+	if(!location)
+		return 0
+	if(location == src)
+		return 1
+
+	return contains(location.loc)

code/modules/nano/interaction/default.dm

@@ -0,0 +1,101 @@
+/var/global/datum/topic_state/default_state = new()
+
+/datum/topic_state/default/href_list(var/mob/user)
+	return list()
+
+/datum/topic_state/default/can_use_topic(var/src_object, var/mob/user)
+	return user.default_can_use_topic(src_object)
+
+/mob/proc/default_can_use_topic(var/src_object)
+	return STATUS_CLOSE // By default no mob can do anything with NanoUI
+
+/mob/dead/observer/default_can_use_topic()
+	if(check_rights(R_ADMIN, 0, src))
+		return STATUS_INTERACTIVE				// Admins are more equal
+	return STATUS_UPDATE						// Ghosts can view updates
+
+/mob/living/silicon/pai/default_can_use_topic(var/src_object)
+	if(src_object == src && !stat)
+		return STATUS_INTERACTIVE
+	else
+		return ..()
+
+/mob/living/silicon/robot/default_can_use_topic(var/src_object)
+	if(stat || !client)
+		return STATUS_CLOSE
+	if(lockcharge || stunned || weakened)
+		return STATUS_DISABLED
+	// robots can interact with things they can see within their view range
+	if((src_object in view(src)) && get_dist(src_object, src) <= src.client.view)
+		return STATUS_INTERACTIVE	// interactive (green visibility)
+	return STATUS_DISABLED			// no updates, completely disabled (red visibility)
+
+/mob/living/silicon/robot/syndicate/default_can_use_topic(var/src_object)
+	. = ..()
+	if(. != STATUS_INTERACTIVE)
+		return
+
+	if(z in config.admin_levels)						// Syndicate borgs can interact with everything on the admin level
+		return STATUS_INTERACTIVE
+	if(istype(get_area(src), /area/syndicate_station))	// If elsewhere, they can interact with everything on the syndicate shuttle
+		return STATUS_INTERACTIVE
+	if(istype(src_object, /obj/machinery))				// Otherwise they can only interact with emagged machinery
+		var/obj/machinery/Machine = src_object
+		if(Machine.emagged)
+			return STATUS_INTERACTIVE
+	return STATUS_UPDATE
+
+/mob/living/silicon/ai/default_can_use_topic(var/src_object)
+	if(!client || check_unable(1))
+		return STATUS_CLOSE
+	// Prevents the AI from using Topic on admin levels (by for example viewing through the court/thunderdome cameras)
+	// unless it's on the same level as the object it's interacting with.
+	var/turf/T = get_turf(src_object)
+	if(!T || !(z == T.z || (T.z in config.player_levels)))
+		return STATUS_CLOSE
+
+	// If an object is in view then we can interact with it
+	if(src_object in view(client.view, src))
+		return STATUS_INTERACTIVE
+
+	// If we're installed in a chassi, rather than transfered to an inteliCard or other container, then check if we have camera view
+	if(is_in_chassis())
+		//stop AIs from leaving windows open and using then after they lose vision
+		//apc_override is needed here because AIs use their own APC when powerless
+		if(cameranet && !cameranet.checkTurfVis(get_turf(src_object)))
+			return apc_override ? STATUS_INTERACTIVE : STATUS_CLOSE
+		return STATUS_INTERACTIVE
+
+	return STATUS_CLOSE
+
+//Some atoms such as vehicles might have special rules for how mobs inside them interact with NanoUI.
+/atom/proc/contents_nano_distance(var/src_object, var/mob/living/user)
+	return user.shared_living_nano_distance(src_object)
+
+/mob/living/proc/shared_living_nano_distance(var/atom/movable/src_object)
+	if (!(src_object in view(4, src))) 	// If the src object is not in visable, disable updates
+		return STATUS_CLOSE
+
+	var/dist = get_dist(src_object, src)
+	if (dist <= 1)
+		return STATUS_INTERACTIVE	// interactive (green visibility)
+	else if (dist <= 2)
+		return STATUS_UPDATE 		// update only (orange visibility)
+	else if (dist <= 4)
+		return STATUS_DISABLED 		// no updates, completely disabled (red visibility)
+	return STATUS_CLOSE
+
+/mob/living/default_can_use_topic(var/src_object)
+	. = shared_nano_interaction(src_object)
+	if(. == STATUS_INTERACTIVE)
+		if(loc)
+			. = loc.contents_nano_distance(src_object, src)
+	if(STATUS_INTERACTIVE)
+		return STATUS_UPDATE
+
+/mob/living/carbon/human/default_can_use_topic(var/src_object)
+	. = shared_nano_interaction(src_object)
+	if(. == STATUS_INTERACTIVE)
+		. = shared_living_nano_distance(src_object)
+		if(. == STATUS_UPDATE && (TK in mutations))	// If we have telekinesis and remain close enough, allow interaction.
+			return STATUS_INTERACTIVE

code/modules/nano/interaction/inventory.dm

@@ -0,0 +1,10 @@
+/*
+	This state checks that the src_object is somewhere in the user's first-level inventory (in hands, on ear, etc.), but not further down (such as in bags).
+*/
+/var/global/datum/topic_state/inventory_state/inventory_state = new()
+
+/datum/topic_state/inventory_state/can_use_topic(var/src_object, var/mob/user)
+	if(!(src_object in src))
+		return STATUS_CLOSE
+
+	return user.shared_nano_interaction()

code/modules/nano/interaction/zlevel.dm

@@ -0,0 +1,13 @@
+/*
+	This state checks that the user is on the same Z-level as src_object
+*/
+
+/var/global/datum/topic_state/z_state/z_state = new()
+
+/datum/topic_state/z_state/can_use_topic(var/src_object, var/mob/user)
+	var/turf/turf_obj = get_turf(src_object)
+	var/turf/turf_usr = get_turf(user)
+	if(!turf_obj || !turf_usr)
+		return STATUS_CLOSE
+
+	return turf_obj.z == turf_usr.z ? STATUS_INTERACTIVE : STATUS_CLOSE