Typing Indicators

code/modules/mob/typing_indicator.dm

@@ -0,0 +1,56 @@
+/// state = overlay/image/object/type/whatever add_overlay will accept
+GLOBAL_LIST_EMPTY(typing_indicator_overlays)
+
+/// Fetches the typing indicator we'll use from GLOB.typing_indicator_overlays
+/mob/proc/get_indicator_overlay(state)
+	. = GLOB.typing_indicator_overlays[state]
+	if(.)
+		return
+	// doesn't exist, make it and cache it
+	if(ispath(state))
+		. = GLOB.typing_indicator_overlays[state] = state
+	// We only support paths for now because anything else isn't necessary yet.
+
+/// Gets the state we will use for typing indicators. Defaults to src.typing_indicator_state
+/mob/proc/get_typing_indicator_icon_state()
+	return typing_indicator_state
+
+/// Generates the mutable appearance for typing indicator. Should prevent stuck overlays.
+/mob/proc/generate_typing_indicator()
+	var/state = get_typing_indicator_icon_state()
+	if(ispath(state))
+		var/atom/thing = new state(null)
+		var/mutable_appearance/generated = new(thing)
+		return generated
+	else
+		CRASH("Unsupported typing indicator state: [state]")
+
+/**
+  * Displays typing indicator.
+  * @param timeout_override - Sets how long until this will disappear on its own without the user finishing their message or logging out. Defaults to src.typing_indicator_timeout
+  * @param state_override - Sets the state that we will fetch. Defaults to src.get_typing_indicator_icon_state()
+  * @param force - shows even if src.typing_indcator_enabled is FALSE.
+  */
+/mob/proc/display_typing_indicator(timeout_override = TYPING_INDICATOR_TIMEOUT, state_override = generate_typing_indicator(), force = FALSE)
+	if((!typing_indicator_enabled && !force) || typing_indicator_current)
+		return
+	typing_indicator_current = state_override
+	add_overlay(state_override)
+	typing_indicator_timerid = addtimer(CALLBACK(src, .proc/clear_typing_indicator), timeout_override, TIMER_STOPPABLE)
+/**
+  * Removes typing indicator.
+  */
+/mob/proc/clear_typing_indicator()
+	cut_overlay(typing_indicator_current)
+	typing_indicator_current = null
+	if(typing_indicator_timerid)
+		deltimer(typing_indicator_timerid)
+		typing_indicator_timerid = null
+
+/// Default typing indicator
+/obj/effect/overlay/typing_indicator
+	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	icon = 'icons/mob/talk.dmi'
+	icon_state = "normal_typing"
+	appearance_flags = RESET_COLOR | TILE_BOUND | PIXEL_SCALE
+	layer = ABOVE_FLY_LAYER