Tablets don't close their UI when changing program (and some fixes) (#73635)

## About The Pull Request

- Tablets now refresh their page when changing programs, this means the
UI will no longer close and reopen itself several times (or even have
several UIs open if shit broke hard enough).
- Removed tablet's attack self because interact already does everything
it had to do.
- Header programs now close when minimized (as there's no button to
close them in the main menu.
- Removed a lot of program UI stuff, it's now handled by the PC itself,
such as header data and ui host.
- Cut off asset sending from TGUI into it's own proc so I can re-send
assets when changing programs
- Added an ejection button for machine computers
- Fixed ID not ejecting into the user's hand when using 'Eject ID'
- Fixes a minor runtime when opening the MODsuit application without a
MODsuit already connected.

## Why It's Good For The Game

Fixes some bugs that I found with tablets

UIS now won't be flickering as bad in front of them, or have
inconsistent placement (like when you move your main menu UI, go to
Messenger, then it's back to the center of the screen).

Video of it in action

https://user-images.githubusercontent.com/53777086/221301417-78321149-0c10-475e-bd29-79f5a4ba0597.mp4

## Changelog

🆑
fix: Being in an application now properly uses the tablet's battery.
fix: Messenger and Themify apps now close when minimized, so don't count
towards the running app limit.
fix: Tablet UIs will now no longer spam open/close the UI when changing
applications
fix: Using the Eject ID button on tablets now ejects into your hand.
fix: Computers now have an Eject ID button
refactor: Cut down a lot of copy paste in tablet & program code, now
it's mostly done by the tablet.
/🆑

code/modules/modular_computers/computers/item/computer.dm

@@ -420,13 +420,6 @@ GLOBAL_LIST_EMPTY(TabletMessengers) // a list of all active messengers, similar
 		update_appearance(UPDATE_ICON)
 	return ..()
 
-// On-click handling. Turns on the computer if it's off and opens the GUI.
-/obj/item/modular_computer/interact(mob/user)
-	if(enabled)
-		ui_interact(user)
-	else
-		turn_on(user)
-
 /obj/item/modular_computer/CtrlShiftClick(mob/user)
 	. = ..()
 	if(.)
@@ -605,7 +598,6 @@ GLOBAL_LIST_EMPTY(TabletMessengers) // a list of all active messengers, similar
 		program.alert_pending = FALSE
 		idle_threads.Remove(program)
 		update_appearance()
-		updateUsrDialog()
 		return TRUE
 
 	if(!program.is_supported_by_hardware(hardware_flag, 1, user))
@@ -625,7 +617,7 @@ GLOBAL_LIST_EMPTY(TabletMessengers) // a list of all active messengers, similar
 	active_program = program
 	program.alert_pending = FALSE
 	update_appearance()
-	updateUsrDialog()
+	ui_interact(user)
 	return TRUE
 
 // Returns 0 for No Signal, 1 for Low Signal and 2 for Good Signal. 3 is for wired connection (always-on)

code/modules/modular_computers/computers/item/computer_ui.dm

@@ -1,20 +1,15 @@
-/obj/item/modular_computer/attack_self(mob/user)
-	. = ..()
-	ui_interact(user)
+/obj/item/modular_computer/interact(mob/user)
+	if(enabled)
+		ui_interact(user)
+	else
+		turn_on(user)
 
 // Operates TGUI
 /obj/item/modular_computer/ui_interact(mob/user, datum/tgui/ui)
-	if(!enabled)
+	if(!enabled || !user.can_read(src, READING_CHECK_LITERACY) || !use_power())
 		if(ui)
 			ui.close()
 		return
-	if(!use_power())
-		if(ui)
-			ui.close()
-		return
-
-	if(!user.can_read(src, READING_CHECK_LITERACY))
-		return
 
 	// Robots don't really need to see the screen, their wireless connection works as long as computer is on.
 	if(!screen_on && !issilicon(user))
@@ -22,27 +17,43 @@
 			ui.close()
 		return
 
-	// If we have an active program switch to it now.
-	if(active_program)
-		if(ui) // This is the main laptop screen. Since we are switching to program's UI close it for now.
-			ui.close()
-		active_program.ui_interact(user)
-		return
-
 	if(honkvirus_amount > 0) // EXTRA annoying, huh!
 		honkvirus_amount--
 		playsound(src, 'sound/items/bikehorn.ogg', 30, TRUE)
 
 	ui = SStgui.try_update_ui(user, src, ui)
-	if (!ui)
-		ui = new(user, src, "NtosMain")
-		ui.set_autoupdate(TRUE)
-		if(ui.open())
-			ui.send_asset(get_asset_datum(/datum/asset/simple/headers))
+	if(!ui)
+		if(active_program)
+			ui = new(user, src, active_program.tgui_id, active_program.filedesc)
+		else
+			ui = new(user, src, "NtosMain")
+		ui.open()
+		return
+
+	var/old_open_ui = ui.interface
+	if(active_program)
+		ui.interface = active_program.tgui_id
+		ui.title = active_program.filedesc
+	else
+		ui.interface = "NtosMain"
+	//opened a new UI
+	if(old_open_ui != ui.interface)
+		update_static_data(user, ui)
+		ui.send_assets()
+
+/obj/item/modular_computer/ui_assets(mob/user)
+	var/list/data = list()
+	data += get_asset_datum(/datum/asset/simple/headers)
+	if(active_program)
+		data += active_program.ui_assets(user)
+	return data
 
 /obj/item/modular_computer/ui_static_data(mob/user)
 	. = ..()
 	var/list/data = list()
+	if(active_program)
+		data += active_program.ui_static_data(user)
+		return data
 
 	data["show_imprint"] = istype(src, /obj/item/modular_computer/pda)
 
@@ -50,6 +61,9 @@
 
 /obj/item/modular_computer/ui_data(mob/user)
 	var/list/data = get_header_data()
+	if(active_program)
+		data += active_program.ui_data(user)
+		return data
 
 	data["login"] = list(
 		IDName = saved_identification || "Unknown",
@@ -61,7 +75,6 @@
 		IDJob = computer_id_slot?.assignment,
 	)
 
-
 	data["removable_media"] = list()
 	if(inserted_disk)
 		data["removable_media"] += "Eject Disk"
@@ -86,9 +99,8 @@
 	data["pai"] = inserted_pai
 	return data
 
-
 // Handles user's GUI input
-/obj/item/modular_computer/ui_act(action, params)
+/obj/item/modular_computer/ui_act(action, list/params, datum/tgui/ui, datum/ui_state/state)
 	. = ..()
 	if(.)
 		return
@@ -99,6 +111,9 @@
 			balloon_alert(human_user, "fingers are too big!")
 			return TRUE
 
+	if(active_program)
+		active_program.ui_act(action, params, ui, state)
+
 	switch(action)
 		if("PC_exit")
 			kill_program()
@@ -107,29 +122,28 @@
 			shutdown_computer()
 			return TRUE
 		if("PC_minimize")
-			var/mob/user = usr
 			if(!active_program)
 				return
+			//header programs can't be minimized.
+			if(active_program.header_program)
+				kill_program()
+				return TRUE
 
 			idle_threads.Add(active_program)
 			active_program.program_state = PROGRAM_STATE_BACKGROUND // Should close any existing UIs
 
 			active_program = null
 			update_appearance()
-			if(user && istype(user))
-				ui_interact(user) // Re-open the UI on this computer. It should show the main screen now.
 
 		if("PC_killprogram")
 			var/prog = params["name"]
-			var/datum/computer_file/program/P = null
-			var/mob/user = usr
-			P = find_file_by_name(prog)
+			var/datum/computer_file/program/killed_program = find_file_by_name(prog)
 
-			if(!istype(P) || P.program_state == PROGRAM_STATE_KILLED)
+			if(!istype(killed_program) || killed_program.program_state == PROGRAM_STATE_KILLED)
 				return
 
-			P.kill_program(forced = TRUE)
-			to_chat(user, span_notice("Program [P.filename].[P.filetype] with PID [rand(100,999)] has been killed."))
+			killed_program.kill_program(forced = TRUE)
+			to_chat(usr, span_notice("Program [killed_program.filename].[killed_program.filetype] with PID [rand(100,999)] has been killed."))
 
 		if("PC_runprogram")
 			open_program(usr, find_file_by_name(params["name"]))
@@ -172,7 +186,7 @@
 						return TRUE
 
 				if("ID")
-					if(RemoveID())
+					if(RemoveID(user))
 						playsound(src, 'sound/machines/card_slide.ogg', 50)
 						return TRUE
 
@@ -192,8 +206,6 @@
 				if("interact")
 					inserted_pai.attack_self(usr)
 			return UI_UPDATE
-		else
-			return
 
 /obj/item/modular_computer/ui_host()
 	if(physical)