Fix/Changes: Combobox callback fixes/changes

With this commit comboboxes won't throw an error for a "nil" callback anymore.
For some reason the game can not keep track of callbacks correctly anymore.

Also added a "oldValue" to the onSelect/onChange function of the combobox to ensure the previous set value is still sent.

CHANGELOG.md

@@ -23,6 +23,10 @@ All notable changes to TTT2 will be documented here. Inspired by [keep a changel
 - Updated file code to read from `data_static` as fallback in new location allowed in .gma (by @EntranceJew)
 - Scoreboard now sets preferred player volume and mute state in client's new `ttt2_voice` table (by @EntranceJew)
   - Keyed by steamid64, making it more reliable than UniqueID or the per-session mute and volume levels.
+- Added "olValue" to the onSelect/onChange function of comboboxes (by @NickCloudAT)
+
+### Fixed
+- Fixed Comboboxes throwing an invalid callback error in some instances (by @NickCloudAT)
 
 ## [v0.11.7b](https://github.com/TTT-2/TTT2/tree/v0.11.7b) (2022-08-27)
 

gamemodes/terrortown/gamemode/client/cl_vskin/vgui/dcombobox_ttt2.lua

@@ -175,17 +175,19 @@ function PANEL:ChooseOptionID(index, ignoreConVar)
 
 	local choice = choices[index]
 	local value = choice.value
+	local oldValue = self.selected and choices[self.selected].value or nil
 
 	self.selected = index
 
 	self:SetText(choice.title)
-	self:OnSelect(index, value, choice.data)
 
 	self:CloseMenu()
 
-	if ignoreConVar then return end
+	if not ignoreConVar then
+		self:SetConVarValues(tostring(value))
+	end
 
-	self:SetConVarValues(tostring(value))
+	self:OnSelect(index, value, choice.data, oldValue)
 end
 
 ---
@@ -241,8 +243,9 @@ end
 -- @param number index
 -- @param string/number value is indexable
 -- @param any data
+-- @param string/number value is indexable
 -- @realm client
-function PANEL:OnSelect(index, value, data)
+function PANEL:OnSelect(index, value, data, oldValue)
 
 end
 
@@ -357,6 +360,22 @@ local function AddConVarChangeCallback(menu, conVar)
 	cvars.AddChangeCallback(conVar, OnConVarChangeCallback, myIdentifierString)
 end
 
+---
+-- The game can not keep track of nil callbacks but does not
+-- remove them automatically. Here we go over all callbacks and delete them
+-- before they get used and throw an error
+local function CleanUpConVarCallbacks(conVar)
+	for k, v in ipairs(cvars.GetConVarCallbacks(conVar)) do
+		if not istable(v) then continue end
+
+		local identifier = v[2] or ""
+
+		if not string.find(identifier, "TTT2F1MenuConVarChangeCallback") or not isfunction(v[1]) then continue end
+
+		cvars.RemoveChangeCallback(conVar, identifier)
+	end
+end
+
 ---
 -- @param string conVarName
 -- @realm client
@@ -369,6 +388,7 @@ function PANEL:SetConVar(conVarName)
 	self:SetValue(conVar:GetString(), true)
 	self:SetDefaultValue(conVar:GetDefault())
 
+	CleanUpConVarCallbacks(conVarName)
 	AddConVarChangeCallback(self, conVarName)
 end
 
@@ -387,6 +407,7 @@ function PANEL:SetServerConVar(conVarName)
 		end
 	end)
 
+	CleanUpConVarCallbacks(conVarName)
 	AddConVarChangeCallback(self, conVarName)
 end
 

gamemodes/terrortown/gamemode/client/cl_vskin/vgui/dform_ttt2.lua

@@ -291,7 +291,7 @@ end
 -- @note Structure of data = {
 -- label, default, choices = { [1] = {title, value, select, icon, additionalData}, [2] = ...},
 -- conVar, serverConVar, selectId or selectTitle or selectValue,
--- function OnChange(value, additionalData, dropDownPanel), master = { function AddSlave(self, slave) }
+-- function OnChange(value, additionalData, oldValue, dropDownPanel), master = { function AddSlave(self, slave) }
 -- }
 -- @note If ConVars are used the values are always strings, so make sure, that you used strings for values, when setting up choices
 -- @return Panel The created combobox
@@ -344,9 +344,9 @@ function PANEL:MakeComboBox(data)
 		end
 	end
 
-	right.OnSelect = function(slf, index, value, additionalData)
+	right.OnSelect = function(slf, index, value, additionalData, oldValue)
 		if data and isfunction(data.OnChange) then
-			data.OnChange(value, additionalData, slf)
+			data.OnChange(value, additionalData, oldValue, slf)
 		end
 	end
 

lua/terrortown/menus/gamemode/language/language.lua

@@ -25,8 +25,8 @@ function CLGAMEMODESUBMENU:Populate(parent)
 		label = "label_language_set",
 		convar = "ttt_language",
 		choices = choices,
-		OnChange = function(value)
-			if value == GetActiveLanguageName() then return end
+		OnChange = function(value, _, oldValue)
+			if value == oldValue then return end
 
 			vguihandler.InvalidateVSkin()
 			vguihandler.Rebuild()