portrait: Update element (#609)

.luacheckrc

@@ -92,6 +92,7 @@ read_globals = {
 	'UnitCastingInfo',
 	'UnitChannelInfo',
 	'UnitClass',
+	'UnitClassBase',
 	'UnitExists',
 	'UnitFactionGroup',
 	'UnitGUID',

elements/portrait.lua

@@ -12,6 +12,10 @@ Portrait - A `PlayerModel` or a `Texture` used to represent the unit's portrait.
 A question mark model will be used if the widget is a PlayerModel and the client doesn't have the model information for
 the unit.
 
+## Options
+
+.showClass - Displays the unit's class in the portrait (boolean)
+
 ## Examples
 
     -- 3D Portrait
@@ -50,7 +54,8 @@ local function Update(self, event, unit)
 
 	local guid = UnitGUID(unit)
 	local isAvailable = UnitIsConnected(unit) and UnitIsVisible(unit)
-	if(event ~= 'OnUpdate' or element.guid ~= guid or element.state ~= isAvailable) then
+	local hasStateChanged = event ~= 'OnUpdate' or element.guid ~= guid or element.state ~= isAvailable
+	if(hasStateChanged) then
 		if(element:IsObjectType('PlayerModel')) then
 			if(not isAvailable) then
 				element:SetCamDistanceScale(0.25)
@@ -66,7 +71,12 @@ local function Update(self, event, unit)
 				element:SetUnit(unit)
 			end
 		else
-			SetPortraitTexture(element, unit)
+			local class = element.showClass and UnitClassBase(unit)
+			if(class) then
+				element:SetAtlas('classicon-' .. class)
+			else
+				SetPortraitTexture(element, unit)
+			end
 		end
 
 		element.guid = guid
@@ -76,11 +86,12 @@ local function Update(self, event, unit)
 	--[[ Callback: Portrait:PostUpdate(unit)
 	Called after the element has been updated.
 
-	* self - the Portrait element
-	* unit - the unit for which the update has been triggered (string)
+	* self            - the Portrait element
+	* unit            - the unit for which the update has been triggered (string)
+	* hasStateChanged - indicates whether the state has changed since the last update (boolean)
 	--]]
 	if(element.PostUpdate) then
-		return element:PostUpdate(unit)
+		return element:PostUpdate(unit, hasStateChanged)
 	end
 end