WoWInterface SVN oUF_BarFader

--[[

        Shared:
         - BarFade [boolean]
         - BarFadeMinAlpha [value] default: 0.25
         - BarFadeMaxAlpha [value] default: 1

--]]
local function NotFull(unit)
        if(UnitHealth(unit) ~= UnitHealthMax(unit)) then
                return true
        else
                if(UnitPowerType(unit) == 6 or UnitPowerType(unit) == 1) then
                        if(UnitMana(unit) > 0) then
                                return true
                        else
                                return false
                        end
                else
                        if(UnitMana(unit) ~= UnitManaMax(unit)) then
                                return true
                        else
                                return false
                        end
                end
        end
end

local function UpdateElement(self)
        if(self.unit == 'player' or self.unit == 'pet' or self.unit == 'focus' or self.unit == 'focustarget' or self.unit == 'targettarget') then
                if(not self.BarFade) then return end

                if(NotFull(self.unit)) then
                        self:SetAlpha(self.BarFadeMaxAlpha or 1)
                elseif(UnitAffectingCombat(self.unit)) then
                        self:SetAlpha(self.BarFadeMaxAlpha or 1)
                elseif(UnitExists(self.unit..'target')) then
                        self:SetAlpha(self.BarFadeMaxAlpha or 1)
                elseif(self.Castbar) then
                        self:SetAlpha(self.Castbar.casting and (self.BarFadeMaxAlpha or 1) or (self.BarFadeMinAlpha or 0.25))
                elseif(self.unit == 'pet' and GetPetHappiness()) then
                        self:SetAlpha((GetPetHappiness() < 3) and (self.BarFadeMaxAlpha or 1) or (self.BarFadeMinAlpha or 0.25))
                else
                        self:SetAlpha(self.BarFadeMinAlpha or 0.25)
                end
        end
end

oUF:RegisterInitCallback(function(obj)
        local addon = CreateFrame('Frame')
        addon:SetScript('OnEvent', function() UpdateElement(obj) end)
        addon:RegisterEvent('PLAYER_LOGIN')
        addon:RegisterEvent('PLAYER_REGEN_ENABLED')
        addon:RegisterEvent('PLAYER_REGEN_DISABLED')
        addon:RegisterEvent('PLAYER_TARGET_CHANGED')
        addon:RegisterEvent('PLAYER_FOCUS_CHANGED')
        addon:RegisterEvent('UNIT_HAPPINESS')
        addon:RegisterEvent('UNIT_HEALTH')
        addon:RegisterEvent('UNIT_MANA')
        addon:RegisterEvent('UNIT_ENERGY')
        addon:RegisterEvent('UNIT_FOCUS')
        addon:RegisterEvent('UNIT_RAGE')
        addon:RegisterEvent('UNIT_RUNIC_POWER')
        addon:RegisterEvent('UNIT_POWER')
        addon:RegisterEvent('UNIT_TARGET')
        addon:RegisterEvent('UNIT_SPELLCAST_START')
        addon:RegisterEvent('UNIT_SPELLCAST_STOP')
        addon:RegisterEvent('UNIT_SPELLCAST_CHANNEL_START')
        addon:RegisterEvent('UNIT_SPELLCAST_CHANNEL_STOP')
end)