Use ClassicAPI animation groups for fades and pulses

Replace hand-rolled OnUpdate alpha loops with engine animation groups:
unit frame aggro/combat glow, tracking icon pulse, new-mail blink,
castbar fade-out, autohide, XP/rep bar fade, info box timeout and the
unlock-mode scale label. Timing no longer depends on framerate, and the
always-running glow driver and tracking OnUpdate are gone.

The XP bar tracks hover through OnEnter/OnLeave instead of MouseIsOver,
so a fade can't restart under the cursor.

api/api.lua

@@ -1555,11 +1555,20 @@ function pfUI.api.EnableAutohide(frame, timeout, combat)
   frame.hover.parent = frame
   frame.hover:Show()
 
+  if not frame.hover.fade then
+    frame.hover.fade = frame:CreateAnimationGroup()
+    local fade = frame.hover.fade:CreateAnimation("Alpha")
+    fade:SetChange(-1)
+    fade:SetDuration(1)
+    frame.hover.fade:SetScript("OnFinished", function() frame:SetAlpha(0) end)
+  end
+
   if combat then
     frame.hover:RegisterEvent("PLAYER_REGEN_ENABLED")
     frame.hover:RegisterEvent("PLAYER_REGEN_DISABLED")
     frame.hover:SetScript("OnEvent", function()
       if event == "PLAYER_REGEN_DISABLED" then
+        this.fade:Stop()
         this.parent:SetAlpha(1)
         this.activeTo = "keep"
       elseif event == "PLAYER_REGEN_ENABLED" then
@@ -1577,11 +1586,11 @@ function pfUI.api.EnableAutohide(frame, timeout, combat)
 
     if MouseIsOver(this, 10, -10, -10, 10) then
       this.activeTo = GetTime() + timeout
+      this.fade:Stop()
       this.parent:SetAlpha(1)
     elseif this.activeTo then
-      if this.activeTo < GetTime() and this.parent:GetAlpha() > 0 then
-        local fps = (60 / math.max(GetFramerate(), 1))
-        this.parent:SetAlpha(this.parent:GetAlpha() - 0.05*fps)
+      if this.activeTo < GetTime() and this.parent:GetAlpha() > 0 and not this.fade:IsPlaying() then
+        this.fade:Play()
       end
     else
       this.activeTo = GetTime() + timeout
@@ -1598,6 +1607,7 @@ function pfUI.api.DisableAutohide(frame)
   frame.hover:SetScript("OnEvent", nil)
   frame.hover:SetScript("OnUpdate", nil)
   frame.hover:Hide()
+  frame.hover.fade:Stop()
   frame:SetAlpha(1)
 end
 

api/ui-widgets.lua

@@ -1160,17 +1160,21 @@ function pfUI.api.CreateInfoBox(text, time, parent, height)
     infobox = CreateFrame("Button", "pfInfoBox", UIParent)
     infobox:Hide()
 
+    infobox.fade = infobox:CreateAnimationGroup()
+    local fade = infobox.fade:CreateAnimation("Alpha")
+    fade:SetChange(-1)
+    fade:SetDuration(.3)
+    infobox.fade:SetScript("OnFinished", function()
+      infobox:Hide()
+      infobox:SetAlpha(1)
+    end)
+
     infobox:SetScript("OnUpdate", function()
       local time = infobox.lastshow + infobox.duration - GetTime()
       infobox.timeout:SetValue(time)
 
       if GetTime() > infobox.lastshow + infobox.duration then
-        infobox:SetAlpha(infobox:GetAlpha()-0.05)
-
-        if infobox:GetAlpha() <= 0.1 then
-          infobox:Hide()
-          infobox:SetAlpha(1)
-        end
+        if not infobox.fade:IsPlaying() then infobox.fade:Play() end
       elseif MouseIsOver(this) then
         this:SetAlpha(max(0.4, this:GetAlpha() - .1))
       else
@@ -1214,6 +1218,7 @@ function pfUI.api.CreateInfoBox(text, time, parent, height)
   infobox:SetParent(parent)
 
   infobox:SetFrameStrata("FULLSCREEN_DIALOG")
+  infobox.fade:Stop()
   infobox:Show()
 end
 

api/unitframes.lua

@@ -219,27 +219,6 @@ function pfUI.api.UnitHasAggro(unit)
   return data.state
 end
 
-pfUI.uf.glow = CreateFrame("Frame", nil, UIParent)
-pfUI.uf.glow:SetScript("OnUpdate", function()
-  local fpsmod = GetFramerate() / 30
-  if not this.val or this.val >= .8 then
-    this.mod = -0.01 / fpsmod
-  elseif this.val <= .4 then
-    this.mod = 0.01  / fpsmod
-  end
-  this.val = this.val + this.mod
-end)
-
-pfUI.uf.glow.mod = 0
-pfUI.uf.glow.val = 0.6
-
-function pfUI.uf.glow.UpdateGlowAnimation()
-  local val = pfUI.uf.glow.val or 0.6
-  if val < 0.4 then val = 0.4 end
-  if val > 0.8 then val = 0.8 end
-  this:SetAlpha(val)
-end
-
 function pfUI.uf:UpdateVisibility()
   local self = self or this
 
@@ -451,7 +430,6 @@ function pfUI.uf:UpdateConfig()
   f.glow:SetBackdrop(glow2)
   f.glow:SetPoint("TOPLEFT", f, "TOPLEFT", -6 - default_border,6 + default_border)
   f.glow:SetPoint("BOTTOMRIGHT", f, "BOTTOMRIGHT", 6 + default_border,-6 - default_border)
-  f.glow:SetScript("OnUpdate", pfUI.uf.glow.UpdateGlowAnimation)
   f.glow:Hide()
 
   f.combat:SetSize(tonumber(f.config.squaresize), tonumber(f.config.squaresize))
@@ -1482,7 +1460,18 @@ function pfUI.uf:CreateUnitFrame(unit, id, config, tick)
   end
 
   f.glow = CreateFrame("Frame", nil, f)
-  f.combat = CreateFrame("Frame", nil, f.hp.bar)
+  -- Pulse between .8 and .4 for good. The group only advances while the glow
+  -- is shown, so a hidden glow costs nothing.
+  f.glow:SetAlpha(.8)
+  f.glow.pulse = f.glow:CreateAnimationGroup()
+  f.glow.pulse:SetLooping("BOUNCE")
+  local fade = f.glow.pulse:CreateAnimation("Alpha")
+  fade:SetChange(-.4)
+  fade:SetDuration(1.3)
+  fade:SetSmoothing("IN_OUT")
+  f.glow.pulse:Play()
+
+  f.combat =CreateFrame("Frame", nil, f.hp.bar)
   f.combat.tex = f.combat:CreateTexture(nil, "OVERLAY")
   f.combat.tex:SetAllPoints()