Make raid first-frame state deterministic

mods/raid-group-header.lua

@@ -23,38 +23,33 @@ module.enable = function(self)
     events = { },
 
     create = function(frame)
-      -- skip if already initialized
-      if init then return else init = true end
+      if init then return end
+      init = true
 
-      -- create shortcut to raid.cluster
       local cluster = frame:GetParent()
-
-      -- initialize header frame on cluster
       local header = CreateFrame("Frame", "ShaguTweaksRaidHeaders", cluster)
       header:SetFrameLevel(128)
       header:SetScale(.9)
       header:SetAllPoints(cluster)
-      header:RegisterEvent("PLAYER_ENTERING_WORLD")
-      header:RegisterEvent("RAID_ROSTER_UPDATE")
-      header:SetScript("OnEvent", function()
-        for i = 1, 40 do
-          if math.mod(i, 5) == 1 then
-            local group = math.ceil(i/5)
 
-            -- create header base frame
+      local function UpdateHeaders()
+        if not cluster.frames then return end
+
+        for group = 1, 8 do
+          local index = (group - 1) * 5 + 1
+          local anchorFrame = cluster.frames[index]
+
+          if anchorFrame then
             if not header[group] then
-              header[group] = header[group] or CreateFrame("Frame", "ShaguTweaksRaidGroupHeader" .. group, header)
-              header[group]:SetPoint("TOP", cluster.frames[i], "TOP", 0, 6)
+              header[group] = CreateFrame("Frame", "ShaguTweaksRaidGroupHeader" .. group, header)
+              header[group]:SetPoint("TOP", anchorFrame, "TOP", 0, 6)
               header[group]:SetWidth(42)
               header[group]:SetHeight(16)
               header[group]:SetBackdrop(backdrop)
               header[group]:SetBackdropBorderColor(.8, .8, .8, 1)
               header[group]:SetBackdropColor(.4, .4, .4, 1)
               ShaguTweaks.DarkenFrame(header[group])
-            end
 
-            -- create header text
-            if not header[group].text then
               header[group].text = header[group]:CreateFontString(nil, "HIGH", "GameFontWhite")
               header[group].text:SetFont(STANDARD_TEXT_FONT, 7, "THINOUTLINE")
               header[group].text:SetAllPoints(header[group])
@@ -63,14 +58,36 @@ module.enable = function(self)
               header[group].text:SetText("Group " .. group)
             end
 
-            -- toggle visibility if needed
-            if RAID_SUBGROUP_LISTS and RAID_SUBGROUP_LISTS[group] and table.getn(RAID_SUBGROUP_LISTS[group]) > 0 then
+            local inRaid = RAID_SUBGROUP_LISTS
+              and RAID_SUBGROUP_LISTS[group]
+              and table.getn(RAID_SUBGROUP_LISTS[group]) > 0
+            local inParty = group == 1
+              and not UnitInRaid("player")
+              and GetNumPartyMembers() > 0
+
+            if inRaid or inParty then
               header[group]:Show()
             else
               header[group]:Hide()
             end
           end
         end
+      end
+
+      header.Update = UpdateHeaders
+      header:RegisterEvent("PLAYER_ENTERING_WORLD")
+      header:RegisterEvent("RAID_ROSTER_UPDATE")
+      header:RegisterEvent("PARTY_MEMBERS_CHANGED")
+      header:SetScript("OnEvent", UpdateHeaders)
+
+      -- The header container is created while the first raid unit frame is
+      -- still being built. Wait until all 40 anchors exist, then initialize
+      -- once even if the PLAYER_ENTERING_WORLD event that created us was missed.
+      header:SetScript("OnUpdate", function()
+        if cluster.frames and cluster.frames[40] then
+          UpdateHeaders()
+          this:SetScript("OnUpdate", nil)
+        end
       end)
     end,