Modernize cast bars, unit-frame clicks, and mark tracking with ClassicAPI (#32)

* Migrate player castbar to ClassicAPI UNIT_SPELLCAST_* events

Drive the player cast path off ClassicAPI's synthesized, player-only
UNIT_SPELLCAST_* events instead of the vanilla SPELLCAST_* plus nampower
SPELL_{START,GO,DELAYED}_SELF mix. START/CHANNEL_START poll UnitCastingInfo/
UnitChannelInfo and stamp; STOP/CHANNEL_STOP/FAILED/INTERRUPTED clear;
SUCCEEDED drives tradeskill craft counting; DELAYED/CHANNEL_UPDATE re-poll.
Since UNIT_SPELLCAST_START fires for chained same-spell recasts, the nampower
SELF deps and their RunNextFrame co-hook-ordering workarounds are gone.
Remote target/focus bars keep SPELL_*_OTHER (the new events are player-only).

Fix the cast-start flash: StampBar now primes the fill on the stamp frame,
and ClearBar no longer snaps the bar to full (that snap lingered in the fade
tail and flashed when the next cast stamped).

Add a red flash on a cancelled cast: new appearance.castbar.failcolor,
flashed by ClearBar only when a cast was actually in progress.

Handle pushback Quartz-style: DELAYED/CHANNEL_UPDATE re-poll just the times
and accumulate the endMs shift into this.delay for the +/- indicator (cast
+X, channel -X), rather than a full restamp.

* Route target/focus castbars through remote UNIT_SPELLCAST_*

ClassicAPI now fires UNIT_SPELLCAST_* for remote tokens (target/focus/...)
via PollRemote, so drop the nampower SPELL_*_OTHER path and drive all three
bars off one event model. The gate is now token-based (arg1 == this.unitstr,
plus the arg1=="player" + UnitIsUnit case for target=self); the RunNextFrame
defer is gone since the remote poll fires after UnitCastingInfo is readable.
Cast detection is now nampower-free across every bar.

Use the event's rank payload (arg5): thread it through RefreshBar into
StampBar, which now only calls C_Spell.GetSpellSubtext as a fallback on the
retarget re-poll (PLAYER_TARGET/FOCUS_CHANGED) where no event is in hand.

* Drive nameplate castbars off UNIT_SPELLCAST_*

ClassicAPI now fires UNIT_SPELLCAST_* for nameplate tokens, so populate the
per-GUID castState cache from UNIT_SPELLCAST_{START,CHANNEL_START} (poll
PollCastInfo for the timing the payload omits) and clear it on
{STOP,CHANNEL_STOP} -- the remote poll fires STOP for natural end, interrupt,
and cancel alike. Replaces the nampower SPELL_{START,FAILED}_OTHER path; the
^nameplate arg1 gate ignores the target/focus/party fires of the same events,
and the NAME_PLATE_UNIT_ADDED seed still catches a plate spawning mid-cast.
Nameplate cast detection is now nampower-free.

* We no longer use these features from SuperWoW/Nampower

* Use secure unit attributes; remove mouseover scripts

Switch unitframes to attribute-driven clicks and remove mouseover tooltip handlers. Adds SetAttribute("unit") in UpdateVisibility and sets frame attributes (unit and type1='target') when creating frames. Removes OnEnter/OnLeave functions and their SetScript registrations and eliminates direct TargetUnit calls in ClickAction

* Use SetShown and simplify component default

Replace explicit Show/Hide conditionals in api/unitframes.lua with SetShown(...) for ressIcon, leaderIcon, lootIcon, pvpIcon, and restIcon to reduce branching and improve readability. Also remove the local shadowing of the parameter 'component' by using assignment (component = component or ""). No intended behavior changes.

* Drive unit-frame clicks via secure attributes

Replace the Lua OnClick dispatch (OnClick/ClickAction/RightClickAction) with
secure frame attributes: default type1=target / type2=menu, and EnableClickCast
now writes type/spell/macrotext/menu/target/focus attributes per button+modifier
instead of caching a clickactions table read at click time. Drops the now-dead
clickactions table and buttons list.

Also set a "unit" attribute on each frame (at creation and re-synced in
UpdateVisibility to the live token, so a party shown on the raid grid reports
partyN, not raidN) so the hovered unit resolves from the frame.

Match the target/focus/menu click keywords exactly rather than by prefix, so a
spell whose name starts with "focus"/"target"/"menu" (e.g. Focus Magic) casts
instead of being swallowed as the keyword action.

* Simplify marktracking colors and refresh per mark

Replace the hand-rolled ParseColor plus its default-color table with
GetStringColor -- the raidmarkercolor_* config keys already carry those same
defaults, so the fallback was dead code.

Restructure the refresh off observed mark tokens: UNIT_HEALTH/UNIT_MAXHEALTH
now arrive as arg1 == "markN", so refresh just that one row (UpdateRow) instead
of rescanning all eight on every nearby unit's health tick. A visibility flip
(into range / death / hp crossing 0) re-packs the rows, so UpdateRow hands off
to a full UpdateDisplay; RAID_TARGET_UPDATE / PLAYER_ENTERING_WORLD stay full
refreshes, with the 1s poll as the range-change backstop.

* not true anymore

* Poll marktracking fallback via C_Timer instead of OnUpdate

The 1s range-change safety net ran a per-frame OnUpdate that no-oped ~59 of
every 60 frames. Replace it with C_Timer.NewTicker(FALLBACK_INTERVAL,
UpdateDisplay) -- one wakeup per second off the shared timer driver -- and drop
the elapsed accumulator. The scanner frame is now purely event-driven.

* SuperWoW is now optional

* Update README feature list

Add 'Mouseover Unit Frames' and 'Click-casting' to the main features list. Update the SuperWoW entry to reflect that it tracks party/raid units on the minimap (replacing the prior SetMouseoverUnit note).

* Replace fixed-interval OnUpdate polls with C_Timer/RunNextFrame

Swap hand-rolled per-frame throttles for the modern timer primitives:

- turtle-wow: one-shot next-frame defer (self-hiding OnUpdate frame) -> RunNextFrame
- panel: clock, combat, and fps widgets -> NewTicker(1); guild roster -> NewTicker(60)
- minimap: coordinates text -> NewTicker(0.1)
- addonbuttons: one-shot init -> RunNextFrame; 5s button rescan -> NewTicker(5),
  guarded by IsShown() to preserve the old "paused while hidden" behavior

Ticker callbacks reference frames via upvalue since 'this' is unbound outside
OnUpdate. Genuine per-frame work (bar fills, fades, drag) and polls already
coordinated through pfUI.throttle are left as-is.

* update pfQuest link

* Use SetShown/SetSize in panel module

Replace manual Show/Hide toggles with SetShown(not ... ) and replace SetWidth/SetHeight with SetSize in modules/panel.lua. Changes simplify toggle logic (timer, WorldMap, chat hide buttons) and unify sizing calls for timer, frames, textures, and microbutton. No behavior changes intended; purely refactor for conciseness and consistency.

* Bump ClassicAPI min version to 1.9.0

* Drive reagent counter from events instead of a polling OnUpdate

The pfReagentCounter frame ran an OnUpdate that (1) progressively rescanned
all 120 action slots one-per-100ms on any slot change and (2) recounted
reagent inventory on a 1s throttle. Replace both with direct event handling:

- ACTIONBAR_SLOT_CHANGED updates just the changed slot (arg1), full-scanning
  only when arg1 is 0/nil, instead of restarting a ~12s rescan on every edit
- BAG_UPDATE_DELAYED recounts tracked reagents directly (it is already
  Blizzard's coalesced bag event, so the extra 1s throttle was redundant)
- PLAYER_ENTERING_WORLD seeds the full reagent map once

UpdateSlot now seeds a new reagent's real count via GetItemCount so a freshly
placed reagent spell shows the correct number immediately. The updatecache ->
BarsUpdate render path and the IsReagentAction/GetReagentCount accessors are
unchanged.

modules/castbar.lua

@@ -16,9 +16,13 @@ pfUI:RegisterModule("castbar", function ()
     end
   end
 
-  -- Clear cast state on the bar. Shows the bar full for one frame, then
-  -- OnUpdate fades it out.
-  local function ClearBar(cb)
+  -- Clear cast state on the bar and start the fade-out. On a normal end the bar
+  -- is left at its current fill (a completed cast is already ~full; nothing
+  -- snaps to full, which used to flash for a frame when the next cast stamped
+  -- the bar). When `failed` is set for a cast that was actually in progress, the
+  -- bar flashes full red before fading — the cancelled-cast indicator.
+  local function ClearBar(cb, failed)
+    local wasActive = cb.endTime ~= nil
     cb.startTime, cb.endTime, cb.isChannel = nil, nil, nil
     cb.activeName, cb.spellID = nil, nil
     cb.isTradeskill = nil
@@ -26,8 +30,11 @@ pfUI:RegisterModule("castbar", function ()
     cb.tradeskillSingleMs, cb.currentCraftStart = nil, nil
     cb.lastMax = nil
     cb.delay = 0
-    cb.bar:SetMinMaxValues(1, 100)
-    cb.bar:SetValue(100)
+    if failed and wasActive then
+      cb.bar:SetStatusBarColor(GetStringColor(C.appearance.castbar.failcolor))
+      cb.bar:SetMinMaxValues(0, 1)
+      cb.bar:SetValue(1)
+    end
     if cb.bar.spark then cb.bar.spark:Hide() end
     cb.fadeout = 1
   end
@@ -65,8 +72,8 @@ pfUI:RegisterModule("castbar", function ()
   end
 
   -- Mark the start of craft 2..N within an active merge (called from the
-  -- SPELLCAST_START / SPELL_START_SELF handlers). Resets the per-craft
-  -- spark to the left edge of the bar.
+  -- UNIT_SPELLCAST_START handler). Resets the per-craft spark to the left
+  -- edge of the bar.
   local function StartTradeskillCraft(cb)
     cb.currentCraftStart = GetTime() * 1000
     local remaining = cb.tradeskillTotal - (cb.tradeskillCompleted or 0)
@@ -79,7 +86,7 @@ pfUI:RegisterModule("castbar", function ()
 
   -- Stamp the bar with cast data and render text/icon/lag once. OnUpdate
   -- then animates the fill from this state without touching C_Spell.
-  local function StampBar(cb, name, tex, startMs, endMs, spellID, isChannel, delayMs, isTradeskill)
+  local function StampBar(cb, name, tex, startMs, endMs, spellID, isChannel, delayMs, isTradeskill, rank)
     cb.startTime = startMs
     cb.endTime = endMs
     cb.isChannel = isChannel
@@ -92,10 +99,13 @@ pfUI:RegisterModule("castbar", function ()
 
     cb.bar:SetStatusBarColor(GetStringColor(C.appearance.castbar[isChannel and "channelcolor" or "castbarcolor"]))
 
-    local rank = ""
-    if spellID then
+    -- Rank: prefer the value the UNIT_SPELLCAST_* event delivered (arg5, passed
+    -- through by RefreshBar). Only the retarget re-poll has no event in hand, so
+    -- it falls back to a lookup.
+    if not rank and spellID then
       rank = C_Spell.GetSpellSubtext(spellID) or ""
     end
+    rank = rank or ""
     local spellname = (cb.showname and name) and (name .. " ") or ""
     local rankstr = (cb.showrank and rank ~= "") and string.format("|cffaaffcc[%s]|r", rank) or ""
     cb.bar.left:SetText(spellname .. rankstr)
@@ -122,11 +132,21 @@ pfUI:RegisterModule("castbar", function ()
 
     cb.bar:SetMinMaxValues(0, duration)
     cb.lastMax = duration
+
+    -- Prime the fill on this frame. StampBar otherwise leaves the previous
+    -- value in place (ClearBar, run on the prior cast's STOP, leaves it full),
+    -- so the bar would flash full for the frame between here and the next
+    -- OnUpdate tick. Reset the throttle too so the timer text updates promptly.
+    local nowSec = GetTime()
+    local cur = isChannel and (endMs / 1000 - nowSec) or (nowSec - startMs / 1000)
+    if cur < 0 then cur = 0 elseif cur > duration then cur = duration end
+    cb.bar:SetValue(cur)
+    cb.tick = 0
   end
 
   -- One-shot poll: read C_Spell for the bar's unit, stamp or clear. Called
   -- from event handlers (cast start, target/focus change), never per-frame.
-  local function RefreshBar(cb)
+  local function RefreshBar(cb, rank)
     local query = cb.unitstr ~= "" and cb.unitstr or cb.unitname
     if not query or (cb.unitstr ~= "" and not UnitExists(cb.unitstr)) then
       ClearBar(cb)
@@ -149,7 +169,7 @@ pfUI:RegisterModule("castbar", function ()
       end
     end
     if name and startMs and endMs then
-      StampBar(cb, name, tex, startMs, endMs, spellID, isChan, delayMs, isTradeskill)
+      StampBar(cb, name, tex, startMs, endMs, spellID, isChan, delayMs, isTradeskill, rank)
     else
       ClearBar(cb)
     end
@@ -294,35 +314,27 @@ pfUI:RegisterModule("castbar", function ()
       end
     end)
 
-    -- Cast lifecycle events. Player bars react to vanilla SPELLCAST_*; non-
-    -- player bars also react to Nampower SPELL_*_OTHER (gated by the
-    -- NP_EnableSpell{Start,Go}Events CVars, enabled by libdebuff) plus the
-    -- retarget event. Player events also feed non-player bars for the
-    -- target=self case.
-    cb:RegisterEvent("SPELLCAST_START")
-    cb:RegisterEvent("SPELLCAST_STOP")
-    cb:RegisterEvent("SPELLCAST_FAILED")
-    cb:RegisterEvent("SPELLCAST_INTERRUPTED")
-    cb:RegisterEvent("SPELLCAST_CHANNEL_START")
-    cb:RegisterEvent("SPELLCAST_CHANNEL_STOP")
-    cb:RegisterEvent("SPELLCAST_CHANNEL_UPDATE")
-    cb:RegisterEvent("SPELL_DELAYED_SELF")
-    -- Chained same-spell recasts never run the client cast path (the 1.12
-    -- engine short-circuits at spellID == current-cast), so vanilla
-    -- SPELLCAST_START never fires for them. nampower's SPELL_START_SELF
-    -- (server-driven) is the only signal that shows them.
-    cb:RegisterEvent("SPELL_START_SELF")
-    if unitstr == "player" then
-      cb:RegisterEvent("SPELL_GO_SELF")
-    end
-    if unitstr ~= "player" and unitstr ~= "" then
-      cb:RegisterEvent("SPELL_START_OTHER")
-      cb:RegisterEvent("SPELL_FAILED_OTHER")
-      if unitstr == "target" then
-        cb:RegisterEvent("PLAYER_TARGET_CHANGED")
-      elseif unitstr == "focus" then
-        cb:RegisterEvent("PLAYER_FOCUS_CHANGED")
-      end
+    -- Cast lifecycle, entirely on ClassicAPI's UNIT_SPELLCAST_* events. They
+    -- fire per unit token: arg1=="player" for the player's own casts, and the
+    -- remote token(s) ("target", "focus", ...) for other units -- so one set of
+    -- events drives every bar with no Nampower dependency. The handler routes an
+    -- event to this bar when arg1 matches its unit, or -- since the player's own
+    -- casts only ever fire arg1=="player" -- when the bar's unit resolves to the
+    -- player (target=self). PLAYER_TARGET/FOCUS_CHANGED re-polls so a unit
+    -- already mid-cast when it becomes the target/focus still shows.
+    cb:RegisterEvent("UNIT_SPELLCAST_START")
+    cb:RegisterEvent("UNIT_SPELLCAST_STOP")
+    cb:RegisterEvent("UNIT_SPELLCAST_FAILED")
+    cb:RegisterEvent("UNIT_SPELLCAST_INTERRUPTED")
+    cb:RegisterEvent("UNIT_SPELLCAST_DELAYED")
+    cb:RegisterEvent("UNIT_SPELLCAST_SUCCEEDED")
+    cb:RegisterEvent("UNIT_SPELLCAST_CHANNEL_START")
+    cb:RegisterEvent("UNIT_SPELLCAST_CHANNEL_STOP")
+    cb:RegisterEvent("UNIT_SPELLCAST_CHANNEL_UPDATE")
+    if unitstr == "target" then
+      cb:RegisterEvent("PLAYER_TARGET_CHANGED")
+    elseif unitstr == "focus" then
+      cb:RegisterEvent("PLAYER_FOCUS_CHANGED")
     end
 
     cb:SetScript("OnEvent", function()
@@ -333,83 +345,33 @@ pfUI:RegisterModule("castbar", function ()
         return
       end
 
-      if event == "SPELL_START_OTHER" then
-        -- arg3=casterGuid. Defer one frame so ClassicAPI's UnitChannelInfo
-        -- can see the engine's +0x228 broadcast for remote-unit channels
-        -- (the cohook+packet handler runs in the same frame; the broadcast
-        -- propagates after).
-        if arg3 == UnitGUID(unit) then
-          local target = this
-          RunNextFrame(function() RefreshBar(target) end)
-        end
+      -- UNIT_SPELLCAST_* fire per unit token (arg1). Handle an event when it's
+      -- for this bar's unit, or -- since the player's own casts only ever fire
+      -- arg1=="player" -- when this bar's unit currently resolves to the player
+      -- (target=self / focus=self).
+      -- Args: arg1=unit, arg2=castGUID, arg3=spellID, arg4=name, arg5=rank.
+      if arg1 ~= unit and not (arg1 == "player" and UnitIsUnit(unit, "player")) then
         return
       end
 
-      if event == "SPELL_FAILED_OTHER" then
-        if arg1 == UnitGUID(unit) then ClearBar(this) end
-        return
-      end
-
-      -- Vanilla SPELLCAST_* + SPELL_DELAYED_SELF fire only for the local
-      -- player. Non-player bars handle them only when their unit currently
-      -- resolves to the player (target=self / focus=self).
-      if not UnitIsUnit(unit, 'player') then return end
-
-      if event == "SPELLCAST_START" or event == "SPELLCAST_CHANNEL_START" then
+      if event == "UNIT_SPELLCAST_START" or event == "UNIT_SPELLCAST_CHANNEL_START" then
+        -- START also fires per craft in a same-spell chain, so an active merge
+        -- just resyncs the current craft's spark/label instead of restamping.
         if this.tradeskillTotal then
-          -- Mid-chain craft N+1 of N. Keep the merged bar; resync the spark
-          -- to the new craft's start and refresh the "(N)" count label.
           StartTradeskillCraft(this)
         else
-          RefreshBar(this)
+          RefreshBar(this, arg5)
           if this.isTradeskill and (this.pendingTradeskillCount or 0) > 1
               and C.castbar.player.mergetradeskill == "1" then
             EnterTradeskillMerge(this, this.startTime, this.endTime, this.pendingTradeskillCount)
           end
           this.pendingTradeskillCount = nil
         end
-      elseif event == "SPELL_START_SELF" then
-        -- Catches chained same-spell recasts (no SPELLCAST_START fires) —
-        -- including tradeskill chaining where craft 2..N reuse one spell.
-        -- Defer one frame so ClassicAPI's SMSG_SPELL_START co-hook has
-        -- stamped g_cast before we poll, regardless of co-hook order.
-        if this.tradeskillTotal then
-          StartTradeskillCraft(this)
-        else
-          local target = this
-          RunNextFrame(function()
-            -- Re-check: SPELL_START_SELF (nampower co-hook) fires before vanilla
-            -- SPELLCAST_START on the same packet, so SPELLCAST_START may have
-            -- entered merge in this same frame. Don't restamp over it.
-            if target.tradeskillTotal then
-              StartTradeskillCraft(target)
-              return
-            end
-            RefreshBar(target)
-            if target.unitstr == "player" and target.isTradeskill
-                and (target.pendingTradeskillCount or 0) > 1
-                and C.castbar.player.mergetradeskill == "1" then
-              EnterTradeskillMerge(target, target.startTime, target.endTime, target.pendingTradeskillCount)
-            end
-            target.pendingTradeskillCount = nil
-          end)
-        end
-      elseif event == "SPELLCAST_CHANNEL_STOP" then
-        -- A channel's stop can arrive after a following cast already claimed
-        -- the bar (channel->cast transition); only clear if a channel is
-        -- actually being shown, so it doesn't wipe an active cast bar.
-        if this.isChannel then ClearBar(this) end
-      elseif event == "SPELLCAST_STOP" then
-        -- During a tradeskill chain, SPELL_GO_SELF already counted this craft
-        -- and either cleared the bar (chain done) or kept it running. Only a
-        -- non-merge cast clears here.
-        if not this.tradeskillTotal then ClearBar(this) end
-      elseif event == "SPELLCAST_FAILED" or event == "SPELLCAST_INTERRUPTED" then
-        ClearBar(this)
-      elseif event == "SPELL_GO_SELF" then
-        -- arg2 = spellId. In a tradeskill merge, count each successful craft
-        -- and clear when the chain is done.
-        if this.tradeskillTotal and arg2 == this.tradeskillSpellID then
+      elseif event == "UNIT_SPELLCAST_SUCCEEDED" then
+        -- Per-craft completion during a tradeskill merge (arg3 = spellID):
+        -- count and clear when the chain is done. A no-op for normal casts,
+        -- which are cleared by UNIT_SPELLCAST_STOP.
+        if this.tradeskillTotal and arg3 == this.tradeskillSpellID then
           this.tradeskillCompleted = (this.tradeskillCompleted or 0) + 1
           if this.tradeskillCompleted >= this.tradeskillTotal then
             ClearBar(this)
@@ -417,33 +379,46 @@ pfUI:RegisterModule("castbar", function ()
             UpdateTradeskillLabel(this)
           end
         end
-      elseif event == "SPELL_DELAYED_SELF" then
-        -- Cast pushback. nampower's event carries the delay (arg2); apply it
-        -- locally rather than re-polling, so the bar doesn't depend on
-        -- ClassicAPI's SMSG_SPELL_DELAYED co-hook having bumped g_cast before
-        -- this fires (co-hook order vs nampower is not guaranteed).
-        if not this.endTime or not arg2 then return end
-        local delayMs = tonumber(arg2) or 0
-        if delayMs > 0 then
-          this.delay = (this.delay or 0) + delayMs / 1000
-          this.endTime = this.endTime + delayMs
-          local newDuration = (this.endTime - this.startTime) / 1000
-          this.bar:SetMinMaxValues(0, newDuration)
-          this.lastMax = newDuration
-        end
-      elseif event == "SPELLCAST_CHANNEL_UPDATE" then
-        -- Channel pushback. ClassicAPI doesn't track channel delay in
-        -- g_channel, so we adjust endTime + delay locally and resize the
-        -- bar so OnUpdate animates against the new total.
-        if not this.endTime or not arg1 then return end
-        local newEndMs = GetTime() * 1000 + arg1
-        local diff = this.endTime - newEndMs
-        if diff > 50 then
-          this.delay = (this.delay or 0) + diff / 1000
-          this.endTime = newEndMs
-          local newDuration = (this.endTime - this.startTime) / 1000
-          this.bar:SetMinMaxValues(0, newDuration)
-          this.lastMax = newDuration
+      elseif event == "UNIT_SPELLCAST_CHANNEL_STOP" then
+        -- A channel's stop can arrive after a following cast already claimed
+        -- the bar (channel->cast transition); only clear if a channel is
+        -- actually being shown, so it doesn't wipe an active cast bar.
+        if this.isChannel then ClearBar(this) end
+      elseif event == "UNIT_SPELLCAST_STOP" then
+        -- STOP fires between crafts in a merge too (each craft is a new cast);
+        -- UNIT_SPELLCAST_SUCCEEDED owns the count, so only a non-merge cast
+        -- clears here.
+        if not this.tradeskillTotal then ClearBar(this) end
+      elseif event == "UNIT_SPELLCAST_FAILED" or event == "UNIT_SPELLCAST_INTERRUPTED" then
+        ClearBar(this, true)
+      elseif event == "UNIT_SPELLCAST_DELAYED" or event == "UNIT_SPELLCAST_CHANNEL_UPDATE" then
+        -- Pushback: a cast delayed later or a channel shortened. Following
+        -- Quartz, re-poll just the times and accumulate the shift into a running
+        -- this.delay for the +/- indicator, rather than a full restamp (which
+        -- would reset that total and re-render icon/text). ClassicAPI moves
+        -- endMs (SpellDelayed_h bumps g_cast.endMs; the MSG_CHANNEL_UPDATE
+        -- co-hook rewrites g_channel.endMs) while startMs stays put, so we diff
+        -- endMs. delay is a positive magnitude; OnUpdate signs it "+" for casts
+        -- and "-" for channels. Skipped during a tradeskill merge.
+        if this.endTime and not this.tradeskillTotal then
+          local query = this.unitstr ~= "" and this.unitstr or this.unitname
+          local startMs, endMs
+          if this.isChannel then
+            local _, _, _, s, e = C_Spell.UnitChannelInfo(query)
+            startMs, endMs = s, e
+          else
+            local _, _, _, s, e = C_Spell.UnitCastingInfo(query)
+            startMs, endMs = s, e
+          end
+          if startMs and endMs then
+            local shift = this.isChannel and (this.endTime - endMs) or (endMs - this.endTime)
+            this.delay = (this.delay or 0) + shift / 1000
+            this.startTime = startMs
+            this.endTime = endMs
+            local newDuration = (endMs - startMs) / 1000
+            this.bar:SetMinMaxValues(0, newDuration)
+            this.lastMax = newDuration
+          end
         end
       end
     end)
@@ -489,10 +464,10 @@ pfUI:RegisterModule("castbar", function ()
     UpdateMovable(pfUI.castbar.player)
 
     -- Tradeskill merge: hook DoTradeSkill so the player castbar knows the
-    -- requested count before the first SPELLCAST_START fires. Always-on hook
-    -- (the config knob is read at event time so toggling takes effect on the
-    -- next craft without a /reload). DoTradeSkill is synchronous; the server
-    -- roundtrip to SPELLCAST_START gives us plenty of time after this hook.
+    -- requested count before the first UNIT_SPELLCAST_START fires. Always-on
+    -- hook (the config knob is read at event time so toggling takes effect on
+    -- the next craft without a /reload). DoTradeSkill is synchronous; the
+    -- server roundtrip to UNIT_SPELLCAST_START gives us plenty of time.
     hooksecurefunc("DoTradeSkill", function(index, num)
       if pfUI.castbar.player then
         pfUI.castbar.player.pendingTradeskillCount = tonumber(num) or 1