frame: add Frame:IsEventRegistered

Vanilla has RegisterEvent / UnregisterEvent as frame methods but not the
query IsEventRegistered (added in a later expansion). There's no engine
Script_* to delegate to, so we replicate the membership check already
embedded in Frame::RegisterEvent (FUN_00702140): find the event by name
in the live event table (SStrCmpI), then walk that entry's subscriber
chain (head@+0xC, next@+4, frame@+8, low-bit/null sentinel) for this
frame. self is resolved via Game::Lua::ResolveObject, yielding the same
CFrameScriptObject* the chain stores.

Registered on the Frame method registry (VAR_FRAME_METHOD_REGISTRY,
alongside RegisterEvent) so it resolves on any frame. Pure read, no new
hooks. Returns a boolean, matching the 3.3.5-era contract; verified
in-game (true for a registered event, false otherwise). Documented in
docs/API.md and README.md.

AddOns/!!!ClassicAPI/Util/TradeSkillLink.lua

@@ -11,12 +11,51 @@
 -- knows (with an "X of Y" summary of the whole skill line), regardless of what
 -- the reader can craft themselves.
 
--- Frame geometry mirrors the real TradeSkillFrame (Blizzard_TradeSkillUI):
--- 768x512, TW-TradeSkill quadrant art, 19 rows of 16px, list at (37,-98).
-local FRAME_W, FRAME_H = 768, 512;
-local NUM_ROWS   = 19;
+-- Frame geometry mirrors the real TradeSkillFrame. Turtle ships an HD
+-- 768x512 two-column frame (TW-TradeSkill art); stock 1.12.1 only has the
+-- vanilla 384x512 single-column art, so on that client we fall back to the
+-- native Blizzard_TradeSkillUI geometry (list on top, detail below) rather
+-- than stretch the wide art. LO holds every layout value that differs.
+local TURTLE     = (TURTLE_WOW_VERSION ~= nil);
+local FRAME_W    = TURTLE and 768 or 384;
+local FRAME_H    = 512;
+local NUM_ROWS   = TURTLE and 19 or 8;
 local ROW_HEIGHT = 16;
 
+local LO = TURTLE and {
+	hit     = { 2, 82, 2, 73 },
+	quads   = {
+		{ "Interface\\TradeSkillFrame\\TW-TradeSkill-TopLeft",   512, 256, "TOPLEFT" },
+		{ "Interface\\TradeSkillFrame\\TW-TradeSkill-TopRight",  256, 256, "TOPRIGHT" },
+		{ "Interface\\TradeSkillFrame\\TW-TradeSkill-BotLeft2",  512, 256, "BOTTOMLEFT" },
+		{ "Interface\\TradeSkillFrame\\TW-TradeSkill-BotRight2", 256, 256, "BOTTOMRIGHT" },
+	},
+	close   = { -77, -8 },
+	bar     = { 596, 15, 76, -44 },
+	barBdr  = { 604, 22 },
+	summary = { "TOPRIGHT", -110, -70 },
+	drop    = { 40, -60 },
+	scroll  = { 296, 330, 37, -98 },
+	detail  = { 379, -113 },
+	exit    = { "CENTER", "BOTTOMRIGHT", -128, 92 },
+} or {
+	hit     = { 0, 34, 0, 75 },
+	quads   = {
+		{ "Interface\\ClassTrainerFrame\\UI-ClassTrainer-TopLeft",  256, 256, "TOPLEFT" },
+		{ "Interface\\ClassTrainerFrame\\UI-ClassTrainer-TopRight", 128, 256, "TOPRIGHT" },
+		{ "Interface\\TradeSkillFrame\\UI-TradeSkill-BotLeft",      256, 256, "BOTTOMLEFT" },
+		{ "Interface\\ClassTrainerFrame\\UI-ClassTrainer-BotRight", 128, 256, "BOTTOMRIGHT" },
+	},
+	close   = { -29, -8 },
+	bar     = { 268, 15, 73, -37 },
+	barBdr  = { 278, 22 },
+	summary = { "TOPRIGHT", -40, -58 },
+	drop    = { 12, -62 },
+	scroll  = { 296, 130, 21, -96 },
+	detail  = { 28, -237 },
+	exit    = { "CENTER", "TOPLEFT", 305, -422 },
+};
+
 local PROFESSION_ICONS = {
 	[171] = "Trade_Alchemy",
 	[164] = "Trade_BlackSmithing",
@@ -32,7 +71,7 @@ local PROFESSION_ICONS = {
 	[356] = "Trade_Fishing",
 };
 
-if TURTLE_WOW_VERSION then
+if TURTLE then
 	PROFESSION_ICONS[142] = "Trade_Survival"
 	PROFESSION_ICONS[755] = "INV_Misc_Gem_01" -- Jewelcrafting
 end
@@ -188,7 +227,7 @@ local function CreateFrame_TradeSkillLink()
 	f:SetPoint("CENTER", 0, 0);
 	f:SetMovable(true);
 	f:EnableMouse(true);
-	f:SetHitRectInsets(2, 82, 2, 73);
+	f:SetHitRectInsets(LO.hit[1], LO.hit[2], LO.hit[3], LO.hit[4]);
 	f:RegisterForDrag("LeftButton");
 	f:SetScript("OnDragStart", function() this:StartMoving(); end);
 	f:SetScript("OnDragStop", function() this:StopMovingOrSizing(); end);
@@ -200,33 +239,30 @@ local function CreateFrame_TradeSkillLink()
 	portrait:SetPoint("TOPLEFT", 7, -6);
 	f.portrait = portrait;
 
-	local function Quad(file, w, h, point)
+	for i = 1, table.getn(LO.quads) do
+		local q = LO.quads[i];
 		local tx = f:CreateTexture(nil, "BORDER");
-		tx:SetTexture("Interface\\TradeSkillFrame\\" .. file);
-		tx:SetSize(w, h);
-		tx:SetPoint(point);
+		tx:SetTexture(q[1]);
+		tx:SetSize(q[2], q[3]);
+		tx:SetPoint(q[4]);
 	end
-	Quad("TW-TradeSkill-TopLeft",   512, 256, "TOPLEFT");
-	Quad("TW-TradeSkill-TopRight",  256, 256, "TOPRIGHT");
-	Quad("TW-TradeSkill-BotLeft2",  512, 256, "BOTTOMLEFT");
-	Quad("TW-TradeSkill-BotRight2", 256, 256, "BOTTOMRIGHT");
 
 	local title = f:CreateFontString(nil, "OVERLAY", "GameFontNormal");
 	title:SetPoint("TOP", 0, -18);
 	f.title = title;
 
 	local close = CreateFrame("Button", nil, f, "UIPanelCloseButton");
-	close:SetPoint("TOPRIGHT", -77, -8);
+	close:SetPoint("TOPRIGHT", LO.close[1], LO.close[2]);
 
 	local exit = CreateFrame("Button", nil, f, "UIPanelButtonTemplate");
 	exit:SetSize(80, 22);
-	exit:SetPoint("CENTER", f, "BOTTOMRIGHT", -128, 92);
+	exit:SetPoint(LO.exit[1], f, LO.exit[2], LO.exit[3], LO.exit[4]);
 	exit:SetText(EXIT or "Exit");
 	exit:SetScript("OnClick", function() f:Hide(); end);
 
 	local bar = CreateFrame("StatusBar", nil, f);
-	bar:SetSize(596, 15);
-	bar:SetPoint("TOPLEFT", 76, -44);
+	bar:SetSize(LO.bar[1], LO.bar[2]);
+	bar:SetPoint("TOPLEFT", LO.bar[3], LO.bar[4]);
 	bar:SetStatusBarTexture("Interface\\PaperDollInfoFrame\\UI-Character-Skills-Bar");
 	bar:SetStatusBarColor(0.0, 0.0, 1.0, 0.5);
 	bar:SetMinMaxValues(0, 1);
@@ -236,7 +272,7 @@ local function CreateFrame_TradeSkillLink()
 	barBg:SetVertexColor(0.0, 0.0, 0.75, 0.5);
 	-- Border: tooltip edge around the bar (TradeSkillRankFrameBorder).
 	local border = CreateFrame("Frame", nil, bar);
-	border:SetSize(604, 22);
+	border:SetSize(LO.barBdr[1], LO.barBdr[2]);
 	border:SetPoint("LEFT", -5, 1);
 	border:SetBackdrop({
 		edgeFile = "Interface\\Tooltips\\UI-Tooltip-Border", edgeSize = 16,
@@ -253,19 +289,19 @@ local function CreateFrame_TradeSkillLink()
 	f.barRank = barRank;
 
 	local summary = f:CreateFontString(nil, "OVERLAY", "GameFontHighlightSmall");
-	summary:SetPoint("TOPRIGHT", -110, -70);
+	summary:SetPoint(LO.summary[1], LO.summary[2], LO.summary[3]);
 	f.summary = summary;
 
 	local dropdown = CreateFrame("Frame", "ClassicAPITradeSkillLinkSubClass", f,
 		"UIDropDownMenuTemplate");
-	dropdown:SetPoint("TOPLEFT", 40, -60);
+	dropdown:SetPoint("TOPLEFT", LO.drop[1], LO.drop[2]);
 	f.dropdown = dropdown;
 	f.subclassFilter = nil; -- nil = all subclasses
 
 	local scroll = CreateFrame("ScrollFrame", "ClassicAPITradeSkillLinkScroll",
 		f, "FauxScrollFrameTemplate");
-	scroll:SetSize(296, 330);
-	scroll:SetPoint("TOPLEFT", 37, -98);
+	scroll:SetSize(LO.scroll[1], LO.scroll[2]);
+	scroll:SetPoint("TOPLEFT", LO.scroll[3], LO.scroll[4]);
 	scroll:SetScript("OnVerticalScroll", function()
 		FauxScrollFrame_OnVerticalScroll(ROW_HEIGHT, function() f:Refresh(); end)
 	end)
@@ -313,7 +349,7 @@ local function CreateFrame_TradeSkillLink()
 
 	local prodIcon = CreateFrame("Button", nil, f);
 	prodIcon:SetSize(37, 37);  -- TradeSkillSkillIcon is 37x37
-	prodIcon:SetPoint("TOPLEFT", 379, -113);
+	prodIcon:SetPoint("TOPLEFT", LO.detail[1], LO.detail[2]);
 	prodIcon:SetNormalTexture("Interface\\Icons\\INV_Misc_QuestionMark");
 	local hdrLeft = prodIcon:CreateTexture(nil, "BACKGROUND");
 	hdrLeft:SetTexture("Interface\\ClassTrainerFrame\\UI-ClassTrainer-DetailHeaderLeft");
@@ -620,3 +656,43 @@ function SetItemRef(link, text, button, chatFrame)
 	end
 	return originalSetItemRef(link, text, button, chatFrame);
 end
+
+local function CreateProfessionLinkButton(parentName, getLink)
+	local parent = _G[parentName];
+	local btnName = parentName .. "LinkButton";
+	if _G[btnName] or not parent then
+		return;
+	end
+	local btn = CreateFrame("Button", btnName, parent);
+	btn:SetSize(16, 16);
+	btn:SetPoint("LEFT", _G[parentName .. "TitleText"], "RIGHT", 4, 0);
+
+	local icon = "Interface\\GossipFrame\\PetitionGossipIcon";
+	btn:SetNormalTexture(icon);
+	btn:SetHighlightTexture(icon, "ADD");
+
+	btn:SetScript("OnClick", function()
+		local link = getLink();
+		if not link then
+			return;
+		end
+		if not ChatFrameEditBox:IsVisible() then
+			ChatFrameEditBox:Show();
+		end
+		ChatFrameEditBox:Insert(link);
+	end);
+	btn:SetScript("OnEnter", function()
+		GameTooltip:SetOwner(this, "ANCHOR_TOPLEFT");
+		GameTooltip:SetText(LINK_TRADESKILL_TOOLTIP, nil, nil, nil, nil, 1);
+		GameTooltip:Show();
+	end);
+	btn:SetScript("OnLeave", GameTooltip_Hide);
+end
+
+EventUtil.ContinueOnAddOnLoaded("Blizzard_TradeSkillUI", function()
+	CreateProfessionLinkButton("TradeSkillFrame", C_TradeSkillUI.GetTradeSkillListLink);
+end);
+
+EventUtil.ContinueOnAddOnLoaded("Blizzard_CraftUI", function()
+	CreateProfessionLinkButton("CraftFrame", C_TradeSkillUI.GetCraftListLink);
+end);

AddOns/!!!ClassicAPI/locales/enUS.lua

@@ -24,3 +24,4 @@ SLASH_EQUIP_SET2 = "/equipset";
 SLASH_FOCUS1 = "/focus";
 SLASH_FOCUS2 = "/focus";
 TARGETFOCUS = "Target Focus";
+LINK_TRADESKILL_TOOLTIP = "Click here to create a link to your profession.";

README.md

@@ -33,7 +33,7 @@ Full per-function reference: **[docs/API.md](docs/API.md)**.
 | [Expansion](docs/API.md#expansion) | `ClassicExpansionAtLeast`, `ClassicExpansionAtMost`, `GetClassicExpansionLevel` |
 | [Faction](docs/API.md#faction) | `C_Reputation.GetFactionDataByIndex`, `C_Reputation.GetFactionStandings`, `C_Reputation.GetLastStandingChange`, `C_Reputation.GetWatchedFactionData`, `C_Reputation.SetWatchedFactionByID`, `GetFactionIDByIndex`, `GetFactionInfoByID`, `GetFactionParentID` |
 | [Focus](docs/API.md#focus) | `ClearFocus`, `FocusUnit` |
-| [Frame](docs/API.md#frame) | `region:SetPoint("point")` (one-arg form), `region:SetSize`, `region:GetSize`, `frame:SetShown`, `frame:SetResizeBounds`, `frame:HookScript` |
+| [Frame](docs/API.md#frame) | `region:SetPoint("point")` (one-arg form), `region:SetSize`, `region:GetSize`, `frame:SetShown`, `frame:SetResizeBounds`, `frame:HookScript`, `frame:IsEventRegistered` |
 | [FriendList](docs/API.md#friendlist) | `C_FriendList.IsWhoQueryPending`, `C_FriendList.SendWhoQueryByName` |
 | [GameObject](docs/API.md#gameobject) | `C_GameObjectInfo.GetGameObjectInfoByID`, `C_GameObjectInfo.RequestLoadGameObjectByID` |
 | [Gossip](docs/API.md#gossip) | `C_GossipInfo.CloseGossip`, `C_GossipInfo.GetActiveQuests`, `C_GossipInfo.GetAvailableQuests`, `C_GossipInfo.GetNumActiveQuests`, `C_GossipInfo.GetNumAvailableQuests`, `C_GossipInfo.GetNumOptions`, `C_GossipInfo.GetOptions`, `C_GossipInfo.GetText`, `C_GossipInfo.SelectActiveQuest`, `C_GossipInfo.SelectAvailableQuest`, `C_GossipInfo.SelectOption`, `C_GossipInfo.SelectOptionByIndex` |

docs/API.md

@@ -137,6 +137,7 @@ build instructions.
   - [`frame:SetShown(shown)`](#framesetshownshown)
   - [`frame:SetResizeBounds(minWidth, minHeight [, maxWidth, maxHeight])`](#framesetresizeboundsminwidth-minheight--maxwidth-maxheight)
   - [`frame:HookScript(scriptType, handler)`](#framehookscriptscripttype-handler)
+  - [`frame:IsEventRegistered(event)`](#frameiseventregisteredevent)
 
 - [FriendList](#friendlist)
   - [`C_FriendList.SendWhoQueryByName(name)`](#c_friendlistsendwhoquerybynamename)
@@ -3143,6 +3144,22 @@ button:HookScript("OnEnter", function(self)
 end)
 ```
 
+### `frame:IsEventRegistered(event)`
+
+Vanilla ships `RegisterEvent` / `UnregisterEvent` but not the query.
+Returns `true` if the frame is currently registered for `event`,
+`false` otherwise (including for an unknown event name). Reuses the
+engine's own subscriber-chain membership check — the same walk
+`RegisterEvent` performs before appending — so the answer is exactly
+what the event dispatcher sees. Works on any frame.
+
+```lua
+local f = CreateFrame("Frame")
+f:RegisterEvent("PLAYER_LOGIN")
+f:IsEventRegistered("PLAYER_LOGIN")   -- true
+f:IsEventRegistered("PLAYER_LOGOUT")  -- false
+```
+
 ## FriendList
 
 ### `C_FriendList.SendWhoQueryByName(name)`

src/Offsets.h

@@ -3463,6 +3463,15 @@ enum Offsets {
     OFF_EVENT_ENTRY_NAME = 0x00,
     OFF_EVENT_ENTRY_HEAD = 0x0C,
 
+    // Subscriber-chain node layout — the linked list hanging off each
+    // entry's +0x0C head, derived from Frame::RegisterEvent
+    // (FUN_00702140): each node is `{ ?, next@+0x04, frame@+0x08 }`, where
+    // `frame` is the CFrameScriptObject* subscriber. A node value with its
+    // low bit set (or null) is the end/empty sentinel. Walked by
+    // Frame:IsEventRegistered to test membership.
+    OFF_EVENT_NODE_NEXT = 0x04,
+    OFF_EVENT_NODE_FRAME = 0x08,
+
     // `Frame::RegisterEvent` — the C++ helper called by the Lua
     // `frame:RegisterEvent(eventName)` method (`Script_RegisterEvent` at
     // `0x00774A40`). `__thiscall` with `(this=frame, eventName)`. Walks

src/frame/Modern.cpp

@@ -186,6 +186,65 @@ int __fastcall Script_HookScript(void *L) {
     return 0;
 }
 
+// ---- IsEventRegistered (Frame) ---------------------------------------------
+
+// `frame:IsEventRegistered("event")` — vanilla has RegisterEvent /
+// UnregisterEvent but not the query. There's no engine Script_* to
+// delegate to, so we replicate the membership check that lives inside
+// Frame::RegisterEvent (FUN_00702140): find the event by name in the live
+// event table, then walk that entry's subscriber chain for this frame.
+// The frame pointer we compare against is the same CFrameScriptObject*
+// the engine stores (Game::Lua::ResolveObject resolves self exactly as
+// Script_RegisterEvent does).
+using SStrCmpI_t = int(__stdcall *)(const char *a, const char *b, int n);
+
+bool FrameHasEvent(void *frame, const char *eventName) {
+    const uint32_t count = *reinterpret_cast<const uint32_t *>(
+        static_cast<uintptr_t>(Offsets::VAR_EVENT_TABLE_COUNT));
+    auto *base = *reinterpret_cast<const uint8_t *const *>(
+        static_cast<uintptr_t>(Offsets::VAR_EVENT_TABLE_BASE_PTR));
+    if (count == 0 || base == nullptr)
+        return false;
+
+    auto sstrcmpi = reinterpret_cast<SStrCmpI_t>(
+        static_cast<uintptr_t>(Offsets::FUN_SSTR_CMP_I));
+
+    for (uint32_t i = 0; i < count; ++i) {
+        const uint8_t *entry = base + i * Offsets::EVENT_ENTRY_STRIDE;
+        const char *name = *reinterpret_cast<const char *const *>(
+            entry + Offsets::OFF_EVENT_ENTRY_NAME);
+        if (name == nullptr)
+            continue;
+        if (sstrcmpi(name, eventName, 0x7FFFFFFF) != 0)
+            continue;
+        // Names are unique, so this is the one entry — walk its chain.
+        uintptr_t node = *reinterpret_cast<const uintptr_t *>(
+            entry + Offsets::OFF_EVENT_ENTRY_HEAD);
+        while ((node & 1) == 0 && node != 0) {
+            if (*reinterpret_cast<void *const *>(
+                    node + Offsets::OFF_EVENT_NODE_FRAME) == frame)
+                return true;
+            node = *reinterpret_cast<const uintptr_t *>(
+                node + Offsets::OFF_EVENT_NODE_NEXT);
+        }
+        return false;
+    }
+    return false;
+}
+
+int __fastcall Script_IsEventRegistered(void *L) {
+    if (!Game::Lua::IsString(L, 2)) {
+        Game::Lua::Error(L, "Usage: frame:IsEventRegistered(\"event\")");
+        return 0;
+    }
+    void *frame = Game::Lua::ResolveObject(L, 1);
+    const char *eventName = Game::Lua::ToString(L, 2);
+    const bool registered =
+        frame != nullptr && eventName != nullptr && FrameHasEvent(frame, eventName);
+    Game::Lua::PushBool(L, registered);
+    return 1;
+}
+
 // ---- SetPoint one-arg form (Script_SetPoint co-hook) -----------------------
 
 // Vanilla's Script_SetPoint accepts every modern form except the bare
@@ -222,6 +281,7 @@ const Game::Lua::FrameMethodEntry g_frameMethods[] = {
                                   Offsets::FUN_SCRIPT_FRAME_HIDE>},
     {"SetResizeBounds", &Script_SetResizeBounds},
     {"HookScript", &Script_HookScript},
+    {"IsEventRegistered", &Script_IsEventRegistered},
 };
 
 const Game::Lua::FrameMethodEntry g_textureMethods[] = {

src/spell/Cast.cpp

@@ -133,6 +133,26 @@ void StampChannel(int spellID, int startMs, int endMs) {
 
 int NowMs() { return static_cast<int>(reinterpret_cast<TickMs_t>(Offsets::FUN_OS_TICKCOUNT_MS)()); }
 
+// Pushes an engine-ms timestamp to Lua as an UNSIGNED 32-bit value.
+//
+// `FUN_OS_TICKCOUNT_MS` returns a 64-bit ms tick from one of two backends
+// (GetTickCount, or a scaled rdtsc — the latter survives warm reboots, so
+// the value can be well past 2^31 even right after a "restart"). We keep
+// ticks in a signed int internally, which is fine for the small deltas and
+// window compares (they cancel), but a direct int->double push surfaces a
+// NEGATIVE startTimeMs/endTimeMs once the tick's high bit is set.
+//
+// The contract is that these match `GetTime()*1000`. Script_GetTime
+// (0x00515EA0) does `(double)(tick & 0xFFFFFFFF) * 0.001` — i.e. it masks
+// the tick to the low 32 bits UNSIGNED, then scales. So reinterpreting our
+// stored tick as uint32 reproduces GetTime()'s exact value for the whole
+// range, including across the ~49.7-day 2^32 wrap (both wrap together).
+// Carrying 64-bit precision here would be WRONG: it would diverge from
+// GetTime() past 2^32 and break addons' (now-start)/(end-start) math.
+void PushMs(void *L, int ms) {
+    Game::Lua::PushNumber(L, static_cast<double>(static_cast<uint32_t>(ms)));
+}
+
 void *Resolve(const char *token) {
     return reinterpret_cast<ResolveUnitToken_t>(Offsets::FUN_RESOLVE_UNIT_TOKEN)(token);
 }
@@ -200,8 +220,8 @@ int PushCastInfo(void *L, const TrackedSpell &c) {
     Game::Lua::PushString(L, name);                          // 1 name
     Game::Lua::PushString(L, name);                          // 2 displayName
     Game::Lua::PushString(L, SpellIconPath(rec));            // 3 textureID (path)
-    Game::Lua::PushNumber(L, static_cast<double>(c.startMs)); // 4 startTimeMs
-    Game::Lua::PushNumber(L, static_cast<double>(c.endMs));   // 5 endTimeMs
+    PushMs(L, c.startMs);                                    // 4 startTimeMs
+    PushMs(L, c.endMs);                                      // 5 endTimeMs
     Game::Lua::PushBool(L, IsTradeskill(rec));               // 6 isTradeskill
     Game::Lua::PushNil(L);                                   // 7 castID
     Game::Lua::PushBool(L, false);                           // 8 notInterruptible
@@ -230,8 +250,8 @@ int PushChannelInfo(void *L, int spellID, int startMs, int endMs, bool haveTimes
     Game::Lua::PushString(L, name);                          // 2 text / displayName
     Game::Lua::PushString(L, SpellIconPath(rec));            // 3 textureID (path)
     if (haveTimes) {
-        Game::Lua::PushNumber(L, static_cast<double>(startMs)); // 4 startTimeMs
-        Game::Lua::PushNumber(L, static_cast<double>(endMs));   // 5 endTimeMs
+        PushMs(L, startMs);                                  // 4 startTimeMs
+        PushMs(L, endMs);                                    // 5 endTimeMs
     } else {
         Game::Lua::PushNil(L);
         Game::Lua::PushNil(L);