feat(editbox): ClearHistory

Empties the up/down input history. The engine's SetHistoryLines internal
(FUN_0077cd90) frees the whole history ring when called with 0, so clear =
free (0) then reallocate at the saved max — dropping every entry and resetting
the write position while keeping the line limit, so the box keeps recording
afterward (matching modern semantics, not "history disabled"). No-op when the
box has no history.

New offsets: OFF_EDITBOX_HISTORY_MAX (+0x388, the ring capacity GetHistoryLines
reads), FUN_EDITBOX_SET_HISTORY_MAX.

Verified in-game: AddHistoryLine + ClearHistory leaves GetHistoryLines
unchanged and the up-arrow history empty; new lines still record.

Author: brues-code

README.md

@@ -67,7 +67,7 @@ reference in **[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`, `region:IsMouseOver`, `region:GetRect`, `region:IsDragging`, `GetMouseFoci`, `frame:SetShown`, `fontstring:GetStringHeight`, `fontstring:GetUnboundedStringWidth`, `fontstring:GetWrappedWidth`, `fontstring:GetNumLines`, `fontstring:GetLineHeight`, `fontstring:IsTruncated`, `fontstring:SetMaxLines`, `fontstring:GetMaxLines`, `fontstring:SetFormattedText`, `texture:SetRotation`, `texture:GetRotation`, `texture:SetVertexOffset`, `texture:GetVertexOffset`, `texture:SetColorTexture`, `texture:SetMask`, `frame:CreateMaskTexture`, `texture:AddMaskTexture`, `texture:RemoveMaskTexture`, `texture:GetNumMaskTextures`, `texture:GetMaskTexture`, `fontstring:SetRotation`, `fontstring:GetRotation`, `editBox:SetCursorPosition`, `editBox:GetCursorPosition`, `editBox:GetUTF8CursorPosition`, `editBox:ClearHighlightText`, `editBox:HasFocus`, `editBox:HasText`, `editBox:SetHighlightColor`, `editBox:GetHighlightColor`, `frame:SetResizeBounds`, `frame:HookScript`, `frame:IsEventRegistered`, `frame:GetEffectiveAlpha`, `frame:SetAttribute`, `frame:SetAttributeNoHandler`, `frame:ClearAttribute`, `frame:GetAttribute`, `OnAttributeChanged` (script), `SetModernScriptArgs`, `GetModernScriptArgs`, `PreClick` (script), `PostClick` (script), `GetClickFrame` |
+| [Frame](docs/API.md#frame) | `region:SetPoint("point")` (one-arg form), `region:SetSize`, `region:GetSize`, `region:IsMouseOver`, `region:GetRect`, `region:IsDragging`, `GetMouseFoci`, `frame:SetShown`, `fontstring:GetStringHeight`, `fontstring:GetUnboundedStringWidth`, `fontstring:GetWrappedWidth`, `fontstring:GetNumLines`, `fontstring:GetLineHeight`, `fontstring:IsTruncated`, `fontstring:SetMaxLines`, `fontstring:GetMaxLines`, `fontstring:SetFormattedText`, `texture:SetRotation`, `texture:GetRotation`, `texture:SetVertexOffset`, `texture:GetVertexOffset`, `texture:SetColorTexture`, `texture:SetMask`, `frame:CreateMaskTexture`, `texture:AddMaskTexture`, `texture:RemoveMaskTexture`, `texture:GetNumMaskTextures`, `texture:GetMaskTexture`, `fontstring:SetRotation`, `fontstring:GetRotation`, `editBox:SetCursorPosition`, `editBox:GetCursorPosition`, `editBox:GetUTF8CursorPosition`, `editBox:ClearHighlightText`, `editBox:HasFocus`, `editBox:HasText`, `editBox:SetHighlightColor`, `editBox:GetHighlightColor`, `editBox:ClearHistory`, `frame:SetResizeBounds`, `frame:HookScript`, `frame:IsEventRegistered`, `frame:GetEffectiveAlpha`, `frame:SetAttribute`, `frame:SetAttributeNoHandler`, `frame:ClearAttribute`, `frame:GetAttribute`, `OnAttributeChanged` (script), `SetModernScriptArgs`, `GetModernScriptArgs`, `PreClick` (script), `PostClick` (script), `GetClickFrame` |
 | [FriendList](docs/API.md#friendlist) | `C_FriendList.GetFriendInfo`, `C_FriendList.GetFriendInfoByIndex`, `C_FriendList.GetNumFriends`, `C_FriendList.GetNumOnlineFriends`, `C_FriendList.GetNumWhoResults`, `C_FriendList.GetWhoInfo`, `C_FriendList.IsFriend`, `C_FriendList.IsIgnored`, `C_FriendList.IsIgnoredByGuid`, `C_FriendList.IsWhoQueryPending`, `C_FriendList.SendWhoQueryByName`, `C_FriendList.SetFriendNotes`, `C_FriendList.SetFriendNotesByIndex` |
 | [GameObject](docs/API.md#gameobject) | `C_GameObjectInfo.GetGameObjectInfoByID`, `C_GameObjectInfo.RequestLoadGameObjectByID`, `ClosestGameObjectPosition` |
 | [Glue](docs/API.md#glue) | `C_Glue.IsOnGlueScreen` |

docs/API.md

@@ -202,6 +202,7 @@ build instructions.
   - [`editBox:HasText()`](#editboxhastext)
   - [`editBox:SetHighlightColor(r, g, b [, a])`](#editboxsethighlightcolorr-g-b--a)
   - [`editBox:GetHighlightColor()`](#editboxgethighlightcolor)
+  - [`editBox:ClearHistory()`](#editboxclearhistory)
   - [`frame:SetResizeBounds(minWidth, minHeight [, maxWidth, maxHeight])`](#framesetresizeboundsminwidth-minheight--maxwidth-maxheight)
   - [`frame:HookScript(scriptType, handler)`](#framehookscriptscripttype-handler)
   - [`frame:IsEventRegistered(event)`](#frameiseventregisteredevent)
@@ -4699,6 +4700,12 @@ ChatFrameEditBox:SetHighlightColor(1, 0, 0)   -- red selection
 Returns the selection-highlight color as four numbers: `r, g, b, a`, each `0`
 to `1`.
 
+### `editBox:ClearHistory()`
+
+Removes every line from the up/down input history. The history line limit
+(`SetHistoryLines`) stays, so the box keeps recording new lines afterward.
+Does nothing when the box has no history.
+
 ### `frame:SetResizeBounds(minWidth, minHeight [, maxWidth, maxHeight])`
 
 The modern rename of vanilla's `SetMinResize` / `SetMaxResize` pair.

src/Offsets.h

@@ -7621,6 +7621,17 @@ enum Offsets {
     // the generic region color accessors. The blinking caret is a SEPARATE
     // region at +0x3d4, deliberately left alone.
     OFF_EDITBOX_HIGHLIGHT_REGION = 0x350,
+    // Input-history ring buffer: max lines (ring capacity) at +0x388 (what
+    // GetHistoryLines reads), write position at +0x38c, container
+    // {size@+0x390, alloc@+0x394, data@+0x398} of {char* text, int exec}
+    // entries. AddHistoryLine writes at +0x38c and advances modulo +0x388.
+    OFF_EDITBOX_HISTORY_MAX = 0x388,
+    // `void __thiscall(editbox, int maxLines)` — the SetHistoryLines internal
+    // (FUN_0077cd90). Reallocates the history ring to maxLines; maxLines == 0
+    // frees the whole buffer and zeroes the container. ClearHistory calls it
+    // with 0 then the saved max — empties every entry and resets the write
+    // position while keeping the limit (so recording still works after).
+    FUN_EDITBOX_SET_HISTORY_MAX = 0x0077cd90,
 
     // --- FontString measure internals (GetStringWidth icon fix + GetStringHeight) ---
     // CSimpleFontString::GetStringWidthInternal — `float(__fastcall)(fs /*ecx*/)`,

src/editbox/Methods.cpp

@@ -22,6 +22,7 @@
 //   HasFocus                                — does this box own keyboard focus
 //   HasText                                 — is the box non-empty
 //   Set/GetHighlightColor                   — the text-selection highlight color
+//   ClearHistory                            — empty the up/down input history
 //
 // The engine already stores and manipulates all of this; we just expose it.
 // Every method is registered on the EditBox method registry, so — like any
@@ -48,6 +49,7 @@ using CollapseSelection_t = void(__thiscall *)(void *editbox);
 using CountChars_t = int(__thiscall *)(void *editbox, int startByte, int byteCount);
 using RegionSetColor_t = void(__thiscall *)(void *region, const uint32_t *colorBGRA);
 using RegionGetColor_t = void(__thiscall *)(void *region, uint32_t *outBGRA);
+using SetHistoryMax_t = void(__thiscall *)(void *editbox, int maxLines);
 
 // A Lua color arg (0..1) clamped and scaled to a 0..255 byte, matching the
 // engine's own float->byte color conversion (truncating, like Texture's
@@ -197,6 +199,27 @@ int __fastcall Script_GetHighlightColor(void *L) {
     return 4;
 }
 
+// Empties the up/down input history, keeping the line limit so the box keeps
+// recording afterward. The engine's SetHistoryLines internal frees the whole
+// ring at max 0, so clear = free (0) then reallocate at the saved max — which
+// drops every entry and resets the write position. No-op when history was
+// never enabled (max 0).
+int __fastcall Script_ClearHistory(void *L) {
+    void *eb = Game::Lua::ResolveObject(L, 1);
+    if (eb == nullptr) {
+        Game::Lua::Error(L, "Usage: EditBox:ClearHistory()");
+        return 0;
+    }
+    const int max = Game::Read<int>(eb, Offsets::OFF_EDITBOX_HISTORY_MAX);
+    if (max > 0) {
+        auto setMax = reinterpret_cast<SetHistoryMax_t>(
+            Offsets::FUN_EDITBOX_SET_HISTORY_MAX);
+        setMax(eb, 0);
+        setMax(eb, max);
+    }
+    return 0;
+}
+
 const Game::Lua::FrameMethodEntry g_methods[] = {
     {"SetCursorPosition", &Script_SetCursorPosition},
     {"GetCursorPosition", &Script_GetCursorPosition},
@@ -206,6 +229,7 @@ const Game::Lua::FrameMethodEntry g_methods[] = {
     {"HasText", &Script_HasText},
     {"SetHighlightColor", &Script_SetHighlightColor},
     {"GetHighlightColor", &Script_GetHighlightColor},
+    {"ClearHistory", &Script_ClearHistory},
 };
 
 void RegisterLuaFunctions() {