Add Classic Era and Cata Classic API compatibility

- Add C_ActionBar.GetSpell fallback using GetActionInfo for versions without modern API
- Add C_ActionBar.IsAssistedCombatAction check to prevent errors on Classic
- Add fallback text for HUD_EDIT_MODE_COLLAPSE/EXPAND_OPTIONS global strings
- Extract editmodeui.blp for arrow textures in Classic versions

Fixes Lua errors on Classic Era (1.15.8) and Cata Classic (5.5.3).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: Tim

Core.lua

@@ -14,6 +14,7 @@ local API_COMPAT = {
     has_modern_spellbook = (C_SpellBook and C_SpellBook.GetNumSpellBookSkillLines ~= nil),
     has_legacy_spell_api = (_G.GetSpellBookItemInfo ~= nil and _G.GetNumSpellTabs ~= nil),
     has_assisted_combat = (C_AssistedCombat and C_AssistedCombat.IsAvailable ~= nil),
+    has_actionbar_getspell = (C_ActionBar and C_ActionBar.GetSpell ~= nil),
 }
 addon.api_compat = API_COMPAT
 
@@ -1563,6 +1564,11 @@ end
 function addon:update_assisted_combat_indicator(button, slot)
     if not slot then return end
 
+    -- Assisted Combat only exists in Retail & Anniversary
+    if not C_ActionBar or not C_ActionBar.IsAssistedCombatAction then
+        return
+    end
+
     local isAssistedCombat = C_ActionBar.IsAssistedCombatAction(slot)
 
     if isAssistedCombat then
@@ -1588,6 +1594,20 @@ function addon:update_assisted_combat_indicator(button, slot)
     end
 end
 
+-- Get spell ID from action slot (version-compatible)
+-- Retail & Anniversary have C_ActionBar.GetSpell, Cata Classic & Classic Era don't
+local function GetSpellFromActionSlot(slot)
+    if API_COMPAT.has_actionbar_getspell then
+        return C_ActionBar.GetSpell(slot)
+    else
+        local actionType, actionID = GetActionInfo(slot)
+        if actionType == "spell" then
+            return actionID
+        end
+    end
+    return nil
+end
+
 -- Handles processing for ACTIONBUTTON
 function addon:process_actionbutton_slot(slot, button)
     if not slot then return end
@@ -1605,7 +1625,7 @@ function addon:process_actionbutton_slot(slot, button)
             button.icon:Show()
 
             -- Store the spell ID if the action contains a spell
-            local spellID = C_ActionBar.GetSpell(adjusted_slot)
+            local spellID = GetSpellFromActionSlot(adjusted_slot)
             if spellID then
                 button.spellid = spellID
             end
@@ -1671,7 +1691,7 @@ function addon:process_multiactionbar_slot(bar, bar_button, button)
         button.icon:Show()
 
         -- Store the spell ID if the action contains a spell
-        local spellID = C_ActionBar.GetSpell(slot)
+        local spellID = GetSpellFromActionSlot(slot)
         if spellID then
             button.spellid = spellID
         end

Frames/Controls.lua

@@ -537,18 +537,26 @@ function addon:create_controls()
         end
     end
 
+    -- Fallback text for Classic versions that don't have these global strings
+    -- Inline texture format: |Tpath:height:width:xoffset:yoffset:texWidth:texHeight:left:right:top:bottom|t
+    -- EditModeUI.blp is 32x256, arrows are at pixel coords calculated from AtlasInfo
+    local ARROW_UP = "|TInterface\\AddOns\\KeyUI\\Media\\Atlas\\editmodeui:11:16:0:3:32:256:1:17:158:169|t"
+    local ARROW_DOWN = "|TInterface\\AddOns\\KeyUI\\Media\\Atlas\\editmodeui:11:16:0:-7:32:256:1:17:145:156|t"
+    local COLLAPSE_TEXT = HUD_EDIT_MODE_COLLAPSE_OPTIONS or ("Collapse options " .. ARROW_UP)
+    local EXPAND_TEXT = HUD_EDIT_MODE_EXPAND_OPTIONS or ("Expand options " .. ARROW_DOWN)
+
     -- Function to toggle the controls_expanded value
     local function toggle_controls_expanded()
         keyui_settings.controls_expanded = not keyui_settings.controls_expanded
 
         -- Update the expander text and controls visibility based on the new state
         if keyui_settings.controls_expanded then
-            controls_frame.expander_text:SetText(HUD_EDIT_MODE_COLLAPSE_OPTIONS)
+            controls_frame.expander_text:SetText(COLLAPSE_TEXT)
             controls_frame:SetHeight(350)
             set_controls_visibility(true)
             controls_frame.expander_text:SetPoint("CENTER", controls_frame, "BOTTOM", 0, 30)
         else
-            controls_frame.expander_text:SetText(HUD_EDIT_MODE_EXPAND_OPTIONS)
+            controls_frame.expander_text:SetText(EXPAND_TEXT)
             controls_frame:SetHeight(200)
             set_controls_visibility(false)
             controls_frame.expander_text:SetPoint("CENTER", controls_frame, "BOTTOM", 0, 30)
@@ -560,9 +568,9 @@ function addon:create_controls()
 
     -- Set the text based on controls_expanded value
     if keyui_settings.controls_expanded then
-        controls_frame.expander_text:SetText(HUD_EDIT_MODE_COLLAPSE_OPTIONS)
+        controls_frame.expander_text:SetText(COLLAPSE_TEXT)
     else
-        controls_frame.expander_text:SetText(HUD_EDIT_MODE_EXPAND_OPTIONS)
+        controls_frame.expander_text:SetText(EXPAND_TEXT)
     end
 
     controls_frame.expander_text:SetFont(addon:GetFont(), addon:GetFontSize(1.0))