Add UI-agnostic button abstraction and new Finalize API

Phase 1 of UI abstraction: Create ActionButton() and EditorButton() wrappers
that work in both Chili and RmlUi modes without editors knowing which mode.

New files:
- ui_controls.lua: ActionButton() and EditorButton() functions
  - Detect mode via IsRmlUiMode()
  - Return Chili buttons OR RmlUi wrappers transparently
  - Editors use these instead of TabbedPanelButton/Button:New directly

Editor changes:
- Finalize() now accepts layout options: {actionButtons = {...}}
  - Old API still works: Finalize(children, opts) for compatibility
  - New API: Finalize({actionButtons = {btn1, btn2}}, opts)
  - Automatically builds ScrollPanel in Chili mode
  - Automatically generates button HTML in RmlUi mode

New implementation methods:
- _FinalizeRmlUiNew(layout, opts): RmlUi mode with new API
- _FinalizeChiliNew(layout, opts): Chili mode with new API
- _FinalizeChiliWindow(children, opts): Extracted for old API

Updated editors:
- heightmap_editor.lua: Now uses ActionButton() and new Finalize API

Editors are now UI-agnostic - no "if RmlUi then" checks needed!
Next: Update remaining 7 simple editors to use new API.

Author: claude

scen_edit/view/editor.lua

@@ -97,7 +97,7 @@ end
 
 --- Called at the end of :init(), to finalize the UI
 --- Override.
--- @tparam table children List of Chili controls.
+-- @tparam table layout Layout options (UI-agnostic) or old-style children array
 -- @tparam table opts Editor options
 -- @tparam[opt=false] boolean opts.notMainWindow If true,
 --   editor will not be added to the main panel (right side), but will instead be a floating window.
@@ -107,23 +107,51 @@ end
 --  Values include "ok", "cancel" and "close"
 -- @tparam boolean opts.disposeOnClose If true, the window will
 --   be disposed when closed. Defaults to true if opts.notMainWindow is true, otherwise it defaults to false.
-function Editor:Finalize(children, opts)
+function Editor:Finalize(layout, opts)
     if not self.__initializing then
         Log.Error("\"Editor.init(self)\" wasn't invoked properly.")
         Log.Error(debug.traceback())
         assert(self.__initializing, "\"Editor.init(self)\" wasn't invoked properly.")
     end
 
+    -- Support old API: if layout is an array, treat it as old-style children array
+    local isOldAPI = layout and #layout > 0
+    if isOldAPI then
+        -- Old API compatibility: Finalize(children, opts)
+        local children = layout
+        opts = opts or {}
+
+        if SB.view and SB.view.useRmlUi then
+            self:_FinalizeRmlUi(children, opts)
+            self.__initializing = false
+            return
+        end
+
+        -- Continue with old Chili mode path
+        self:_FinalizeButtons(children, opts)
+        self:_FinalizeChiliWindow(children, opts)
+        self.__initializing = false
+        return
+    end
+
+    -- New API: Finalize({actionButtons = {...}}, opts)
+    layout = layout or {}
     opts = opts or {}
 
-    -- In RmlUi mode, generate RML from fields instead of creating Chili controls
+    -- In RmlUi mode, generate RML from fields and buttons
     if SB.view and SB.view.useRmlUi then
-        self:_FinalizeRmlUi(children, opts)
+        self:_FinalizeRmlUiNew(layout, opts)
         self.__initializing = false
         return
     end
 
-    -- Chili mode continues below
+    -- New Chili mode path
+    self:_FinalizeChiliNew(layout, opts)
+    self.__initializing = false
+end
+
+-- Old Chili mode path (extracted for old API compatibility)
+function Editor:_FinalizeChiliWindow(children, opts)
     self:_FinalizeButtons(children, opts)
 
     local OnShow = {function() self:__OnShow() end}
@@ -846,6 +874,79 @@ function Editor:_FinalizeRmlUi(children, opts)
     self.hidden = true
 end
 
+-- New RmlUi finalization (new API with layout options)
+function Editor:_FinalizeRmlUiNew(layout, opts)
+    self.actionButtons = layout.actionButtons or {}
+    self.regularButtons = {}
+
+    -- Generate RML for action buttons (placed at top)
+    local buttonsHtml = ''
+    if #self.actionButtons > 0 then
+        buttonsHtml = '<div class="action-buttons-panel">'
+        for _, button in ipairs(self.actionButtons) do
+            buttonsHtml = buttonsHtml .. button:GenerateRml()
+        end
+        buttonsHtml = buttonsHtml .. '</div>'
+    end
+
+    -- Generate RML for all fields
+    local fieldsHtml = ''
+    for _, fieldName in ipairs(self.fieldOrder) do
+        local field = self.fields[fieldName]
+        if field and not field._isGroupChild then
+            if field.GenerateRml then
+                fieldsHtml = fieldsHtml .. field:GenerateRml()
+            else
+                -- Check if it's a control with a button inside
+                if field.ctrl and field.ctrl.GenerateRml then
+                    fieldsHtml = fieldsHtml .. field.ctrl:GenerateRml()
+                    table.insert(self.regularButtons, field.ctrl)
+                end
+            end
+        end
+    end
+
+    -- Combine buttons and fields
+    self.generatedRml = buttonsHtml .. fieldsHtml
+
+    -- Mark as hidden by default
+    self.hidden = true
+end
+
+-- New Chili finalization (new API with layout options)
+function Editor:_FinalizeChiliNew(layout, opts)
+    local actionButtons = layout.actionButtons or {}
+    local customControls = layout.customControls or {}
+
+    -- Build children array for Chili
+    local children = {}
+
+    -- Add action buttons first
+    for _, btn in ipairs(actionButtons) do
+        table.insert(children, btn)
+    end
+
+    -- Add custom controls if provided
+    for _, ctrl in ipairs(customControls) do
+        table.insert(children, ctrl)
+    end
+
+    -- Add ScrollPanel with fields
+    local yPos = #actionButtons > 0 and 70 or 0
+    table.insert(children, ScrollPanel:New {
+        x = 0,
+        y = yPos,
+        bottom = 30,
+        right = 0,
+        borderColor = {0,0,0,0},
+        horizontalScrollbar = false,
+        children = { self.stackPanel },
+    })
+
+    -- Use the old Chili window creation
+    self:_FinalizeChiliWindow(children, opts)
+end
+
 -- Show the editor in RmlUi mode
 function Editor:ShowRmlUi()
     self.hidden = false

scen_edit/view/map/heightmap_editor.lua

@@ -38,7 +38,7 @@ function HeightmapEditor:init()
         end
     }))
 
-    self.btnAddState = TabbedPanelButton({
+    self.btnAddState = ActionButton({
         x = 0,
         y = 0,
         tooltip = "Left Click to add height, Right Click to remove height",
@@ -53,7 +53,7 @@ function HeightmapEditor:init()
         },
     })
 
-    self.btnSetState = TabbedPanelButton({
+    self.btnSetState = ActionButton({
         x = 70,
         y = 0,
         tooltip = "Left Click to set height. Right click to sample height",
@@ -68,7 +68,7 @@ function HeightmapEditor:init()
         },
     })
 
-    self.btnSmoothState = TabbedPanelButton({
+    self.btnSmoothState = ActionButton({
         x = 140,
         y = 0,
         tooltip = "Click to smooth terrain",
@@ -89,7 +89,7 @@ function HeightmapEditor:init()
     })
 
     self:AddControl("btn-show-elevation", {
-        Button:New {
+        EditorButton {
             caption = "Show elevation",
             width = 200,
             height = 40,
@@ -139,22 +139,13 @@ function HeightmapEditor:init()
     self:Update("size")
     self:SetInvisibleFields("applyDir")
 
-    local children = {
-        self.btnAddState,
-        self.btnSetState,
-        self.btnSmoothState,
-        ScrollPanel:New {
-            x = 0,
-            y = 70,
-            bottom = 30,
-            right = 0,
-            borderColor = {0,0,0,0},
-            horizontalScrollbar = false,
-            children = { self.stackPanel },
-        },
-    }
-
-    self:Finalize(children)
+    self:Finalize({
+        actionButtons = {
+            self.btnAddState,
+            self.btnSetState,
+            self.btnSmoothState,
+        }
+    })
 end
 
 function HeightmapEditor:OnLeaveState(state)

scen_edit/view/ui_controls.lua

@@ -0,0 +1,58 @@
+-- UI-agnostic control wrappers for editors
+-- Editors should use these instead of Chili components directly
+-- These create Chili controls OR RmlUi wrappers depending on mode
+
+-- Detect if RmlUi mode is active
+local function IsRmlUiMode()
+    return SB.view and SB.view.useRmlUi
+end
+
+-- ActionButton - replacement for TabbedPanelButton
+-- Used for editor action buttons like "Add", "Set", "Smooth", "Paint", etc.
+function ActionButton(opts)
+    if IsRmlUiMode() then
+        -- Extract caption and image from children (Chili pattern)
+        local caption = ""
+        local image = nil
+        if opts.children then
+            for _, child in ipairs(opts.children) do
+                if child.caption then
+                    caption = child.caption
+                elseif child.file then
+                    image = child.file
+                end
+            end
+        end
+
+        return RmlUiTabbedPanelButton({
+            x = opts.x,
+            y = opts.y,
+            tooltip = opts.tooltip or "",
+            OnClick = opts.OnClick or {},
+            caption = caption,
+            image = image,
+        })
+    else
+        -- Chili mode - use original TabbedPanelButton
+        return TabbedPanelButton(opts)
+    end
+end
+
+-- EditorButton - replacement for Button:New in AddControl
+-- Used for regular buttons like "Show elevation", "Compile", etc.
+function EditorButton(opts)
+    if IsRmlUiMode() then
+        return RmlUiButton({
+            caption = opts.caption or "Button",
+            OnClick = opts.OnClick or {},
+            width = opts.width,
+            height = opts.height,
+            tooltip = opts.tooltip,
+        })
+    else
+        -- Chili mode - use original Button
+        return Button:New(opts)
+    end
+end
+
+Log.Notice("UI controls abstraction layer loaded")

scen_edit/view/view.lua

@@ -51,6 +51,7 @@ function View:InitializeRmlUi()
     SB.Include(Path.Join(SB.DIRS.SRC, 'view/rmlui_component.lua'))  -- Base class for components
     SB.Include(Path.Join(SB.DIRS.SRC, 'view/rmlui_fields.lua'))
     SB.Include(Path.Join(SB.DIRS.SRC, 'view/rmlui_field_compat.lua'))  -- Makes StringField() etc work
+    SB.Include(Path.Join(SB.DIRS.SRC, 'view/ui_controls.lua'))  -- ActionButton(), EditorButton()
 
     -- Load main UI template
     local rmlPath = Path.Join(SB.DIRS.SRC, 'view/rml/springboard_main.rml')
@@ -174,6 +175,9 @@ function View:SetupRmlUiEvents()
 end
 
 function View:InitializeChili()
+    -- Load UI controls abstraction (ActionButton, EditorButton)
+    SB.Include(Path.Join(SB.DIRS.SRC, 'view/ui_controls.lua'))
+
     self.tabbedWindow = TabbedWindow()
     self.bottomBar = BottomBar()
     self.teamSelector = TeamSelector()