Create a Metatable for UI elements.

assets/base/script/gui.lua

@@ -1,10 +1,51 @@
-local env = {}
+local env = { Gui = {}}
+local Gui = env.Gui
 setmetatable(env, {__index = _G})
 
-env.Gui = {}
+elem_mt = {
+    __index = function(elem, key)
+        -- Don't directly access the traits table.
+        if key == "traits" then return nil end
 
-local function create_gui_table(elem_type, data)
+        -- Attempt to get a value from the table, e.g. type, key, children, etc.
+        local val = rawget(elem, key)
+        -- Attempt to get a value from the metatable, e.g. a function.
+        if val == nil then val = rawget(getmetatable(elem), key) end
+        -- Attempt to get a value from the traits array.
+        if val == nil then val = rawget(rawget(elem, "traits"), key) end
+
+        return val
+    end,
+
+    __newindex = function(elem, key, val)
+        if key == "type" or key == "key" or key == "callbacks" then rawset(elem, key, val) end
+        rawset(rawget(elem, "traits"), key, val)
+    end,
+
+    get = function(tbl, key)
+        if type(key) == number then return rawget(tbl, "children")[key] end
+
+        for _,v in pairs(rawget(tbl, "children")) do
+            if v == key then return v end
+        end
+    end,
+
+    append = function(tbl, elem)
+        if type(elem) == "function" then elem = zepha.build_ui(elem) end
+        table.insert(rawget(tbl, "children"), elem)
+    end,
+
+    prepend = function(tbl, elem)
+        if type(elem) == "function" then elem = zepha.build_ui(elem) end
+        table.insert(rawget(tbl, "children"), 0, elem)
+    end,
+}
+
+-- create_element
+-- Build a GUI Element with the provided constructor data, apply the metatable.
+local function create_element(elem_type, data)
     local element = {}
+
     element.type = elem_type
     element.children = {}
     element.callbacks = {}
@@ -23,21 +64,31 @@ local function create_gui_table(elem_type, data)
         end
     end
 
+    setmetatable(element, elem_mt)
     return element
 end
 
-env.Gui.Body          = function(data) return create_gui_table("body", data) end
-env.Gui.Rect          = function(data) return create_gui_table("rect", data) end
-env.Gui.Text          = function(data) return create_gui_table("text", data) end
-env.Gui.Model         = function(data) return create_gui_table("model", data) end
-env.Gui.Button        = function(data) return create_gui_table("button", data) end
-env.Gui.InventoryList = function(data) return create_gui_table("inventory_list", data) end
+-- register_element
+-- Add an element to the Gui namespace.
+local function register_element(key)
+    if type(key) == "table" then
+        for _,v in pairs(key) do register_element(v) end
+        return
+    end
+    Gui[key] = function(data) return create_element(key, data) end
+end
 
+register_element({"Body", "Rect", "Text", "Model", "Button", "InventoryList"})
+
+-- pc
+-- Formats a number to be a percent string.
 env.pc = function(num)
     return tostring(num) .. "%"
 end
 
-zepha.create_menu = function(fn)
+-- zepha.build_ui
+-- Allows you to Build UI Elements with the GUI namespace outside of a callback.
+zepha.build_gui = function(fn)
     setfenv(fn, env)
     return fn()
 end

src/game/hud/GameGuiBuilder.cpp

@@ -14,7 +14,7 @@ std::shared_ptr<GuiComponent> GameGuiBuilder::createComponent(const SerialGui::E
 
     switch (Util::hash(elem.type.c_str())) {
         default: break;
-        case Util::hash("inventory_list"): {
+        case Util::hash("InventoryList"): {
             c = GuiInventoryList::fromSerialized(elem, defs, bounds, refs);
             break;
         }

src/game/hud/GuiBuilder.cpp

@@ -120,22 +120,22 @@ std::shared_ptr<GuiComponent> GuiBuilder::createComponent(const SerialGui::Eleme
 
     switch (Util::hash(elem.type.c_str())) {
         default: break;
-        case Util::hash("body"): {
+        case Util::hash("Body"): {
             auto body = GuiRect::fromSerialized(elem, textures, bounds);
             body->setScale(bounds);
             c = body;
             break;
         }
-        case Util::hash("rect"):
+        case Util::hash("Rect"):
             c = GuiRect::fromSerialized(elem, textures, bounds);
             break;
-        case Util::hash("button"):
+        case Util::hash("Button"):
             c = GuiImageButton::fromSerialized(elem, textures, bounds);
             break;
-        case Util::hash("text"):
+        case Util::hash("Text"):
             c = GuiText::fromSerialized(elem, textures, bounds);
             break;
-        case Util::hash("model"):
+        case Util::hash("Model"):
             c = GuiModel::fromSerialized(elem, textures, models, bounds);
             break;
     }

subgames/minimal/menu/script/main.lua

@@ -1,4 +1,4 @@
-local menu = zepha.create_menu(function()
+local menu = zepha.build_gui(function()
      return Gui.Body {
          background = "#214a21",
 

subgames/parentheses/menu/script/main.lua

@@ -1,4 +1,4 @@
-zepha.set_gui(zepha.create_menu(function()
+zepha.set_gui(zepha.build_gui(function()
     return Gui.Body {
         background = "#124778",
 

subgames/zeus/menu/script/main.lua

@@ -1,4 +1,4 @@
-zepha.set_gui(zepha.create_menu(function()
+zepha.set_gui(zepha.build_gui(function()
     return Gui.Body {
         background = "zeus_background",
 

subgames/zeus/mods/zeus_default/script/entity/bee.venus

@@ -1,5 +1,3 @@
-local friendly = false
-
 zepha.register_entity("zeus:default:bee", {
     display = "model",
     display_object = "zeus:default:bee",
@@ -13,6 +11,7 @@ zepha.register_entity("zeus:default:bee", {
 
         self.object.anims:set_anim("fly"):play()
     },
+
     on_update = (self, delta) => {
         self.object.pos = self.object.pos +
             V(0.03 * math.sin(math.rad(self.object.yaw + 90)), 0, 0.03 * math.cos(math.rad(self.object.yaw + 90)))

subgames/zeus/mods/zeus_inventory/script/menu.lua

@@ -1,4 +1,4 @@
-local menu = zepha.create_menu(function()
+local menu = zepha.build_gui(function()
     return Gui.Body {
         background = "#0003",