Fix models and buttons, and let containers handle inventories properly.

init.lua

@@ -362,27 +362,30 @@ local fs_model = {
             out[#out +1] = x:render()
         end
         out[#out +1] = string.format(
-            "model[%f,%f;%f,%f;%s;%s;%s;%f;%s;%s;%s;%f]",
+            "model[%f,%f;%f,%f;%s;%s;%s;%s;%s;%s;%s;%s]",
             x or get(e, "x"), y or get(e, "y"),
             w or get(e, "w"), h or get(e, "h"),
             e.__id,
             get(e, "mesh"), get(e, "textures"),
             get(e, "_rotation") or "", get(e, "_continuous") or "",
-            get(e, "_mouse_control"),
-            get(e, "_animation") or "", get(e, "_animation_speed")
+            get(e, "_mouse_control") or "",
+            get(e, "_animation") or "", get(e, "_animation_speed") or ""
         )
         return table.concat(out)
     end,
     rotation = function(e, rot, continuous)
         e._rotation = rot
         e._continuous = continuous
+        return e
     end,
     mouse_control = function(e, mouse_control)
         e._mouse_control = mouse_control ~= false and true or false
+        return e
     end,
     animated = function(frames, speed)
         e._animation = frames
         e._animation_speed = speed or 1
+        return e
     end,
     style = add_elem_style,
     tooltip = add_elem_tooltip,
@@ -390,7 +393,7 @@ local fs_model = {
 fs_model.__index = fs_model
 setmetatable(fs_model, {
     __call = function(_, x, y, w, h, mesh, textures)
-        local e = {x = x, y = y, w = w, h = h, mesh = mesh, textures = textures, mouse_control = true}
+        local e = {x = x, y = y, w = w, h = h, mesh = mesh, textures = textures, mouse_control = true, _styles = {}}
         e.__id = new_id()
         setmetatable(e, fs_model)
         table.insert(ctx, e)
@@ -421,12 +424,15 @@ local fs_button = {
     image = function(e, img, pressed_img)
         e._image = img
         e._image_pressed = pressed_img
+        return e
     end,
     item_image = function(e, item)
         e._item = item
+        return e
     end,
     exit = function(e)
         e._exit = true
+        return e
     end,
     onclick = function(e, fn)
         ctx._events.on_click[e.__id] = fn
@@ -472,9 +478,10 @@ local fs_list = {
         w = w or get(e, "w")
         h = h or get(e, "h")
         
-        -- These lines will cause `w` and `h` to be interpreted as formspec coordinates rather than numbers of slots.
-        --  w = w -((w -1) /4)
-        --  h = h -((h -1) /4)
+        -- Interpret `w` and `h` as formspec coordinates rather than numbers of slots.
+        -- This is necessary so that inventories in flex containers will work correctly.
+          w = w -((w -1) /4)
+          h = h -((h -1) /4)
         
         return string.format("list[%s;%s;%f,%f;%d,%d;%s]", get(e, "location"), get(e, "list"), x or get(e, "x"), y or get(e, "y"), w, h, get(e, "start"))
     end