feat: add gtk_ui function for loading .ui

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to `ewwii` are documented here.
 This changelog follows the [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) format,
 and this project adheres to [Semantic Versioning](https://semver.org/).
 
+## [UNRELEASED]
+
+## Added
+
+- `gtk_ui` function for loading .ui files.
+
 ## [0.3.1] - 2025-11-01
 
 ## Fixed

Cargo.lock

@@ -486,7 +486,7 @@ dependencies = [
 
 [[package]]
 name = "ewwii"
-version = "0.3.0"
+version = "0.3.1"
 dependencies = [
  "anyhow",
  "bincode",

crates/ewwii/src/widgets/build_widget.rs

@@ -56,6 +56,9 @@ fn build_gtk_widget_from_node(
         WidgetNode::CircularProgress { props } => {
             build_circular_progress_bar(props, widget_reg)?.upcast()
         }
+        WidgetNode::GtkUI { props } => {
+            build_gtk_ui_file(props)?.upcast()
+        }
         // WidgetNode::Graph { props } => build_graph(props, widget_reg)?.upcast(),
         // WidgetNode::Transform { props } => build_transform(props, widget_reg)?.upcast(),
         WidgetNode::Slider { props } => build_gtk_scale(props, widget_reg)?.upcast(),

crates/ewwii/src/widgets/widget_definitions.rs

@@ -1971,6 +1971,25 @@ pub(super) fn build_gtk_combo_box_text(
     Ok(gtk_widget)
 }
 
+pub(super) fn build_gtk_ui_file(
+    props: &Map,
+) -> Result<gtk4::Widget> {
+    let path = get_string_prop(&props, "file", None)?;
+    let main_id = get_string_prop(&props, "id", None)?;
+
+    if !std::path::Path::new(&path).exists() {
+        return Err(anyhow::anyhow!("UI file not found: {}", path));
+    }
+
+    let builder = gtk4::Builder::from_file(&path);
+
+    let gtk_widget = builder
+        .object(&main_id)
+        .ok_or_else(|| anyhow::anyhow!("No widget with id '{}' in {}", main_id, path))?;
+
+    Ok(gtk_widget)
+}
+
 pub(super) fn build_gtk_expander(
     props: &Map,
     children: &Vec<WidgetNode>,

crates/rhai_impl/src/ast.rs

@@ -32,7 +32,10 @@ pub enum WidgetNode {
     Transform { props: Map },
     EventBox { props: Map, children: Vec<WidgetNode> },
     ToolTip { props: Map, children: Vec<WidgetNode> },
+
+    // Special
     LocalBind { props: Map, children: Vec<WidgetNode> },
+    GtkUI { props: Map },
 
     // Top-level macros
     DefWindow { name: String, props: Map, node: Box<WidgetNode> },
@@ -166,6 +169,9 @@ pub fn get_id_to_widget_info<'a>(
                 get_id_to_widget_info(child, id_to_props, Some(id))?;
             }
         }
+        WidgetNode::GtkUI { props } => {
+            insert_wdgt_info(node, props, "GtkUI", &[], parent_id, id_to_props)?;
+        }
         WidgetNode::ColorChooser { props } => {
             // let id = hash_props_and_type(props, "ColorChooser");
             insert_wdgt_info(node, props, "ColorChooser", &[], parent_id, id_to_props)?;

crates/rhai_impl/src/builtins.rs

@@ -84,6 +84,17 @@ pub fn register_all_widgets(
     register_with_children!("tooltip", ToolTip);
     register_with_children!("localbind", LocalBind);
 
+    // == Special widget
+    engine.register_fn(
+        "gtk_ui",
+        |path: &str, load: &str| -> Result<WidgetNode, Box<EvalAltResult>> {
+            let mut props = Map::new();
+            props.insert("file".into(), path.into());
+            props.insert("id".into(), load.into());
+            Ok(WidgetNode::GtkUI { props })
+        },
+    );
+
     // == Special signal
     let keep_signal_clone = keep_signal.clone();
     engine.register_fn(

crates/rhai_impl/src/dyn_id.rs

@@ -106,6 +106,7 @@ impl WidgetNode {
             | node @ WidgetNode::ColorChooser { props }
             | node @ WidgetNode::CircularProgress { props }
             | node @ WidgetNode::Graph { props }
+            | node @ WidgetNode::GtkUI { props }
             | node @ WidgetNode::Transform { props } => {
                 let new_props = with_dyn_id(props.clone(), parent_path);
                 match node {
@@ -129,6 +130,7 @@ impl WidgetNode {
                         WidgetNode::CircularProgress { props: new_props }
                     }
                     WidgetNode::Graph { .. } => WidgetNode::Graph { props: new_props },
+                    WidgetNode::GtkUI { .. } => WidgetNode::GtkUI { props: new_props },
                     WidgetNode::Transform { .. } => WidgetNode::Transform { props: new_props },
                     _ => unreachable!(),
                 }