Lots of owork on a calculator example, transparency, etc.

lib/ruin_app/src/primitives/button.rs

@@ -31,6 +31,11 @@ pub fn button() -> ButtonBuilder {
 impl ButtonBuilder {
     impl_props_methods!();
 
+    pub fn shadow(mut self, shadow: impl crate::converters::IntoShadow) -> Self {
+        self.props = self.props.shadow(shadow);
+        self
+    }
+
     pub fn on_press(mut self, handler: impl Fn(&RoutedPointerEvent) + 'static) -> Self {
         self.on_press = Some(Rc::new(handler));
         self
@@ -44,6 +49,9 @@ impl ButtonBuilder {
     pub fn children(mut self, children: impl Children) -> View {
         let id = allocate_element_id();
         self.props.element = self.props.element.id(id);
+        if let Some(widget_ref) = &self.props.widget_ref {
+            let _ = widget_ref.set(Some(id));
+        }
         let had_style = self.props.partial_text_style.is_some();
         if let Some(style) = self.props.partial_text_style.take() {
             push_text_style(style);