wgui: fix cosmic text not rendering anything

wgui/src/widget/label.rs

@@ -1,6 +1,6 @@
 use std::{cell::RefCell, rc::Rc};
 
-use cosmic_text::{Attrs, AttrsList, Buffer, Metrics, Shaping, Wrap};
+use cosmic_text::{Attrs, AttrsList, BorrowedWithFontSystem, Buffer, Metrics, Shaping, Wrap};
 use slotmap::Key;
 use taffy::AvailableSpace;
 
@@ -68,6 +68,16 @@ impl WidgetLabel {
 		)
 	}
 
+	fn with_buffer<F, R>(buffer: &Rc<RefCell<Buffer>>, globals: &Globals, func: F) -> R
+	where
+		F: FnOnce(BorrowedWithFontSystem<'_, Buffer>) -> R,
+	{
+		let mut font_system = globals.font_system.system.lock();
+		let mut buffer = buffer.borrow_mut();
+		let buffer = buffer.borrow_with(&mut font_system);
+		func(buffer)
+	}
+
 	// set text without layout/re-render update.
 	// Not recommended unless the widget wasn't rendered yet (first init).
 	pub fn set_text_simple(&mut self, globals: &mut Globals, translation: Translation) -> bool {
@@ -78,14 +88,16 @@ impl WidgetLabel {
 		self.params.content = translation;
 		let attrs = Attrs::from(&self.params.style);
 
-		let mut buffer = self.buffer.borrow_mut();
+		let text = self.params.content.generate(&mut globals.i18n_builtin);
-		buffer.set_rich_text(
-			[(self.params.content.generate(&mut globals.i18n_builtin).as_ref(), attrs)],
-			&Attrs::new(),
-			Shaping::Advanced,
-			self.params.style.align.map(Into::into),
-		);
 
+		WidgetLabel::with_buffer(&self.buffer, globals, |mut buffer| {
+			buffer.set_rich_text(
+				[(text.as_ref(), attrs)],
+				&Attrs::new(),
+				Shaping::Advanced,
+				self.params.style.align.map(Into::into),
+			);
+		});
 		true
 	}
 
@@ -118,8 +130,9 @@ impl WidgetObj for WidgetLabel {
 	fn draw(&mut self, state: &mut super::DrawState, _params: &super::DrawParams) {
 		let boundary = drawing::Boundary::construct_relative(state.transform_stack);
 
-		let mut buffer = self.buffer.borrow_mut();
+		WidgetLabel::with_buffer(&self.buffer, state.globals, |mut buffer| {
-		buffer.set_size(Some(boundary.size.x), Some(boundary.size.y));
+			buffer.set_size(Some(boundary.size.x), Some(boundary.size.y));
+		});
 
 		state.primitives.push(drawing::RenderPrimitive::Text(
 			PrimitiveExtent {
@@ -133,7 +146,7 @@ impl WidgetObj for WidgetLabel {
 
 	fn measure(
 		&mut self,
-		_globals: &Globals,
+		globals: &Globals,
 		known_dimensions: taffy::Size<Option<f32>>,
 		available_space: taffy::Size<taffy::AvailableSpace>,
 	) -> taffy::Size<f32> {
@@ -144,19 +157,18 @@ impl WidgetObj for WidgetLabel {
 			AvailableSpace::Definite(width) => Some(width),
 		});
 
-		let mut buffer = self.buffer.borrow_mut();
+		WidgetLabel::with_buffer(&self.buffer, globals, |mut buffer| {
-		buffer.set_size(width_constraint, None);
+			buffer.set_size(width_constraint, None);
-
+			// Determine measured size of text
-		// Determine measured size of text
+			let (width, total_lines) = buffer.layout_runs().fold((0.0, 0usize), |(width, total_lines), run| {
-		let (width, total_lines) = buffer.layout_runs().fold((0.0, 0usize), |(width, total_lines), run| {
+				(run.line_w.max(width), total_lines + 1)
-			(run.line_w.max(width), total_lines + 1)
+			});
-		});
+			let height = total_lines as f32 * buffer.metrics().line_height;
-		let height = total_lines as f32 * buffer.metrics().line_height;
+			taffy::Size {
-
+				width: width + 1.0, /* f32 aliasing fix */
-		taffy::Size {
+				height,
-			width: width + 1.0, /* f32 aliasing fix */
+			}
-			height,
+		})
-		}
 	}
 
 	fn get_id(&self) -> WidgetID {