sized spans!

src/core/text.rs

@@ -41,7 +41,7 @@ impl Widget for Text {
         // reuse TextureHandle
     }
 
-    fn size(&mut self, ctx: SizeCtx) -> Vec2 {
+    fn size(&mut self, ctx: &mut SizeCtx) -> Vec2 {
         let (handle, offset) =
             ctx.text
                 .draw(&mut self.buf, &self.content, &self.attrs, ctx.textures);