initial text wrapping impl (resizing will break)

src/core/text.rs

@@ -44,11 +44,8 @@ impl Text {
         UiRegion::from_size_align(self.size, self.align)
     }
 
-    fn update_buf(&mut self, font_system: &mut FontSystem) {
-        self.buf.set_metrics(
-            font_system,
-            Metrics::new(self.attrs.font_size, self.attrs.line_height),
-        );
+    fn update_buf(&mut self, font_system: &mut FontSystem, width: Option<f32>) {
+        self.attrs.apply(font_system, &mut self.buf, width);
         if self.content.changed {
             self.content.changed = false;
             self.buf.set_text(
@@ -63,8 +60,13 @@ impl Text {
 
 impl Widget for Text {
     fn draw(&mut self, painter: &mut Painter) {
+        let width = if self.attrs.wrap {
+            Some(painter.px_size().x)
+        } else {
+            None
+        };
         let font_system = &mut painter.text_data().font_system;
-        self.update_buf(font_system);
+        self.update_buf(font_system, width);
         let (handle, offset) = painter.render_text(&mut self.buf, &self.attrs);
         let dims = handle.size();
         self.size = offset.size(&handle);
@@ -75,7 +77,7 @@ impl Widget for Text {
     }
 
     fn desired_size(&mut self, ctx: &mut SizeCtx) -> UiVec2 {
-        self.update_buf(&mut ctx.text.font_system);
+        self.update_buf(&mut ctx.text.font_system, None);
         let (handle, offset) = ctx.draw_text(&mut self.buf, &self.attrs);
         UiVec2::abs(offset.size(&handle))
     }
@@ -137,7 +139,7 @@ impl FnOnce<(&mut Ui,)> for TextBuilder {
         };
         text.content.changed = false;
         self.attrs
-            .apply(&mut args.0.text.font_system, &mut text.buf);
+            .apply(&mut args.0.text.font_system, &mut text.buf, None);
         text
     }
 }