sized spans!

src/layout/widget.rs

@@ -1,18 +1,26 @@
-use crate::layout::{Painter, TextData, Textures, Ui, Vec2, WidgetId, WidgetIdFnRet};
+use crate::layout::{Painter, TextData, Textures, Ui, Vec2, WidgetId, WidgetIdFnRet, Widgets};
 
 use std::{any::Any, marker::PhantomData};
 
 pub trait Widget: Any {
     fn draw(&mut self, painter: &mut Painter);
-    fn size(&mut self, ctx: SizeCtx) -> Vec2 {
+    fn size(&mut self, ctx: &mut SizeCtx) -> Vec2 {
         ctx.size
     }
 }
 
 pub struct SizeCtx<'a> {
+    pub screen_size: Vec2,
     pub size: Vec2,
     pub text: &'a mut TextData,
     pub textures: &'a mut Textures,
+    pub(super) widgets: &'a Widgets,
+}
+
+impl SizeCtx<'_> {
+    pub fn size<W>(&mut self, id: &WidgetId<W>) -> Vec2 {
+        self.widgets.get_dyn_dynamic(&id.id).size(self)
+    }
 }
 
 pub struct WidgetTag;