Replace placement calls with region nodes

src/widget/position/scroll.rs

@@ -13,12 +13,12 @@ impl Widget for Scroll {
     fn draw(&mut self, painter: &mut Painter) -> Size {
         let container_len = painter.px_len(self.axis);
         // Draw in the whole container only when its scrolling-axis length is
-        // not already known, then place it at the scrolled offset.
+        // not already known, then draw it at the scrolled offset.
         let (answer_len, measured) = match painter.known_len(&self.inner, self.axis, UiRegion::FULL)
         {
             Some(len) => (len, None),
             None => {
-                let size = painter.place(&self.inner, UiRegion::FULL).size();
+                let size = painter.widget_within(&self.inner, UiRegion::FULL).size();
                 (size.axis(self.axis), Some(size))
             }
         };
@@ -43,7 +43,7 @@ impl Widget for Scroll {
 
         let mut region = UiRegion::FULL.offset(Vec2::from_axis(self.axis, -self.amt, 0.0));
         region.axis_mut(self.axis).end = region.axis(self.axis).start.offset(self.content_len);
-        let placed = painter.place(&self.inner, region).size();
+        let placed = painter.widget_within(&self.inner, region).size();
         measured.unwrap_or_else(|| Size::from_axis(self.axis, answer_len, placed.axis(!self.axis)))
     }
 }