refactor project structure (start of redoing atomic branch without atomics)

src/widget/position/align.rs

@@ -0,0 +1,35 @@
+use crate::prelude::*;
+
+pub struct Aligned {
+    pub inner: WidgetId,
+    pub align: Align,
+}
+
+impl Widget for Aligned {
+    fn draw(&mut self, painter: &mut Painter) {
+        let region = match self.align.tuple() {
+            (Some(x), Some(y)) => painter
+                .size(&self.inner)
+                .to_uivec2()
+                .align(RegionAlign { x, y }),
+            (Some(x), None) => {
+                let x = painter.size_ctx().width(&self.inner).apply_rest().align(x);
+                UiRegion::new(x, UiSpan::FULL)
+            }
+            (None, Some(y)) => {
+                let y = painter.size_ctx().height(&self.inner).apply_rest().align(y);
+                UiRegion::new(UiSpan::FULL, y)
+            }
+            (None, None) => UiRegion::FULL,
+        };
+        painter.widget_within(&self.inner, region);
+    }
+
+    fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
+        ctx.width(&self.inner)
+    }
+
+    fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
+        ctx.height(&self.inner)
+    }
+}