spans now good (other than direction) + refactor

src/base/trait_fns.rs

@@ -0,0 +1,37 @@
+use super::*;
+use crate::{UIRegion, Vec2, WidgetArrLike, WidgetFn, WidgetLike};
+
+pub trait WidgetUtil {
+    fn pad(self, padding: impl Into<Padding>) -> impl WidgetLike<Widget = Regioned>;
+    fn center(self, size: impl Into<Vec2>) -> impl WidgetLike<Widget = Regioned>;
+}
+
+impl<W: WidgetLike> WidgetUtil for W {
+    fn pad(self, padding: impl Into<Padding>) -> impl WidgetLike<Widget = Regioned> {
+        WidgetFn(|ui| Regioned {
+            region: padding.into().region(),
+            inner: self.add(ui).erase_type(),
+        })
+    }
+
+    fn center(self, size: impl Into<Vec2>) -> impl WidgetLike<Widget = Regioned> {
+        WidgetFn(|ui| Regioned {
+            region: UIRegion::center(size.into()),
+            inner: self.add(ui).erase_type(),
+        })
+    }
+}
+
+pub trait WidgetArrUtil<const LEN: usize> {
+    fn span(self, dir: Dir, lengths: [impl Into<SpanLen>; LEN]) -> impl WidgetLike<Widget = Span>;
+}
+
+impl<const LEN: usize, Wa: WidgetArrLike<LEN>> WidgetArrUtil<LEN> for Wa {
+    fn span(self, dir: Dir, lengths: [impl Into<SpanLen>; LEN]) -> impl WidgetLike<Widget = Span> {
+        let lengths = lengths.map(Into::into);
+        WidgetFn(move |ui| Span {
+            dir,
+            children: self.ui(ui).arr.into_iter().zip(lengths).collect(),
+        })
+    }
+}