app work

src/core/position/pad.rs

@@ -38,7 +38,8 @@ pub struct Padding {
 }
 
 impl Padding {
-    pub fn uniform(amt: f32) -> Self {
+    pub fn uniform(amt: impl UiNum) -> Self {
+        let amt = amt.to_f32();
         Self {
             left: amt,
             right: amt,
@@ -54,6 +55,24 @@ impl Padding {
         region.bot_right.abs.y -= self.bottom;
         region
     }
+    pub fn x(amt: impl UiNum) -> Self {
+        let amt = amt.to_f32();
+        Self {
+            left: amt,
+            right: amt,
+            top: 0.0,
+            bottom: 0.0,
+        }
+    }
+    pub fn y(amt: impl UiNum) -> Self {
+        let amt = amt.to_f32();
+        Self {
+            left: 0.0,
+            right: 0.0,
+            top: amt,
+            bottom: amt,
+        }
+    }
 }
 
 impl<T: UiNum> From<T> for Padding {

src/core/position/span.rs

@@ -3,6 +3,7 @@ use crate::prelude::*;
 pub struct Span {
     pub children: Vec<(WidgetId, SpanLen)>,
     pub dir: Dir,
+    pub spacing: f32,
 }
 
 impl Widget for Span {
@@ -36,6 +37,7 @@ impl Widget for Span {
                 child_region.flip(self.dir.axis);
             }
             painter.widget_within(child, child_region);
+            start.abs += self.spacing;
         }
     }
 
@@ -45,7 +47,10 @@ impl Widget for Span {
         let dir_len = if total.ratio != 0.0 {
             UiScalar::rel_max()
         } else {
-            UiScalar::new(total.rel, total.abs)
+            UiScalar::new(
+                total.rel,
+                total.abs + self.spacing * self.children.len().saturating_sub(1) as f32,
+            )
         };
         let mut max_ortho = UiScalar::ZERO;
         for (child, _) in &self.children {
@@ -68,9 +73,15 @@ impl Span {
         Self {
             children: Vec::new(),
             dir,
+            spacing: 0.0,
         }
     }
 
+    pub fn spacing(mut self, spacing: impl UiNum) -> Self {
+        self.spacing = spacing.to_f32();
+        self
+    }
+
     fn setup(&mut self, ctx: &mut SizeCtx) -> SpanLenSums {
         self.children
             .iter_mut()

src/core/trait_fns.rs

@@ -78,6 +78,7 @@ impl<const LEN: usize, Wa: WidgetArrLike<LEN, Tag>, Tag> CoreWidgetArr<LEN, Wa,
         move |ui| Span {
             children: self.ui(ui).arr.into_iter().zip(lengths).collect(),
             dir,
+            spacing: 0.0,
         }
     }
     fn stack(self) -> StackBuilder<LEN, Wa, Tag> {

src/layout/painter.rs

@@ -44,6 +44,7 @@ pub struct WidgetInstance {
     pub resize: Option<(Id, UiVec2)>,
     pub mask: MaskIdx,
     pub layer: usize,
+    pub desired_size: UiVec2,
 }
 
 #[derive(Default)]
@@ -178,6 +179,17 @@ impl<'a> PainterCtx<'a> {
 
         // draw widgets
         painter.ctx.widgets.get_dyn_dynamic(id).draw(&mut painter);
+        let desired_size = SizeCtx {
+            text: painter.ctx.text,
+            textures: painter.ctx.textures,
+            widgets: painter.ctx.widgets,
+            checked: &mut Default::default(),
+            screen_size: painter.ctx.screen_size,
+            px_dependent: painter.ctx.px_dependent,
+            id: painter.id,
+            region: UiRegion::full(),
+        }
+        .size_raw(id);
 
         let sized_children = painter.sized_children;
 
@@ -191,6 +203,7 @@ impl<'a> PainterCtx<'a> {
             children: painter.children,
             resize,
             mask: painter.mask,
+            desired_size,
             layer,
         };
         for (cid, size) in sized_children {
@@ -394,6 +407,9 @@ impl SizeCtx<'_> {
         // }
         self.size_inner(id.id, self.region)
     }
+    fn size_raw(&mut self, id: Id) -> UiVec2 {
+        self.size_inner(id, self.region)
+    }
     pub fn size_within<W>(&mut self, id: &WidgetId<W>, region: UiRegion) -> UiVec2 {
         self.size_inner(id.id, region.within(&self.region))
     }

src/layout/pos.rs

@@ -1,4 +1,4 @@
-use std::marker::Destruct;
+use std::{fmt::Display, marker::Destruct};
 
 use crate::{
     layout::{Align, Axis, UiNum, Vec2},
@@ -114,6 +114,12 @@ impl UiVec2 {
     }
 }
 
+impl Display for UiVec2 {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "rel {} / abs {}", self.rel, self.abs)
+    }
+}
+
 impl_op!(UiVec2 Add add; rel abs);
 impl_op!(UiVec2 Sub sub; rel abs);
 
@@ -307,6 +313,12 @@ impl UiRegion {
     }
 }
 
+impl Display for UiRegion {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{} -> {}", self.top_left, self.bot_right)
+    }
+}
+
 #[derive(Debug)]
 pub struct ScreenRegion {
     pub top_left: Vec2,

src/layout/ui.rs

@@ -170,6 +170,19 @@ impl Ui {
             font_system: &mut self.data.text.font_system,
         }
     }
+
+    pub fn debug(&self, label: &str) {
+        for (id, inst) in &self.data.active {
+            let l = &self.data.widgets.data(id).unwrap().label;
+            if l != label {
+                continue;
+            }
+            println!("\"{label}\" {{");
+            println!("    region: {}", inst.region);
+            println!("    desired_size: {}", inst.desired_size);
+            println!("}}");
+        }
+    }
 }
 
 impl<W: Widget> Index<&WidgetId<W>> for Ui {

src/layout/vec2.rs

@@ -96,3 +96,9 @@ impl std::fmt::Debug for Vec2 {
         write!(f, "({}, {})", self.x, self.y)
     }
 }
+
+impl std::fmt::Display for Vec2 {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "({}, {})", self.x, self.y)
+    }
+}

src/layout/widget.rs

@@ -9,6 +9,10 @@ pub trait Widget: Any {
     }
 }
 
+impl Widget for () {
+    fn draw(&mut self, painter: &mut Painter) {}
+}
+
 pub struct WidgetTag;
 pub struct FnTag;