fix(core): 🐛 wrong clamp in WrapRender layout

core/src/builtin_widgets.rs

@@ -984,10 +984,10 @@ impl<'a> FatObj<Widget<'a>> {
           scrollable,
           layout_box,
           class,
-          cursor,
           constrained_box,
           tooltips,
           margin,
+          cursor,
           mix_builtin,
           request_focus,
           transform,
@@ -1107,3 +1107,8 @@ where
 
   fn with_child(self, child: C) -> Self::Target { self.map(|host| host.with_child(child)) }
 }
+
+impl Declare for FatObj<()> {
+  type Builder = Self;
+  fn declarer() -> Self::Builder { FatObj::default() }
+}

core/src/builtin_widgets/align.rs

@@ -87,11 +87,14 @@ impl WrapRender for HAlignWidget {
       clamp.min.width = clamp.max.width;
     }
 
-    let child_size = host.perform_layout(clamp, ctx);
-    let x = align.align_value(child_size.width, clamp.max.width);
+    let host_size = host.perform_layout(clamp, ctx);
+    let x = align.align_value(host_size.width, clamp.max.width);
     let pos = ctx.box_pos().unwrap_or_default();
     ctx.update_position(ctx.widget_id(), Point::new(x, pos.y));
-    clamp.clamp(child_size)
+
+    // The size should not be clamped; it should simply follow its host. If the host
+    // ignores the constraint, the align widget should do the same.
+    host_size
   }
 }
 
@@ -101,11 +104,14 @@ impl WrapRender for VAlignWidget {
     if align == Align::Stretch {
       clamp.min.height = clamp.max.height;
     }
-    let child_size = host.perform_layout(clamp, ctx);
-    let y = align.align_value(child_size.height, clamp.max.height);
+    let host_size = host.perform_layout(clamp, ctx);
+    let y = align.align_value(host_size.height, clamp.max.height);
     let pos = ctx.box_pos().unwrap_or_default();
     ctx.update_position(ctx.widget_id(), Point::new(pos.x, y));
-    clamp.clamp(child_size)
+
+    // The size should not be clamped; it should simply follow its host. If the host
+    // ignores the constraint, the align widget should do the same.
+    host_size
   }
 }
 

core/src/builtin_widgets/margin.rs

@@ -132,10 +132,9 @@ pub(crate) fn space_around_layout(
   // widget is already set during layout.
   // ctx.force_child_relayout(child);
 
-  let thickness = edges.thickness();
-  let zero = Size::zero();
-  let min = (clamp.min - thickness).max(zero);
-  let max = (clamp.max - thickness).max(zero);
+  let thickness = edges.thickness().min(clamp.max);
+  let min = (clamp.min - thickness).max(ZERO_SIZE);
+  let max = clamp.max - thickness;
 
   // Shrink the clamp of child.
   let child_clamp = BoxClamp { min, max };
@@ -144,8 +143,7 @@ pub(crate) fn space_around_layout(
   let pos = pos + Vector::new(edges.left, edges.top);
   ctx.update_position(child, pos);
 
-  // Expand the size, so the child have padding.
-  clamp.clamp(size + thickness)
+  size + thickness
 }
 
 #[cfg(test)]