Allowing rendering 0-size layouts

CHANGELOG.md

@@ -183,6 +183,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   overflowing math.
 - Fonts already loaded into a `FontCollection` when the window is first opened
   are now properly loaded.
+- Widgets of 0-size are now still rendered, even though all the drawing
+  operations will be clipped away. This allows the `ComponentProbe` to still
+  actively probe when placed in a location and given no space.
 
 ### Added
 

examples/component-probe.rs

@@ -0,0 +1,17 @@
+use cushy::styles::components::PrimaryColor;
+use cushy::widget::MakeWidget;
+use cushy::widgets::{ComponentProbe, Space};
+use cushy::Run;
+use kludgine::Color;
+
+fn main() -> cushy::Result {
+    let probe = ComponentProbe::new(PrimaryColor, Color::CLEAR_WHITE);
+
+    Space::colored(probe.value().clone())
+        .expand()
+        .and(probe)
+        .into_layers()
+        .contain()
+        .pad()
+        .run()
+}

src/context.rs

@@ -689,10 +689,7 @@ impl<'context, 'clip, 'gfx, 'pass> GraphicsContext<'context, 'clip, 'gfx, 'pass>
     /// Invokes [`Widget::redraw()`](crate::widget::Widget::redraw) on this
     /// context's widget.
     pub fn redraw(&mut self) {
-        let Some(layout) = self.last_layout() else {
-            return;
-        };
-        if layout.size.width <= 0 || layout.size.height <= 0 {
+        if self.last_layout().is_none() {
             return;
         }
 

src/widgets/component_probe.rs

@@ -90,6 +90,15 @@ where
         &mut self.child
     }
 
+    fn adjust_child_constraints(
+        &mut self,
+        available_space: figures::Size<crate::ConstraintLimit>,
+        context: &mut crate::context::LayoutContext<'_, '_, '_, '_>,
+    ) -> figures::Size<crate::ConstraintLimit> {
+        self.probed.set(context.get(&self.component));
+        available_space
+    }
+
     fn redraw_foreground(&mut self, context: &mut crate::context::GraphicsContext<'_, '_, '_, '_>) {
         self.probed.set(context.get(&self.component));
     }

src/widgets/stack.rs

@@ -124,10 +124,8 @@ impl Stack {
 
 impl Widget for Stack {
     fn redraw(&mut self, context: &mut GraphicsContext<'_, '_, '_, '_>) {
-        for (layout, child) in self.layout.iter().zip(&self.synced_children) {
-            if layout.size > 0 {
-                context.for_other(child).redraw();
-            }
+        for child in &self.synced_children {
+            context.for_other(child).redraw();
         }
     }
 
@@ -166,21 +164,19 @@ impl Widget for Stack {
         );
 
         for (layout, child) in self.layout.iter().zip(&self.synced_children) {
-            if layout.size > 0 {
-                context.set_child_layout(
-                    child,
-                    Rect::new(
-                        self.layout
-                            .orientation
-                            .make_point(layout.offset, UPx::ZERO)
-                            .into_signed(),
-                        self.layout
-                            .orientation
-                            .make_size(layout.size, self.layout.others[0])
-                            .into_signed(),
-                    ),
-                );
-            }
+            context.set_child_layout(
+                child,
+                Rect::new(
+                    self.layout
+                        .orientation
+                        .make_point(layout.offset, UPx::ZERO)
+                        .into_signed(),
+                    self.layout
+                        .orientation
+                        .make_size(layout.size, self.layout.others[0])
+                        .into_signed(),
+                ),
+            );
         }
 
         content_size