refactor(core): 💡 separate the BoxDecoration into distinct widgets …

…for border, background, and radius.

CHANGELOG.md

@@ -36,6 +36,10 @@ Please only add new entries below the [Unreleased](#unreleased---releasedate) he
 - **macros**: Added the `part_reader!` macro to generate a partial reader from a reference of a reader. (#688 @M-Adoo)
 - **macros**: The `simple_declare` now supports the `stateless` meta attribute, `#[simple_declare(stateless)]`. (#688 @M-Adoo)
 
+### Changed
+
+- **widgets**: Replace `BoxDecoration` with three separate widgets: `BorderWidget`, `RadiusWidget`, and `Background`. (#691 @M-Adoo)
+
 ### Fixed
 
 - **Core**: `PartData` allows the use of a reference to create a write reference, which is unsafe. Introduce `PartRef` and `PartMut` to replace it. (#690 @M-Adoo)
@@ -44,6 +48,7 @@ Please only add new entries below the [Unreleased](#unreleased---releasedate) he
 ### Breading
 
 - **core**: Removed `PartData`. (#690 @M-Adoo)
+- **core**: Removed `BoxDecoration`. (#691 @M-Adoo)
 
 ## [0.4.0-alpha.22] - 2025-01-08
 

core/src/builtin_widgets.rs

@@ -26,8 +26,6 @@ mod foreground;
 mod padding;
 pub use foreground::*;
 pub use padding::*;
-mod box_decoration;
-pub use box_decoration::*;
 mod scrollable;
 pub use scrollable::*;
 mod transform_widget;
@@ -82,6 +80,12 @@ mod tooltips;
 pub use tooltips::*;
 mod providers;
 pub use providers::*;
+mod border;
+pub use border::*;
+mod radius;
+pub use radius::*;
+mod background;
+pub use background::*;
 
 use crate::prelude::*;
 
@@ -120,7 +124,9 @@ pub struct FatObj<T> {
   padding: Option<State<Padding>>,
   fitted_box: Option<State<FittedBox>>,
   constrained_box: Option<State<ConstrainedBox>>,
-  box_decoration: Option<State<BoxDecoration>>,
+  radius: Option<State<RadiusWidget>>,
+  border: Option<State<BorderWidget>>,
+  background: Option<State<Background>>,
   foreground: Option<State<Foreground>>,
   scrollable: Option<State<ScrollableWidget>>,
   layout_box: Option<State<LayoutBox>>,
@@ -168,7 +174,9 @@ impl<T> FatObj<T> {
       mix_builtin: self.mix_builtin,
       request_focus: self.request_focus,
       fitted_box: self.fitted_box,
-      box_decoration: self.box_decoration,
+      border: self.border,
+      radius: self.radius,
+      background: self.background,
       foreground: self.foreground,
       padding: self.padding,
       layout_box: self.layout_box,
@@ -198,7 +206,9 @@ impl<T> FatObj<T> {
       && self.mix_builtin.is_none()
       && self.request_focus.is_none()
       && self.fitted_box.is_none()
-      && self.box_decoration.is_none()
+      && self.border.is_none()
+      && self.radius.is_none()
+      && self.background.is_none()
       && self.foreground.is_none()
       && self.padding.is_none()
       && self.layout_box.is_none()
@@ -297,11 +307,21 @@ impl<T> FatObj<T> {
       .get_or_insert_with(|| State::value(<_>::default()))
   }
 
-  /// Returns the `State<BoxDecoration>` widget from the FatObj. If it doesn't
-  /// exist, a new one will be created.
-  pub fn get_box_decoration_widget(&mut self) -> &State<BoxDecoration> {
+  pub fn get_border_widget(&mut self) -> &State<BorderWidget> {
+    self
+      .border
+      .get_or_insert_with(|| State::value(<_>::default()))
+  }
+
+  pub fn get_radius_widget(&mut self) -> &State<RadiusWidget> {
+    self
+      .radius
+      .get_or_insert_with(|| State::value(<_>::default()))
+  }
+
+  pub fn get_background_widget(&mut self) -> &State<Background> {
     self
-      .box_decoration
+      .background
       .get_or_insert_with(|| State::value(<_>::default()))
   }
 
@@ -808,8 +828,8 @@ impl<T> FatObj<T> {
   }
 
   /// Initializes the background of the widget.
-  pub fn background<const M: usize>(self, v: impl DeclareInto<Option<Brush>, M>) -> Self {
-    self.declare_builtin_init(v, Self::get_box_decoration_widget, |m, v| m.background = v)
+  pub fn background<const M: usize>(self, v: impl DeclareInto<Brush, M>) -> Self {
+    self.declare_builtin_init(v, Self::get_background_widget, |m, v| m.background = v)
   }
 
   /// Initializes the foreground of the widget.
@@ -818,13 +838,13 @@ impl<T> FatObj<T> {
   }
 
   /// Initializes the border of the widget.
-  pub fn border<const M: usize>(self, v: impl DeclareInto<Option<Border>, M>) -> Self {
-    self.declare_builtin_init(v, Self::get_box_decoration_widget, |m, v| m.border = v)
+  pub fn border<const M: usize>(self, v: impl DeclareInto<Border, M>) -> Self {
+    self.declare_builtin_init(v, Self::get_border_widget, |m, v| m.border = v)
   }
 
   /// Initializes the border radius of the widget.
-  pub fn border_radius<const M: usize>(self, v: impl DeclareInto<Option<Radius>, M>) -> Self {
-    self.declare_builtin_init(v, Self::get_box_decoration_widget, |m, v| m.border_radius = v)
+  pub fn radius<const M: usize>(self, v: impl DeclareInto<Radius, M>) -> Self {
+    self.declare_builtin_init(v, Self::get_radius_widget, |m, v| m.radius = v)
   }
 
   /// Initializes the extra space within the widget.
@@ -1005,7 +1025,11 @@ impl<'a> FatObj<Widget<'a>> {
     ]);
 
     compose_builtin_widgets!(
-      host + [track_id, padding, fitted_box, foreground, box_decoration, scrollable, layout_box]
+      host
+        + [
+          track_id, padding, fitted_box, foreground, border, background, radius, scrollable,
+          layout_box
+        ]
     );
     if let Some(providers) = self.providers {
       host = Providers::new(providers).with_child(host);

core/src/builtin_widgets/background.rs

@@ -0,0 +1,43 @@
+use wrap_render::WrapRender;
+
+use super::*;
+
+/// A widget that utilizes the background brush to paint a background box based
+/// on the layout size. If a `Radius` is provided, the corners of the box will
+/// be rounded.
+#[derive(Default, Clone)]
+pub struct Background {
+  /// The background of the box.
+  pub background: Brush,
+}
+
+impl Declare for Background {
+  type Builder = FatObj<()>;
+  #[inline]
+  fn declarer() -> Self::Builder { FatObj::new(()) }
+}
+
+impl WrapRender for Background {
+  fn paint(&self, host: &dyn Render, ctx: &mut PaintingCtx) {
+    let size = ctx.box_size().unwrap();
+
+    if !size.is_empty() {
+      let rect = Rect::from_size(size);
+      let (provider_ctx, painter) = ctx.provider_ctx_and_painter();
+      let old_brush = painter.fill_brush().clone();
+
+      painter.set_fill_brush(self.background.clone());
+      if let Some(radius) = Provider::of::<Radius>(provider_ctx) {
+        painter.rect_round(&rect, &radius);
+      } else {
+        painter.rect(&rect);
+      }
+      painter.fill();
+
+      painter.set_fill_brush(old_brush);
+    }
+    host.paint(ctx);
+  }
+}
+
+impl_compose_child_for_wrap_render!(Background, DirtyPhase::Paint);