Introduce useful helpers in `layout` module

17 files changed, 50 insertions, 84 deletions

diff --git a/widget/src/button.rs b/widget/src/button.rs
index 1ce4f662..86abee77 100644
--- a/widget/src/button.rs
+++ b/widget/src/button.rs
@@ -10,8 +10,8 @@ use crate::core::touch;
 use crate::core::widget::tree::{self, Tree};
 use crate::core::widget::Operation;
 use crate::core::{
-    Background, Clipboard, Color, Element, Layout, Length, Padding, Point,
-    Rectangle, Shell, Size, Vector, Widget,
+    Background, Clipboard, Color, Element, Layout, Length, Padding, Rectangle,
+    Shell, Size, Vector, Widget,
 };
 
 pub use iced_style::button::{Appearance, StyleSheet};
@@ -430,20 +430,7 @@ pub fn layout(
     padding: Padding,
     layout_content: impl FnOnce(&layout::Limits) -> layout::Node,
 ) -> layout::Node {
-    let limits = limits.width(width).height(height);
-
-    let content = layout_content(&limits.shrink(padding));
-    let padding = padding.fit(content.size(), limits.max());
-
-    let size = limits
-        .shrink(padding)
-        .resolve(content.size(), width, height)
-        .expand(padding);
-
-    layout::Node::with_children(
-        size,
-        vec![content.move_to(Point::new(padding.left, padding.top))],
-    )
+    layout::padded(limits, width, height, padding, layout_content)
 }
 
 /// Returns the [`mouse::Interaction`] of a [`Button`].
diff --git a/widget/src/canvas.rs b/widget/src/canvas.rs
index 2bf09eec..4e42a671 100644
--- a/widget/src/canvas.rs
+++ b/widget/src/canvas.rs
@@ -133,9 +133,7 @@ where
         _renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        let size = limits.resolve(Size::ZERO, self.width, self.height);
-
-        layout::Node::new(size)
+        layout::atomic(limits, self.width, self.height)
     }
 
     fn on_event(
diff --git a/widget/src/container.rs b/widget/src/container.rs
index 93d8daba..c98de41c 100644
--- a/widget/src/container.rs
+++ b/widget/src/container.rs
@@ -321,27 +321,19 @@ pub fn layout(
     vertical_alignment: alignment::Vertical,
     layout_content: impl FnOnce(&layout::Limits) -> layout::Node,
 ) -> layout::Node {
-    let limits = limits
-        .width(width)
-        .height(height)
-        .max_width(max_width)
-        .max_height(max_height);
-
-    let content = layout_content(&limits.shrink(padding).loose());
-    let padding = padding.fit(content.size(), limits.max());
-    let size = limits
-        .shrink(padding)
-        .resolve(content.size(), width, height);
-
-    layout::Node::with_children(
-        size.expand(padding),
-        vec![content
-            .move_to(Point::new(padding.left, padding.top))
-            .align(
+    layout::positioned(
+        &limits.max_width(max_width).max_height(max_height),
+        width,
+        height,
+        padding,
+        |limits| layout_content(&limits.loose()),
+        |content, size| {
+            content.align(
                 Alignment::from(horizontal_alignment),
                 Alignment::from(vertical_alignment),
                 size,
-            )],
+            )
+        },
     )
 }
 
diff --git a/widget/src/image.rs b/widget/src/image.rs
index 6750c1b3..e906ac13 100644
--- a/widget/src/image.rs
+++ b/widget/src/image.rs
@@ -99,7 +99,7 @@ where
     };
 
     // The size to be available to the widget prior to `Shrink`ing
-    let raw_size = limits.resolve(image_size, width, height);
+    let raw_size = limits.resolve(width, height, image_size);
 
     // The uncropped size of the image when fit to the bounds above
     let full_size = content_fit.fit(image_size, raw_size);
diff --git a/widget/src/image/viewer.rs b/widget/src/image/viewer.rs
index dc910f1f..98080577 100644
--- a/widget/src/image/viewer.rs
+++ b/widget/src/image/viewer.rs
@@ -113,9 +113,9 @@ where
         let Size { width, height } = renderer.dimensions(&self.handle);
 
         let mut size = limits.resolve(
-            Size::new(width as f32, height as f32),
             self.width,
             self.height,
+            Size::new(width as f32, height as f32),
         );
 
         let expansion_size = if height > width {
diff --git a/widget/src/overlay/menu.rs b/widget/src/overlay/menu.rs
index b9e06de8..f83eebea 100644
--- a/widget/src/overlay/menu.rs
+++ b/widget/src/overlay/menu.rs
@@ -369,7 +369,7 @@ where
                     * self.options.len() as f32,
             );
 
-            limits.resolve(intrinsic, Length::Fill, Length::Shrink)
+            limits.resolve(Length::Fill, Length::Shrink, intrinsic)
         };
 
         layout::Node::new(size)
diff --git a/widget/src/pane_grid.rs b/widget/src/pane_grid.rs
index 36c785b7..cf1f0455 100644
--- a/widget/src/pane_grid.rs
+++ b/widget/src/pane_grid.rs
@@ -489,7 +489,7 @@ pub fn layout<Renderer, T>(
         &layout::Limits,
     ) -> layout::Node,
 ) -> layout::Node {
-    let size = limits.resolve(Size::ZERO, width, height);
+    let size = limits.resolve(width, height, Size::ZERO);
 
     let regions = node.pane_regions(spacing, size);
     let children = contents
diff --git a/widget/src/pick_list.rs b/widget/src/pick_list.rs
index d83b0624..2576a1e8 100644
--- a/widget/src/pick_list.rs
+++ b/widget/src/pick_list.rs
@@ -392,7 +392,6 @@ where
 {
     use std::f32;
 
-    let limits = limits.width(width).height(Length::Shrink);
     let font = font.unwrap_or_else(|| renderer.default_font());
     let text_size = text_size.unwrap_or_else(|| renderer.default_size());
 
@@ -451,8 +450,10 @@ where
         );
 
         limits
+            .width(width)
+            .height(Length::Shrink)
             .shrink(padding)
-            .resolve(intrinsic, width, Length::Shrink)
+            .resolve(width, Length::Shrink, intrinsic)
             .expand(padding)
     };
 
diff --git a/widget/src/progress_bar.rs b/widget/src/progress_bar.rs
index a05923a2..15f1277b 100644
--- a/widget/src/progress_bar.rs
+++ b/widget/src/progress_bar.rs
@@ -98,13 +98,11 @@ where
         _renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        let size = limits.resolve(
-            Size::ZERO,
+        layout::atomic(
+            limits,
             self.width,
             self.height.unwrap_or(Length::Fixed(Self::DEFAULT_HEIGHT)),
-        );
-
-        layout::Node::new(size)
+        )
     }
 
     fn draw(
diff --git a/widget/src/rule.rs b/widget/src/rule.rs
index 4ab16c40..cded9cb1 100644
--- a/widget/src/rule.rs
+++ b/widget/src/rule.rs
@@ -75,7 +75,7 @@ where
         _renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        layout::Node::new(limits.resolve(Size::ZERO, self.width, self.height))
+        layout::atomic(limits, self.width, self.height)
     }
 
     fn draw(
diff --git a/widget/src/scrollable.rs b/widget/src/scrollable.rs
index 5197afde..70db490a 100644
--- a/widget/src/scrollable.rs
+++ b/widget/src/scrollable.rs
@@ -469,28 +469,25 @@ pub fn layout<Renderer>(
     direction: &Direction,
     layout_content: impl FnOnce(&Renderer, &layout::Limits) -> layout::Node,
 ) -> layout::Node {
-    let limits = limits.width(width).height(height);
-
-    let child_limits = layout::Limits::new(
-        Size::new(limits.min().width, limits.min().height),
-        Size::new(
-            if direction.horizontal().is_some() {
-                f32::INFINITY
-            } else {
-                limits.max().width
-            },
-            if direction.vertical().is_some() {
-                f32::MAX
-            } else {
-                limits.max().height
-            },
-        ),
-    );
-
-    let content = layout_content(renderer, &child_limits);
-    let size = limits.resolve(content.size(), width, height);
+    layout::contained(limits, width, height, |limits| {
+        let child_limits = layout::Limits::new(
+            Size::new(limits.min().width, limits.min().height),
+            Size::new(
+                if direction.horizontal().is_some() {
+                    f32::INFINITY
+                } else {
+                    limits.max().width
+                },
+                if direction.vertical().is_some() {
+                    f32::MAX
+                } else {
+                    limits.max().height
+                },
+            ),
+        );
 
-    layout::Node::with_children(size, vec![content])
+        layout_content(renderer, &child_limits)
+    })
 }
 
 /// Processes an [`Event`] and updates the [`State`] of a [`Scrollable`]
diff --git a/widget/src/shader.rs b/widget/src/shader.rs
index 82432c6c..16b68c55 100644
--- a/widget/src/shader.rs
+++ b/widget/src/shader.rs
@@ -83,10 +83,7 @@ where
         _renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        let limits = limits.width(self.width).height(self.height);
-        let size = limits.resolve(Size::ZERO, self.width, self.height);
-
-        layout::Node::new(size)
+        layout::atomic(limits, self.width, self.height)
     }
 
     fn on_event(
diff --git a/widget/src/slider.rs b/widget/src/slider.rs
index 27588852..1bc94661 100644
--- a/widget/src/slider.rs
+++ b/widget/src/slider.rs
@@ -172,9 +172,7 @@ where
         _renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        let size = limits.resolve(Size::ZERO, self.width, self.height);
-
-        layout::Node::new(size)
+        layout::atomic(limits, self.width, self.height)
     }
 
     fn on_event(
diff --git a/widget/src/space.rs b/widget/src/space.rs
index 9fd4dcb9..eef990d1 100644
--- a/widget/src/space.rs
+++ b/widget/src/space.rs
@@ -58,7 +58,7 @@ where
         _renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        layout::Node::new(limits.resolve(Size::ZERO, self.width, self.height))
+        layout::atomic(limits, self.width, self.height)
     }
 
     fn draw(
diff --git a/widget/src/svg.rs b/widget/src/svg.rs
index 75ab238a..830abb0f 100644
--- a/widget/src/svg.rs
+++ b/widget/src/svg.rs
@@ -114,7 +114,7 @@ where
         let image_size = Size::new(width as f32, height as f32);
 
         // The size to be available to the widget prior to `Shrink`ing
-        let raw_size = limits.resolve(image_size, self.width, self.height);
+        let raw_size = limits.resolve(self.width, self.height, image_size);
 
         // The uncropped size of the image when fit to the bounds above
         let full_size = self.content_fit.fit(image_size, raw_size);
diff --git a/widget/src/text_input.rs b/widget/src/text_input.rs
index 7e91105c..d8540658 100644
--- a/widget/src/text_input.rs
+++ b/widget/src/text_input.rs
@@ -508,8 +508,8 @@ where
     let padding = padding.fit(Size::ZERO, limits.max());
     let height = line_height.to_absolute(text_size);
 
-    let limits = limits.width(width).shrink(padding).height(height);
-    let text_bounds = limits.resolve(Size::ZERO, width, height);
+    let limits = limits.width(width).shrink(padding);
+    let text_bounds = limits.resolve(width, height, Size::ZERO);
 
     let placeholder_text = Text {
         font,
diff --git a/widget/src/vertical_slider.rs b/widget/src/vertical_slider.rs
index 35bc2fe2..a3029d76 100644
--- a/widget/src/vertical_slider.rs
+++ b/widget/src/vertical_slider.rs
@@ -169,9 +169,7 @@ where
         _renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        let size = limits.resolve(Size::ZERO, self.width, self.height);
-
-        layout::Node::new(size)
+        layout::atomic(limits, self.width, self.height)
     }
 
     fn on_event(