Make `Shrink` have priority over `Fill` in layout

7 files changed, 107 insertions, 78 deletions

diff --git a/core/src/layout.rs b/core/src/layout.rs
index caf315b6..277473fe 100644
--- a/core/src/layout.rs
+++ b/core/src/layout.rs
@@ -71,12 +71,12 @@ pub fn next_to_each_other(
     left: impl FnOnce(&Limits) -> Node,
     right: impl FnOnce(&Limits) -> Node,
 ) -> Node {
-    let mut left_node = left(limits);
+    let left_node = left(limits);
     let left_size = left_node.size();
 
     let right_limits = limits.shrink(Size::new(left_size.width + spacing, 0.0));
 
-    let mut right_node = right(&right_limits);
+    let right_node = right(&right_limits);
     let right_size = right_node.size();
 
     let (left_y, right_y) = if left_size.height > right_size.height {
@@ -85,14 +85,14 @@ pub fn next_to_each_other(
         ((right_size.height - left_size.height) / 2.0, 0.0)
     };
 
-    left_node.move_to(Point::new(0.0, left_y));
-    right_node.move_to(Point::new(left_size.width + spacing, right_y));
-
     Node::with_children(
         Size::new(
             left_size.width + spacing + right_size.width,
             left_size.height.max(right_size.height),
         ),
-        vec![left_node, right_node],
+        vec![
+            left_node.move_to(Point::new(0.0, left_y)),
+            right_node.move_to(Point::new(left_size.width + spacing, right_y)),
+        ],
     )
 }
diff --git a/core/src/layout/flex.rs b/core/src/layout/flex.rs
index c02b63d8..738dc81d 100644
--- a/core/src/layout/flex.rs
+++ b/core/src/layout/flex.rs
@@ -20,7 +20,7 @@ use crate::Element;
 
 use crate::layout::{Limits, Node};
 use crate::widget;
-use crate::{Alignment, Padding, Point, Size};
+use crate::{Alignment, Length, Padding, Point, Size};
 
 /// The main axis of a flex layout.
 #[derive(Debug)]
@@ -63,6 +63,8 @@ pub fn resolve<Message, Renderer>(
     axis: Axis,
     renderer: &Renderer,
     limits: &Limits,
+    width: Length,
+    height: Length,
     padding: Padding,
     spacing: f32,
     align_items: Alignment,
@@ -72,12 +74,12 @@ pub fn resolve<Message, Renderer>(
 where
     Renderer: crate::Renderer,
 {
-    let limits = limits.pad(padding);
+    let limits = limits.width(width).height(height).shrink(padding);
     let total_spacing = spacing * items.len().saturating_sub(1) as f32;
     let max_cross = axis.cross(limits.max());
 
     let mut fill_sum = 0;
-    let mut cross = axis.cross(limits.min()).max(axis.cross(limits.fill()));
+    let mut cross = 0.0f32;
     let mut available = axis.main(limits.max()) - total_spacing;
 
     let mut nodes: Vec<Node> = Vec::with_capacity(items.len());
@@ -109,7 +111,16 @@ where
         }
     }
 
-    let remaining = available.max(0.0);
+    let remaining = match axis {
+        Axis::Horizontal => match width {
+            Length::Shrink => 0.0,
+            _ => available.max(0.0),
+        },
+        Axis::Vertical => match height {
+            Length::Shrink => 0.0,
+            _ => available.max(0.0),
+        },
+    };
 
     for (i, (child, tree)) in items.iter().zip(trees).enumerate() {
         let fill_factor = match axis {
@@ -154,18 +165,18 @@ where
 
         let (x, y) = axis.pack(main, pad.1);
 
-        node.move_to(Point::new(x, y));
+        node.move_to_mut(Point::new(x, y));
 
         match axis {
             Axis::Horizontal => {
-                node.align(
+                node.align_mut(
                     Alignment::Start,
                     align_items,
                     Size::new(0.0, cross),
                 );
             }
             Axis::Vertical => {
-                node.align(
+                node.align_mut(
                     align_items,
                     Alignment::Start,
                     Size::new(cross, 0.0),
@@ -179,7 +190,7 @@ where
     }
 
     let (width, height) = axis.pack(main - pad.0, cross);
-    let size = limits.resolve(Size::new(width, height));
+    let size = limits.resolve(Size::new(width, height), width, height);
 
-    Node::with_children(size.pad(padding), nodes)
+    Node::with_children(size.expand(padding), nodes)
 }
diff --git a/core/src/layout/limits.rs b/core/src/layout/limits.rs
index 39a3d98b..eef4c4c9 100644
--- a/core/src/layout/limits.rs
+++ b/core/src/layout/limits.rs
@@ -1,12 +1,11 @@
 #![allow(clippy::manual_clamp)]
-use crate::{Length, Padding, Size};
+use crate::{Length, Size};
 
 /// A set of size constraints for layouting.
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct Limits {
     min: Size,
     max: Size,
-    fill: Size,
 }
 
 impl Limits {
@@ -14,16 +13,11 @@ impl Limits {
     pub const NONE: Limits = Limits {
         min: Size::ZERO,
         max: Size::INFINITY,
-        fill: Size::INFINITY,
     };
 
     /// Creates new [`Limits`] with the given minimum and maximum [`Size`].
     pub const fn new(min: Size, max: Size) -> Limits {
-        Limits {
-            min,
-            max,
-            fill: Size::INFINITY,
-        }
+        Limits { min, max }
     }
 
     /// Returns the minimum [`Size`] of the [`Limits`].
@@ -36,26 +30,15 @@ impl Limits {
         self.max
     }
 
-    /// Returns the fill [`Size`] of the [`Limits`].
-    pub fn fill(&self) -> Size {
-        self.fill
-    }
-
     /// Applies a width constraint to the current [`Limits`].
     pub fn width(mut self, width: impl Into<Length>) -> Limits {
         match width.into() {
-            Length::Shrink => {
-                self.fill.width = self.min.width;
-            }
-            Length::Fill | Length::FillPortion(_) => {
-                self.fill.width = self.fill.width.min(self.max.width);
-            }
+            Length::Shrink | Length::Fill | Length::FillPortion(_) => {}
             Length::Fixed(amount) => {
                 let new_width = amount.min(self.max.width).max(self.min.width);
 
                 self.min.width = new_width;
                 self.max.width = new_width;
-                self.fill.width = new_width;
             }
         }
 
@@ -65,19 +48,13 @@ impl Limits {
     /// Applies a height constraint to the current [`Limits`].
     pub fn height(mut self, height: impl Into<Length>) -> Limits {
         match height.into() {
-            Length::Shrink => {
-                self.fill.height = self.min.height;
-            }
-            Length::Fill | Length::FillPortion(_) => {
-                self.fill.height = self.fill.height.min(self.max.height);
-            }
+            Length::Shrink | Length::Fill | Length::FillPortion(_) => {}
             Length::Fixed(amount) => {
                 let new_height =
                     amount.min(self.max.height).max(self.min.height);
 
                 self.min.height = new_height;
                 self.max.height = new_height;
-                self.fill.height = new_height;
             }
         }
 
@@ -112,13 +89,10 @@ impl Limits {
         self
     }
 
-    /// Shrinks the current [`Limits`] to account for the given padding.
-    pub fn pad(&self, padding: Padding) -> Limits {
-        self.shrink(Size::new(padding.horizontal(), padding.vertical()))
-    }
-
     /// Shrinks the current [`Limits`] by the given [`Size`].
-    pub fn shrink(&self, size: Size) -> Limits {
+    pub fn shrink(&self, size: impl Into<Size>) -> Limits {
+        let size = size.into();
+
         let min = Size::new(
             (self.min().width - size.width).max(0.0),
             (self.min().height - size.height).max(0.0),
@@ -129,12 +103,7 @@ impl Limits {
             (self.max().height - size.height).max(0.0),
         );
 
-        let fill = Size::new(
-            (self.fill.width - size.width).max(0.0),
-            (self.fill.height - size.height).max(0.0),
-        );
-
-        Limits { min, max, fill }
+        Limits { min, max }
     }
 
     /// Removes the minimum width constraint for the current [`Limits`].
@@ -142,22 +111,38 @@ impl Limits {
         Limits {
             min: Size::ZERO,
             max: self.max,
-            fill: self.fill,
         }
     }
 
     /// Computes the resulting [`Size`] that fits the [`Limits`] given the
     /// intrinsic size of some content.
-    pub fn resolve(&self, intrinsic_size: Size) -> Size {
-        Size::new(
-            intrinsic_size
-                .width
-                .min(self.max.width)
-                .max(self.fill.width),
-            intrinsic_size
+    pub fn resolve(
+        &self,
+        intrinsic_size: Size,
+        width: impl Into<Length>,
+        height: impl Into<Length>,
+    ) -> Size {
+        let width = match width.into() {
+            Length::Fill | Length::FillPortion(_) => self.max.width,
+            Length::Fixed(amount) => {
+                amount.min(self.max.width).max(self.min.width)
+            }
+            Length::Shrink => {
+                intrinsic_size.width.min(self.max.width).max(self.min.width)
+            }
+        };
+
+        let height = match height.into() {
+            Length::Fill | Length::FillPortion(_) => self.max.height,
+            Length::Fixed(amount) => {
+                amount.min(self.max.height).max(self.min.height)
+            }
+            Length::Shrink => intrinsic_size
                 .height
                 .min(self.max.height)
-                .max(self.fill.height),
-        )
+                .max(self.min.height),
+        };
+
+        Size::new(width, height)
     }
 }
diff --git a/core/src/layout/node.rs b/core/src/layout/node.rs
index 2b44a7d5..00087431 100644
--- a/core/src/layout/node.rs
+++ b/core/src/layout/node.rs
@@ -1,4 +1,4 @@
-use crate::{Alignment, Point, Rectangle, Size, Vector};
+use crate::{Alignment, Padding, Point, Rectangle, Size, Vector};
 
 /// The bounds of an element and its children.
 #[derive(Debug, Clone, Default)]
@@ -26,6 +26,14 @@ impl Node {
         }
     }
 
+    /// Creates a new [`Node`] that wraps a single child with some [`Padding`].
+    pub fn container(child: Self, padding: Padding) -> Self {
+        Self::with_children(
+            child.bounds.size().expand(padding),
+            vec![child.move_to(Point::new(padding.left, padding.top))],
+        )
+    }
+
     /// Returns the [`Size`] of the [`Node`].
     pub fn size(&self) -> Size {
         Size::new(self.bounds.width, self.bounds.height)
@@ -43,6 +51,17 @@ impl Node {
 
     /// Aligns the [`Node`] in the given space.
     pub fn align(
+        mut self,
+        horizontal_alignment: Alignment,
+        vertical_alignment: Alignment,
+        space: Size,
+    ) -> Self {
+        self.align_mut(horizontal_alignment, vertical_alignment, space);
+        self
+    }
+
+    /// Mutable reference version of [`align`].
+    pub fn align_mut(
         &mut self,
         horizontal_alignment: Alignment,
         vertical_alignment: Alignment,
@@ -70,7 +89,13 @@ impl Node {
     }
 
     /// Moves the [`Node`] to the given position.
-    pub fn move_to(&mut self, position: Point) {
+    pub fn move_to(mut self, position: Point) -> Self {
+        self.move_to_mut(position);
+        self
+    }
+
+    /// Mutable reference version of [`move_to`].
+    pub fn move_to_mut(&mut self, position: Point) {
         self.bounds.x = position.x;
         self.bounds.y = position.y;
     }
diff --git a/core/src/padding.rs b/core/src/padding.rs
index 0b1bba13..a63f6e29 100644
--- a/core/src/padding.rs
+++ b/core/src/padding.rs
@@ -154,3 +154,9 @@ impl From<[f32; 4]> for Padding {
         }
     }
 }
+
+impl From<Padding> for Size {
+    fn from(padding: Padding) -> Self {
+        Self::new(padding.horizontal(), padding.vertical())
+    }
+}
diff --git a/core/src/size.rs b/core/src/size.rs
index 7ef2f602..90e50d13 100644
--- a/core/src/size.rs
+++ b/core/src/size.rs
@@ -1,4 +1,4 @@
-use crate::{Padding, Vector};
+use crate::Vector;
 
 /// An amount of space in 2 dimensions.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -26,15 +26,7 @@ impl Size {
     /// A [`Size`] with infinite width and height.
     pub const INFINITY: Size = Size::new(f32::INFINITY, f32::INFINITY);
 
-    /// Increments the [`Size`] to account for the given padding.
-    pub fn pad(&self, padding: Padding) -> Self {
-        Size {
-            width: self.width + padding.horizontal(),
-            height: self.height + padding.vertical(),
-        }
-    }
-
-    /// Returns the minimum of each component of this size and another
+    /// Returns the minimum of each component of this size and another.
     pub fn min(self, other: Self) -> Self {
         Size {
             width: self.width.min(other.width),
@@ -42,13 +34,23 @@ impl Size {
         }
     }
 
-    /// Returns the maximum of each component of this size and another
+    /// Returns the maximum of each component of this size and another.
     pub fn max(self, other: Self) -> Self {
         Size {
             width: self.width.max(other.width),
             height: self.height.max(other.height),
         }
     }
+
+    /// Expands this [`Size`] by the given amount.
+    pub fn expand(self, other: impl Into<Size>) -> Self {
+        let other = other.into();
+
+        Size {
+            width: self.width + other.width,
+            height: self.height + other.height,
+        }
+    }
 }
 
 impl From<[f32; 2]> for Size {
diff --git a/core/src/widget/text.rs b/core/src/widget/text.rs
index e020b030..e47e4178 100644
--- a/core/src/widget/text.rs
+++ b/core/src/widget/text.rs
@@ -224,7 +224,7 @@ where
         shaping,
     });
 
-    let size = limits.resolve(paragraph.min_bounds());
+    let size = limits.resolve(paragraph.min_bounds(), width, height);
 
     layout::Node::new(size)
 }