Add span method to Line<OriginZeroLine>

src/compute/grid/types/coordinates.rs

@@ -1,7 +1,8 @@
 //! Taffy uses two coordinate systems to refer to grid lines (the gaps/gutters between rows/columns):
 use super::super::types::TrackCounts;
+use crate::geometry::Line;
+use core::cmp::{max, Ordering};
 use core::ops::{Add, AddAssign, Sub};
-use std::cmp::Ordering;
 
 /// Represents a grid line position in "CSS Grid Line" coordinates
 ///
@@ -115,6 +116,13 @@ impl OriginZeroLine {
     }
 }
 
+impl Line<OriginZeroLine> {
+    /// The number of tracks between the start and end lines
+    pub(crate) fn span(self) -> u16 {
+        max(self.end.0 - self.start.0, 0) as u16
+    }
+}
+
 /// A trait for the different coordinates used to define grid lines.
 pub trait GridCoordinate: Copy {}
 impl GridCoordinate for GridLine {}

src/compute/grid/types/grid_item.rs

@@ -10,7 +10,6 @@ use crate::prelude::LayoutTree;
 use crate::resolve::MaybeResolve;
 use crate::style::{AvailableSpace, LengthPercentageAuto, MaxTrackSizingFunction, MinTrackSizingFunction, Style};
 use crate::style_helpers::*;
-use core::cmp::max;
 use core::ops::Range;
 
 /// Represents a single grid item
@@ -111,8 +110,8 @@ impl GridItem {
     /// Returns the number of tracks that this item spans in the specified axis
     pub fn span(&self, axis: AbstractAxis) -> u16 {
         match axis {
-            AbstractAxis::Block => max(self.row.end.0 - self.row.start.0, 0) as u16,
-            AbstractAxis::Inline => max(self.column.end.0 - self.column.start.0, 0) as u16,
+            AbstractAxis::Block => self.row.span(),
+            AbstractAxis::Inline => self.column.span(),
         }
     }