Introduce a Units trait

examples/custom_tree_owned_partial.rs

@@ -13,7 +13,7 @@ use common::image::{image_measure_function, ImageContext};
 use common::text::{text_measure_function, FontMetrics, TextContext, WritingMode, LOREM_IPSUM};
 use taffy::{
     compute_cached_layout, compute_flexbox_layout, compute_grid_layout, compute_leaf_layout, compute_root_layout,
-    prelude::*, Cache, CacheTree, Layout, Style,
+    prelude::*, Cache, CacheTree, DefaultUnits, Layout, Style,
 };
 
 #[derive(Debug, Copy, Clone)]
@@ -138,7 +138,7 @@ impl taffy::LayoutPartialTree for Node {
     where
         Self: 'a;
 
-    type CustomIdent = String;
+    type Units = DefaultUnits;
 
     fn get_core_container_style(&self, node_id: NodeId) -> Self::CoreContainerStyle<'_> {
         &self.node_from_id(node_id).style

examples/custom_tree_owned_unsafe.rs

@@ -9,7 +9,7 @@ use taffy::tree::Cache;
 use taffy::util::print_tree;
 use taffy::{
     compute_cached_layout, compute_flexbox_layout, compute_grid_layout, compute_leaf_layout, compute_root_layout,
-    prelude::*, round_layout, CacheTree,
+    prelude::*, round_layout, CacheTree, DefaultUnits,
 };
 
 #[derive(Debug, Copy, Clone)]
@@ -136,7 +136,7 @@ impl LayoutPartialTree for StatelessLayoutTree {
     where
         Self: 'a;
 
-    type CustomIdent = String;
+    type Units = DefaultUnits;
 
     fn get_core_container_style(&self, node_id: NodeId) -> Self::CoreContainerStyle<'_> {
         unsafe { &node_from_id(node_id).style }

examples/custom_tree_vec.rs

@@ -7,7 +7,7 @@ use common::text::{text_measure_function, FontMetrics, TextContext, WritingMode,
 use taffy::util::print_tree;
 use taffy::{
     compute_cached_layout, compute_flexbox_layout, compute_grid_layout, compute_leaf_layout, compute_root_layout,
-    prelude::*, round_layout, Cache, CacheTree,
+    prelude::*, round_layout, Cache, CacheTree, DefaultUnits,
 };
 
 #[derive(Debug, Copy, Clone)]
@@ -139,7 +139,7 @@ impl taffy::TraversePartialTree for Tree {
 impl taffy::TraverseTree for Tree {}
 
 impl taffy::LayoutPartialTree for Tree {
-    type CustomIdent = String;
+    type Units = DefaultUnits;
 
     type CoreContainerStyle<'a>
         = &'a Style

src/compute/grid/explicit_grid.rs

@@ -323,7 +323,7 @@ mod test {
     use crate::compute::grid::util::*;
     use crate::geometry::AbsoluteAxis;
     use crate::prelude::*;
-    use crate::sys::DefaultCheapStr;
+    use crate::DefaultUnits;
 
     #[test]
     fn explicit_grid_sizing_no_repeats() {
@@ -352,7 +352,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_auto_fill_exact_fit() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             size: Size { width: length(120.0), height: length(80.0) },
             grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
@@ -383,7 +383,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_auto_fill_non_exact_fit() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             size: Size { width: length(140.0), height: length(90.0) },
             grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
@@ -414,7 +414,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_auto_fill_min_size_exact_fit() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             min_size: Size { width: length(120.0), height: length(80.0) },
             grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
@@ -445,7 +445,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_auto_fill_min_size_non_exact_fit() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             min_size: Size { width: length(140.0), height: length(90.0) },
             grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
@@ -476,7 +476,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_auto_fill_multiple_repeated_tracks() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             size: Size { width: length(140.0), height: length(100.0) },
             grid_template_columns: vec![repeat(AutoFill, vec![length(40.0), length(20.0)])],
@@ -507,7 +507,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_auto_fill_gap() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             size: Size { width: length(140.0), height: length(100.0) },
             grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
@@ -539,7 +539,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_no_defined_size() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             grid_template_columns: vec![repeat(AutoFill, vec![length(40.0), percent(0.5), length(20.0)])],
             grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])],
@@ -570,7 +570,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_mix_repeated_and_non_repeated() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             size: Size { width: length(140.0), height: length(100.0) },
             grid_template_columns: vec![length(20.0), repeat(AutoFill, vec![length(40.0)])],
@@ -602,7 +602,7 @@ mod test {
     #[test]
     fn explicit_grid_sizing_mix_with_padding() {
         use RepetitionCount::AutoFill;
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             size: Size { width: length(120.0), height: length(120.0) },
             padding: Rect { left: length(10.0), right: length(10.0), top: length(20.0), bottom: length(20.0) },
@@ -642,7 +642,7 @@ mod test {
         let maxpx100 = MaxTrackSizingFunction::from_length(100.0);
 
         // Setup test
-        let grid_style: Style<DefaultCheapStr> = Style {
+        let grid_style: Style<DefaultUnits> = Style {
             display: Display::Grid,
             gap: length(20.0),
             grid_template_columns: vec![length(100.0), minmax(length(100.0), fr(2.0)), fr(1.0)],

src/compute/grid/implicit_grid.rs

@@ -2,7 +2,7 @@
 //! to reduce the number of allocations required when creating a grid.
 use crate::geometry::Line;
 use crate::style::{GenericGridPlacement, GridPlacement};
-use crate::{CheapCloneStr, GridItemStyle};
+use crate::{CheapCloneStr, GridItemStyle, Units};
 use core::cmp::{max, min};
 
 use super::types::TrackCounts;
@@ -72,9 +72,9 @@ fn get_known_child_positions<'a, S: GridItemStyle + 'a>(
         // Note: that the children reference the lines in between (and around) the tracks not tracks themselves,
         // and thus we must subtract 1 to get an accurate estimate of the number of tracks
         let (child_col_min, child_col_max, child_col_span) =
-            child_min_line_max_line_span::<S::CustomIdent>(child_style.grid_column(), explicit_col_count);
+            child_min_line_max_line_span::<<S::Units as Units>::Str>(child_style.grid_column(), explicit_col_count);
         let (child_row_min, child_row_max, child_row_span) =
-            child_min_line_max_line_span::<S::CustomIdent>(child_style.grid_row(), explicit_row_count);
+            child_min_line_max_line_span::<<S::Units as Units>::Str>(child_style.grid_row(), explicit_row_count);
         col_min = min(col_min, child_col_min);
         col_max = max(col_max, child_col_max);
         col_max_span = max(col_max_span, child_col_span);

src/compute/grid/placement.rs

@@ -7,7 +7,7 @@ use crate::geometry::{AbsoluteAxis, InBothAbsAxis};
 use crate::style::{AlignItems, GridAutoFlow, OriginZeroGridPlacement};
 use crate::tree::NodeId;
 use crate::util::sys::Vec;
-use crate::{CoreStyle, GridItemStyle};
+use crate::GridItemStyle;
 
 /// 8.5. Grid Item Placement Algorithm
 /// Place items into the grid, generating new rows/column into the implicit grid as required
@@ -20,7 +20,7 @@ pub(super) fn place_grid_items<'a, S, ChildIter>(
     grid_auto_flow: GridAutoFlow,
     align_items: AlignItems,
     justify_items: AlignItems,
-    named_line_resolver: &NamedLineResolver<<S as CoreStyle>::CustomIdent>,
+    named_line_resolver: &NamedLineResolver<S::Units>,
 ) where
     S: GridItemStyle + 'a,
     ChildIter: Iterator<Item = (usize, NodeId, S)>,

src/compute/grid/types/named.rs

@@ -2,7 +2,7 @@
 
 use crate::{
     CheapCloneStr, GenericGridTemplateComponent, GenericRepetition as _, GridAreaAxis, GridAreaEnd, GridContainerStyle,
-    GridPlacement, GridTemplateArea, Line, NonNamedGridPlacement, RepetitionCount,
+    GridPlacement, GridTemplateArea, Line, NonNamedGridPlacement, RepetitionCount, Units,
 };
 use core::{borrow::Borrow, cmp::Ordering, fmt::Debug};
 
@@ -44,15 +44,15 @@ impl<T: CheapCloneStr> Borrow<str> for StrHasher<T> {
 
 /// Resolver that takes grid lines names and area names as input and can then be used to
 /// resolve line names of grid placement properties into line numbers.
-pub(crate) struct NamedLineResolver<S: CheapCloneStr> {
+pub(crate) struct NamedLineResolver<U: Units> {
     /// Map of row line names to line numbers. Each line name may correspond to multiple lines
     /// so we store a `Vec`
-    row_lines: Map<StrHasher<S>, Vec<u16>>,
+    row_lines: Map<StrHasher<U::Str>, Vec<u16>>,
     /// Map of column line names to line numbers. Each line name may correspond to multiple lines
     /// so we store a `Vec`
-    column_lines: Map<StrHasher<S>, Vec<u16>>,
+    column_lines: Map<StrHasher<U::Str>, Vec<u16>>,
     /// Map of area names to area definitions (start and end lines numbers in each axis)
-    areas: Map<StrHasher<S>, GridTemplateArea<S>>,
+    areas: Map<StrHasher<U::Str>, GridTemplateArea<U::Str>>,
     /// Number of columns implied by grid area definitions
     area_column_count: u16,
     /// Number of rows implied by grid area definitions
@@ -70,16 +70,16 @@ fn upsert_line_name_map<S: CheapCloneStr>(map: &mut Map<StrHasher<S>, Vec<u16>>,
     map.entry(StrHasher(key)).and_modify(|lines| lines.push(value)).or_insert_with(|| single_value_vec(value));
 }
 
-impl<S: CheapCloneStr> NamedLineResolver<S> {
+impl<U: Units> NamedLineResolver<U> {
     /// Create and initialise a new `NamedLineResolver`
     pub(crate) fn new(
-        style: &impl GridContainerStyle<CustomIdent = S>,
+        style: &impl GridContainerStyle<Units = U>,
         column_auto_repetitions: u16,
         row_auto_repetitions: u16,
     ) -> Self {
-        let mut areas: Map<StrHasher<S>, GridTemplateArea<_>> = Map::new();
-        let mut column_lines: Map<StrHasher<S>, Vec<u16>> = Map::new();
-        let mut row_lines: Map<StrHasher<S>, Vec<u16>> = Map::new();
+        let mut areas: Map<StrHasher<U::Str>, GridTemplateArea<_>> = Map::new();
+        let mut column_lines: Map<StrHasher<U::Str>, Vec<u16>> = Map::new();
+        let mut row_lines: Map<StrHasher<U::Str>, Vec<u16>> = Map::new();
 
         let mut area_column_count = 0;
         let mut area_row_count = 0;
@@ -91,13 +91,13 @@ impl<S: CheapCloneStr> NamedLineResolver<S> {
                 area_column_count = area_column_count.max(area.column_end.max(1) - 1);
                 area_row_count = area_row_count.max(area.row_end.max(1) - 1);
 
-                let col_start_name = S::from(format!("{}-start", area.name.as_ref()));
+                let col_start_name = U::Str::from(format!("{}-start", area.name.as_ref()));
                 upsert_line_name_map(&mut column_lines, col_start_name, area.column_start);
-                let col_end_name = S::from(format!("{}-end", area.name.as_ref()));
+                let col_end_name = U::Str::from(format!("{}-end", area.name.as_ref()));
                 upsert_line_name_map(&mut column_lines, col_end_name, area.column_end);
-                let row_start_name = S::from(format!("{}-start", area.name.as_ref()));
+                let row_start_name = U::Str::from(format!("{}-start", area.name.as_ref()));
                 upsert_line_name_map(&mut row_lines, row_start_name, area.row_start);
-                let row_end_name = S::from(format!("{}-end", area.name.as_ref()));
+                let row_end_name = U::Str::from(format!("{}-end", area.name.as_ref()));
                 upsert_line_name_map(&mut row_lines, row_end_name, area.row_end);
             }
         }
@@ -197,21 +197,21 @@ impl<S: CheapCloneStr> NamedLineResolver<S> {
 
     /// Resolve named lines for both the `start` and `end` of a row-axis grid placement
     #[inline(always)]
-    pub(crate) fn resolve_row_names(&self, line: &Line<GridPlacement<S>>) -> Line<NonNamedGridPlacement> {
+    pub(crate) fn resolve_row_names(&self, line: &Line<GridPlacement<U::Str>>) -> Line<NonNamedGridPlacement> {
         self.resolve_line_names(line, GridAreaAxis::Row)
     }
 
     /// Resolve named lines for both the `start` and `end` of a column-axis grid placement
     #[inline(always)]
-    pub(crate) fn resolve_column_names(&self, line: &Line<GridPlacement<S>>) -> Line<NonNamedGridPlacement> {
+    pub(crate) fn resolve_column_names(&self, line: &Line<GridPlacement<U::Str>>) -> Line<NonNamedGridPlacement> {
         self.resolve_line_names(line, GridAreaAxis::Column)
     }
 
     /// Resolve named lines for both the `start` and `end` of a grid placement
     #[inline(always)]
     pub(crate) fn resolve_line_names(
         &self,
-        line: &Line<GridPlacement<S>>,
+        line: &Line<GridPlacement<U::Str>>,
         axis: GridAreaAxis,
     ) -> Line<NonNamedGridPlacement> {
         let start_holder;
@@ -293,7 +293,7 @@ impl<S: CheapCloneStr> NamedLineResolver<S> {
     /// Resolve the grid line for a named grid line or span
     fn find_line_index(
         &self,
-        name: &S,
+        name: &U::Str,
         idx: i16,
         axis: GridAreaAxis,
         end: GridAreaEnd,
@@ -390,7 +390,7 @@ impl<S: CheapCloneStr> NamedLineResolver<S> {
     }
 }
 
-impl<S: CheapCloneStr> Debug for NamedLineResolver<S> {
+impl<U: Units> Debug for NamedLineResolver<U> {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         writeln!(f, "Grid Areas:")?;
         for area in self.areas.values() {

src/compute/grid/util/test_helpers.rs

@@ -1,7 +1,7 @@
 //! Helpers for use in unit tests within the grid module
 use super::super::OriginZeroLine;
-use crate::prelude::*;
 use crate::style::{Dimension, GridPlacement, Style};
+use crate::{prelude::*, DefaultUnits};
 
 pub(crate) trait CreateParentTestNode {
     fn into_grid(self) -> Style;
@@ -23,7 +23,7 @@ pub(crate) trait CreateChildTestNode {
 impl CreateChildTestNode
     for (GridPlacement<String>, GridPlacement<String>, GridPlacement<String>, GridPlacement<String>)
 {
-    fn into_grid_child(self) -> Style<String> {
+    fn into_grid_child(self) -> Style<DefaultUnits> {
         Style {
             display: Display::Grid,
             grid_column: Line { start: self.0, end: self.1 },

src/style/block.rs

@@ -6,7 +6,7 @@ pub trait BlockContainerStyle: CoreStyle {
     /// Defines which row in the grid the item should start and end at
     #[inline(always)]
     fn text_align(&self) -> TextAlign {
-        Style::<Self::CustomIdent>::DEFAULT.text_align
+        Style::<Self::Units>::DEFAULT.text_align
     }
 }