//! Helper functions for initialising GridTrack's from styles //! This mainly consists of evaluating GridAutoTracks use super::types::{GridTrack, TrackCounts}; use crate::geometry::{AbsoluteAxis, Size}; use crate::style::{GridTrackRepetition, LengthPercentage, NonRepeatedTrackSizingFunction, TrackSizingFunction}; use crate::style_helpers::TaffyAuto; use crate::util::sys::{ceil, floor, Vec}; use crate::util::MaybeMath; use crate::util::ResolveOrZero; use crate::{GridContainerStyle, MaybeResolve}; /// Compute the number of rows and columns in the explicit grid pub(crate) fn compute_explicit_grid_size_in_axis( style: &impl GridContainerStyle, template: &[TrackSizingFunction], inner_container_size: Size>, axis: AbsoluteAxis, ) -> u16 { // If template contains no tracks, then there are trivially zero explicit tracks if template.is_empty() { return 0; } // If there are any repetitions that contains no tracks, then the whole definition should be considered invalid // and we default to no explicit tracks let template_has_repetitions_with_zero_tracks = template.iter().any(|track_def| match track_def { TrackSizingFunction::Single(_) => false, TrackSizingFunction::Repeat(_, tracks) => tracks.is_empty(), }); if template_has_repetitions_with_zero_tracks { return 0; } // Compute that number of track generated by single track definition and repetitions with a fixed repetition count let non_auto_repeating_track_count = template .iter() .map(|track_def| { use GridTrackRepetition::{AutoFill, AutoFit, Count}; match track_def { TrackSizingFunction::Single(_) => 1, TrackSizingFunction::Repeat(Count(count), tracks) => count * tracks.len() as u16, TrackSizingFunction::Repeat(AutoFit | AutoFill, _) => 0, } }) .sum::(); let auto_repetition_count = template.iter().filter(|track_def| track_def.is_auto_repetition()).count() as u16; let all_track_defs_have_fixed_component = template.iter().all(|track_def| match track_def { TrackSizingFunction::Single(sizing_function) => sizing_function.has_fixed_component(), TrackSizingFunction::Repeat(_, tracks) => { tracks.iter().all(|sizing_function| sizing_function.has_fixed_component()) } }); let template_is_valid = auto_repetition_count == 0 || (auto_repetition_count == 1 && all_track_defs_have_fixed_component); // If the template is invalid because it contains multiple auto-repetition definitions or it combines an auto-repetition // definition with non-fixed-size track sizing functions, then disregard it entirely and default to zero explicit tracks if !template_is_valid { return 0; } // If there are no repetitions, then the number of explicit tracks is simply equal to the lengths of the track definition // vector (as each item in the Vec represents one track). if auto_repetition_count == 0 { return non_auto_repeating_track_count; } let repetition_definition = template .iter() .find_map(|def| { use GridTrackRepetition::{AutoFill, AutoFit, Count}; match def { TrackSizingFunction::Single(_) => None, TrackSizingFunction::Repeat(Count(_), _) => None, TrackSizingFunction::Repeat(AutoFit | AutoFill, tracks) => Some(tracks), } }) .unwrap(); let repetition_track_count = repetition_definition.len() as u16; // Otherwise, run logic to resolve the auto-repeated track count: // // If the grid container has a definite size or max size in the relevant axis: // - then the number of repetitions is the largest possible positive integer that does not cause the grid to overflow the content // box of its grid container. // Otherwise, if the grid container has a definite min size in the relevant axis: // - then the number of repetitions is the smallest possible positive integer that fulfills that minimum requirement // Otherwise, the specified track list repeats only once. let style_size_is_definite = style.size().get_abs(axis).maybe_resolve(inner_container_size.get_abs(axis)).is_some(); let style_max_size_is_definite = style.max_size().get_abs(axis).maybe_resolve(inner_container_size.get_abs(axis)).is_some(); let size_is_maximum = style_size_is_definite | style_max_size_is_definite; // Determine the number of repetitions let num_repetitions: u16 = match inner_container_size.get_abs(axis) { None => 1, Some(inner_container_size) => { let parent_size = Some(inner_container_size); /// ...treating each track as its max track sizing function if that is definite or as its minimum track sizing function /// otherwise, flooring the max track sizing function by the min track sizing function if both are definite fn track_definite_value(sizing_function: &NonRepeatedTrackSizingFunction, parent_size: Option) -> f32 { let max_size = sizing_function.max.definite_value(parent_size); let min_size = sizing_function.min.definite_value(parent_size); max_size.map(|max| max.maybe_min(min_size)).or(min_size).unwrap() } let non_repeating_track_used_space: f32 = template .iter() .map(|track_def| { use GridTrackRepetition::{AutoFill, AutoFit, Count}; match track_def { TrackSizingFunction::Single(sizing_function) => { track_definite_value(sizing_function, parent_size) } TrackSizingFunction::Repeat(Count(count), repeated_tracks) => { let sum = repeated_tracks .iter() .map(|sizing_function| track_definite_value(sizing_function, parent_size)) .sum::(); sum * (*count as f32) } TrackSizingFunction::Repeat(AutoFit | AutoFill, _) => 0.0, } }) .sum(); let gap_size = style.gap().get_abs(axis).resolve_or_zero(Some(inner_container_size)); // Compute the amount of space that a single repetition of the repeated track list takes let per_repetition_track_used_space: f32 = repetition_definition .iter() .map(|sizing_function| track_definite_value(sizing_function, parent_size)) .sum::(); // We special case the first repetition here because the number of gaps in the first repetition // depends on the number of non-repeating tracks in the template let first_repetition_and_non_repeating_tracks_used_space = non_repeating_track_used_space + per_repetition_track_used_space + ((non_auto_repeating_track_count + repetition_track_count).saturating_sub(1) as f32 * gap_size); // If a single repetition already overflows the container then we return 1 as the repetition count // (the number of repetitions is floored at 1) if first_repetition_and_non_repeating_tracks_used_space > inner_container_size { 1u16 } else { let per_repetition_gap_used_space = (repetition_definition.len() as f32) * gap_size; let per_repetition_used_space = per_repetition_track_used_space + per_repetition_gap_used_space; let num_repetition_that_fit = (inner_container_size - first_repetition_and_non_repeating_tracks_used_space) / per_repetition_used_space; // If the container size is a preferred or maximum size: // Then we return the maximum number of repetitions that fit into the container without overflowing. // If the container size is a minimum size: // - Then we return the minimum number of repetitions required to overflow the size. // // In all cases we add the additional repetition that was already accounted for in the special-case computation above if size_is_maximum { (floor(num_repetition_that_fit) as u16) + 1 } else { (ceil(num_repetition_that_fit) as u16) + 1 } } } }; non_auto_repeating_track_count + (repetition_track_count * num_repetitions) } /// Resolve the track sizing functions of explicit tracks, automatically created tracks, and gutters /// given a set of track counts and all of the relevant styles pub(super) fn initialize_grid_tracks( tracks: &mut Vec, counts: TrackCounts, track_template: &[TrackSizingFunction], auto_tracks: &[NonRepeatedTrackSizingFunction], gap: LengthPercentage, track_has_items: impl Fn(usize) -> bool, ) { // Clear vector (in case this is a re-layout), reserve space for all tracks ahead of time to reduce allocations, // and push the initial gutter tracks.clear(); tracks.reserve((counts.len() * 2) + 1); tracks.push(GridTrack::gutter(gap)); // Create negative implicit tracks if counts.negative_implicit > 0 { if auto_tracks.is_empty() { let iter = core::iter::repeat(NonRepeatedTrackSizingFunction::AUTO); create_implicit_tracks(tracks, counts.negative_implicit, iter, gap) } else { let offset = auto_tracks.len() - (counts.negative_implicit as usize % auto_tracks.len()); let iter = auto_tracks.iter().copied().cycle().skip(offset); create_implicit_tracks(tracks, counts.negative_implicit, iter, gap) } } let mut current_track_index = (counts.negative_implicit) as usize; // Create explicit tracks // An explicit check against the count (rather than just relying on track_template being empty) is required here // because a count of zero can result from the track_template being invalid, in which case it should be ignored. if counts.explicit > 0 { track_template.iter().for_each(|track_sizing_function| { use GridTrackRepetition::{AutoFill, AutoFit, Count}; match track_sizing_function { TrackSizingFunction::Single(sizing_function) => { tracks.push(GridTrack::new( sizing_function.min_sizing_function(), sizing_function.max_sizing_function(), )); tracks.push(GridTrack::gutter(gap)); current_track_index += 1; } TrackSizingFunction::Repeat(Count(count), repeated_tracks) => { let track_iter = repeated_tracks.iter().cycle().take(repeated_tracks.len() * *count as usize); track_iter.for_each(|sizing_function| { tracks.push(GridTrack::new( sizing_function.min_sizing_function(), sizing_function.max_sizing_function(), )); tracks.push(GridTrack::gutter(gap)); current_track_index += 1; }); } TrackSizingFunction::Repeat(repetition_kind @ (AutoFit | AutoFill), repeated_tracks) => { let auto_repeated_track_count = (counts.explicit - (track_template.len() as u16 - 1)) as usize; let iter = repeated_tracks.iter().copied().cycle(); for track_def in iter.take(auto_repeated_track_count) { let mut track = GridTrack::new(track_def.min_sizing_function(), track_def.max_sizing_function()); let mut gutter = GridTrack::gutter(gap); // Auto-fit tracks that don't contain should be collapsed. if *repetition_kind == AutoFit && !track_has_items(current_track_index) { track.collapse(); gutter.collapse(); } tracks.push(track); tracks.push(gutter); current_track_index += 1; } } } }); } // Create positive implicit tracks if auto_tracks.is_empty() { let iter = core::iter::repeat(NonRepeatedTrackSizingFunction::AUTO); create_implicit_tracks(tracks, counts.positive_implicit, iter, gap) } else { let iter = auto_tracks.iter().copied().cycle(); create_implicit_tracks(tracks, counts.positive_implicit, iter, gap) } // Mark first and last grid lines as collapsed tracks.first_mut().unwrap().collapse(); tracks.last_mut().unwrap().collapse(); } /// Utility function for repeating logic of creating implicit tracks fn create_implicit_tracks( tracks: &mut Vec, count: u16, mut auto_tracks_iter: impl Iterator, gap: LengthPercentage, ) { for _ in 0..count { let track_def = auto_tracks_iter.next().unwrap(); tracks.push(GridTrack::new(track_def.min_sizing_function(), track_def.max_sizing_function())); tracks.push(GridTrack::gutter(gap)); } } #[cfg(test)] mod test { use super::compute_explicit_grid_size_in_axis; use super::initialize_grid_tracks; use crate::compute::grid::types::GridTrackKind; use crate::compute::grid::types::TrackCounts; use crate::compute::grid::util::*; use crate::geometry::AbsoluteAxis; use crate::prelude::*; #[test] fn explicit_grid_sizing_no_repeats() { let grid_style = (600.0, 600.0, 2, 4).into_grid(); let preferred_size = grid_style.size.map(|s| s.into_option()); let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, preferred_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, preferred_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 2); assert_eq!(height, 4); } #[test] fn explicit_grid_sizing_auto_fill_exact_fit() { use GridTrackRepetition::AutoFill; let grid_style = Style { display: Display::Grid, size: Size { width: length(120.0), height: length(80.0) }, grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])], grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])], ..Default::default() }; let preferred_size = grid_style.size.map(|s| s.into_option()); let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, preferred_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, preferred_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 3); assert_eq!(height, 4); } #[test] fn explicit_grid_sizing_auto_fill_non_exact_fit() { use GridTrackRepetition::AutoFill; let grid_style = Style { display: Display::Grid, size: Size { width: length(140.0), height: length(90.0) }, grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])], grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])], ..Default::default() }; let preferred_size = grid_style.size.map(|s| s.into_option()); let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, preferred_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, preferred_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 3); assert_eq!(height, 4); } #[test] fn explicit_grid_sizing_auto_fill_min_size_exact_fit() { use GridTrackRepetition::AutoFill; let grid_style = 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)])], grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])], ..Default::default() }; let inner_container_size = Size { width: Some(120.0), height: Some(80.0) }; let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, inner_container_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, inner_container_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 3); assert_eq!(height, 4); } #[test] fn explicit_grid_sizing_auto_fill_min_size_non_exact_fit() { use GridTrackRepetition::AutoFill; let grid_style = 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)])], grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])], ..Default::default() }; let inner_container_size = Size { width: Some(140.0), height: Some(90.0) }; let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, inner_container_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, inner_container_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 4); assert_eq!(height, 5); } #[test] fn explicit_grid_sizing_auto_fill_multiple_repeated_tracks() { use GridTrackRepetition::AutoFill; let grid_style = 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)])], grid_template_rows: vec![repeat(AutoFill, vec![length(20.0), length(10.0)])], ..Default::default() }; let preferred_size = grid_style.size.map(|s| s.into_option()); let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, preferred_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, preferred_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 4); // 2 repetitions * 2 repeated tracks = 4 tracks in total assert_eq!(height, 6); // 3 repetitions * 2 repeated tracks = 4 tracks in total } #[test] fn explicit_grid_sizing_auto_fill_gap() { use GridTrackRepetition::AutoFill; let grid_style = Style { display: Display::Grid, size: Size { width: length(140.0), height: length(100.0) }, grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])], grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])], gap: length(20.0), ..Default::default() }; let preferred_size = grid_style.size.map(|s| s.into_option()); let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, preferred_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, preferred_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 2); // 2 tracks + 1 gap assert_eq!(height, 3); // 3 tracks + 2 gaps } #[test] fn explicit_grid_sizing_no_defined_size() { use GridTrackRepetition::AutoFill; let grid_style = 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)])], gap: length(20.0), ..Default::default() }; let preferred_size = grid_style.size.map(|s| s.into_option()); let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, preferred_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, preferred_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 3); assert_eq!(height, 1); } #[test] fn explicit_grid_sizing_mix_repeated_and_non_repeated() { use GridTrackRepetition::AutoFill; let grid_style = 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)])], grid_template_rows: vec![length(40.0), repeat(AutoFill, vec![length(20.0)])], gap: length(20.0), ..Default::default() }; let preferred_size = grid_style.size.map(|s| s.into_option()); let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, preferred_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, preferred_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 3); // 3 tracks + 2 gaps assert_eq!(height, 2); // 2 tracks + 1 gap } #[test] fn explicit_grid_sizing_mix_with_padding() { use GridTrackRepetition::AutoFill; let grid_style = 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) }, grid_template_columns: vec![repeat(AutoFill, vec![length(20.0)])], grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])], ..Default::default() }; let inner_container_size = Size { width: Some(100.0), height: Some(80.0) }; let width = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_columns, inner_container_size, AbsoluteAxis::Horizontal, ); let height = compute_explicit_grid_size_in_axis( &grid_style, &grid_style.grid_template_rows, inner_container_size, AbsoluteAxis::Vertical, ); assert_eq!(width, 5); // 40px horizontal padding assert_eq!(height, 4); // 20px vertical padding } #[test] fn test_initialize_grid_tracks() { let px0 = LengthPercentage::Length(0.0); let px20 = LengthPercentage::Length(20.0); let px100 = LengthPercentage::Length(100.0); // Setup test let track_template = vec![length(100.0), minmax(length(100.0), fr(2.0)), fr(1.0)]; let track_counts = TrackCounts { negative_implicit: 3, explicit: track_template.len() as u16, positive_implicit: 3 }; let auto_tracks = vec![auto(), length(100.0)]; let gap = px20; // Call function let mut tracks = Vec::new(); initialize_grid_tracks(&mut tracks, track_counts, &track_template, &auto_tracks, gap, |_| false); // Assertions let expected = vec![ // Gutter (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px0), MaxTrackSizingFunction::Fixed(px0)), // Negative implicit tracks (GridTrackKind::Track, MinTrackSizingFunction::Fixed(px100), MaxTrackSizingFunction::Fixed(px100)), (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px20), MaxTrackSizingFunction::Fixed(px20)), (GridTrackKind::Track, MinTrackSizingFunction::Auto, MaxTrackSizingFunction::Auto), (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px20), MaxTrackSizingFunction::Fixed(px20)), (GridTrackKind::Track, MinTrackSizingFunction::Fixed(px100), MaxTrackSizingFunction::Fixed(px100)), (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px20), MaxTrackSizingFunction::Fixed(px20)), // Explicit tracks (GridTrackKind::Track, MinTrackSizingFunction::Fixed(px100), MaxTrackSizingFunction::Fixed(px100)), (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px20), MaxTrackSizingFunction::Fixed(px20)), (GridTrackKind::Track, MinTrackSizingFunction::Fixed(px100), MaxTrackSizingFunction::Fraction(2.0)), // Note: separate min-max functions (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px20), MaxTrackSizingFunction::Fixed(px20)), (GridTrackKind::Track, MinTrackSizingFunction::Auto, MaxTrackSizingFunction::Fraction(1.0)), // Note: min sizing function of flex sizing functions is auto (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px20), MaxTrackSizingFunction::Fixed(px20)), // Positive implicit tracks (GridTrackKind::Track, MinTrackSizingFunction::Auto, MaxTrackSizingFunction::Auto), (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px20), MaxTrackSizingFunction::Fixed(px20)), (GridTrackKind::Track, MinTrackSizingFunction::Fixed(px100), MaxTrackSizingFunction::Fixed(px100)), (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px20), MaxTrackSizingFunction::Fixed(px20)), (GridTrackKind::Track, MinTrackSizingFunction::Auto, MaxTrackSizingFunction::Auto), (GridTrackKind::Gutter, MinTrackSizingFunction::Fixed(px0), MaxTrackSizingFunction::Fixed(px0)), ]; assert_eq!(tracks.len(), expected.len(), "Number of tracks doesn't match"); for (idx, (actual, (kind, min, max))) in tracks.into_iter().zip(expected).enumerate() { assert_eq!(actual.kind, kind, "Track {idx} (0-based index)"); assert_eq!(actual.min_track_sizing_function, min, "Track {idx} (0-based index)"); assert_eq!(actual.max_track_sizing_function, max, "Track {idx} (0-based index)"); } } }