taffy/compute/grid/
explicit_grid.rs

1//! Helper functions for initialising GridTrack's from styles
2//! This mainly consists of evaluating GridAutoTracks
3use super::types::{GridTrack, TrackCounts};
4use crate::geometry::AbsoluteAxis;
5use crate::style::{LengthPercentage, RepetitionCount, TrackSizingFunction};
6use crate::style_helpers::TaffyAuto;
7use crate::util::sys::{ceil, floor, Vec};
8use crate::util::MaybeMath;
9use crate::util::ResolveOrZero;
10use crate::{GenericGridTemplateComponent, GenericRepetition, GridContainerStyle};
11
12/// The auto-repeat fit strategy to use
13pub(crate) enum AutoRepeatStrategy {
14    /// If the grid container has a definite size or max size in the relevant axis:
15    ///   - then the number of repetitions is the largest possible positive integer that does not cause the grid to overflow the content
16    ///     box of its grid container.
17    MaxRepetitionsThatDoNotOverflow,
18    /// Otherwise, if the grid container has a definite min size in the relevant axis:
19    ///   - then the number of repetitions is the smallest possible positive integer that fulfills that minimum requirement
20    MinRepetitionsThatDoOverflow,
21}
22
23/// Compute the number of rows and columns in the explicit grid
24pub(crate) fn compute_explicit_grid_size_in_axis(
25    style: &impl GridContainerStyle,
26    auto_fit_container_size: Option<f32>,
27    auto_fit_strategy: AutoRepeatStrategy,
28    resolve_calc_value: impl Fn(*const (), f32) -> f32,
29    axis: AbsoluteAxis,
30) -> (u16, u16) {
31    let template = match axis {
32        AbsoluteAxis::Horizontal => style.grid_template_columns(),
33        AbsoluteAxis::Vertical => style.grid_template_rows(),
34    };
35    let Some(template) = template else {
36        return (0, 0);
37    };
38
39    // If template contains no tracks, then there are trivially zero explicit tracks
40    let track_count = template.len();
41    if track_count == 0 {
42        return (0, 0);
43    }
44
45    // If there are any repetitions that contains no tracks, then the whole definition should be considered invalid
46    // and we default to no explicit tracks
47    let template_has_repetitions_with_zero_tracks = template.clone().any(|track_def| match track_def {
48        GenericGridTemplateComponent::Single(_) => false,
49        GenericGridTemplateComponent::Repeat(repeat) => repeat.track_count() == 0,
50    });
51    if template_has_repetitions_with_zero_tracks {
52        return (0, 0);
53    }
54
55    // Compute that number of track generated by single track definition and repetitions with a fixed repetition count
56    let non_auto_repeating_track_count = template
57        .clone()
58        .map(|track_def| match track_def {
59            GenericGridTemplateComponent::Single(_) => 1,
60            GenericGridTemplateComponent::Repeat(repeat) => match repeat.count() {
61                RepetitionCount::Count(count) => count * repeat.track_count(),
62                RepetitionCount::AutoFit | RepetitionCount::AutoFill => 0,
63            },
64        })
65        .sum::<u16>();
66
67    let auto_repetition_count: u16 = template.clone().filter(|track_def| track_def.is_auto_repetition()).count() as u16;
68    let all_track_defs_have_fixed_component = template.clone().all(|track_def| match track_def {
69        GenericGridTemplateComponent::Single(sizing_function) => sizing_function.has_fixed_component(),
70        GenericGridTemplateComponent::Repeat(repeat) => {
71            repeat.tracks().all(|sizing_function| sizing_function.has_fixed_component())
72        }
73    });
74
75    let template_is_valid =
76        auto_repetition_count == 0 || (auto_repetition_count == 1 && all_track_defs_have_fixed_component);
77
78    // If the template is invalid because it contains multiple auto-repetition definitions or it combines an auto-repetition
79    // definition with non-fixed-size track sizing functions, then disregard it entirely and default to zero explicit tracks
80    if !template_is_valid {
81        return (0, 0);
82    }
83
84    // If there are no repetitions, then the number of explicit tracks is simply equal to the lengths of the track definition
85    // vector (as each item in the Vec represents one track).
86    if auto_repetition_count == 0 {
87        return (0, non_auto_repeating_track_count);
88    }
89
90    let repetition_definition = template
91        .clone()
92        .find_map(|def| match def {
93            GenericGridTemplateComponent::Single(_) => None,
94            GenericGridTemplateComponent::Repeat(repeat) => match repeat.count() {
95                RepetitionCount::Count(_) => None,
96                RepetitionCount::AutoFit | RepetitionCount::AutoFill => Some(repeat),
97            },
98        })
99        .unwrap();
100    let repetition_definition_iter = repetition_definition.tracks();
101    let repetition_track_count = repetition_definition_iter.len() as u16;
102
103    // Determine the number of repetitions
104    let num_repetitions: u16 = match auto_fit_container_size {
105        None => 1,
106        Some(inner_container_size) => {
107            let parent_size = Some(inner_container_size);
108
109            /// ...treating each track as its max track sizing function if that is definite or as its minimum track sizing function
110            /// otherwise, flooring the max track sizing function by the min track sizing function if both are definite
111            fn track_definite_value(
112                sizing_function: TrackSizingFunction,
113                parent_size: Option<f32>,
114                calc_resolver: impl Fn(*const (), f32) -> f32,
115            ) -> f32 {
116                let max_size = sizing_function.max.definite_value(parent_size, &calc_resolver);
117                let min_size = sizing_function.min.definite_value(parent_size, &calc_resolver);
118                max_size.map(|max| max.maybe_max(min_size)).or(min_size).unwrap()
119            }
120
121            let non_repeating_track_used_space: f32 = template
122                .clone()
123                .map(|track_def| match track_def {
124                    GenericGridTemplateComponent::Single(sizing_function) => {
125                        track_definite_value(sizing_function, parent_size, &resolve_calc_value)
126                    }
127                    GenericGridTemplateComponent::Repeat(repeat) => match repeat.count() {
128                        RepetitionCount::Count(count) => {
129                            let sum = repeat
130                                .tracks()
131                                .map(|sizing_function| {
132                                    track_definite_value(sizing_function, parent_size, &resolve_calc_value)
133                                })
134                                .sum::<f32>();
135                            sum * (count as f32)
136                        }
137                        RepetitionCount::AutoFit | RepetitionCount::AutoFill => 0.0,
138                    },
139                })
140                .sum();
141            let gap_size = style.gap().get_abs(axis).resolve_or_zero(Some(inner_container_size), &resolve_calc_value);
142
143            // Compute the amount of space that a single repetition of the repeated track list takes
144            let per_repetition_track_used_space: f32 = repetition_definition_iter
145                .map(|sizing_function| track_definite_value(sizing_function, parent_size, &resolve_calc_value))
146                .sum::<f32>();
147
148            // We special case the first repetition here because the number of gaps in the first repetition
149            // depends on the number of non-repeating tracks in the template
150            let first_repetition_and_non_repeating_tracks_used_space = non_repeating_track_used_space
151                + per_repetition_track_used_space
152                + ((non_auto_repeating_track_count + repetition_track_count).saturating_sub(1) as f32 * gap_size);
153
154            // If a single repetition already overflows the container then we return 1 as the repetition count
155            // (the number of repetitions is floored at 1)
156            if first_repetition_and_non_repeating_tracks_used_space > inner_container_size {
157                1u16
158            } else {
159                let per_repetition_gap_used_space = (repetition_track_count as f32) * gap_size;
160                let per_repetition_used_space = per_repetition_track_used_space + per_repetition_gap_used_space;
161                let num_repetition_that_fit = (inner_container_size
162                    - first_repetition_and_non_repeating_tracks_used_space)
163                    / per_repetition_used_space;
164
165                // If the container size is a preferred or maximum size:
166                //   Then we return the maximum number of repetitions that fit into the container without overflowing.
167                // If the container size is a minimum size:
168                //   - Then we return the minimum number of repetitions required to overflow the size.
169                //
170                // In all cases we add the additional repetition that was already accounted for in the special-case computation above
171                match auto_fit_strategy {
172                    AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow => (floor(num_repetition_that_fit) as u16) + 1,
173                    AutoRepeatStrategy::MinRepetitionsThatDoOverflow => (ceil(num_repetition_that_fit) as u16) + 1,
174                }
175            }
176        }
177    };
178
179    let grid_template_track_count = non_auto_repeating_track_count + (repetition_track_count * num_repetitions);
180    (num_repetitions, grid_template_track_count)
181}
182
183/// Resolve the track sizing functions of explicit tracks, automatically created tracks, and gutters
184/// given a set of track counts and all of the relevant styles
185pub(super) fn initialize_grid_tracks(
186    tracks: &mut Vec<GridTrack>,
187    counts: TrackCounts,
188    style: &impl GridContainerStyle,
189    axis: AbsoluteAxis,
190    track_has_items: impl Fn(usize) -> bool,
191) {
192    // Extract styles
193    let track_template;
194    let auto_tracks;
195    let gap;
196    match axis {
197        AbsoluteAxis::Horizontal => {
198            track_template = style.grid_template_columns();
199            auto_tracks = style.grid_auto_columns();
200            gap = style.gap().width;
201        }
202        AbsoluteAxis::Vertical => {
203            track_template = style.grid_template_rows();
204            auto_tracks = style.grid_auto_rows();
205            gap = style.gap().height;
206        }
207    };
208
209    // Clear vector (in case this is a re-layout), reserve space for all tracks ahead of time to reduce allocations,
210    // and push the initial gutter
211    tracks.clear();
212    tracks.reserve((counts.len() * 2) + 1);
213    tracks.push(GridTrack::gutter(gap));
214
215    let auto_track_count = auto_tracks.len();
216
217    // Create negative implicit tracks
218    if counts.negative_implicit > 0 {
219        if auto_track_count == 0 {
220            let iter = core::iter::repeat(TrackSizingFunction::AUTO);
221            create_implicit_tracks(tracks, counts.negative_implicit, iter, gap)
222        } else {
223            let offset = auto_track_count - (counts.negative_implicit as usize % auto_track_count);
224            let iter = auto_tracks.clone().cycle().skip(offset);
225            create_implicit_tracks(tracks, counts.negative_implicit, iter, gap)
226        }
227    }
228
229    let mut current_track_index = (counts.negative_implicit) as usize;
230
231    // Create explicit tracks
232    // An explicit check against the count (rather than just relying on track_template being empty) is required here
233    // because a count of zero can result from the track_template being invalid, in which case it should be ignored.
234    if counts.explicit > 0 {
235        if let Some(track_template) = track_template {
236            track_template.clone().for_each(|track_sizing_function| {
237                match track_sizing_function {
238                    GenericGridTemplateComponent::Single(sizing_function) => {
239                        tracks.push(GridTrack::new(
240                            sizing_function.min_sizing_function(),
241                            sizing_function.max_sizing_function(),
242                        ));
243                        tracks.push(GridTrack::gutter(gap));
244                        current_track_index += 1;
245                    }
246                    GenericGridTemplateComponent::Repeat(repeat) => match repeat.count() {
247                        RepetitionCount::Count(count) => {
248                            let track_iter = repeat.tracks();
249                            let track_iter = track_iter.cycle().take(repeat.track_count() as usize * count as usize);
250                            track_iter.for_each(|sizing_function| {
251                                tracks.push(GridTrack::new(
252                                    sizing_function.min_sizing_function(),
253                                    sizing_function.max_sizing_function(),
254                                ));
255                                tracks.push(GridTrack::gutter(gap));
256                                current_track_index += 1;
257                            });
258                        }
259                        RepetitionCount::AutoFit | RepetitionCount::AutoFill => {
260                            let auto_repeated_track_count =
261                                (counts.explicit - (track_template.len() as u16 - 1)) as usize;
262                            let iter = repeat.tracks().cycle();
263                            for track_def in iter.take(auto_repeated_track_count) {
264                                let mut track =
265                                    GridTrack::new(track_def.min_sizing_function(), track_def.max_sizing_function());
266                                let mut gutter = GridTrack::gutter(gap);
267
268                                // Auto-fit tracks that don't contain should be collapsed.
269                                if repeat.count() == RepetitionCount::AutoFit && !track_has_items(current_track_index) {
270                                    track.collapse();
271                                    gutter.collapse();
272                                }
273
274                                tracks.push(track);
275                                tracks.push(gutter);
276
277                                current_track_index += 1;
278                            }
279                        }
280                    },
281                }
282            });
283        }
284    }
285
286    let grid_area_tracks = (counts.negative_implicit + counts.explicit) - current_track_index as u16;
287
288    // Create positive implicit tracks
289    if auto_track_count == 0 {
290        let iter = core::iter::repeat(TrackSizingFunction::AUTO);
291        create_implicit_tracks(tracks, counts.positive_implicit + grid_area_tracks, iter, gap)
292    } else {
293        let iter = auto_tracks.clone().cycle();
294        create_implicit_tracks(tracks, counts.positive_implicit + grid_area_tracks, iter, gap)
295    }
296
297    // Mark first and last grid lines as collapsed
298    tracks.first_mut().unwrap().collapse();
299    tracks.last_mut().unwrap().collapse();
300}
301
302/// Utility function for repeating logic of creating implicit tracks
303fn create_implicit_tracks(
304    tracks: &mut Vec<GridTrack>,
305    count: u16,
306    mut auto_tracks_iter: impl Iterator<Item = TrackSizingFunction>,
307    gap: LengthPercentage,
308) {
309    for _ in 0..count {
310        let track_def = auto_tracks_iter.next().unwrap();
311        tracks.push(GridTrack::new(track_def.min_sizing_function(), track_def.max_sizing_function()));
312        tracks.push(GridTrack::gutter(gap));
313    }
314}
315
316#[cfg(test)]
317mod test {
318    use super::compute_explicit_grid_size_in_axis;
319    use super::initialize_grid_tracks;
320    use crate::compute::grid::explicit_grid::AutoRepeatStrategy;
321    use crate::compute::grid::types::GridTrackKind;
322    use crate::compute::grid::types::TrackCounts;
323    use crate::compute::grid::util::*;
324    use crate::geometry::AbsoluteAxis;
325    use crate::prelude::*;
326    use crate::sys::DefaultCheapStr;
327
328    #[test]
329    fn explicit_grid_sizing_no_repeats() {
330        let grid_style = (600.0, 600.0, 2, 4).into_grid();
331        let preferred_size = grid_style.size.map(|s| s.into_option());
332        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
333            &grid_style,
334            preferred_size.get_abs(AbsoluteAxis::Horizontal),
335            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
336            |_, _| 42.42,
337            AbsoluteAxis::Horizontal,
338        );
339        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
340            &grid_style,
341            preferred_size.get_abs(AbsoluteAxis::Vertical),
342            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
343            |_, _| 42.42,
344            AbsoluteAxis::Vertical,
345        );
346        assert_eq!(col_count, 2);
347        assert_eq!(row_count, 4);
348        assert_eq!(auto_col_reps, 0);
349        assert_eq!(auto_row_reps, 0);
350    }
351
352    #[test]
353    fn explicit_grid_sizing_auto_fill_exact_fit() {
354        use RepetitionCount::AutoFill;
355        let grid_style: Style<DefaultCheapStr> = Style {
356            display: Display::Grid,
357            size: Size { width: length(120.0), height: length(80.0) },
358            grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
359            grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])],
360            ..Default::default()
361        };
362        let preferred_size = grid_style.size.map(|s| s.into_option());
363        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
364            &grid_style,
365            preferred_size.get_abs(AbsoluteAxis::Horizontal),
366            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
367            |_, _| 42.42,
368            AbsoluteAxis::Horizontal,
369        );
370        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
371            &grid_style,
372            preferred_size.get_abs(AbsoluteAxis::Vertical),
373            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
374            |_, _| 42.42,
375            AbsoluteAxis::Vertical,
376        );
377        assert_eq!(col_count, 3);
378        assert_eq!(row_count, 4);
379        assert_eq!(auto_col_reps, 3);
380        assert_eq!(auto_row_reps, 4);
381    }
382
383    #[test]
384    fn explicit_grid_sizing_auto_fill_non_exact_fit() {
385        use RepetitionCount::AutoFill;
386        let grid_style: Style<DefaultCheapStr> = Style {
387            display: Display::Grid,
388            size: Size { width: length(140.0), height: length(90.0) },
389            grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
390            grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])],
391            ..Default::default()
392        };
393        let preferred_size = grid_style.size.map(|s| s.into_option());
394        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
395            &grid_style,
396            preferred_size.get_abs(AbsoluteAxis::Horizontal),
397            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
398            |_, _| 42.42,
399            AbsoluteAxis::Horizontal,
400        );
401        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
402            &grid_style,
403            preferred_size.get_abs(AbsoluteAxis::Vertical),
404            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
405            |_, _| 42.42,
406            AbsoluteAxis::Vertical,
407        );
408        assert_eq!(col_count, 3);
409        assert_eq!(row_count, 4);
410        assert_eq!(auto_col_reps, 3);
411        assert_eq!(auto_row_reps, 4);
412    }
413
414    #[test]
415    fn explicit_grid_sizing_auto_fill_min_size_exact_fit() {
416        use RepetitionCount::AutoFill;
417        let grid_style: Style<DefaultCheapStr> = Style {
418            display: Display::Grid,
419            min_size: Size { width: length(120.0), height: length(80.0) },
420            grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
421            grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])],
422            ..Default::default()
423        };
424        let inner_container_size = Size { width: Some(120.0), height: Some(80.0) };
425        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
426            &grid_style,
427            inner_container_size.get_abs(AbsoluteAxis::Horizontal),
428            AutoRepeatStrategy::MinRepetitionsThatDoOverflow,
429            |_, _| 42.42,
430            AbsoluteAxis::Horizontal,
431        );
432        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
433            &grid_style,
434            inner_container_size.get_abs(AbsoluteAxis::Vertical),
435            AutoRepeatStrategy::MinRepetitionsThatDoOverflow,
436            |_, _| 42.42,
437            AbsoluteAxis::Vertical,
438        );
439        assert_eq!(col_count, 3);
440        assert_eq!(row_count, 4);
441        assert_eq!(auto_col_reps, 3);
442        assert_eq!(auto_row_reps, 4);
443    }
444
445    #[test]
446    fn explicit_grid_sizing_auto_fill_min_size_non_exact_fit() {
447        use RepetitionCount::AutoFill;
448        let grid_style: Style<DefaultCheapStr> = Style {
449            display: Display::Grid,
450            min_size: Size { width: length(140.0), height: length(90.0) },
451            grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
452            grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])],
453            ..Default::default()
454        };
455        let inner_container_size = Size { width: Some(140.0), height: Some(90.0) };
456        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
457            &grid_style,
458            inner_container_size.get_abs(AbsoluteAxis::Horizontal),
459            AutoRepeatStrategy::MinRepetitionsThatDoOverflow,
460            |_, _| 42.42,
461            AbsoluteAxis::Horizontal,
462        );
463        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
464            &grid_style,
465            inner_container_size.get_abs(AbsoluteAxis::Vertical),
466            AutoRepeatStrategy::MinRepetitionsThatDoOverflow,
467            |_, _| 42.42,
468            AbsoluteAxis::Vertical,
469        );
470        assert_eq!(col_count, 4);
471        assert_eq!(row_count, 5);
472        assert_eq!(auto_col_reps, 4);
473        assert_eq!(auto_row_reps, 5);
474    }
475
476    #[test]
477    fn explicit_grid_sizing_auto_fill_multiple_repeated_tracks() {
478        use RepetitionCount::AutoFill;
479        let grid_style: Style<DefaultCheapStr> = Style {
480            display: Display::Grid,
481            size: Size { width: length(140.0), height: length(100.0) },
482            grid_template_columns: vec![repeat(AutoFill, vec![length(40.0), length(20.0)])],
483            grid_template_rows: vec![repeat(AutoFill, vec![length(20.0), length(10.0)])],
484            ..Default::default()
485        };
486        let preferred_size = grid_style.size.map(|s| s.into_option());
487        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
488            &grid_style,
489            preferred_size.get_abs(AbsoluteAxis::Horizontal),
490            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
491            |_, _| 42.42,
492            AbsoluteAxis::Horizontal,
493        );
494        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
495            &grid_style,
496            preferred_size.get_abs(AbsoluteAxis::Vertical),
497            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
498            |_, _| 42.42,
499            AbsoluteAxis::Vertical,
500        );
501        assert_eq!(col_count, 4); // 2 repetitions * 2 repeated tracks = 4 tracks in total
502        assert_eq!(row_count, 6); // 3 repetitions * 2 repeated tracks = 4 tracks in total
503        assert_eq!(auto_col_reps, 2);
504        assert_eq!(auto_row_reps, 3);
505    }
506
507    #[test]
508    fn explicit_grid_sizing_auto_fill_gap() {
509        use RepetitionCount::AutoFill;
510        let grid_style: Style<DefaultCheapStr> = Style {
511            display: Display::Grid,
512            size: Size { width: length(140.0), height: length(100.0) },
513            grid_template_columns: vec![repeat(AutoFill, vec![length(40.0)])],
514            grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])],
515            gap: length(20.0),
516            ..Default::default()
517        };
518        let preferred_size = grid_style.size.map(|s| s.into_option());
519        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
520            &grid_style,
521            preferred_size.get_abs(AbsoluteAxis::Horizontal),
522            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
523            |_, _| 42.42,
524            AbsoluteAxis::Horizontal,
525        );
526        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
527            &grid_style,
528            preferred_size.get_abs(AbsoluteAxis::Vertical),
529            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
530            |_, _| 42.42,
531            AbsoluteAxis::Vertical,
532        );
533        assert_eq!(col_count, 2); // 2 tracks + 1 gap
534        assert_eq!(row_count, 3); // 3 tracks + 2 gaps
535        assert_eq!(auto_col_reps, 2);
536        assert_eq!(auto_row_reps, 3);
537    }
538
539    #[test]
540    fn explicit_grid_sizing_no_defined_size() {
541        use RepetitionCount::AutoFill;
542        let grid_style: Style<DefaultCheapStr> = Style {
543            display: Display::Grid,
544            grid_template_columns: vec![repeat(AutoFill, vec![length(40.0), percent(0.5), length(20.0)])],
545            grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])],
546            gap: length(20.0),
547            ..Default::default()
548        };
549        let preferred_size = grid_style.size.map(|s| s.into_option());
550        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
551            &grid_style,
552            preferred_size.get_abs(AbsoluteAxis::Horizontal),
553            AutoRepeatStrategy::MinRepetitionsThatDoOverflow,
554            |_, _| 42.42,
555            AbsoluteAxis::Horizontal,
556        );
557        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
558            &grid_style,
559            preferred_size.get_abs(AbsoluteAxis::Vertical),
560            AutoRepeatStrategy::MinRepetitionsThatDoOverflow,
561            |_, _| 42.42,
562            AbsoluteAxis::Vertical,
563        );
564        assert_eq!(col_count, 3);
565        assert_eq!(row_count, 1);
566        assert_eq!(auto_col_reps, 1);
567        assert_eq!(auto_row_reps, 1);
568    }
569
570    #[test]
571    fn explicit_grid_sizing_mix_repeated_and_non_repeated() {
572        use RepetitionCount::AutoFill;
573        let grid_style: Style<DefaultCheapStr> = Style {
574            display: Display::Grid,
575            size: Size { width: length(140.0), height: length(100.0) },
576            grid_template_columns: vec![length(20.0), repeat(AutoFill, vec![length(40.0)])],
577            grid_template_rows: vec![length(40.0), repeat(AutoFill, vec![length(20.0)])],
578            gap: length(20.0),
579            ..Default::default()
580        };
581        let preferred_size = grid_style.size.map(|s| s.into_option());
582        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
583            &grid_style,
584            preferred_size.get_abs(AbsoluteAxis::Horizontal),
585            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
586            |_, _| 42.42,
587            AbsoluteAxis::Horizontal,
588        );
589        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
590            &grid_style,
591            preferred_size.get_abs(AbsoluteAxis::Vertical),
592            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
593            |_, _| 42.42,
594            AbsoluteAxis::Vertical,
595        );
596        assert_eq!(col_count, 3); // 3 tracks + 2 gaps
597        assert_eq!(row_count, 2); // 2 tracks + 1 gap
598        assert_eq!(auto_col_reps, 2);
599        assert_eq!(auto_row_reps, 1);
600    }
601
602    #[test]
603    fn explicit_grid_sizing_mix_with_padding() {
604        use RepetitionCount::AutoFill;
605        let grid_style: Style<DefaultCheapStr> = Style {
606            display: Display::Grid,
607            size: Size { width: length(120.0), height: length(120.0) },
608            padding: Rect { left: length(10.0), right: length(10.0), top: length(20.0), bottom: length(20.0) },
609            grid_template_columns: vec![repeat(AutoFill, vec![length(20.0)])],
610            grid_template_rows: vec![repeat(AutoFill, vec![length(20.0)])],
611            ..Default::default()
612        };
613        let inner_container_size = Size { width: Some(100.0), height: Some(80.0) };
614        let (auto_col_reps, col_count) = compute_explicit_grid_size_in_axis(
615            &grid_style,
616            inner_container_size.get_abs(AbsoluteAxis::Horizontal),
617            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
618            |_, _| 42.42,
619            AbsoluteAxis::Horizontal,
620        );
621        let (auto_row_reps, row_count) = compute_explicit_grid_size_in_axis(
622            &grid_style,
623            inner_container_size.get_abs(AbsoluteAxis::Vertical),
624            AutoRepeatStrategy::MaxRepetitionsThatDoNotOverflow,
625            |_, _| 42.42,
626            AbsoluteAxis::Vertical,
627        );
628        assert_eq!(col_count, 5); // 40px horizontal padding
629        assert_eq!(row_count, 4); // 20px vertical padding
630        assert_eq!(auto_col_reps, 5);
631        assert_eq!(auto_row_reps, 4);
632    }
633
634    #[test]
635    fn test_initialize_grid_tracks() {
636        let minpx0 = MinTrackSizingFunction::from_length(0.0);
637        let minpx20 = MinTrackSizingFunction::from_length(20.0);
638        let minpx100 = MinTrackSizingFunction::from_length(100.0);
639
640        let maxpx0 = MaxTrackSizingFunction::from_length(0.0);
641        let maxpx20 = MaxTrackSizingFunction::from_length(20.0);
642        let maxpx100 = MaxTrackSizingFunction::from_length(100.0);
643
644        // Setup test
645        let grid_style: Style<DefaultCheapStr> = Style {
646            display: Display::Grid,
647            gap: length(20.0),
648            grid_template_columns: vec![length(100.0), minmax(length(100.0), fr(2.0)), fr(1.0)],
649            grid_auto_columns: vec![auto(), length(100.0)],
650            ..Default::default()
651        };
652        let track_counts = TrackCounts {
653            negative_implicit: 3,
654            explicit: grid_style.grid_template_columns.len() as u16,
655            positive_implicit: 3,
656        };
657
658        // Call function
659        let mut tracks = Vec::new();
660        initialize_grid_tracks(&mut tracks, track_counts, &grid_style, AbsoluteAxis::Horizontal, |_| false);
661
662        // Assertions
663        let expected = vec![
664            // Gutter
665            (GridTrackKind::Gutter, minpx0, maxpx0),
666            // Negative implicit tracks
667            (GridTrackKind::Track, minpx100, maxpx100),
668            (GridTrackKind::Gutter, minpx20, maxpx20),
669            (GridTrackKind::Track, auto(), auto()),
670            (GridTrackKind::Gutter, minpx20, maxpx20),
671            (GridTrackKind::Track, minpx100, maxpx100),
672            (GridTrackKind::Gutter, minpx20, maxpx20),
673            // Explicit tracks
674            (GridTrackKind::Track, minpx100, maxpx100),
675            (GridTrackKind::Gutter, minpx20, maxpx20),
676            (GridTrackKind::Track, minpx100, MaxTrackSizingFunction::from_fr(2.0)), // Note: separate min-max functions
677            (GridTrackKind::Gutter, minpx20, maxpx20),
678            (GridTrackKind::Track, auto(), MaxTrackSizingFunction::from_fr(1.0)), // Note: min sizing function of flex sizing functions is AUTO
679            (GridTrackKind::Gutter, minpx20, maxpx20),
680            // Positive implicit tracks
681            (GridTrackKind::Track, auto(), auto()),
682            (GridTrackKind::Gutter, minpx20, maxpx20),
683            (GridTrackKind::Track, minpx100, maxpx100),
684            (GridTrackKind::Gutter, minpx20, maxpx20),
685            (GridTrackKind::Track, auto(), auto()),
686            (GridTrackKind::Gutter, minpx0, maxpx0),
687        ];
688
689        assert_eq!(tracks.len(), expected.len(), "Number of tracks doesn't match");
690
691        for (idx, (actual, (kind, min, max))) in tracks.into_iter().zip(expected).enumerate() {
692            assert_eq!(actual.kind, kind, "Track {idx} (0-based index)");
693            assert_eq!(actual.min_track_sizing_function, min, "Track {idx} (0-based index)");
694            assert_eq!(actual.max_track_sizing_function, max, "Track {idx} (0-based index)");
695        }
696    }
697}
taffy/compute/grid/explicit_grid.rs

taffy/compute/grid/
explicit_grid.rs
