update parents list on remove (#511)
1//! UI [`Node`] types and related data structures.
2//!
3//! Layouts are composed of multiple nodes, which live in a tree-like data structure.
4use slotmap::{DefaultKey, SlotMap, SparseSecondaryMap};
5
6/// A node in a layout.
7pub type Node = slotmap::DefaultKey;
8
9use crate::error::{TaffyError, TaffyResult};
10use crate::geometry::Size;
11use crate::layout::{Cache, Layout};
12use crate::prelude::LayoutTree;
13use crate::style::{AvailableSpace, Style};
14#[cfg(any(feature = "std", feature = "alloc"))]
15use crate::sys::Box;
16use crate::sys::{new_vec_with_capacity, ChildrenVec, Vec};
17use crate::{data::NodeData, error};
18
19/// A function type that can be used in a [`MeasureFunc`]
20///
21/// This trait is automatically implemented for all types (including closures) that define a function with the appropriate type signature.
22pub trait Measurable: Send + Sync + Fn(Size<Option<f32>>, Size<AvailableSpace>) -> Size<f32> {}
23impl<F: Send + Sync + Fn(Size<Option<f32>>, Size<AvailableSpace>) -> Size<f32>> Measurable for F {}
24
25/// A function that can be used to compute the intrinsic size of a node
26pub enum MeasureFunc {
27 /// Stores an unboxed function
28 Raw(fn(Size<Option<f32>>, Size<AvailableSpace>) -> Size<f32>),
29
30 /// Stores a boxed function
31 #[cfg(any(feature = "std", feature = "alloc"))]
32 Boxed(Box<dyn Measurable>),
33}
34
35/// Global configuration values for a Taffy instance
36pub(crate) struct TaffyConfig {
37 /// Whether to round layout values
38 pub(crate) use_rounding: bool,
39}
40
41impl Default for TaffyConfig {
42 fn default() -> Self {
43 Self { use_rounding: true }
44 }
45}
46
47/// A tree of UI [`Nodes`](`Node`), suitable for UI layout
48pub struct Taffy {
49 /// The [`NodeData`] for each node stored in this tree
50 pub(crate) nodes: SlotMap<Node, NodeData>,
51
52 /// Functions/closures that compute the intrinsic size of leaf nodes
53 pub(crate) measure_funcs: SparseSecondaryMap<Node, MeasureFunc>,
54
55 /// The children of each node
56 ///
57 /// The indexes in the outer vector correspond to the position of the parent [`NodeData`]
58 pub(crate) children: SlotMap<Node, ChildrenVec<Node>>,
59
60 /// The parents of each node
61 ///
62 /// The indexes in the outer vector correspond to the position of the child [`NodeData`]
63 pub(crate) parents: SlotMap<Node, Option<Node>>,
64
65 /// Layout mode configuration
66 pub(crate) config: TaffyConfig,
67
68 /// Hack to allow the `LayoutTree::layout_mut` function to expose the `NodeData.unrounded_layout` of a node to
69 /// the layout algorithms during layout, while exposing the `NodeData.final_layout` when called by external users.
70 /// This allows us to fix <https://github.com/DioxusLabs/taffy/issues/501> without breaking backwards compatibility
71 pub(crate) is_layouting: bool,
72}
73
74impl Default for Taffy {
75 fn default() -> Self {
76 Taffy::new()
77 }
78}
79
80impl LayoutTree for Taffy {
81 type ChildIter<'a> = core::slice::Iter<'a, DefaultKey>;
82
83 fn children(&self, node: Node) -> Self::ChildIter<'_> {
84 self.children[node].iter()
85 }
86
87 fn child_count(&self, node: Node) -> usize {
88 self.children[node].len()
89 }
90
91 fn is_childless(&self, node: Node) -> bool {
92 self.children[node].is_empty()
93 }
94
95 fn parent(&self, node: Node) -> Option<Node> {
96 self.parents.get(node).copied().flatten()
97 }
98
99 fn style(&self, node: Node) -> &Style {
100 &self.nodes[node].style
101 }
102
103 #[inline(always)]
104 fn layout(&self, node: Node) -> &Layout {
105 if self.is_layouting && self.config.use_rounding {
106 &self.nodes[node].unrounded_layout
107 } else {
108 &self.nodes[node].final_layout
109 }
110 }
111
112 #[inline(always)]
113 fn layout_mut(&mut self, node: Node) -> &mut Layout {
114 if self.is_layouting && self.config.use_rounding {
115 &mut self.nodes[node].unrounded_layout
116 } else {
117 &mut self.nodes[node].final_layout
118 }
119 }
120
121 #[inline(always)]
122 fn mark_dirty(&mut self, node: Node) -> TaffyResult<()> {
123 self.mark_dirty_internal(node)
124 }
125
126 fn measure_node(
127 &self,
128 node: Node,
129 known_dimensions: Size<Option<f32>>,
130 available_space: Size<AvailableSpace>,
131 ) -> Size<f32> {
132 match &self.measure_funcs[node] {
133 MeasureFunc::Raw(measure) => measure(known_dimensions, available_space),
134
135 #[cfg(any(feature = "std", feature = "alloc"))]
136 MeasureFunc::Boxed(measure) => (measure as &dyn Fn(_, _) -> _)(known_dimensions, available_space),
137 }
138 }
139
140 fn needs_measure(&self, node: Node) -> bool {
141 self.nodes[node].needs_measure && self.measure_funcs.get(node).is_some()
142 }
143
144 fn cache_mut(&mut self, node: Node, index: usize) -> &mut Option<Cache> {
145 &mut self.nodes[node].size_cache[index]
146 }
147
148 fn child(&self, node: Node, id: usize) -> Node {
149 self.children[node][id]
150 }
151}
152
153#[allow(clippy::iter_cloned_collect)] // due to no-std support, we need to use `iter_cloned` instead of `collect`
154impl Taffy {
155 /// Creates a new [`Taffy`]
156 ///
157 /// The default capacity of a [`Taffy`] is 16 nodes.
158 #[must_use]
159 pub fn new() -> Self {
160 Self::with_capacity(16)
161 }
162
163 /// Creates a new [`Taffy`] that can store `capacity` nodes before reallocation
164 #[must_use]
165 pub fn with_capacity(capacity: usize) -> Self {
166 Self {
167 // TODO: make this method const upstream,
168 // so constructors here can be const
169 nodes: SlotMap::with_capacity(capacity),
170 children: SlotMap::with_capacity(capacity),
171 parents: SlotMap::with_capacity(capacity),
172 measure_funcs: SparseSecondaryMap::with_capacity(capacity),
173 config: TaffyConfig::default(),
174 is_layouting: false,
175 }
176 }
177
178 /// Enable rounding of layout values. Rounding is enabled by default.
179 pub fn enable_rounding(&mut self) {
180 self.config.use_rounding = true;
181 }
182
183 /// Disable rounding of layout values. Rounding is enabled by default.
184 pub fn disable_rounding(&mut self) {
185 self.config.use_rounding = false;
186 }
187
188 /// Creates and adds a new unattached leaf node to the tree, and returns the [`Node`] of the new node
189 pub fn new_leaf(&mut self, layout: Style) -> TaffyResult<Node> {
190 let id = self.nodes.insert(NodeData::new(layout));
191 let _ = self.children.insert(new_vec_with_capacity(0));
192 let _ = self.parents.insert(None);
193
194 Ok(id)
195 }
196
197 /// Creates and adds a new unattached leaf node to the tree, and returns the [`Node`] of the new node
198 ///
199 /// Creates and adds a new leaf node with a supplied [`MeasureFunc`]
200 pub fn new_leaf_with_measure(&mut self, layout: Style, measure: MeasureFunc) -> TaffyResult<Node> {
201 let mut data = NodeData::new(layout);
202 data.needs_measure = true;
203
204 let id = self.nodes.insert(data);
205 self.measure_funcs.insert(id, measure);
206
207 let _ = self.children.insert(new_vec_with_capacity(0));
208 let _ = self.parents.insert(None);
209
210 Ok(id)
211 }
212
213 /// Creates and adds a new node, which may have any number of `children`
214 pub fn new_with_children(&mut self, layout: Style, children: &[Node]) -> TaffyResult<Node> {
215 let id = self.nodes.insert(NodeData::new(layout));
216
217 for child in children {
218 self.parents[*child] = Some(id);
219 }
220
221 let _ = self.children.insert(children.iter().copied().collect::<_>());
222 let _ = self.parents.insert(None);
223
224 Ok(id)
225 }
226
227 /// Drops all nodes in the tree
228 pub fn clear(&mut self) {
229 self.nodes.clear();
230 self.children.clear();
231 self.parents.clear();
232 }
233
234 /// Remove a specific [`Node`] from the tree and drops it
235 ///
236 /// Returns the id of the node removed.
237 pub fn remove(&mut self, node: Node) -> TaffyResult<Node> {
238 if let Some(parent) = self.parents[node] {
239 if let Some(children) = self.children.get_mut(parent) {
240 children.retain(|f| *f != node);
241 }
242 }
243
244 if let Some(children) = self.children.get(node) {
245 for child in children.iter().copied() {
246 self.parents[child] = None;
247 }
248 }
249
250 let _ = self.children.remove(node);
251 let _ = self.parents.remove(node);
252 let _ = self.nodes.remove(node);
253
254 Ok(node)
255 }
256
257 /// Sets the [`MeasureFunc`] of the associated node
258 pub fn set_measure(&mut self, node: Node, measure: Option<MeasureFunc>) -> TaffyResult<()> {
259 if let Some(measure) = measure {
260 self.nodes[node].needs_measure = true;
261 self.measure_funcs.insert(node, measure);
262 } else {
263 self.nodes[node].needs_measure = false;
264 self.measure_funcs.remove(node);
265 }
266
267 self.mark_dirty_internal(node)?;
268
269 Ok(())
270 }
271
272 /// Adds a `child` [`Node`] under the supplied `parent`
273 pub fn add_child(&mut self, parent: Node, child: Node) -> TaffyResult<()> {
274 self.parents[child] = Some(parent);
275 self.children[parent].push(child);
276 self.mark_dirty_internal(parent)?;
277
278 Ok(())
279 }
280
281 /// Directly sets the `children` of the supplied `parent`
282 pub fn set_children(&mut self, parent: Node, children: &[Node]) -> TaffyResult<()> {
283 // Remove node as parent from all its current children.
284 for child in &self.children[parent] {
285 self.parents[*child] = None;
286 }
287
288 // Build up relation node <-> child
289 for child in children {
290 self.parents[*child] = Some(parent);
291 }
292
293 self.children[parent] = children.iter().copied().collect::<_>();
294
295 self.mark_dirty_internal(parent)?;
296
297 Ok(())
298 }
299
300 /// Removes the `child` of the parent `node`
301 ///
302 /// The child is not removed from the tree entirely, it is simply no longer attached to its previous parent.
303 pub fn remove_child(&mut self, parent: Node, child: Node) -> TaffyResult<Node> {
304 let index = self.children[parent].iter().position(|n| *n == child).unwrap();
305 self.remove_child_at_index(parent, index)
306 }
307
308 /// Removes the child at the given `index` from the `parent`
309 ///
310 /// The child is not removed from the tree entirely, it is simply no longer attached to its previous parent.
311 pub fn remove_child_at_index(&mut self, parent: Node, child_index: usize) -> TaffyResult<Node> {
312 let child_count = self.children[parent].len();
313 if child_index >= child_count {
314 return Err(error::TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count });
315 }
316
317 let child = self.children[parent].remove(child_index);
318 self.parents[child] = None;
319
320 self.mark_dirty_internal(parent)?;
321
322 Ok(child)
323 }
324
325 /// Replaces the child at the given `child_index` from the `parent` node with the new `child` node
326 ///
327 /// The child is not removed from the tree entirely, it is simply no longer attached to its previous parent.
328 pub fn replace_child_at_index(&mut self, parent: Node, child_index: usize, new_child: Node) -> TaffyResult<Node> {
329 let child_count = self.children[parent].len();
330 if child_index >= child_count {
331 return Err(error::TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count });
332 }
333
334 self.parents[new_child] = Some(parent);
335 let old_child = core::mem::replace(&mut self.children[parent][child_index], new_child);
336 self.parents[old_child] = None;
337
338 self.mark_dirty_internal(parent)?;
339
340 Ok(old_child)
341 }
342
343 /// Returns the child [`Node`] of the parent `node` at the provided `child_index`
344 pub fn child_at_index(&self, parent: Node, child_index: usize) -> TaffyResult<Node> {
345 let child_count = self.children[parent].len();
346 if child_index >= child_count {
347 return Err(error::TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count });
348 }
349
350 Ok(self.children[parent][child_index])
351 }
352
353 /// Returns the number of children of the `parent` [`Node`]
354 pub fn child_count(&self, parent: Node) -> TaffyResult<usize> {
355 Ok(self.children[parent].len())
356 }
357
358 /// Returns a list of children that belong to the parent [`Node`]
359 pub fn children(&self, parent: Node) -> TaffyResult<Vec<Node>> {
360 Ok(self.children[parent].iter().copied().collect::<_>())
361 }
362
363 /// Sets the [`Style`] of the provided `node`
364 pub fn set_style(&mut self, node: Node, style: Style) -> TaffyResult<()> {
365 self.nodes[node].style = style;
366 self.mark_dirty_internal(node)?;
367 Ok(())
368 }
369
370 /// Gets the [`Style`] of the provided `node`
371 pub fn style(&self, node: Node) -> TaffyResult<&Style> {
372 Ok(&self.nodes[node].style)
373 }
374
375 /// Return this node layout relative to its parent
376 pub fn layout(&self, node: Node) -> TaffyResult<&Layout> {
377 Ok(&self.nodes[node].final_layout)
378 }
379
380 /// Marks the layout computation of this node and its children as outdated
381 ///
382 /// Performs a recursive depth-first search up the tree until the root node is reached
383 ///
384 /// WARNING: this will stack-overflow if the tree contains a cycle
385 fn mark_dirty_internal(&mut self, node: Node) -> TaffyResult<()> {
386 /// WARNING: this will stack-overflow if the tree contains a cycle
387 fn mark_dirty_recursive(
388 nodes: &mut SlotMap<Node, NodeData>,
389 parents: &SlotMap<Node, Option<Node>>,
390 node_id: Node,
391 ) {
392 nodes[node_id].mark_dirty();
393
394 if let Some(Some(node)) = parents.get(node_id) {
395 mark_dirty_recursive(nodes, parents, *node);
396 }
397 }
398
399 mark_dirty_recursive(&mut self.nodes, &self.parents, node);
400
401 Ok(())
402 }
403
404 /// Indicates whether the layout of this node (and its children) need to be recomputed
405 pub fn dirty(&self, node: Node) -> TaffyResult<bool> {
406 Ok(self.nodes[node].size_cache.iter().all(|entry| entry.is_none()))
407 }
408
409 /// Updates the stored layout of the provided `node` and its children
410 pub fn compute_layout(&mut self, node: Node, available_space: Size<AvailableSpace>) -> Result<(), TaffyError> {
411 crate::compute::compute_layout(self, node, available_space)
412 }
413}
414
415#[cfg(test)]
416mod tests {
417 #![allow(clippy::bool_assert_comparison)]
418
419 use super::*;
420 use crate::style::{Dimension, Display, FlexDirection};
421 use crate::style_helpers::*;
422 use crate::sys;
423
424 #[test]
425 fn new_should_allocate_default_capacity() {
426 const DEFAULT_CAPACITY: usize = 16; // This is the capacity defined in the `impl Default`
427 let taffy = Taffy::new();
428
429 assert!(taffy.children.capacity() >= DEFAULT_CAPACITY);
430 assert!(taffy.parents.capacity() >= DEFAULT_CAPACITY);
431 assert!(taffy.nodes.capacity() >= DEFAULT_CAPACITY);
432 }
433
434 #[test]
435 fn test_with_capacity() {
436 const CAPACITY: usize = 8;
437 let taffy = Taffy::with_capacity(CAPACITY);
438
439 assert!(taffy.children.capacity() >= CAPACITY);
440 assert!(taffy.parents.capacity() >= CAPACITY);
441 assert!(taffy.nodes.capacity() >= CAPACITY);
442 }
443
444 #[test]
445 fn test_new_leaf() {
446 let mut taffy = Taffy::new();
447
448 let res = taffy.new_leaf(Style::default());
449 assert!(res.is_ok());
450 let node = res.unwrap();
451
452 // node should be in the taffy tree and have no children
453 assert!(taffy.child_count(node).unwrap() == 0);
454 }
455
456 #[test]
457 fn new_leaf_with_measure() {
458 let mut taffy = Taffy::new();
459
460 let res = taffy.new_leaf_with_measure(Style::default(), MeasureFunc::Raw(|_, _| Size::ZERO));
461 assert!(res.is_ok());
462 let node = res.unwrap();
463
464 // node should be in the taffy tree and have no children
465 assert!(taffy.child_count(node).unwrap() == 0);
466 }
467
468 /// Test that new_with_children works as expected
469 #[test]
470 fn test_new_with_children() {
471 let mut taffy = Taffy::new();
472 let child0 = taffy.new_leaf(Style::default()).unwrap();
473 let child1 = taffy.new_leaf(Style::default()).unwrap();
474 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
475
476 // node should have two children
477 assert_eq!(taffy.child_count(node).unwrap(), 2);
478 assert_eq!(taffy.children(node).unwrap()[0], child0);
479 assert_eq!(taffy.children(node).unwrap()[1], child1);
480 }
481
482 #[test]
483 fn remove_node_should_remove() {
484 let mut taffy = Taffy::new();
485
486 let node = taffy.new_leaf(Style::default()).unwrap();
487
488 let _ = taffy.remove(node).unwrap();
489 }
490
491 #[test]
492 fn remove_node_should_detach_herarchy() {
493 let mut taffy = Taffy::new();
494
495 // Build a linear tree layout: <0> <- <1> <- <2>
496 let node2 = taffy.new_leaf(Style::default()).unwrap();
497 let node1 = taffy.new_with_children(Style::default(), &[node2]).unwrap();
498 let node0 = taffy.new_with_children(Style::default(), &[node1]).unwrap();
499
500 // Both node0 and node1 should have 1 child nodes
501 assert_eq!(taffy.children(node0).unwrap().as_slice(), &[node1]);
502 assert_eq!(taffy.children(node1).unwrap().as_slice(), &[node2]);
503
504 // Disconnect the tree: <0> <2>
505 let _ = taffy.remove(node1).unwrap();
506
507 // Both remaining nodes should have no child nodes
508 assert!(taffy.children(node0).unwrap().is_empty());
509 assert!(taffy.children(node2).unwrap().is_empty());
510 }
511
512 #[test]
513 fn remove_last_node() {
514 let mut taffy = Taffy::new();
515
516 let parent = taffy.new_leaf(Style::default()).unwrap();
517 let child = taffy.new_leaf(Style::default()).unwrap();
518 taffy.add_child(parent, child).unwrap();
519
520 taffy.remove(child).unwrap();
521 taffy.remove(parent).unwrap();
522 }
523
524 #[test]
525 fn set_measure() {
526 let mut taffy = Taffy::new();
527 let node = taffy
528 .new_leaf_with_measure(Style::default(), MeasureFunc::Raw(|_, _| Size { width: 200.0, height: 200.0 }))
529 .unwrap();
530 taffy.compute_layout(node, Size::MAX_CONTENT).unwrap();
531 assert_eq!(taffy.layout(node).unwrap().size.width, 200.0);
532
533 taffy.set_measure(node, Some(MeasureFunc::Raw(|_, _| Size { width: 100.0, height: 100.0 }))).unwrap();
534 taffy.compute_layout(node, Size::MAX_CONTENT).unwrap();
535 assert_eq!(taffy.layout(node).unwrap().size.width, 100.0);
536 }
537
538 #[test]
539 fn set_measure_of_previously_unmeasured_node() {
540 let mut taffy = Taffy::new();
541 let node = taffy.new_leaf(Style::default()).unwrap();
542 taffy.compute_layout(node, Size::MAX_CONTENT).unwrap();
543 assert_eq!(taffy.layout(node).unwrap().size.width, 0.0);
544
545 taffy.set_measure(node, Some(MeasureFunc::Raw(|_, _| Size { width: 100.0, height: 100.0 }))).unwrap();
546 taffy.compute_layout(node, Size::MAX_CONTENT).unwrap();
547 assert_eq!(taffy.layout(node).unwrap().size.width, 100.0);
548 }
549
550 /// Test that adding `add_child()` works
551 #[test]
552 fn add_child() {
553 let mut taffy = Taffy::new();
554 let node = taffy.new_leaf(Style::default()).unwrap();
555 assert_eq!(taffy.child_count(node).unwrap(), 0);
556
557 let child0 = taffy.new_leaf(Style::default()).unwrap();
558 taffy.add_child(node, child0).unwrap();
559 assert_eq!(taffy.child_count(node).unwrap(), 1);
560
561 let child1 = taffy.new_leaf(Style::default()).unwrap();
562 taffy.add_child(node, child1).unwrap();
563 assert_eq!(taffy.child_count(node).unwrap(), 2);
564 }
565
566 #[test]
567 fn set_children() {
568 let mut taffy = Taffy::new();
569
570 let child0 = taffy.new_leaf(Style::default()).unwrap();
571 let child1 = taffy.new_leaf(Style::default()).unwrap();
572 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
573
574 assert_eq!(taffy.child_count(node).unwrap(), 2);
575 assert_eq!(taffy.children(node).unwrap()[0], child0);
576 assert_eq!(taffy.children(node).unwrap()[1], child1);
577
578 let child2 = taffy.new_leaf(Style::default()).unwrap();
579 let child3 = taffy.new_leaf(Style::default()).unwrap();
580 taffy.set_children(node, &[child2, child3]).unwrap();
581
582 assert_eq!(taffy.child_count(node).unwrap(), 2);
583 assert_eq!(taffy.children(node).unwrap()[0], child2);
584 assert_eq!(taffy.children(node).unwrap()[1], child3);
585 }
586
587 /// Test that removing a child works
588 #[test]
589 fn remove_child() {
590 let mut taffy = Taffy::new();
591 let child0 = taffy.new_leaf(Style::default()).unwrap();
592 let child1 = taffy.new_leaf(Style::default()).unwrap();
593 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
594
595 assert_eq!(taffy.child_count(node).unwrap(), 2);
596
597 taffy.remove_child(node, child0).unwrap();
598 assert_eq!(taffy.child_count(node).unwrap(), 1);
599 assert_eq!(taffy.children(node).unwrap()[0], child1);
600
601 taffy.remove_child(node, child1).unwrap();
602 assert_eq!(taffy.child_count(node).unwrap(), 0);
603 }
604
605 #[test]
606 fn remove_child_at_index() {
607 let mut taffy = Taffy::new();
608 let child0 = taffy.new_leaf(Style::default()).unwrap();
609 let child1 = taffy.new_leaf(Style::default()).unwrap();
610 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
611
612 assert_eq!(taffy.child_count(node).unwrap(), 2);
613
614 taffy.remove_child_at_index(node, 0).unwrap();
615 assert_eq!(taffy.child_count(node).unwrap(), 1);
616 assert_eq!(taffy.children(node).unwrap()[0], child1);
617
618 taffy.remove_child_at_index(node, 0).unwrap();
619 assert_eq!(taffy.child_count(node).unwrap(), 0);
620 }
621
622 #[test]
623 fn replace_child_at_index() {
624 let mut taffy = Taffy::new();
625
626 let child0 = taffy.new_leaf(Style::default()).unwrap();
627 let child1 = taffy.new_leaf(Style::default()).unwrap();
628
629 let node = taffy.new_with_children(Style::default(), &[child0]).unwrap();
630 assert_eq!(taffy.child_count(node).unwrap(), 1);
631 assert_eq!(taffy.children(node).unwrap()[0], child0);
632
633 taffy.replace_child_at_index(node, 0, child1).unwrap();
634 assert_eq!(taffy.child_count(node).unwrap(), 1);
635 assert_eq!(taffy.children(node).unwrap()[0], child1);
636 }
637 #[test]
638 fn test_child_at_index() {
639 let mut taffy = Taffy::new();
640 let child0 = taffy.new_leaf(Style::default()).unwrap();
641 let child1 = taffy.new_leaf(Style::default()).unwrap();
642 let child2 = taffy.new_leaf(Style::default()).unwrap();
643 let node = taffy.new_with_children(Style::default(), &[child0, child1, child2]).unwrap();
644
645 assert!(if let Ok(result) = taffy.child_at_index(node, 0) { result == child0 } else { false });
646 assert!(if let Ok(result) = taffy.child_at_index(node, 1) { result == child1 } else { false });
647 assert!(if let Ok(result) = taffy.child_at_index(node, 2) { result == child2 } else { false });
648 }
649 #[test]
650 fn test_child_count() {
651 let mut taffy = Taffy::new();
652 let child0 = taffy.new_leaf(Style::default()).unwrap();
653 let child1 = taffy.new_leaf(Style::default()).unwrap();
654 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
655
656 assert!(if let Ok(count) = taffy.child_count(node) { count == 2 } else { false });
657 assert!(if let Ok(count) = taffy.child_count(child0) { count == 0 } else { false });
658 assert!(if let Ok(count) = taffy.child_count(child1) { count == 0 } else { false });
659 }
660
661 #[allow(clippy::vec_init_then_push)]
662 #[test]
663 fn test_children() {
664 let mut taffy = Taffy::new();
665 let child0 = taffy.new_leaf(Style::default()).unwrap();
666 let child1 = taffy.new_leaf(Style::default()).unwrap();
667 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
668
669 let mut children: sys::Vec<Node> = sys::Vec::new();
670 children.push(child0);
671 children.push(child1);
672
673 let children_result = taffy.children(node).unwrap();
674 assert_eq!(children_result, children);
675
676 assert!(taffy.children(child0).unwrap().is_empty());
677 }
678 #[test]
679 fn test_set_style() {
680 let mut taffy = Taffy::new();
681
682 let node = taffy.new_leaf(Style::default()).unwrap();
683 assert_eq!(taffy.style(node).unwrap().display, Display::Flex);
684
685 taffy.set_style(node, Style { display: Display::None, ..Style::default() }).unwrap();
686 assert_eq!(taffy.style(node).unwrap().display, Display::None);
687 }
688 #[test]
689 fn test_style() {
690 let mut taffy = Taffy::new();
691
692 let style = Style { display: Display::None, flex_direction: FlexDirection::RowReverse, ..Default::default() };
693
694 let node = taffy.new_leaf(style.clone()).unwrap();
695
696 let res = taffy.style(node);
697 assert!(res.is_ok());
698 assert!(res.unwrap() == &style);
699 }
700 #[test]
701 fn test_layout() {
702 let mut taffy = Taffy::new();
703 let node = taffy.new_leaf(Style::default()).unwrap();
704
705 // TODO: Improve this test?
706 let res = taffy.layout(node);
707 assert!(res.is_ok());
708 }
709
710 #[test]
711 fn test_mark_dirty() {
712 let mut taffy = Taffy::new();
713 let child0 = taffy.new_leaf(Style::default()).unwrap();
714 let child1 = taffy.new_leaf(Style::default()).unwrap();
715 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
716
717 taffy.compute_layout(node, Size::MAX_CONTENT).unwrap();
718
719 assert_eq!(taffy.dirty(child0).unwrap(), false);
720 assert_eq!(taffy.dirty(child1).unwrap(), false);
721 assert_eq!(taffy.dirty(node).unwrap(), false);
722
723 taffy.mark_dirty(node).unwrap();
724 assert_eq!(taffy.dirty(child0).unwrap(), false);
725 assert_eq!(taffy.dirty(child1).unwrap(), false);
726 assert_eq!(taffy.dirty(node).unwrap(), true);
727
728 taffy.compute_layout(node, Size::MAX_CONTENT).unwrap();
729 taffy.mark_dirty(child0).unwrap();
730 assert_eq!(taffy.dirty(child0).unwrap(), true);
731 assert_eq!(taffy.dirty(child1).unwrap(), false);
732 assert_eq!(taffy.dirty(node).unwrap(), true);
733 }
734
735 #[test]
736 fn compute_layout_should_produce_valid_result() {
737 let mut taffy = Taffy::new();
738 let node_result = taffy.new_leaf(Style {
739 size: Size { width: Dimension::Points(10f32), height: Dimension::Points(10f32) },
740 ..Default::default()
741 });
742 assert!(node_result.is_ok());
743 let node = node_result.unwrap();
744 let layout_result = taffy.compute_layout(
745 node,
746 Size { width: AvailableSpace::Definite(100.), height: AvailableSpace::Definite(100.) },
747 );
748 assert!(layout_result.is_ok());
749 }
750
751 #[test]
752 fn measure_func_is_send_and_sync() {
753 fn is_send_and_sync<T: Send + Sync>() {}
754 is_send_and_sync::<MeasureFunc>();
755 }
756}