Update to latest rustfmt (format associated types with GATs) (#737)
1//! Contains [TaffyTree](crate::tree::TaffyTree): the default implementation of [LayoutTree](crate::tree::LayoutTree), and the error type for Taffy.
2#[cfg(not(feature = "std"))]
3use slotmap::SecondaryMap;
4#[cfg(feature = "std")]
5use slotmap::SparseSecondaryMap as SecondaryMap;
6use slotmap::{DefaultKey, SlotMap};
7
8use crate::geometry::Size;
9use crate::style::{AvailableSpace, Display, Style};
10use crate::tree::{
11 Cache, Layout, LayoutInput, LayoutOutput, LayoutPartialTree, NodeId, PrintTree, RoundTree, RunMode,
12 TraversePartialTree, TraverseTree,
13};
14use crate::util::debug::{debug_log, debug_log_node};
15use crate::util::sys::{new_vec_with_capacity, ChildrenVec, Vec};
16
17use crate::compute::{
18 compute_cached_layout, compute_hidden_layout, compute_leaf_layout, compute_root_layout, round_layout,
19};
20#[cfg(feature = "block_layout")]
21use crate::{compute::compute_block_layout, LayoutBlockContainer};
22#[cfg(feature = "flexbox")]
23use crate::{compute::compute_flexbox_layout, LayoutFlexboxContainer};
24#[cfg(feature = "grid")]
25use crate::{compute::compute_grid_layout, LayoutGridContainer};
26
27/// The error Taffy generates on invalid operations
28pub type TaffyResult<T> = Result<T, TaffyError>;
29
30/// An error that occurs while trying to access or modify a node's children by index.
31#[derive(Debug, Clone, PartialEq, Eq)]
32pub enum TaffyError {
33 /// The parent node does not have a child at `child_index`. It only has `child_count` children
34 ChildIndexOutOfBounds {
35 /// The parent node whose child was being looked up
36 parent: NodeId,
37 /// The index that was looked up
38 child_index: usize,
39 /// The total number of children the parent has
40 child_count: usize,
41 },
42 /// The parent node was not found in the [`TaffyTree`](crate::TaffyTree) instance.
43 InvalidParentNode(NodeId),
44 /// The child node was not found in the [`TaffyTree`](crate::TaffyTree) instance.
45 InvalidChildNode(NodeId),
46 /// The supplied node was not found in the [`TaffyTree`](crate::TaffyTree) instance.
47 InvalidInputNode(NodeId),
48}
49
50impl core::fmt::Display for TaffyError {
51 fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
52 match self {
53 TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count } => {
54 write!(f, "Index (is {child_index}) should be < child_count ({child_count}) for parent node {parent:?}")
55 }
56 TaffyError::InvalidParentNode(parent) => {
57 write!(f, "Parent Node {parent:?} is not in the TaffyTree instance")
58 }
59 TaffyError::InvalidChildNode(child) => write!(f, "Child Node {child:?} is not in the TaffyTree instance"),
60 TaffyError::InvalidInputNode(node) => write!(f, "Supplied Node {node:?} is not in the TaffyTree instance"),
61 }
62 }
63}
64
65#[cfg(feature = "std")]
66impl std::error::Error for TaffyError {}
67
68/// Global configuration values for a TaffyTree instance
69#[derive(Debug, Clone, Copy)]
70pub(crate) struct TaffyConfig {
71 /// Whether to round layout values
72 pub(crate) use_rounding: bool,
73}
74
75impl Default for TaffyConfig {
76 fn default() -> Self {
77 Self { use_rounding: true }
78 }
79}
80
81/// Layout information for a given [`Node`](crate::node::Node)
82///
83/// Stored in a [`TaffyTree`].
84#[derive(Debug, Clone, PartialEq)]
85struct NodeData {
86 /// The layout strategy used by this node
87 pub(crate) style: Style,
88
89 /// The always unrounded results of the layout computation. We must store this separately from the rounded
90 /// layout to avoid errors from rounding already-rounded values. See <https://github.com/DioxusLabs/taffy/issues/501>.
91 pub(crate) unrounded_layout: Layout,
92
93 /// The final results of the layout computation.
94 /// These may be rounded or unrounded depending on what the `use_rounding` config setting is set to.
95 pub(crate) final_layout: Layout,
96
97 /// Whether the node has context data associated with it or not
98 pub(crate) has_context: bool,
99
100 /// The cached results of the layout computation
101 pub(crate) cache: Cache,
102}
103
104impl NodeData {
105 /// Create the data for a new node
106 #[must_use]
107 pub const fn new(style: Style) -> Self {
108 Self {
109 style,
110 cache: Cache::new(),
111 unrounded_layout: Layout::new(),
112 final_layout: Layout::new(),
113 has_context: false,
114 }
115 }
116
117 /// Marks a node and all of its ancestors as requiring relayout
118 ///
119 /// This clears any cached data and signals that the data must be recomputed.
120 #[inline]
121 pub fn mark_dirty(&mut self) {
122 self.cache.clear()
123 }
124}
125
126/// An entire tree of UI nodes. The entry point to Taffy's high-level API.
127///
128/// Allows you to build a tree of UI nodes, run Taffy's layout algorithms over that tree, and then access the resultant layout.]
129#[derive(Debug, Clone)]
130pub struct TaffyTree<NodeContext = ()> {
131 /// The [`NodeData`] for each node stored in this tree
132 nodes: SlotMap<DefaultKey, NodeData>,
133
134 /// Functions/closures that compute the intrinsic size of leaf nodes
135 node_context_data: SecondaryMap<DefaultKey, NodeContext>,
136
137 /// The children of each node
138 ///
139 /// The indexes in the outer vector correspond to the position of the parent [`NodeData`]
140 children: SlotMap<DefaultKey, ChildrenVec<NodeId>>,
141
142 /// The parents of each node
143 ///
144 /// The indexes in the outer vector correspond to the position of the child [`NodeData`]
145 parents: SlotMap<DefaultKey, Option<NodeId>>,
146
147 /// Layout mode configuration
148 config: TaffyConfig,
149}
150
151impl Default for TaffyTree {
152 fn default() -> TaffyTree<()> {
153 TaffyTree::new()
154 }
155}
156
157/// Iterator that wraps a slice of nodes, lazily converting them to u64
158pub struct TaffyTreeChildIter<'a>(core::slice::Iter<'a, NodeId>);
159impl Iterator for TaffyTreeChildIter<'_> {
160 type Item = NodeId;
161
162 fn next(&mut self) -> Option<Self::Item> {
163 self.0.next().copied()
164 }
165}
166
167// TraversePartialTree impl for TaffyTree
168impl<NodeContext> TraversePartialTree for TaffyTree<NodeContext> {
169 type ChildIter<'a>
170 = TaffyTreeChildIter<'a>
171 where
172 Self: 'a;
173
174 #[inline(always)]
175 fn child_ids(&self, parent_node_id: NodeId) -> Self::ChildIter<'_> {
176 TaffyTreeChildIter(self.children[parent_node_id.into()].iter())
177 }
178
179 #[inline(always)]
180 fn child_count(&self, parent_node_id: NodeId) -> usize {
181 self.children[parent_node_id.into()].len()
182 }
183
184 #[inline(always)]
185 fn get_child_id(&self, parent_node_id: NodeId, id: usize) -> NodeId {
186 self.children[parent_node_id.into()][id]
187 }
188}
189
190// TraverseTree impl for TaffyTree
191impl<NodeContext> TraverseTree for TaffyTree<NodeContext> {}
192
193// PrintTree impl for TaffyTree
194impl<NodeContext> PrintTree for TaffyTree<NodeContext> {
195 #[inline(always)]
196 fn get_debug_label(&self, node_id: NodeId) -> &'static str {
197 let node = &self.nodes[node_id.into()];
198 let display = node.style.display;
199 let num_children = self.child_count(node_id);
200
201 match (num_children, display) {
202 (_, Display::None) => "NONE",
203 (0, _) => "LEAF",
204 #[cfg(feature = "block_layout")]
205 (_, Display::Block) => "BLOCK",
206 #[cfg(feature = "flexbox")]
207 (_, Display::Flex) => {
208 use crate::FlexDirection;
209 match node.style.flex_direction {
210 FlexDirection::Row | FlexDirection::RowReverse => "FLEX ROW",
211 FlexDirection::Column | FlexDirection::ColumnReverse => "FLEX COL",
212 }
213 }
214 #[cfg(feature = "grid")]
215 (_, Display::Grid) => "GRID",
216 }
217 }
218
219 #[inline(always)]
220 fn get_final_layout(&self, node_id: NodeId) -> &Layout {
221 if self.config.use_rounding {
222 &self.nodes[node_id.into()].final_layout
223 } else {
224 &self.nodes[node_id.into()].unrounded_layout
225 }
226 }
227}
228
229/// View over the Taffy tree that holds the tree itself along with a reference to the context
230/// and implements LayoutTree. This allows the context to be stored outside of the TaffyTree struct
231/// which makes the lifetimes of the context much more flexible.
232pub(crate) struct TaffyView<'t, NodeContext, MeasureFunction>
233where
234 MeasureFunction:
235 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>,
236{
237 /// A reference to the TaffyTree
238 pub(crate) taffy: &'t mut TaffyTree<NodeContext>,
239 /// The context provided for passing to measure functions if layout is run over this struct
240 pub(crate) measure_function: MeasureFunction,
241}
242
243// TraversePartialTree impl for TaffyView
244impl<NodeContext, MeasureFunction> TraversePartialTree for TaffyView<'_, NodeContext, MeasureFunction>
245where
246 MeasureFunction:
247 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>,
248{
249 type ChildIter<'a>
250 = TaffyTreeChildIter<'a>
251 where
252 Self: 'a;
253
254 #[inline(always)]
255 fn child_ids(&self, parent_node_id: NodeId) -> Self::ChildIter<'_> {
256 self.taffy.child_ids(parent_node_id)
257 }
258
259 #[inline(always)]
260 fn child_count(&self, parent_node_id: NodeId) -> usize {
261 self.taffy.child_count(parent_node_id)
262 }
263
264 #[inline(always)]
265 fn get_child_id(&self, parent_node_id: NodeId, child_index: usize) -> NodeId {
266 self.taffy.get_child_id(parent_node_id, child_index)
267 }
268}
269
270// TraverseTree impl for TaffyView
271impl<NodeContext, MeasureFunction> TraverseTree for TaffyView<'_, NodeContext, MeasureFunction> where
272 MeasureFunction:
273 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>
274{
275}
276
277// LayoutPartialTree impl for TaffyView
278impl<NodeContext, MeasureFunction> LayoutPartialTree for TaffyView<'_, NodeContext, MeasureFunction>
279where
280 MeasureFunction:
281 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>,
282{
283 type CoreContainerStyle<'a>
284 = &'a Style
285 where
286 Self: 'a;
287 type CacheMut<'b>
288 = &'b mut Cache
289 where
290 Self: 'b;
291
292 #[inline(always)]
293 fn get_core_container_style(&self, node_id: NodeId) -> Self::CoreContainerStyle<'_> {
294 &self.taffy.nodes[node_id.into()].style
295 }
296
297 #[inline(always)]
298 fn get_cache_mut(&mut self, node: NodeId) -> &mut Cache {
299 &mut self.taffy.nodes[node.into()].cache
300 }
301
302 #[inline(always)]
303 fn set_unrounded_layout(&mut self, node_id: NodeId, layout: &Layout) {
304 self.taffy.nodes[node_id.into()].unrounded_layout = *layout;
305 }
306
307 #[inline(always)]
308 fn compute_child_layout(&mut self, node: NodeId, inputs: LayoutInput) -> LayoutOutput {
309 // If RunMode is PerformHiddenLayout then this indicates that an ancestor node is `Display::None`
310 // and thus that we should lay out this node using hidden layout regardless of it's own display style.
311 if inputs.run_mode == RunMode::PerformHiddenLayout {
312 debug_log!("HIDDEN");
313 return compute_hidden_layout(self, node);
314 }
315
316 // We run the following wrapped in "compute_cached_layout", which will check the cache for an entry matching the node and inputs and:
317 // - Return that entry if exists
318 // - Else call the passed closure (below) to compute the result
319 //
320 // If there was no cache match and a new result needs to be computed then that result will be added to the cache
321 compute_cached_layout(self, node, inputs, |tree, node, inputs| {
322 let display_mode = tree.taffy.nodes[node.into()].style.display;
323 let has_children = tree.child_count(node) > 0;
324
325 debug_log!(display_mode);
326 debug_log_node!(
327 inputs.known_dimensions,
328 inputs.parent_size,
329 inputs.available_space,
330 inputs.run_mode,
331 inputs.sizing_mode
332 );
333
334 // Dispatch to a layout algorithm based on the node's display style and whether the node has children or not.
335 match (display_mode, has_children) {
336 (Display::None, _) => compute_hidden_layout(tree, node),
337 #[cfg(feature = "block_layout")]
338 (Display::Block, true) => compute_block_layout(tree, node, inputs),
339 #[cfg(feature = "flexbox")]
340 (Display::Flex, true) => compute_flexbox_layout(tree, node, inputs),
341 #[cfg(feature = "grid")]
342 (Display::Grid, true) => compute_grid_layout(tree, node, inputs),
343 (_, false) => {
344 let node_key = node.into();
345 let style = &tree.taffy.nodes[node_key].style;
346 let has_context = tree.taffy.nodes[node_key].has_context;
347 let node_context = has_context.then(|| tree.taffy.node_context_data.get_mut(node_key)).flatten();
348 let measure_function = |known_dimensions, available_space| {
349 (tree.measure_function)(known_dimensions, available_space, node, node_context, style)
350 };
351 compute_leaf_layout(inputs, style, measure_function)
352 }
353 }
354 })
355 }
356}
357
358#[cfg(feature = "block_layout")]
359impl<NodeContext, MeasureFunction> LayoutBlockContainer for TaffyView<'_, NodeContext, MeasureFunction>
360where
361 MeasureFunction:
362 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>,
363{
364 type BlockContainerStyle<'a>
365 = &'a Style
366 where
367 Self: 'a;
368 type BlockItemStyle<'a>
369 = &'a Style
370 where
371 Self: 'a;
372
373 #[inline(always)]
374 fn get_block_container_style(&self, node_id: NodeId) -> Self::BlockContainerStyle<'_> {
375 self.get_core_container_style(node_id)
376 }
377
378 #[inline(always)]
379 fn get_block_child_style(&self, child_node_id: NodeId) -> Self::BlockItemStyle<'_> {
380 self.get_core_container_style(child_node_id)
381 }
382}
383
384#[cfg(feature = "flexbox")]
385impl<NodeContext, MeasureFunction> LayoutFlexboxContainer for TaffyView<'_, NodeContext, MeasureFunction>
386where
387 MeasureFunction:
388 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>,
389{
390 type FlexboxContainerStyle<'a>
391 = &'a Style
392 where
393 Self: 'a;
394 type FlexboxItemStyle<'a>
395 = &'a Style
396 where
397 Self: 'a;
398
399 #[inline(always)]
400 fn get_flexbox_container_style(&self, node_id: NodeId) -> Self::FlexboxContainerStyle<'_> {
401 &self.taffy.nodes[node_id.into()].style
402 }
403
404 #[inline(always)]
405 fn get_flexbox_child_style(&self, child_node_id: NodeId) -> Self::FlexboxItemStyle<'_> {
406 &self.taffy.nodes[child_node_id.into()].style
407 }
408}
409
410#[cfg(feature = "grid")]
411impl<NodeContext, MeasureFunction> LayoutGridContainer for TaffyView<'_, NodeContext, MeasureFunction>
412where
413 MeasureFunction:
414 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>,
415{
416 type GridContainerStyle<'a>
417 = &'a Style
418 where
419 Self: 'a;
420 type GridItemStyle<'a>
421 = &'a Style
422 where
423 Self: 'a;
424
425 #[inline(always)]
426 fn get_grid_container_style(&self, node_id: NodeId) -> Self::GridContainerStyle<'_> {
427 &self.taffy.nodes[node_id.into()].style
428 }
429
430 #[inline(always)]
431 fn get_grid_child_style(&self, child_node_id: NodeId) -> Self::GridItemStyle<'_> {
432 &self.taffy.nodes[child_node_id.into()].style
433 }
434}
435
436// RoundTree impl for TaffyView
437impl<NodeContext, MeasureFunction> RoundTree for TaffyView<'_, NodeContext, MeasureFunction>
438where
439 MeasureFunction:
440 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>,
441{
442 #[inline(always)]
443 fn get_unrounded_layout(&self, node: NodeId) -> &Layout {
444 &self.taffy.nodes[node.into()].unrounded_layout
445 }
446
447 #[inline(always)]
448 fn set_final_layout(&mut self, node_id: NodeId, layout: &Layout) {
449 self.taffy.nodes[node_id.into()].final_layout = *layout;
450 }
451}
452
453#[allow(clippy::iter_cloned_collect)] // due to no-std support, we need to use `iter_cloned` instead of `collect`
454impl<NodeContext> TaffyTree<NodeContext> {
455 /// Creates a new [`TaffyTree`]
456 ///
457 /// The default capacity of a [`TaffyTree`] is 16 nodes.
458 #[must_use]
459 pub fn new() -> Self {
460 Self::with_capacity(16)
461 }
462
463 /// Creates a new [`TaffyTree`] that can store `capacity` nodes before reallocation
464 #[must_use]
465 pub fn with_capacity(capacity: usize) -> Self {
466 TaffyTree {
467 // TODO: make this method const upstream,
468 // so constructors here can be const
469 nodes: SlotMap::with_capacity(capacity),
470 children: SlotMap::with_capacity(capacity),
471 parents: SlotMap::with_capacity(capacity),
472 node_context_data: SecondaryMap::with_capacity(capacity),
473 config: TaffyConfig::default(),
474 }
475 }
476
477 /// Enable rounding of layout values. Rounding is enabled by default.
478 pub fn enable_rounding(&mut self) {
479 self.config.use_rounding = true;
480 }
481
482 /// Disable rounding of layout values. Rounding is enabled by default.
483 pub fn disable_rounding(&mut self) {
484 self.config.use_rounding = false;
485 }
486
487 /// Creates and adds a new unattached leaf node to the tree, and returns the node of the new node
488 pub fn new_leaf(&mut self, layout: Style) -> TaffyResult<NodeId> {
489 let id = self.nodes.insert(NodeData::new(layout));
490 let _ = self.children.insert(new_vec_with_capacity(0));
491 let _ = self.parents.insert(None);
492
493 Ok(id.into())
494 }
495
496 /// Creates and adds a new unattached leaf node to the tree, and returns the [`NodeId`] of the new node
497 ///
498 /// Creates and adds a new leaf node with a supplied context
499 pub fn new_leaf_with_context(&mut self, layout: Style, context: NodeContext) -> TaffyResult<NodeId> {
500 let mut data = NodeData::new(layout);
501 data.has_context = true;
502
503 let id = self.nodes.insert(data);
504 self.node_context_data.insert(id, context);
505
506 let _ = self.children.insert(new_vec_with_capacity(0));
507 let _ = self.parents.insert(None);
508
509 Ok(id.into())
510 }
511
512 /// Creates and adds a new node, which may have any number of `children`
513 pub fn new_with_children(&mut self, layout: Style, children: &[NodeId]) -> TaffyResult<NodeId> {
514 let id = NodeId::from(self.nodes.insert(NodeData::new(layout)));
515
516 for child in children {
517 self.parents[(*child).into()] = Some(id);
518 }
519
520 let _ = self.children.insert(children.iter().copied().collect::<_>());
521 let _ = self.parents.insert(None);
522
523 Ok(id)
524 }
525
526 /// Drops all nodes in the tree
527 pub fn clear(&mut self) {
528 self.nodes.clear();
529 self.children.clear();
530 self.parents.clear();
531 }
532
533 /// Remove a specific node from the tree and drop it
534 ///
535 /// Returns the id of the node removed.
536 pub fn remove(&mut self, node: NodeId) -> TaffyResult<NodeId> {
537 let key = node.into();
538 if let Some(parent) = self.parents[key] {
539 if let Some(children) = self.children.get_mut(parent.into()) {
540 children.retain(|f| *f != node);
541 }
542 }
543
544 // Remove "parent" references to a node when removing that node
545 if let Some(children) = self.children.get(key) {
546 for child in children.iter().copied() {
547 self.parents[child.into()] = None;
548 }
549 }
550
551 let _ = self.children.remove(key);
552 let _ = self.parents.remove(key);
553 let _ = self.nodes.remove(key);
554
555 Ok(node)
556 }
557
558 /// Sets the context data associated with the node
559 pub fn set_node_context(&mut self, node: NodeId, measure: Option<NodeContext>) -> TaffyResult<()> {
560 let key = node.into();
561 if let Some(measure) = measure {
562 self.nodes[key].has_context = true;
563 self.node_context_data.insert(key, measure);
564 } else {
565 self.nodes[key].has_context = false;
566 self.node_context_data.remove(key);
567 }
568
569 self.mark_dirty(node)?;
570
571 Ok(())
572 }
573
574 /// Gets a reference to the the context data associated with the node
575 pub fn get_node_context(&self, node: NodeId) -> Option<&NodeContext> {
576 self.node_context_data.get(node.into())
577 }
578
579 /// Gets a mutable reference to the the context data associated with the node
580 pub fn get_node_context_mut(&mut self, node: NodeId) -> Option<&mut NodeContext> {
581 self.node_context_data.get_mut(node.into())
582 }
583
584 /// Gets mutable references to the the context data associated with the nodes. All keys must be valid and disjoint, otherwise None is returned.
585 pub fn get_disjoint_node_context_mut<const N: usize>(
586 &mut self,
587 keys: [NodeId; N],
588 ) -> Option<[&mut NodeContext; N]> {
589 self.node_context_data.get_disjoint_mut(keys.map(|k| k.into()))
590 }
591
592 /// Adds a `child` node under the supplied `parent`
593 pub fn add_child(&mut self, parent: NodeId, child: NodeId) -> TaffyResult<()> {
594 let parent_key = parent.into();
595 let child_key = child.into();
596 self.parents[child_key] = Some(parent);
597 self.children[parent_key].push(child);
598 self.mark_dirty(parent)?;
599
600 Ok(())
601 }
602
603 /// Inserts a `child` node at the given `child_index` under the supplied `parent`, shifting all children after it to the right.
604 pub fn insert_child_at_index(&mut self, parent: NodeId, child_index: usize, child: NodeId) -> TaffyResult<()> {
605 let parent_key = parent.into();
606
607 let child_count = self.children[parent_key].len();
608 if child_index > child_count {
609 return Err(TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count });
610 }
611
612 self.parents[child.into()] = Some(parent);
613 self.children[parent_key].insert(child_index, child);
614 self.mark_dirty(parent)?;
615
616 Ok(())
617 }
618
619 /// Directly sets the `children` of the supplied `parent`
620 pub fn set_children(&mut self, parent: NodeId, children: &[NodeId]) -> TaffyResult<()> {
621 let parent_key = parent.into();
622
623 // Remove node as parent from all its current children.
624 for child in &self.children[parent_key] {
625 self.parents[(*child).into()] = None;
626 }
627
628 // Build up relation node <-> child
629 for child in children {
630 self.parents[(*child).into()] = Some(parent);
631 }
632
633 let parent_children = &mut self.children[parent_key];
634 parent_children.clear();
635 children.iter().for_each(|child| parent_children.push(*child));
636
637 self.mark_dirty(parent)?;
638
639 Ok(())
640 }
641
642 /// Removes the `child` of the parent `node`
643 ///
644 /// The child is not removed from the tree entirely, it is simply no longer attached to its previous parent.
645 pub fn remove_child(&mut self, parent: NodeId, child: NodeId) -> TaffyResult<NodeId> {
646 let index = self.children[parent.into()].iter().position(|n| *n == child).unwrap();
647 self.remove_child_at_index(parent, index)
648 }
649
650 /// Removes the child at the given `index` from the `parent`
651 ///
652 /// The child is not removed from the tree entirely, it is simply no longer attached to its previous parent.
653 pub fn remove_child_at_index(&mut self, parent: NodeId, child_index: usize) -> TaffyResult<NodeId> {
654 let parent_key = parent.into();
655 let child_count = self.children[parent_key].len();
656 if child_index >= child_count {
657 return Err(TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count });
658 }
659
660 let child = self.children[parent_key].remove(child_index);
661 self.parents[child.into()] = None;
662
663 self.mark_dirty(parent)?;
664
665 Ok(child)
666 }
667
668 /// Replaces the child at the given `child_index` from the `parent` node with the new `child` node
669 ///
670 /// The child is not removed from the tree entirely, it is simply no longer attached to its previous parent.
671 pub fn replace_child_at_index(
672 &mut self,
673 parent: NodeId,
674 child_index: usize,
675 new_child: NodeId,
676 ) -> TaffyResult<NodeId> {
677 let parent_key = parent.into();
678
679 let child_count = self.children[parent_key].len();
680 if child_index >= child_count {
681 return Err(TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count });
682 }
683
684 self.parents[new_child.into()] = Some(parent);
685 let old_child = core::mem::replace(&mut self.children[parent_key][child_index], new_child);
686 self.parents[old_child.into()] = None;
687
688 self.mark_dirty(parent)?;
689
690 Ok(old_child)
691 }
692
693 /// Returns the child node of the parent `node` at the provided `child_index`
694 pub fn child_at_index(&self, parent: NodeId, child_index: usize) -> TaffyResult<NodeId> {
695 let parent_key = parent.into();
696 let child_count = self.children[parent_key].len();
697 if child_index >= child_count {
698 return Err(TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count });
699 }
700
701 Ok(self.children[parent_key][child_index])
702 }
703
704 /// Returns the total number of nodes in the tree
705 pub fn total_node_count(&self) -> usize {
706 self.nodes.len()
707 }
708
709 /// Returns the `NodeId` of the parent node of the specified node (if it exists)
710 ///
711 /// - Return None if the specified node has no parent
712 /// - Panics if the specified node does not exist
713 pub fn parent(&self, child_id: NodeId) -> Option<NodeId> {
714 self.parents[child_id.into()]
715 }
716
717 /// Returns a list of children that belong to the parent node
718 pub fn children(&self, parent: NodeId) -> TaffyResult<Vec<NodeId>> {
719 Ok(self.children[parent.into()].iter().copied().collect::<_>())
720 }
721
722 /// Sets the [`Style`] of the provided `node`
723 pub fn set_style(&mut self, node: NodeId, style: Style) -> TaffyResult<()> {
724 self.nodes[node.into()].style = style;
725 self.mark_dirty(node)?;
726 Ok(())
727 }
728
729 /// Gets the [`Style`] of the provided `node`
730 pub fn style(&self, node: NodeId) -> TaffyResult<&Style> {
731 Ok(&self.nodes[node.into()].style)
732 }
733
734 /// Return this node layout relative to its parent
735 pub fn layout(&self, node: NodeId) -> TaffyResult<&Layout> {
736 if self.config.use_rounding {
737 Ok(&self.nodes[node.into()].final_layout)
738 } else {
739 Ok(&self.nodes[node.into()].unrounded_layout)
740 }
741 }
742
743 /// Marks the layout of this node and its ancestors as outdated
744 ///
745 /// WARNING: this may stack-overflow if the tree contains a cycle
746 pub fn mark_dirty(&mut self, node: NodeId) -> TaffyResult<()> {
747 /// WARNING: this will stack-overflow if the tree contains a cycle
748 fn mark_dirty_recursive(
749 nodes: &mut SlotMap<DefaultKey, NodeData>,
750 parents: &SlotMap<DefaultKey, Option<NodeId>>,
751 node_key: DefaultKey,
752 ) {
753 nodes[node_key].mark_dirty();
754
755 if let Some(Some(node)) = parents.get(node_key) {
756 mark_dirty_recursive(nodes, parents, (*node).into());
757 }
758 }
759
760 mark_dirty_recursive(&mut self.nodes, &self.parents, node.into());
761
762 Ok(())
763 }
764
765 /// Indicates whether the layout of this node needs to be recomputed
766 pub fn dirty(&self, node: NodeId) -> TaffyResult<bool> {
767 Ok(self.nodes[node.into()].cache.is_empty())
768 }
769
770 /// Updates the stored layout of the provided `node` and its children
771 pub fn compute_layout_with_measure<MeasureFunction>(
772 &mut self,
773 node_id: NodeId,
774 available_space: Size<AvailableSpace>,
775 measure_function: MeasureFunction,
776 ) -> Result<(), TaffyError>
777 where
778 MeasureFunction:
779 FnMut(Size<Option<f32>>, Size<AvailableSpace>, NodeId, Option<&mut NodeContext>, &Style) -> Size<f32>,
780 {
781 let use_rounding = self.config.use_rounding;
782 let mut taffy_view = TaffyView { taffy: self, measure_function };
783 compute_root_layout(&mut taffy_view, node_id, available_space);
784 if use_rounding {
785 round_layout(&mut taffy_view, node_id);
786 }
787 Ok(())
788 }
789
790 /// Updates the stored layout of the provided `node` and its children
791 pub fn compute_layout(&mut self, node: NodeId, available_space: Size<AvailableSpace>) -> Result<(), TaffyError> {
792 self.compute_layout_with_measure(node, available_space, |_, _, _, _, _| Size::ZERO)
793 }
794
795 /// Prints a debug representation of the tree's layout
796 #[cfg(feature = "std")]
797 pub fn print_tree(&mut self, root: NodeId) {
798 crate::util::print_tree(self, root)
799 }
800
801 /// Returns an instance of LayoutTree representing the TaffyTree
802 #[cfg(test)]
803 pub(crate) fn as_layout_tree(&mut self) -> impl LayoutPartialTree + '_ {
804 TaffyView { taffy: self, measure_function: |_, _, _, _, _| Size::ZERO }
805 }
806}
807
808#[cfg(test)]
809mod tests {
810
811 use super::*;
812 use crate::style::{Dimension, Display, FlexDirection};
813 use crate::style_helpers::*;
814 use crate::util::sys;
815
816 fn size_measure_function(
817 known_dimensions: Size<Option<f32>>,
818 _available_space: Size<AvailableSpace>,
819 _node_id: NodeId,
820 node_context: Option<&mut Size<f32>>,
821 _style: &Style,
822 ) -> Size<f32> {
823 known_dimensions.unwrap_or(node_context.cloned().unwrap_or(Size::ZERO))
824 }
825
826 #[test]
827 fn new_should_allocate_default_capacity() {
828 const DEFAULT_CAPACITY: usize = 16; // This is the capacity defined in the `impl Default`
829 let taffy: TaffyTree<()> = TaffyTree::new();
830
831 assert!(taffy.children.capacity() >= DEFAULT_CAPACITY);
832 assert!(taffy.parents.capacity() >= DEFAULT_CAPACITY);
833 assert!(taffy.nodes.capacity() >= DEFAULT_CAPACITY);
834 }
835
836 #[test]
837 fn test_with_capacity() {
838 const CAPACITY: usize = 8;
839 let taffy: TaffyTree<()> = TaffyTree::with_capacity(CAPACITY);
840
841 assert!(taffy.children.capacity() >= CAPACITY);
842 assert!(taffy.parents.capacity() >= CAPACITY);
843 assert!(taffy.nodes.capacity() >= CAPACITY);
844 }
845
846 #[test]
847 fn test_new_leaf() {
848 let mut taffy: TaffyTree<()> = TaffyTree::new();
849
850 let res = taffy.new_leaf(Style::default());
851 assert!(res.is_ok());
852 let node = res.unwrap();
853
854 // node should be in the taffy tree and have no children
855 assert!(taffy.child_count(node) == 0);
856 }
857
858 #[test]
859 fn new_leaf_with_context() {
860 let mut taffy: TaffyTree<Size<f32>> = TaffyTree::new();
861
862 let res = taffy.new_leaf_with_context(Style::default(), Size::ZERO);
863 assert!(res.is_ok());
864 let node = res.unwrap();
865
866 // node should be in the taffy tree and have no children
867 assert!(taffy.child_count(node) == 0);
868 }
869
870 /// Test that new_with_children works as expected
871 #[test]
872 fn test_new_with_children() {
873 let mut taffy: TaffyTree<()> = TaffyTree::new();
874 let child0 = taffy.new_leaf(Style::default()).unwrap();
875 let child1 = taffy.new_leaf(Style::default()).unwrap();
876 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
877
878 // node should have two children
879 assert_eq!(taffy.child_count(node), 2);
880 assert_eq!(taffy.children(node).unwrap()[0], child0);
881 assert_eq!(taffy.children(node).unwrap()[1], child1);
882 }
883
884 #[test]
885 fn remove_node_should_remove() {
886 let mut taffy: TaffyTree<()> = TaffyTree::new();
887
888 let node = taffy.new_leaf(Style::default()).unwrap();
889
890 let _ = taffy.remove(node).unwrap();
891 }
892
893 #[test]
894 fn remove_node_should_detach_hierarchy() {
895 let mut taffy: TaffyTree<()> = TaffyTree::new();
896
897 // Build a linear tree layout: <0> <- <1> <- <2>
898 let node2 = taffy.new_leaf(Style::default()).unwrap();
899 let node1 = taffy.new_with_children(Style::default(), &[node2]).unwrap();
900 let node0 = taffy.new_with_children(Style::default(), &[node1]).unwrap();
901
902 // Both node0 and node1 should have 1 child nodes
903 assert_eq!(taffy.children(node0).unwrap().as_slice(), &[node1]);
904 assert_eq!(taffy.children(node1).unwrap().as_slice(), &[node2]);
905
906 // Disconnect the tree: <0> <2>
907 let _ = taffy.remove(node1).unwrap();
908
909 // Both remaining nodes should have no child nodes
910 assert!(taffy.children(node0).unwrap().is_empty());
911 assert!(taffy.children(node2).unwrap().is_empty());
912 }
913
914 #[test]
915 fn remove_last_node() {
916 let mut taffy: TaffyTree<()> = TaffyTree::new();
917
918 let parent = taffy.new_leaf(Style::default()).unwrap();
919 let child = taffy.new_leaf(Style::default()).unwrap();
920 taffy.add_child(parent, child).unwrap();
921
922 taffy.remove(child).unwrap();
923 taffy.remove(parent).unwrap();
924 }
925
926 #[test]
927 fn set_measure() {
928 let mut taffy: TaffyTree<Size<f32>> = TaffyTree::new();
929 let node = taffy.new_leaf_with_context(Style::default(), Size { width: 200.0, height: 200.0 }).unwrap();
930 taffy.compute_layout_with_measure(node, Size::MAX_CONTENT, size_measure_function).unwrap();
931 assert_eq!(taffy.layout(node).unwrap().size.width, 200.0);
932
933 taffy.set_node_context(node, Some(Size { width: 100.0, height: 100.0 })).unwrap();
934 taffy.compute_layout_with_measure(node, Size::MAX_CONTENT, size_measure_function).unwrap();
935 assert_eq!(taffy.layout(node).unwrap().size.width, 100.0);
936 }
937
938 #[test]
939 fn set_measure_of_previously_unmeasured_node() {
940 let mut taffy: TaffyTree<Size<f32>> = TaffyTree::new();
941 let node = taffy.new_leaf(Style::default()).unwrap();
942 taffy.compute_layout_with_measure(node, Size::MAX_CONTENT, size_measure_function).unwrap();
943 assert_eq!(taffy.layout(node).unwrap().size.width, 0.0);
944
945 taffy.set_node_context(node, Some(Size { width: 100.0, height: 100.0 })).unwrap();
946 taffy.compute_layout_with_measure(node, Size::MAX_CONTENT, size_measure_function).unwrap();
947 assert_eq!(taffy.layout(node).unwrap().size.width, 100.0);
948 }
949
950 /// Test that adding `add_child()` works
951 #[test]
952 fn add_child() {
953 let mut taffy: TaffyTree<()> = TaffyTree::new();
954 let node = taffy.new_leaf(Style::default()).unwrap();
955 assert_eq!(taffy.child_count(node), 0);
956
957 let child0 = taffy.new_leaf(Style::default()).unwrap();
958 taffy.add_child(node, child0).unwrap();
959 assert_eq!(taffy.child_count(node), 1);
960
961 let child1 = taffy.new_leaf(Style::default()).unwrap();
962 taffy.add_child(node, child1).unwrap();
963 assert_eq!(taffy.child_count(node), 2);
964 }
965
966 #[test]
967 fn insert_child_at_index() {
968 let mut taffy: TaffyTree<()> = TaffyTree::new();
969
970 let child0 = taffy.new_leaf(Style::default()).unwrap();
971 let child1 = taffy.new_leaf(Style::default()).unwrap();
972 let child2 = taffy.new_leaf(Style::default()).unwrap();
973
974 let node = taffy.new_leaf(Style::default()).unwrap();
975 assert_eq!(taffy.child_count(node), 0);
976
977 taffy.insert_child_at_index(node, 0, child0).unwrap();
978 assert_eq!(taffy.child_count(node), 1);
979 assert_eq!(taffy.children(node).unwrap()[0], child0);
980
981 taffy.insert_child_at_index(node, 0, child1).unwrap();
982 assert_eq!(taffy.child_count(node), 2);
983 assert_eq!(taffy.children(node).unwrap()[0], child1);
984 assert_eq!(taffy.children(node).unwrap()[1], child0);
985
986 taffy.insert_child_at_index(node, 1, child2).unwrap();
987 assert_eq!(taffy.child_count(node), 3);
988 assert_eq!(taffy.children(node).unwrap()[0], child1);
989 assert_eq!(taffy.children(node).unwrap()[1], child2);
990 assert_eq!(taffy.children(node).unwrap()[2], child0);
991 }
992
993 #[test]
994 fn set_children() {
995 let mut taffy: TaffyTree<()> = TaffyTree::new();
996
997 let child0 = taffy.new_leaf(Style::default()).unwrap();
998 let child1 = taffy.new_leaf(Style::default()).unwrap();
999 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
1000
1001 assert_eq!(taffy.child_count(node), 2);
1002 assert_eq!(taffy.children(node).unwrap()[0], child0);
1003 assert_eq!(taffy.children(node).unwrap()[1], child1);
1004
1005 let child2 = taffy.new_leaf(Style::default()).unwrap();
1006 let child3 = taffy.new_leaf(Style::default()).unwrap();
1007 taffy.set_children(node, &[child2, child3]).unwrap();
1008
1009 assert_eq!(taffy.child_count(node), 2);
1010 assert_eq!(taffy.children(node).unwrap()[0], child2);
1011 assert_eq!(taffy.children(node).unwrap()[1], child3);
1012 }
1013
1014 /// Test that removing a child works
1015 #[test]
1016 fn remove_child() {
1017 let mut taffy: TaffyTree<()> = TaffyTree::new();
1018 let child0 = taffy.new_leaf(Style::default()).unwrap();
1019 let child1 = taffy.new_leaf(Style::default()).unwrap();
1020 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
1021
1022 assert_eq!(taffy.child_count(node), 2);
1023
1024 taffy.remove_child(node, child0).unwrap();
1025 assert_eq!(taffy.child_count(node), 1);
1026 assert_eq!(taffy.children(node).unwrap()[0], child1);
1027
1028 taffy.remove_child(node, child1).unwrap();
1029 assert_eq!(taffy.child_count(node), 0);
1030 }
1031
1032 #[test]
1033 fn remove_child_at_index() {
1034 let mut taffy: TaffyTree<()> = TaffyTree::new();
1035 let child0 = taffy.new_leaf(Style::default()).unwrap();
1036 let child1 = taffy.new_leaf(Style::default()).unwrap();
1037 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
1038
1039 assert_eq!(taffy.child_count(node), 2);
1040
1041 taffy.remove_child_at_index(node, 0).unwrap();
1042 assert_eq!(taffy.child_count(node), 1);
1043 assert_eq!(taffy.children(node).unwrap()[0], child1);
1044
1045 taffy.remove_child_at_index(node, 0).unwrap();
1046 assert_eq!(taffy.child_count(node), 0);
1047 }
1048
1049 // Related to: https://github.com/DioxusLabs/taffy/issues/510
1050 #[test]
1051 fn remove_child_updates_parents() {
1052 let mut taffy: TaffyTree<()> = TaffyTree::new();
1053
1054 let parent = taffy.new_leaf(Style::default()).unwrap();
1055 let child = taffy.new_leaf(Style::default()).unwrap();
1056
1057 taffy.add_child(parent, child).unwrap();
1058
1059 taffy.remove(parent).unwrap();
1060
1061 // Once the parent is removed this shouldn't panic.
1062 assert!(taffy.set_children(child, &[]).is_ok());
1063 }
1064
1065 #[test]
1066 fn replace_child_at_index() {
1067 let mut taffy: TaffyTree<()> = TaffyTree::new();
1068
1069 let child0 = taffy.new_leaf(Style::default()).unwrap();
1070 let child1 = taffy.new_leaf(Style::default()).unwrap();
1071
1072 let node = taffy.new_with_children(Style::default(), &[child0]).unwrap();
1073 assert_eq!(taffy.child_count(node), 1);
1074 assert_eq!(taffy.children(node).unwrap()[0], child0);
1075
1076 taffy.replace_child_at_index(node, 0, child1).unwrap();
1077 assert_eq!(taffy.child_count(node), 1);
1078 assert_eq!(taffy.children(node).unwrap()[0], child1);
1079 }
1080 #[test]
1081 fn test_child_at_index() {
1082 let mut taffy: TaffyTree<()> = TaffyTree::new();
1083 let child0 = taffy.new_leaf(Style::default()).unwrap();
1084 let child1 = taffy.new_leaf(Style::default()).unwrap();
1085 let child2 = taffy.new_leaf(Style::default()).unwrap();
1086 let node = taffy.new_with_children(Style::default(), &[child0, child1, child2]).unwrap();
1087
1088 assert!(if let Ok(result) = taffy.child_at_index(node, 0) { result == child0 } else { false });
1089 assert!(if let Ok(result) = taffy.child_at_index(node, 1) { result == child1 } else { false });
1090 assert!(if let Ok(result) = taffy.child_at_index(node, 2) { result == child2 } else { false });
1091 }
1092 #[test]
1093 fn test_child_count() {
1094 let mut taffy: TaffyTree<()> = TaffyTree::new();
1095 let child0 = taffy.new_leaf(Style::default()).unwrap();
1096 let child1 = taffy.new_leaf(Style::default()).unwrap();
1097 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
1098
1099 assert!(taffy.child_count(node) == 2);
1100 assert!(taffy.child_count(child0) == 0);
1101 assert!(taffy.child_count(child1) == 0);
1102 }
1103
1104 #[allow(clippy::vec_init_then_push)]
1105 #[test]
1106 fn test_children() {
1107 let mut taffy: TaffyTree<()> = TaffyTree::new();
1108 let child0 = taffy.new_leaf(Style::default()).unwrap();
1109 let child1 = taffy.new_leaf(Style::default()).unwrap();
1110 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
1111
1112 let mut children = sys::Vec::new();
1113 children.push(child0);
1114 children.push(child1);
1115
1116 let children_result = taffy.children(node).unwrap();
1117 assert_eq!(children_result, children);
1118
1119 assert!(taffy.children(child0).unwrap().is_empty());
1120 }
1121 #[test]
1122 fn test_set_style() {
1123 let mut taffy: TaffyTree<()> = TaffyTree::new();
1124
1125 let node = taffy.new_leaf(Style::default()).unwrap();
1126 assert_eq!(taffy.style(node).unwrap().display, Display::Flex);
1127
1128 taffy.set_style(node, Style { display: Display::None, ..Style::default() }).unwrap();
1129 assert_eq!(taffy.style(node).unwrap().display, Display::None);
1130 }
1131 #[test]
1132 fn test_style() {
1133 let mut taffy: TaffyTree<()> = TaffyTree::new();
1134
1135 let style = Style { display: Display::None, flex_direction: FlexDirection::RowReverse, ..Default::default() };
1136
1137 let node = taffy.new_leaf(style.clone()).unwrap();
1138
1139 let res = taffy.style(node);
1140 assert!(res.is_ok());
1141 assert!(res.unwrap() == &style);
1142 }
1143 #[test]
1144 fn test_layout() {
1145 let mut taffy: TaffyTree<()> = TaffyTree::new();
1146 let node = taffy.new_leaf(Style::default()).unwrap();
1147
1148 // TODO: Improve this test?
1149 let res = taffy.layout(node);
1150 assert!(res.is_ok());
1151 }
1152
1153 #[test]
1154 fn test_mark_dirty() {
1155 let mut taffy: TaffyTree<()> = TaffyTree::new();
1156 let child0 = taffy.new_leaf(Style::default()).unwrap();
1157 let child1 = taffy.new_leaf(Style::default()).unwrap();
1158 let node = taffy.new_with_children(Style::default(), &[child0, child1]).unwrap();
1159
1160 taffy.compute_layout(node, Size::MAX_CONTENT).unwrap();
1161
1162 assert_eq!(taffy.dirty(child0), Ok(false));
1163 assert_eq!(taffy.dirty(child1), Ok(false));
1164 assert_eq!(taffy.dirty(node), Ok(false));
1165
1166 taffy.mark_dirty(node).unwrap();
1167 assert_eq!(taffy.dirty(child0), Ok(false));
1168 assert_eq!(taffy.dirty(child1), Ok(false));
1169 assert_eq!(taffy.dirty(node), Ok(true));
1170
1171 taffy.compute_layout(node, Size::MAX_CONTENT).unwrap();
1172 taffy.mark_dirty(child0).unwrap();
1173 assert_eq!(taffy.dirty(child0), Ok(true));
1174 assert_eq!(taffy.dirty(child1), Ok(false));
1175 assert_eq!(taffy.dirty(node), Ok(true));
1176 }
1177
1178 #[test]
1179 fn compute_layout_should_produce_valid_result() {
1180 let mut taffy: TaffyTree<()> = TaffyTree::new();
1181 let node_result = taffy.new_leaf(Style {
1182 size: Size { width: Dimension::Length(10f32), height: Dimension::Length(10f32) },
1183 ..Default::default()
1184 });
1185 assert!(node_result.is_ok());
1186 let node = node_result.unwrap();
1187 let layout_result = taffy.compute_layout(
1188 node,
1189 Size { width: AvailableSpace::Definite(100.), height: AvailableSpace::Definite(100.) },
1190 );
1191 assert!(layout_result.is_ok());
1192 }
1193
1194 #[test]
1195 fn make_sure_layout_location_is_top_left() {
1196 use crate::prelude::Rect;
1197
1198 let mut taffy: TaffyTree<()> = TaffyTree::new();
1199
1200 let node = taffy
1201 .new_leaf(Style {
1202 size: Size { width: Dimension::Percent(1f32), height: Dimension::Percent(1f32) },
1203 ..Default::default()
1204 })
1205 .unwrap();
1206
1207 let root = taffy
1208 .new_with_children(
1209 Style {
1210 size: Size { width: Dimension::Length(100f32), height: Dimension::Length(100f32) },
1211 padding: Rect {
1212 left: length(10f32),
1213 right: length(20f32),
1214 top: length(30f32),
1215 bottom: length(40f32),
1216 },
1217 ..Default::default()
1218 },
1219 &[node],
1220 )
1221 .unwrap();
1222
1223 taffy.compute_layout(root, Size::MAX_CONTENT).unwrap();
1224
1225 // If Layout::location represents top-left coord, 'node' location
1226 // must be (due applied 'root' padding): {x: 10, y: 30}.
1227 //
1228 // It's important, since result will be different for each other
1229 // coordinate space:
1230 // - bottom-left: {x: 10, y: 40}
1231 // - top-right: {x: 20, y: 30}
1232 // - bottom-right: {x: 20, y: 40}
1233 let layout = taffy.layout(node).unwrap();
1234 assert_eq!(layout.location.x, 10f32);
1235 assert_eq!(layout.location.y, 30f32);
1236 }
1237}