cranpose_ui/widgets/nodes/
layout_node.rs

1use std::{
2    any::TypeId,
3    cell::{Cell, RefCell},
4    collections::HashMap,
5    hash::{Hash, Hasher},
6    rc::Rc,
7};
8
9use cranpose_core::{Node, NodeId};
10use cranpose_foundation::{
11    InvalidationKind, ModifierInvalidation, NodeCapabilities, SemanticsConfiguration,
12};
13use cranpose_ui_layout::{Constraints, MeasurePolicy};
14
15#[cfg(test)]
16use crate::layout::LayoutRuntimeDebugStats;
17use crate::{
18    layout::{LayoutRuntimeState, MeasuredNode},
19    modifier::{
20        Modifier, ModifierChainHandle, ModifierLocalSource, ModifierLocalToken,
21        ModifierLocalsHandle, ModifierNodeSlices, Point, ResolvedModifierLocal, ResolvedModifiers,
22        Size,
23    },
24};
25
26#[derive(Clone, Copy)]
27enum LayoutInvalidationDispatchDiag {
28    Disabled,
29    All,
30    Node(NodeId),
31}
32
33fn layout_invalidation_dispatch_diag() -> LayoutInvalidationDispatchDiag {
34    static MODE: std::sync::OnceLock<LayoutInvalidationDispatchDiag> = std::sync::OnceLock::new();
35    *MODE.get_or_init(|| {
36        let Some(value) = std::env::var_os("CRANPOSE_LAYOUT_INVALIDATION_DISPATCH_DIAG") else {
37            return LayoutInvalidationDispatchDiag::Disabled;
38        };
39        if value == "all" {
40            return LayoutInvalidationDispatchDiag::All;
41        }
42        value.to_string_lossy().parse::<NodeId>().map_or(
43            LayoutInvalidationDispatchDiag::Disabled,
44            LayoutInvalidationDispatchDiag::Node,
45        )
46    })
47}
48
49fn log_layout_invalidation_dispatch(
50    id: NodeId,
51    invalidation: &ModifierInvalidation,
52    curr_caps: NodeCapabilities,
53    prev_caps: NodeCapabilities,
54    modifier: &Modifier,
55) {
56    let enabled = match layout_invalidation_dispatch_diag() {
57        LayoutInvalidationDispatchDiag::Disabled => false,
58        LayoutInvalidationDispatchDiag::All => true,
59        LayoutInvalidationDispatchDiag::Node(target) => target == id,
60    };
61    if enabled {
62        log::warn!(
63            "[layout-invalidation-dispatch] node={id} invalidation={invalidation:?} curr_caps={curr_caps:?} prev_caps={prev_caps:?} modifier={modifier}"
64        );
65    }
66}
67
68/// Retained layout state for a LayoutNode.
69/// This mirrors Jetpack Compose's approach where each node stores its own
70/// measured size and placed position, eliminating the need for per-frame
71/// LayoutTree reconstruction.
72#[derive(Clone, Debug, Default)]
73pub struct LayoutState {
74    size: Size,
75    position: Point,
76    is_placed: bool,
77    node_id: Option<NodeId>,
78    /// Offset of the content box relative to the node origin (e.g. due to padding).
79    pub content_offset: Point,
80}
81
82impl LayoutState {
83    pub fn size(&self) -> Size {
84        self.size
85    }
86
87    pub fn position(&self) -> Point {
88        self.position
89    }
90
91    /// The same state placed at the origin: what a window root's own scene
92    /// starts from, since the position its parent gave it belongs to the
93    /// parent's window.
94    pub fn at_origin(mut self) -> Self {
95        self.position = Point::default();
96        self
97    }
98
99    pub fn is_placed(&self) -> bool {
100        self.is_placed
101    }
102
103    pub(crate) fn set_node_id(&mut self, node_id: NodeId) {
104        self.node_id = Some(node_id);
105    }
106
107    /// Writes the measured size, self-reporting an actual change to the
108    /// scene phase.
109    pub fn set_size(&mut self, size: Size) {
110        if self.size != size {
111            if let Some(id) = self.node_id {
112                crate::render_state::record_geometry_scene_node(id);
113            }
114            self.size = size;
115        }
116    }
117
118    /// Writes the placed position and marks the node placed, self-reporting
119    /// an actual move to the scene phase.
120    pub fn place(&mut self, position: Point) {
121        if self.position != position {
122            if let Some(id) = self.node_id {
123                crate::render_state::record_geometry_scene_node(id);
124            }
125            self.position = position;
126        }
127        self.is_placed = true;
128    }
129
130    /// Clears the placed flag at the start of a layout pass.
131    pub fn clear_placed(&mut self) {
132        self.is_placed = false;
133    }
134}
135
136#[derive(Clone)]
137struct MeasurementCacheEntry {
138    constraints: Constraints,
139    measured: Rc<MeasuredNode>,
140}
141
142#[derive(Clone, Copy, Debug)]
143pub enum IntrinsicKind {
144    MinWidth(f32),
145    MaxWidth(f32),
146    MinHeight(f32),
147    MaxHeight(f32),
148}
149
150impl IntrinsicKind {
151    fn discriminant(&self) -> u8 {
152        match self {
153            IntrinsicKind::MinWidth(_) => 0,
154            IntrinsicKind::MaxWidth(_) => 1,
155            IntrinsicKind::MinHeight(_) => 2,
156            IntrinsicKind::MaxHeight(_) => 3,
157        }
158    }
159
160    fn value_bits(&self) -> u32 {
161        match self {
162            IntrinsicKind::MinWidth(value)
163            | IntrinsicKind::MaxWidth(value)
164            | IntrinsicKind::MinHeight(value)
165            | IntrinsicKind::MaxHeight(value) => value.to_bits(),
166        }
167    }
168}
169
170impl PartialEq for IntrinsicKind {
171    fn eq(&self, other: &Self) -> bool {
172        self.discriminant() == other.discriminant() && self.value_bits() == other.value_bits()
173    }
174}
175
176impl Eq for IntrinsicKind {}
177
178impl Hash for IntrinsicKind {
179    fn hash<H: Hasher>(&self, state: &mut H) {
180        self.discriminant().hash(state);
181        self.value_bits().hash(state);
182    }
183}
184
185#[derive(Default)]
186struct NodeCacheState {
187    epoch: u64,
188    measurements: Vec<MeasurementCacheEntry>,
189    intrinsics: Vec<(IntrinsicKind, f32)>,
190}
191
192#[derive(Clone, Default)]
193pub(crate) struct LayoutNodeCacheHandles {
194    state: Rc<RefCell<NodeCacheState>>,
195}
196
197impl LayoutNodeCacheHandles {
198    pub(crate) fn clear(&self) {
199        let mut state = self.state.borrow_mut();
200        state.measurements.clear();
201        state.intrinsics.clear();
202        state.epoch = 0;
203    }
204
205    pub(crate) fn activate(&self, epoch: u64) {
206        let mut state = self.state.borrow_mut();
207        if state.epoch != epoch {
208            state.measurements.clear();
209            state.intrinsics.clear();
210            state.epoch = epoch;
211        }
212    }
213
214    pub(crate) fn epoch(&self) -> u64 {
215        self.state.borrow().epoch
216    }
217
218    pub(crate) fn get_measurement(&self, constraints: Constraints) -> Option<Rc<MeasuredNode>> {
219        let state = self.state.borrow();
220        state
221            .measurements
222            .iter()
223            .find(|entry| entry.constraints == constraints)
224            .map(|entry| Rc::clone(&entry.measured))
225    }
226
227    pub(crate) fn store_measurement(&self, constraints: Constraints, measured: Rc<MeasuredNode>) {
228        let mut state = self.state.borrow_mut();
229        if let Some(entry) = state
230            .measurements
231            .iter_mut()
232            .find(|entry| entry.constraints == constraints)
233        {
234            entry.measured = measured;
235        } else {
236            state.measurements.push(MeasurementCacheEntry {
237                constraints,
238                measured,
239            });
240        }
241    }
242
243    pub(crate) fn get_intrinsic(&self, kind: &IntrinsicKind) -> Option<f32> {
244        let state = self.state.borrow();
245        state
246            .intrinsics
247            .iter()
248            .find(|(stored_kind, _)| stored_kind == kind)
249            .map(|(_, value)| *value)
250    }
251
252    pub(crate) fn store_intrinsic(&self, kind: IntrinsicKind, value: f32) {
253        let mut state = self.state.borrow_mut();
254        if let Some((_, existing)) = state
255            .intrinsics
256            .iter_mut()
257            .find(|(stored_kind, _)| stored_kind == &kind)
258        {
259            *existing = value;
260        } else {
261            state.intrinsics.push((kind, value));
262        }
263    }
264}
265
266pub struct LayoutNode {
267    /// Composable definitions responsible for this node, captured only for inspection builds.
268    #[cfg(feature = "inspection")]
269    pub source_trace: Rc<[cranpose_core::source_trace::SourceLocation]>,
270    pub modifier: Modifier,
271    modifier_chain: ModifierChainHandle,
272    resolved_modifiers: ResolvedModifiers,
273    modifier_capabilities: NodeCapabilities,
274    modifier_child_capabilities: NodeCapabilities,
275    pub measure_policy: Rc<dyn MeasurePolicy>,
276    density: crate::density::Density,
277    /// The actual children of this node (folded view - includes virtual nodes as-is)
278    pub children: Vec<NodeId>,
279    cache: LayoutNodeCacheHandles,
280    needs_measure: Cell<bool>,
281    needs_layout: Cell<bool>,
282    needs_semantics: Cell<bool>,
283    /// The chain's modal and hidden flags, read by the modal count and the
284    /// modal walk: dropped whenever the chain syncs or semantics are
285    /// invalidated, the two ways its semantics change.
286    semantics_reach: Cell<Option<cranpose_foundation::SemanticsReach>>,
287    needs_redraw: Cell<bool>,
288    needs_pointer_pass: Cell<bool>,
289    needs_focus_sync: Cell<bool>,
290    parent: Cell<Option<NodeId>>,
291    folded_parent: Cell<Option<NodeId>>,
292    id: Cell<Option<NodeId>>,
293    owner_context_id: Cell<Option<crate::render_state::AppContextId>>,
294    debug_modifiers: Cell<bool>,
295    is_virtual: bool,
296    virtual_children_count: Cell<usize>,
297
298    modifier_slices_snapshot: RefCell<Rc<ModifierNodeSlices>>,
299    modifier_slices_dirty: Cell<bool>,
300
301    layout_state: Rc<RefCell<LayoutState>>,
302    layout_runtime_state: Rc<RefCell<LayoutRuntimeState>>,
303    /// Where the chain's layout modifiers put their content, written by
304    /// layout and read by the draws and text the slices collect.
305    coordinator_geometry: Rc<crate::modifier::CoordinatorGeometry>,
306}
307
308pub(crate) const RECYCLED_LAYOUT_NODE_POOL_LIMIT: usize = 128;
309
310thread_local! {
311    static EMPTY_MEASURE_POLICY: Rc<dyn MeasurePolicy> =
312        Rc::new(crate::layout::policies::EmptyMeasurePolicy);
313}
314
315fn empty_measure_policy() -> Rc<dyn MeasurePolicy> {
316    EMPTY_MEASURE_POLICY.with(Rc::clone)
317}
318
319impl LayoutNode {
320    pub fn new(modifier: Modifier, measure_policy: Rc<dyn MeasurePolicy>) -> Self {
321        Self::new_with_virtual(modifier, measure_policy, false)
322    }
323
324    /// Create a virtual LayoutNode for subcomposition slot containers.
325    /// Virtual nodes are transparent - their children are flattened into parent's children list.
326    pub fn new_virtual() -> Self {
327        Self::new_with_virtual(Modifier::empty(), empty_measure_policy(), true)
328    }
329
330    fn new_recycled_shell(is_virtual: bool) -> Self {
331        let mut shell =
332            Self::new_with_virtual(Modifier::empty(), empty_measure_policy(), is_virtual);
333        shell.needs_measure.set(false);
334        shell.needs_layout.set(false);
335        shell.needs_semantics.set(false);
336        shell.needs_redraw.set(false);
337        shell.needs_pointer_pass.set(false);
338        shell.needs_focus_sync.set(false);
339        shell.parent.set(None);
340        shell.folded_parent.set(None);
341        shell.id.set(None);
342        shell.owner_context_id.set(None);
343        shell.debug_modifiers.set(false);
344        shell.virtual_children_count.set(0);
345        shell.cache = LayoutNodeCacheHandles::default();
346        shell.modifier_slices_snapshot = RefCell::new(Rc::default());
347        shell.modifier_slices_dirty = Cell::new(true);
348        shell.layout_state = Rc::new(RefCell::new(LayoutState::default()));
349        shell.layout_runtime_state = Rc::new(RefCell::new(LayoutRuntimeState::default()));
350        shell.coordinator_geometry = Rc::default();
351        shell
352    }
353
354    fn new_with_virtual(
355        modifier: Modifier,
356        measure_policy: Rc<dyn MeasurePolicy>,
357        is_virtual: bool,
358    ) -> Self {
359        let mut node = Self {
360            #[cfg(feature = "inspection")]
361            source_trace: cranpose_core::source_trace::current_source_trace(),
362            modifier,
363            modifier_chain: ModifierChainHandle::new(),
364            resolved_modifiers: ResolvedModifiers::default(),
365            modifier_capabilities: NodeCapabilities::default(),
366            modifier_child_capabilities: NodeCapabilities::default(),
367            measure_policy,
368            density: crate::density::Density::default(),
369            children: Vec::new(),
370            cache: LayoutNodeCacheHandles::default(),
371            needs_measure: Cell::new(true),
372            needs_layout: Cell::new(true),
373            needs_semantics: Cell::new(true),
374            semantics_reach: Cell::new(None),
375            needs_redraw: Cell::new(true),
376            needs_pointer_pass: Cell::new(false),
377            needs_focus_sync: Cell::new(false),
378            parent: Cell::new(None),
379            folded_parent: Cell::new(None),
380            id: Cell::new(None),
381            owner_context_id: Cell::new(None),
382            debug_modifiers: Cell::new(false),
383            is_virtual,
384            virtual_children_count: Cell::new(0),
385            modifier_slices_snapshot: RefCell::new(Rc::default()),
386            modifier_slices_dirty: Cell::new(true),
387            layout_state: Rc::new(RefCell::new(LayoutState::default())),
388            layout_runtime_state: Rc::new(RefCell::new(LayoutRuntimeState::default())),
389            coordinator_geometry: Rc::default(),
390        };
391        node.sync_modifier_chain();
392        node
393    }
394
395    pub fn set_modifier(&mut self, modifier: Modifier) {
396        #[cfg(feature = "inspection")]
397        {
398            let trace = cranpose_core::source_trace::current_source_trace();
399            if !trace.is_empty() {
400                self.source_trace = trace;
401            }
402        }
403        // An equal modifier leaves every element's node as it was. Only a
404        // chain reading modifier locals resyncs, since its parent may now
405        // provide others.
406        if self.modifier == modifier
407            && !self
408                .modifier_capabilities
409                .contains(NodeCapabilities::MODIFIER_LOCALS)
410        {
411            return;
412        }
413        let modifier_changed = !self.modifier.structural_eq(&modifier);
414        self.modifier = modifier;
415        self.sync_modifier_chain();
416        if modifier_changed {
417            self.cache.clear();
418            self.request_semantics_update();
419        }
420    }
421
422    fn sync_modifier_chain(&mut self) {
423        let prev_caps = self.modifier_capabilities;
424        let start_parent = self.parent();
425        let mut resolver = move |token: &ModifierLocalToken| {
426            resolve_modifier_local_from_parent_chain(start_parent, token)
427        };
428        self.modifier_chain
429            .set_debug_logging(self.debug_modifiers.get());
430        self.modifier_chain.set_node_id(self.id.get());
431        let modifier_local_invalidations = self
432            .modifier_chain
433            .update_with_resolver(&self.modifier, &mut resolver);
434        self.resolved_modifiers = self.modifier_chain.resolved_modifiers();
435        self.modifier_capabilities = self.modifier_chain.capabilities();
436        self.modifier_child_capabilities = self.modifier_chain.aggregate_child_capabilities();
437        self.forget_semantics_reach();
438        self.modifier_slices_dirty.set(true);
439
440        let mut invalidations = self.modifier_chain.take_invalidations();
441        invalidations.extend(modifier_local_invalidations);
442        self.dispatch_modifier_invalidations_with_prev(&invalidations, prev_caps);
443        self.refresh_registry_state();
444    }
445
446    fn update_modifier_slices_cache(&self) {
447        let mut snapshot = self.modifier_slices_snapshot.borrow_mut();
448        crate::modifier::collect_modifier_slices_into_shared(
449            self.modifier_chain.chain(),
450            &mut snapshot,
451            &self.coordinator_geometry,
452            self.density.density(),
453        );
454        self.modifier_slices_dirty.set(false);
455    }
456
457    pub(crate) fn mark_modifier_slices_dirty(&self) {
458        self.modifier_slices_dirty.set(true);
459    }
460
461    #[cfg(test)]
462    fn dispatch_modifier_invalidations(&self, invalidations: &[ModifierInvalidation]) {
463        self.dispatch_modifier_invalidations_with_prev(invalidations, NodeCapabilities::empty());
464    }
465
466    fn dispatch_modifier_invalidations_with_prev(
467        &self,
468        invalidations: &[ModifierInvalidation],
469        prev_caps: NodeCapabilities,
470    ) {
471        let curr_caps = self.modifier_capabilities;
472        for invalidation in invalidations {
473            self.modifier_slices_dirty.set(true);
474            let has_capability =
475                |capability| curr_caps.contains(capability) || prev_caps.contains(capability);
476            match invalidation.kind() {
477                InvalidationKind::Layout => {
478                    if has_capability(NodeCapabilities::LAYOUT) {
479                        self.mark_needs_measure();
480                        if let Some(id) = self.id.get() {
481                            log_layout_invalidation_dispatch(
482                                id,
483                                invalidation,
484                                curr_caps,
485                                prev_caps,
486                                &self.modifier,
487                            );
488                            let inside_composition =
489                                cranpose_core::composer_context::try_with_composer(|_| ())
490                                    .is_some();
491                            if inside_composition {
492                                cranpose_core::bubble_measure_dirty_in_composer(id);
493                            } else {
494                                crate::schedule_layout_repass(id);
495                            }
496                        }
497                    }
498                }
499                InvalidationKind::Draw => {
500                    if has_capability(NodeCapabilities::DRAW)
501                        || invalidation.capabilities().contains(NodeCapabilities::DRAW)
502                    {
503                        self.mark_needs_redraw();
504                    }
505                }
506                InvalidationKind::PointerInput => {
507                    if has_capability(NodeCapabilities::POINTER_INPUT) {
508                        self.mark_needs_pointer_pass();
509                        crate::request_pointer_invalidation();
510                        if let Some(id) = self.id.get() {
511                            crate::schedule_pointer_repass(id);
512                        }
513                    }
514                }
515                InvalidationKind::Semantics => {
516                    self.request_semantics_update();
517                }
518                InvalidationKind::Focus => {
519                    if has_capability(NodeCapabilities::FOCUS) {
520                        self.mark_needs_focus_sync();
521                        crate::request_focus_invalidation();
522                        if let Some(id) = self.id.get() {
523                            crate::schedule_focus_invalidation(id);
524                        }
525                    }
526                }
527            }
528        }
529    }
530
531    /// The grid this node was composed against.
532    pub fn density(&self) -> crate::density::Density {
533        self.density
534    }
535
536    /// Records the grid the composition provided, re-measuring if it moved.
537    pub fn set_density(&mut self, density: crate::density::Density) {
538        if self.density != density {
539            self.density = density;
540            self.cache.clear();
541            self.modifier_slices_dirty.set(true);
542            self.mark_needs_measure();
543        }
544    }
545
546    pub fn set_measure_policy(&mut self, policy: Rc<dyn MeasurePolicy>) {
547        if !Rc::ptr_eq(&self.measure_policy, &policy) {
548            self.measure_policy = policy;
549            self.cache.clear();
550            self.mark_needs_measure();
551            if let Some(id) = self.id.get() {
552                cranpose_core::bubble_measure_dirty_in_composer(id);
553            }
554        }
555    }
556
557    /// Mark this node as needing measure. Also marks it as needing layout.
558    pub fn mark_needs_measure(&self) {
559        self.needs_measure.set(true);
560        self.needs_layout.set(true);
561    }
562
563    /// Mark this node as needing layout (but not necessarily measure).
564    pub fn mark_needs_layout(&self) {
565        self.needs_layout.set(true);
566    }
567
568    /// Mark this node as needing redraw without forcing measure/layout.
569    pub fn mark_needs_redraw(&self) {
570        self.needs_redraw.set(true);
571        if let Some(id) = self.id.get() {
572            crate::schedule_draw_repass(id);
573        }
574        crate::request_render_invalidation();
575    }
576
577    /// Check if this node needs measure.
578    pub fn needs_measure(&self) -> bool {
579        self.needs_measure.get()
580    }
581
582    /// Check if this node needs layout.
583    pub fn needs_layout(&self) -> bool {
584        self.needs_layout.get()
585    }
586
587    /// Mark this node as needing semantics recomputation.
588    pub fn mark_needs_semantics(&self) {
589        self.needs_semantics.set(true);
590        self.forget_semantics_reach();
591    }
592
593    pub(crate) fn clear_needs_semantics(&self) {
594        self.needs_semantics.set(false);
595    }
596
597    /// Returns true when semantics need to be recomputed.
598    pub fn needs_semantics(&self) -> bool {
599        self.needs_semantics.get()
600    }
601
602    /// Returns true when this node requested a redraw since the last render pass.
603    pub fn needs_redraw(&self) -> bool {
604        self.needs_redraw.get()
605    }
606
607    pub fn clear_needs_redraw(&self) {
608        self.needs_redraw.set(false);
609    }
610
611    fn request_semantics_update(&self) {
612        let already_dirty = self.needs_semantics.replace(true);
613        if already_dirty {
614            return;
615        }
616
617        if let Some(id) = self.id.get() {
618            cranpose_core::queue_semantics_invalidation(id);
619        }
620    }
621
622    pub(crate) fn clear_needs_measure(&self) {
623        self.needs_measure.set(false);
624    }
625
626    pub(crate) fn clear_needs_layout(&self) {
627        self.needs_layout.set(false);
628    }
629
630    /// Marks this node as needing a fresh pointer-input pass.
631    pub fn mark_needs_pointer_pass(&self) {
632        self.needs_pointer_pass.set(true);
633    }
634
635    /// Returns true when pointer-input state needs to be recomputed.
636    pub fn needs_pointer_pass(&self) -> bool {
637        self.needs_pointer_pass.get()
638    }
639
640    /// Clears the pointer-input dirty flag after hosts service it.
641    pub fn clear_needs_pointer_pass(&self) {
642        self.needs_pointer_pass.set(false);
643    }
644
645    /// Marks this node as needing a focus synchronization.
646    pub fn mark_needs_focus_sync(&self) {
647        self.needs_focus_sync.set(true);
648    }
649
650    /// Returns true when focus state needs to be synchronized.
651    pub fn needs_focus_sync(&self) -> bool {
652        self.needs_focus_sync.get()
653    }
654
655    /// Clears the focus dirty flag after the focus manager processes it.
656    pub fn clear_needs_focus_sync(&self) {
657        self.needs_focus_sync.set(false);
658    }
659
660    /// Set this node's ID (called by applier after creation).
661    pub fn set_node_id(&mut self, id: NodeId) {
662        if let Some(existing) = self.id.replace(Some(id))
663            && let Some(owner_context_id) = self.owner_context_id.take()
664        {
665            unregister_layout_node(owner_context_id, existing);
666        }
667        self.layout_state.borrow_mut().set_node_id(id);
668        let owner_context_id = register_layout_node(id, self);
669        self.owner_context_id.set(Some(owner_context_id));
670        self.refresh_registry_state();
671
672        self.modifier_chain.set_node_id(Some(id));
673        let invalidations = self.modifier_chain.take_invalidations();
674        self.dispatch_modifier_invalidations_with_prev(&invalidations, NodeCapabilities::empty());
675        // The slices carry the node's id; they are collected again when next read.
676        self.modifier_slices_dirty.set(true);
677    }
678
679    /// Get this node's ID.
680    pub fn node_id(&self) -> Option<NodeId> {
681        self.id.get()
682    }
683
684    /// Set this node's parent (called when node is added as child).
685    /// Sets both folded_parent (direct) and parent (first non-virtual ancestor for bubbling).
686    pub fn set_parent(&self, parent: NodeId) {
687        self.folded_parent.set(Some(parent));
688        self.parent.set(Some(parent));
689        self.refresh_registry_state();
690    }
691
692    /// Clear this node's parent (called when node is removed from parent).
693    pub fn clear_parent(&self) {
694        self.folded_parent.set(None);
695        self.parent.set(None);
696        self.refresh_registry_state();
697    }
698
699    /// Get this node's parent for dirty flag bubbling (may skip virtual nodes).
700    pub fn parent(&self) -> Option<NodeId> {
701        self.parent.get()
702    }
703
704    /// Get this node's direct parent (may be a virtual node).
705    pub fn folded_parent(&self) -> Option<NodeId> {
706        self.folded_parent.get()
707    }
708
709    /// Returns true if this is a virtual node (transparent container for subcomposition).
710    pub fn is_virtual(&self) -> bool {
711        self.is_virtual
712    }
713
714    pub(crate) fn cache_handles(&self) -> LayoutNodeCacheHandles {
715        self.cache.clone()
716    }
717
718    pub fn resolved_modifiers(&self) -> ResolvedModifiers {
719        self.resolved_modifiers
720    }
721
722    pub fn modifier_capabilities(&self) -> NodeCapabilities {
723        self.modifier_capabilities
724    }
725
726    /// Whether this node's modifier chain makes it the root of a separate
727    /// window. Its parent lays out as if it had no size and its parent's
728    /// scene skips it; its own scene starts here.
729    pub fn is_window_root(&self) -> bool {
730        self.modifier_capabilities
731            .contains(NodeCapabilities::WINDOW_ROOT)
732    }
733
734    pub fn modifier_child_capabilities(&self) -> NodeCapabilities {
735        self.modifier_child_capabilities
736    }
737
738    pub fn set_debug_modifiers(&mut self, enabled: bool) {
739        self.debug_modifiers.set(enabled);
740        self.modifier_chain.set_debug_logging(enabled);
741    }
742
743    pub fn debug_modifiers_enabled(&self) -> bool {
744        self.debug_modifiers.get()
745    }
746
747    pub fn modifier_locals_handle(&self) -> ModifierLocalsHandle {
748        self.modifier_chain.modifier_locals_handle()
749    }
750
751    pub fn has_layout_modifier_nodes(&self) -> bool {
752        self.modifier_capabilities
753            .contains(NodeCapabilities::LAYOUT)
754    }
755
756    pub fn has_draw_modifier_nodes(&self) -> bool {
757        self.modifier_capabilities.contains(NodeCapabilities::DRAW)
758    }
759
760    pub fn has_pointer_input_modifier_nodes(&self) -> bool {
761        self.modifier_capabilities
762            .contains(NodeCapabilities::POINTER_INPUT)
763    }
764
765    pub fn has_semantics_modifier_nodes(&self) -> bool {
766        self.modifier_capabilities
767            .contains(NodeCapabilities::SEMANTICS)
768    }
769
770    pub fn has_focus_modifier_nodes(&self) -> bool {
771        self.modifier_capabilities.contains(NodeCapabilities::FOCUS)
772    }
773
774    fn refresh_registry_state(&self) {
775        if let (Some(id), Some(owner_context_id)) = (self.id.get(), self.owner_context_id.get()) {
776            let parent = self.parent();
777            let capabilities = self.modifier_child_capabilities();
778            let modifier_locals = self.modifier_locals_handle();
779            let _ = crate::render_state::with_layout_node_registry_by_app_context(
780                owner_context_id,
781                |registry| {
782                    registry.update_entry(id, parent, capabilities, modifier_locals);
783                },
784            );
785        }
786    }
787
788    pub fn modifier_slices_snapshot(&self) -> Rc<ModifierNodeSlices> {
789        if self.modifier_slices_dirty.get() {
790            self.update_modifier_slices_cache();
791        }
792        self.modifier_slices_snapshot.borrow().clone()
793    }
794
795    /// Returns a clone of the current layout state.
796    pub fn layout_state(&self) -> LayoutState {
797        self.layout_state.borrow().clone()
798    }
799
800    /// Returns the measured size of this node.
801    pub fn measured_size(&self) -> Size {
802        self.layout_state.borrow().size
803    }
804
805    /// Returns the position of this node relative to its parent.
806    pub fn position(&self) -> Point {
807        self.layout_state.borrow().position
808    }
809
810    /// Returns true if this node has been placed in the current layout pass.
811    pub fn is_placed(&self) -> bool {
812        self.layout_state.borrow().is_placed
813    }
814
815    /// Updates the measured size of this node. Called during measurement.
816    /// [`LayoutState::set_size`] self-reports actual changes to the scene
817    /// phase.
818    pub fn set_measured_size(&self, size: Size) {
819        self.layout_state.borrow_mut().set_size(size);
820    }
821
822    /// Updates the position of this node. Called during placement.
823    /// [`LayoutState::place`] self-reports actual moves to the scene phase.
824    pub fn set_position(&self, position: Point) {
825        self.layout_state.borrow_mut().place(position);
826    }
827
828    /// Records the content offset (e.g. from padding).
829    pub fn set_content_offset(&self, offset: Point) {
830        self.layout_state.borrow_mut().content_offset = offset;
831    }
832
833    /// Clears the is_placed flag. Called at the start of a layout pass.
834    pub fn clear_placed(&self) {
835        self.layout_state.borrow_mut().is_placed = false;
836    }
837
838    pub fn semantics_configuration(&self) -> Option<SemanticsConfiguration> {
839        crate::modifier::collect_semantics_from_chain(self.modifier_chain.chain())
840    }
841
842    /// Drops the cached reach and queues the node for the modal count.
843    fn forget_semantics_reach(&self) {
844        self.semantics_reach.set(None);
845        crate::modal_nodes::reach_changed(self.id.get());
846    }
847
848    /// Whether this node's modifiers make it modal or hidden.
849    pub fn semantics_reach(&self) -> cranpose_foundation::SemanticsReach {
850        if let Some(reach) = self.semantics_reach.get() {
851            return reach;
852        }
853        let reach = crate::modifier::semantics_reach_of_chain(self.modifier_chain.chain());
854        self.semantics_reach.set(Some(reach));
855        reach
856    }
857
858    pub(crate) fn modifier_chain(&self) -> &ModifierChainHandle {
859        &self.modifier_chain
860    }
861
862    /// Access the text field modifier node (if present) with a mutable callback.
863    ///
864    /// This is used for keyboard event dispatch to text fields.
865    /// Returns `None` if no text field modifier is found in the chain.
866    pub fn with_text_field_modifier_mut<R>(
867        &mut self,
868        f: impl FnMut(&mut crate::TextFieldModifierNode) -> R,
869    ) -> Option<R> {
870        self.modifier_chain.with_text_field_modifier_mut(f)
871    }
872
873    /// Returns a handle to the shared layout state.
874    /// Used by layout system to update state without borrowing the Applier.
875    pub fn layout_state_handle(&self) -> Rc<RefCell<LayoutState>> {
876        self.layout_state.clone()
877    }
878
879    pub(crate) fn coordinator_geometry(&self) -> Rc<crate::modifier::CoordinatorGeometry> {
880        Rc::clone(&self.coordinator_geometry)
881    }
882
883    pub(crate) fn layout_runtime_state_handle(&self) -> Rc<RefCell<LayoutRuntimeState>> {
884        self.layout_runtime_state.clone()
885    }
886
887    #[cfg(test)]
888    pub(crate) fn layout_runtime_debug_stats(&self) -> LayoutRuntimeDebugStats {
889        self.layout_runtime_state.borrow().debug_stats()
890    }
891}
892impl Clone for LayoutNode {
893    fn clone(&self) -> Self {
894        let mut node = Self {
895            #[cfg(feature = "inspection")]
896            source_trace: self.source_trace.clone(),
897            modifier: self.modifier.clone(),
898            modifier_chain: ModifierChainHandle::new(),
899            resolved_modifiers: ResolvedModifiers::default(),
900            modifier_capabilities: self.modifier_capabilities,
901            modifier_child_capabilities: self.modifier_child_capabilities,
902            measure_policy: self.measure_policy.clone(),
903            density: self.density,
904            children: self.children.clone(),
905            cache: self.cache.clone(),
906            needs_measure: Cell::new(self.needs_measure.get()),
907            needs_layout: Cell::new(self.needs_layout.get()),
908            needs_semantics: Cell::new(self.needs_semantics.get()),
909            semantics_reach: Cell::new(None),
910            needs_redraw: Cell::new(self.needs_redraw.get()),
911            needs_pointer_pass: Cell::new(self.needs_pointer_pass.get()),
912            needs_focus_sync: Cell::new(self.needs_focus_sync.get()),
913            parent: Cell::new(self.parent.get()),
914            folded_parent: Cell::new(self.folded_parent.get()),
915            id: Cell::new(None),
916            owner_context_id: Cell::new(None),
917            debug_modifiers: Cell::new(self.debug_modifiers.get()),
918            is_virtual: self.is_virtual,
919            virtual_children_count: Cell::new(self.virtual_children_count.get()),
920            modifier_slices_snapshot: RefCell::new(Rc::default()),
921            modifier_slices_dirty: Cell::new(true),
922            layout_state: self.layout_state.clone(),
923            layout_runtime_state: self.layout_runtime_state.clone(),
924            coordinator_geometry: Rc::clone(&self.coordinator_geometry),
925        };
926        node.sync_modifier_chain();
927        node
928    }
929}
930
931impl Node for LayoutNode {
932    fn mount(&mut self) {
933        let (chain, mut context) = self.modifier_chain.chain_and_context_mut();
934        chain.repair_chain();
935        chain.attach_nodes(&mut *context);
936        crate::modal_nodes::reach_changed(self.id.get());
937    }
938
939    fn unmount(&mut self) {
940        self.modifier_chain.chain_mut().detach_nodes();
941    }
942
943    fn set_node_id(&mut self, id: NodeId) {
944        LayoutNode::set_node_id(self, id);
945    }
946
947    fn insert_child(&mut self, child: NodeId) -> bool {
948        if self.children.contains(&child) {
949            return false;
950        }
951        if is_virtual_node(child) {
952            let count = self.virtual_children_count.get();
953            self.virtual_children_count.set(count + 1);
954        }
955        self.children.push(child);
956        self.cache.clear();
957        self.mark_needs_measure();
958        true
959    }
960
961    fn remove_child(&mut self, child: NodeId) -> bool {
962        let before = self.children.len();
963        self.children.retain(|&id| id != child);
964        let removed = self.children.len() < before;
965        if removed {
966            if is_virtual_node(child) {
967                let count = self.virtual_children_count.get();
968                if count > 0 {
969                    self.virtual_children_count.set(count - 1);
970                }
971            }
972            self.cache.clear();
973            self.mark_needs_measure();
974        }
975        removed
976    }
977
978    fn move_child(&mut self, from: usize, to: usize) {
979        if from == to || from >= self.children.len() {
980            return;
981        }
982        let child = self.children.remove(from);
983        let target = to.min(self.children.len());
984        self.children.insert(target, child);
985        self.cache.clear();
986        self.mark_needs_measure();
987    }
988
989    fn update_children(&mut self, children: &[NodeId]) {
990        self.children.clear();
991        self.children.extend_from_slice(children);
992        self.cache.clear();
993        self.mark_needs_measure();
994    }
995
996    fn collect_children_into(&self, out: &mut smallvec::SmallVec<[NodeId; 8]>) {
997        out.clear();
998        out.extend_from_slice(&self.children);
999    }
1000
1001    fn on_attached_to_parent(&mut self, parent: NodeId) {
1002        self.set_parent(parent);
1003    }
1004
1005    fn on_removed_from_parent(&mut self) {
1006        self.clear_parent();
1007    }
1008
1009    fn parent(&self) -> Option<NodeId> {
1010        self.parent.get()
1011    }
1012
1013    fn mark_needs_layout(&self) {
1014        self.needs_layout.set(true);
1015    }
1016
1017    fn needs_layout(&self) -> bool {
1018        self.needs_layout.get()
1019    }
1020
1021    fn mark_needs_measure(&self) {
1022        self.needs_measure.set(true);
1023        self.needs_layout.set(true);
1024    }
1025
1026    fn needs_measure(&self) -> bool {
1027        self.needs_measure.get()
1028    }
1029
1030    fn mark_needs_semantics(&self) {
1031        self.needs_semantics.set(true);
1032        self.forget_semantics_reach();
1033    }
1034
1035    fn needs_semantics(&self) -> bool {
1036        self.needs_semantics.get()
1037    }
1038
1039    fn set_parent_for_bubbling(&mut self, parent: NodeId) {
1040        if self.parent.get().is_none() {
1041            self.parent.set(Some(parent));
1042        }
1043    }
1044
1045    fn recycle_key(&self) -> Option<TypeId> {
1046        Some(TypeId::of::<Self>())
1047    }
1048
1049    fn recycle_pool_limit(&self) -> Option<usize> {
1050        Some(RECYCLED_LAYOUT_NODE_POOL_LIMIT)
1051    }
1052
1053    fn prepare_for_recycle(&mut self) {
1054        *self = Self::new_recycled_shell(self.is_virtual);
1055    }
1056
1057    fn rehouse_for_recycle(&self) -> Option<Box<dyn cranpose_core::Node>> {
1058        Some(Box::new(Self::new_recycled_shell(self.is_virtual)))
1059    }
1060
1061    fn rehouse_for_live_compaction(&mut self) -> Option<Box<dyn cranpose_core::Node>> {
1062        let mut previous = std::mem::replace(self, Self::new_recycled_shell(self.is_virtual));
1063        let node_id = previous.id.replace(None);
1064        let parent = previous.parent.get();
1065        let folded_parent = previous.folded_parent.get();
1066        let debug_modifiers = previous.debug_modifiers.get();
1067        let needs_measure = previous.needs_measure.get();
1068        let needs_layout = previous.needs_layout.get();
1069        let needs_semantics = previous.needs_semantics.get();
1070        let needs_redraw = previous.needs_redraw.get();
1071        let needs_pointer_pass = previous.needs_pointer_pass.get();
1072        let needs_focus_sync = previous.needs_focus_sync.get();
1073        let virtual_children_count = previous.virtual_children_count.get();
1074        let children = previous.children.to_vec();
1075        let modifier = previous.modifier.rehouse_for_live_compaction();
1076        let measure_policy = previous.measure_policy.clone();
1077        let layout_state = previous.layout_state.clone();
1078        let layout_runtime_state = previous.layout_runtime_state.clone();
1079        let coordinator_geometry = Rc::clone(&previous.coordinator_geometry);
1080
1081        previous.modifier_chain.chain_mut().detach_nodes();
1082
1083        let mut compact = Self::new_with_virtual(modifier, measure_policy, previous.is_virtual);
1084        compact.children = children;
1085        #[cfg(feature = "inspection")]
1086        {
1087            compact.source_trace = previous.source_trace.clone();
1088        }
1089        compact.parent.set(parent);
1090        compact.folded_parent.set(folded_parent);
1091        compact.id.set(node_id);
1092        compact.debug_modifiers.set(debug_modifiers);
1093        compact.needs_measure.set(needs_measure);
1094        compact.needs_layout.set(needs_layout);
1095        compact.needs_semantics.set(needs_semantics);
1096        compact.needs_redraw.set(needs_redraw);
1097        compact.needs_pointer_pass.set(needs_pointer_pass);
1098        compact.needs_focus_sync.set(needs_focus_sync);
1099        compact.virtual_children_count.set(virtual_children_count);
1100        compact.layout_state = layout_state;
1101        compact.layout_runtime_state = layout_runtime_state;
1102        compact.coordinator_geometry = coordinator_geometry;
1103        compact.sync_modifier_chain();
1104        if let Some(id) = node_id {
1105            let owner_context_id = register_layout_node(id, &compact);
1106            compact.owner_context_id.set(Some(owner_context_id));
1107        }
1108
1109        Some(Box::new(compact))
1110    }
1111}
1112
1113impl Drop for LayoutNode {
1114    fn drop(&mut self) {
1115        if let (Some(id), Some(owner_context_id)) = (self.id.get(), self.owner_context_id.get()) {
1116            unregister_layout_node(owner_context_id, id);
1117        }
1118    }
1119}
1120
1121const MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY: usize = 128;
1122const VIRTUAL_NODE_ID_START: NodeId = 0xC0000000;
1123
1124#[cfg(test)]
1125#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
1126struct LayoutNodeRegistryDebugStats {
1127    len: usize,
1128    capacity: usize,
1129}
1130
1131struct LayoutNodeRegistryEntry {
1132    parent: Option<NodeId>,
1133    modifier_child_capabilities: NodeCapabilities,
1134    modifier_locals: ModifierLocalsHandle,
1135    is_virtual: bool,
1136}
1137
1138pub(crate) struct LayoutNodeRegistryState {
1139    entries: RefCell<HashMap<NodeId, LayoutNodeRegistryEntry>>,
1140    virtual_node_id_counter: Cell<NodeId>,
1141}
1142
1143impl LayoutNodeRegistryState {
1144    pub(crate) fn new() -> Self {
1145        Self {
1146            entries: RefCell::new(HashMap::new()),
1147            virtual_node_id_counter: Cell::new(VIRTUAL_NODE_ID_START),
1148        }
1149    }
1150
1151    fn register(&self, id: NodeId, node: &LayoutNode) {
1152        self.entries.borrow_mut().insert(
1153            id,
1154            LayoutNodeRegistryEntry {
1155                parent: node.parent(),
1156                modifier_child_capabilities: node.modifier_child_capabilities(),
1157                modifier_locals: node.modifier_locals_handle(),
1158                is_virtual: node.is_virtual(),
1159            },
1160        );
1161    }
1162
1163    fn unregister(&self, id: NodeId) {
1164        let mut entries = self.entries.borrow_mut();
1165        entries.remove(&id);
1166        let should_shrink = (entries.len() <= MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY
1167            && entries.capacity() > MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY)
1168            || entries.capacity()
1169                > entries
1170                    .len()
1171                    .max(MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY)
1172                    .saturating_mul(4);
1173        if should_shrink {
1174            let retained = entries
1175                .len()
1176                .max(MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY);
1177            let mut rebuilt = HashMap::new();
1178            rebuilt.reserve(retained);
1179            rebuilt.extend(entries.drain());
1180            *entries = rebuilt;
1181        }
1182    }
1183
1184    fn update_entry(
1185        &self,
1186        id: NodeId,
1187        parent: Option<NodeId>,
1188        modifier_child_capabilities: NodeCapabilities,
1189        modifier_locals: ModifierLocalsHandle,
1190    ) {
1191        if let Some(entry) = self.entries.borrow_mut().get_mut(&id) {
1192            entry.parent = parent;
1193            entry.modifier_child_capabilities = modifier_child_capabilities;
1194            entry.modifier_locals = modifier_locals;
1195        }
1196    }
1197
1198    #[cfg(test)]
1199    fn stats(&self) -> LayoutNodeRegistryDebugStats {
1200        let entries = self.entries.borrow();
1201        LayoutNodeRegistryDebugStats {
1202            len: entries.len(),
1203            capacity: entries.capacity(),
1204        }
1205    }
1206
1207    fn is_virtual_node(&self, id: NodeId) -> bool {
1208        self.entries
1209            .borrow()
1210            .get(&id)
1211            .is_some_and(|entry| entry.is_virtual)
1212    }
1213
1214    fn allocate_virtual_node_id(&self) -> NodeId {
1215        let id = self.virtual_node_id_counter.get();
1216        self.virtual_node_id_counter.set(id.wrapping_add(1));
1217        id
1218    }
1219
1220    fn resolve_modifier_local_from_parent_chain(
1221        &self,
1222        start: Option<NodeId>,
1223        token: &ModifierLocalToken,
1224    ) -> Option<ResolvedModifierLocal> {
1225        let mut current = start;
1226        while let Some(parent_id) = current {
1227            let (next_parent, resolved) = {
1228                let entries = self.entries.borrow();
1229                if let Some(entry) = entries.get(&parent_id) {
1230                    let resolved = if entry
1231                        .modifier_child_capabilities
1232                        .contains(NodeCapabilities::MODIFIER_LOCALS)
1233                    {
1234                        entry
1235                            .modifier_locals
1236                            .borrow()
1237                            .resolve(token)
1238                            .map(|value| value.with_source(ModifierLocalSource::Ancestor))
1239                    } else {
1240                        None
1241                    };
1242                    (entry.parent, resolved)
1243                } else {
1244                    (None, None)
1245                }
1246            };
1247            if let Some(value) = resolved {
1248                return Some(value);
1249            }
1250            current = next_parent;
1251        }
1252        None
1253    }
1254}
1255
1256pub(crate) fn register_layout_node(
1257    id: NodeId,
1258    node: &LayoutNode,
1259) -> crate::render_state::AppContextId {
1260    let owner_context_id = crate::render_state::current_app_context_id();
1261    let _ = crate::render_state::with_layout_node_registry_by_app_context(
1262        owner_context_id,
1263        |registry| {
1264            registry.register(id, node);
1265        },
1266    );
1267    owner_context_id
1268}
1269
1270pub(crate) fn unregister_layout_node(
1271    owner_context_id: crate::render_state::AppContextId,
1272    id: NodeId,
1273) {
1274    let _ = crate::render_state::with_layout_node_registry_by_app_context(
1275        owner_context_id,
1276        |registry| {
1277            registry.unregister(id);
1278        },
1279    );
1280}
1281
1282#[cfg(test)]
1283fn layout_node_registry_stats() -> LayoutNodeRegistryDebugStats {
1284    crate::render_state::with_layout_node_registry(LayoutNodeRegistryState::stats)
1285}
1286
1287pub(crate) fn is_virtual_node(id: NodeId) -> bool {
1288    crate::render_state::with_layout_node_registry(|registry| registry.is_virtual_node(id))
1289}
1290
1291pub(crate) fn allocate_virtual_node_id() -> NodeId {
1292    crate::render_state::with_layout_node_registry(
1293        LayoutNodeRegistryState::allocate_virtual_node_id,
1294    )
1295}
1296
1297fn resolve_modifier_local_from_parent_chain(
1298    start: Option<NodeId>,
1299    token: &ModifierLocalToken,
1300) -> Option<ResolvedModifierLocal> {
1301    crate::render_state::with_layout_node_registry(|registry| {
1302        registry.resolve_modifier_local_from_parent_chain(start, token)
1303    })
1304}
1305
1306#[cfg(test)]
1307#[path = "tests/layout_node_tests.rs"]
1308mod tests;
cranpose_ui/widgets/nodes/layout_node.rs

cranpose_ui/widgets/nodes/
layout_node.rs
