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 every frame by the modal
284    /// walk: dropped whenever the chain syncs or semantics are invalidated,
285    /// 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}
304
305pub(crate) const RECYCLED_LAYOUT_NODE_POOL_LIMIT: usize = 128;
306
307thread_local! {
308    static EMPTY_MEASURE_POLICY: Rc<dyn MeasurePolicy> =
309        Rc::new(crate::layout::policies::EmptyMeasurePolicy);
310}
311
312fn empty_measure_policy() -> Rc<dyn MeasurePolicy> {
313    EMPTY_MEASURE_POLICY.with(Rc::clone)
314}
315
316impl LayoutNode {
317    pub fn new(modifier: Modifier, measure_policy: Rc<dyn MeasurePolicy>) -> Self {
318        Self::new_with_virtual(modifier, measure_policy, false)
319    }
320
321    /// Create a virtual LayoutNode for subcomposition slot containers.
322    /// Virtual nodes are transparent - their children are flattened into parent's children list.
323    pub fn new_virtual() -> Self {
324        Self::new_with_virtual(Modifier::empty(), empty_measure_policy(), true)
325    }
326
327    fn new_recycled_shell(is_virtual: bool) -> Self {
328        let mut shell =
329            Self::new_with_virtual(Modifier::empty(), empty_measure_policy(), is_virtual);
330        shell.needs_measure.set(false);
331        shell.needs_layout.set(false);
332        shell.needs_semantics.set(false);
333        shell.needs_redraw.set(false);
334        shell.needs_pointer_pass.set(false);
335        shell.needs_focus_sync.set(false);
336        shell.parent.set(None);
337        shell.folded_parent.set(None);
338        shell.id.set(None);
339        shell.owner_context_id.set(None);
340        shell.debug_modifiers.set(false);
341        shell.virtual_children_count.set(0);
342        shell.cache = LayoutNodeCacheHandles::default();
343        shell.modifier_slices_snapshot = RefCell::new(Rc::default());
344        shell.modifier_slices_dirty = Cell::new(true);
345        shell.layout_state = Rc::new(RefCell::new(LayoutState::default()));
346        shell.layout_runtime_state = Rc::new(RefCell::new(LayoutRuntimeState::default()));
347        shell
348    }
349
350    fn new_with_virtual(
351        modifier: Modifier,
352        measure_policy: Rc<dyn MeasurePolicy>,
353        is_virtual: bool,
354    ) -> Self {
355        let mut node = Self {
356            #[cfg(feature = "inspection")]
357            source_trace: cranpose_core::source_trace::current_source_trace(),
358            modifier,
359            modifier_chain: ModifierChainHandle::new(),
360            resolved_modifiers: ResolvedModifiers::default(),
361            modifier_capabilities: NodeCapabilities::default(),
362            modifier_child_capabilities: NodeCapabilities::default(),
363            measure_policy,
364            density: crate::density::Density::default(),
365            children: Vec::new(),
366            cache: LayoutNodeCacheHandles::default(),
367            needs_measure: Cell::new(true),
368            needs_layout: Cell::new(true),
369            needs_semantics: Cell::new(true),
370            semantics_reach: Cell::new(None),
371            needs_redraw: Cell::new(true),
372            needs_pointer_pass: Cell::new(false),
373            needs_focus_sync: Cell::new(false),
374            parent: Cell::new(None),
375            folded_parent: Cell::new(None),
376            id: Cell::new(None),
377            owner_context_id: Cell::new(None),
378            debug_modifiers: Cell::new(false),
379            is_virtual,
380            virtual_children_count: Cell::new(0),
381            modifier_slices_snapshot: RefCell::new(Rc::default()),
382            modifier_slices_dirty: Cell::new(true),
383            layout_state: Rc::new(RefCell::new(LayoutState::default())),
384            layout_runtime_state: Rc::new(RefCell::new(LayoutRuntimeState::default())),
385        };
386        node.sync_modifier_chain();
387        node
388    }
389
390    pub fn set_modifier(&mut self, modifier: Modifier) {
391        #[cfg(feature = "inspection")]
392        {
393            let trace = cranpose_core::source_trace::current_source_trace();
394            if !trace.is_empty() {
395                self.source_trace = trace;
396            }
397        }
398        // An equal modifier leaves every element's node as it was. Only a
399        // chain reading modifier locals resyncs, since its parent may now
400        // provide others.
401        if self.modifier == modifier
402            && !self
403                .modifier_capabilities
404                .contains(NodeCapabilities::MODIFIER_LOCALS)
405        {
406            return;
407        }
408        let modifier_changed = !self.modifier.structural_eq(&modifier);
409        self.modifier = modifier;
410        self.sync_modifier_chain();
411        if modifier_changed {
412            self.cache.clear();
413            self.request_semantics_update();
414        }
415    }
416
417    fn sync_modifier_chain(&mut self) {
418        let prev_caps = self.modifier_capabilities;
419        let start_parent = self.parent();
420        let mut resolver = move |token: &ModifierLocalToken| {
421            resolve_modifier_local_from_parent_chain(start_parent, token)
422        };
423        self.modifier_chain
424            .set_debug_logging(self.debug_modifiers.get());
425        self.modifier_chain.set_node_id(self.id.get());
426        let modifier_local_invalidations = self
427            .modifier_chain
428            .update_with_resolver(&self.modifier, &mut resolver);
429        self.resolved_modifiers = self.modifier_chain.resolved_modifiers();
430        self.modifier_capabilities = self.modifier_chain.capabilities();
431        self.modifier_child_capabilities = self.modifier_chain.aggregate_child_capabilities();
432        self.semantics_reach.set(None);
433        self.modifier_slices_dirty.set(true);
434
435        let mut invalidations = self.modifier_chain.take_invalidations();
436        invalidations.extend(modifier_local_invalidations);
437        self.dispatch_modifier_invalidations_with_prev(&invalidations, prev_caps);
438        self.refresh_registry_state();
439    }
440
441    fn update_modifier_slices_cache(&self) {
442        let mut snapshot = self.modifier_slices_snapshot.borrow_mut();
443        crate::modifier::collect_modifier_slices_into_shared(
444            self.modifier_chain.chain(),
445            &mut snapshot,
446        );
447        self.modifier_slices_dirty.set(false);
448    }
449
450    pub(crate) fn mark_modifier_slices_dirty(&self) {
451        self.modifier_slices_dirty.set(true);
452    }
453
454    #[cfg(test)]
455    fn dispatch_modifier_invalidations(&self, invalidations: &[ModifierInvalidation]) {
456        self.dispatch_modifier_invalidations_with_prev(invalidations, NodeCapabilities::empty());
457    }
458
459    fn dispatch_modifier_invalidations_with_prev(
460        &self,
461        invalidations: &[ModifierInvalidation],
462        prev_caps: NodeCapabilities,
463    ) {
464        let curr_caps = self.modifier_capabilities;
465        for invalidation in invalidations {
466            self.modifier_slices_dirty.set(true);
467            let has_capability =
468                |capability| curr_caps.contains(capability) || prev_caps.contains(capability);
469            match invalidation.kind() {
470                InvalidationKind::Layout => {
471                    if has_capability(NodeCapabilities::LAYOUT) {
472                        self.mark_needs_measure();
473                        if let Some(id) = self.id.get() {
474                            log_layout_invalidation_dispatch(
475                                id,
476                                invalidation,
477                                curr_caps,
478                                prev_caps,
479                                &self.modifier,
480                            );
481                            let inside_composition =
482                                cranpose_core::composer_context::try_with_composer(|_| ())
483                                    .is_some();
484                            if inside_composition {
485                                cranpose_core::bubble_measure_dirty_in_composer(id);
486                            } else {
487                                crate::schedule_layout_repass(id);
488                            }
489                        }
490                    }
491                }
492                InvalidationKind::Draw => {
493                    if has_capability(NodeCapabilities::DRAW)
494                        || invalidation.capabilities().contains(NodeCapabilities::DRAW)
495                    {
496                        self.mark_needs_redraw();
497                    }
498                }
499                InvalidationKind::PointerInput => {
500                    if has_capability(NodeCapabilities::POINTER_INPUT) {
501                        self.mark_needs_pointer_pass();
502                        crate::request_pointer_invalidation();
503                        if let Some(id) = self.id.get() {
504                            crate::schedule_pointer_repass(id);
505                        }
506                    }
507                }
508                InvalidationKind::Semantics => {
509                    self.request_semantics_update();
510                }
511                InvalidationKind::Focus => {
512                    if has_capability(NodeCapabilities::FOCUS) {
513                        self.mark_needs_focus_sync();
514                        crate::request_focus_invalidation();
515                        if let Some(id) = self.id.get() {
516                            crate::schedule_focus_invalidation(id);
517                        }
518                    }
519                }
520            }
521        }
522    }
523
524    /// The grid this node was composed against.
525    pub fn density(&self) -> crate::density::Density {
526        self.density
527    }
528
529    /// Records the grid the composition provided, re-measuring if it moved.
530    pub fn set_density(&mut self, density: crate::density::Density) {
531        if self.density != density {
532            self.density = density;
533            self.cache.clear();
534            self.mark_needs_measure();
535        }
536    }
537
538    pub fn set_measure_policy(&mut self, policy: Rc<dyn MeasurePolicy>) {
539        if !Rc::ptr_eq(&self.measure_policy, &policy) {
540            self.measure_policy = policy;
541            self.cache.clear();
542            self.mark_needs_measure();
543            if let Some(id) = self.id.get() {
544                cranpose_core::bubble_measure_dirty_in_composer(id);
545            }
546        }
547    }
548
549    /// Mark this node as needing measure. Also marks it as needing layout.
550    pub fn mark_needs_measure(&self) {
551        self.needs_measure.set(true);
552        self.needs_layout.set(true);
553    }
554
555    /// Mark this node as needing layout (but not necessarily measure).
556    pub fn mark_needs_layout(&self) {
557        self.needs_layout.set(true);
558    }
559
560    /// Mark this node as needing redraw without forcing measure/layout.
561    pub fn mark_needs_redraw(&self) {
562        self.needs_redraw.set(true);
563        if let Some(id) = self.id.get() {
564            crate::schedule_draw_repass(id);
565        }
566        crate::request_render_invalidation();
567    }
568
569    /// Check if this node needs measure.
570    pub fn needs_measure(&self) -> bool {
571        self.needs_measure.get()
572    }
573
574    /// Check if this node needs layout.
575    pub fn needs_layout(&self) -> bool {
576        self.needs_layout.get()
577    }
578
579    /// Mark this node as needing semantics recomputation.
580    pub fn mark_needs_semantics(&self) {
581        self.needs_semantics.set(true);
582        self.semantics_reach.set(None);
583    }
584
585    pub(crate) fn clear_needs_semantics(&self) {
586        self.needs_semantics.set(false);
587    }
588
589    /// Returns true when semantics need to be recomputed.
590    pub fn needs_semantics(&self) -> bool {
591        self.needs_semantics.get()
592    }
593
594    /// Returns true when this node requested a redraw since the last render pass.
595    pub fn needs_redraw(&self) -> bool {
596        self.needs_redraw.get()
597    }
598
599    pub fn clear_needs_redraw(&self) {
600        self.needs_redraw.set(false);
601    }
602
603    fn request_semantics_update(&self) {
604        let already_dirty = self.needs_semantics.replace(true);
605        if already_dirty {
606            return;
607        }
608
609        if let Some(id) = self.id.get() {
610            cranpose_core::queue_semantics_invalidation(id);
611        }
612    }
613
614    pub(crate) fn clear_needs_measure(&self) {
615        self.needs_measure.set(false);
616    }
617
618    pub(crate) fn clear_needs_layout(&self) {
619        self.needs_layout.set(false);
620    }
621
622    /// Marks this node as needing a fresh pointer-input pass.
623    pub fn mark_needs_pointer_pass(&self) {
624        self.needs_pointer_pass.set(true);
625    }
626
627    /// Returns true when pointer-input state needs to be recomputed.
628    pub fn needs_pointer_pass(&self) -> bool {
629        self.needs_pointer_pass.get()
630    }
631
632    /// Clears the pointer-input dirty flag after hosts service it.
633    pub fn clear_needs_pointer_pass(&self) {
634        self.needs_pointer_pass.set(false);
635    }
636
637    /// Marks this node as needing a focus synchronization.
638    pub fn mark_needs_focus_sync(&self) {
639        self.needs_focus_sync.set(true);
640    }
641
642    /// Returns true when focus state needs to be synchronized.
643    pub fn needs_focus_sync(&self) -> bool {
644        self.needs_focus_sync.get()
645    }
646
647    /// Clears the focus dirty flag after the focus manager processes it.
648    pub fn clear_needs_focus_sync(&self) {
649        self.needs_focus_sync.set(false);
650    }
651
652    /// Set this node's ID (called by applier after creation).
653    pub fn set_node_id(&mut self, id: NodeId) {
654        if let Some(existing) = self.id.replace(Some(id))
655            && let Some(owner_context_id) = self.owner_context_id.take()
656        {
657            unregister_layout_node(owner_context_id, existing);
658        }
659        self.layout_state.borrow_mut().set_node_id(id);
660        let owner_context_id = register_layout_node(id, self);
661        self.owner_context_id.set(Some(owner_context_id));
662        self.refresh_registry_state();
663
664        self.modifier_chain.set_node_id(Some(id));
665        let invalidations = self.modifier_chain.take_invalidations();
666        self.dispatch_modifier_invalidations_with_prev(&invalidations, NodeCapabilities::empty());
667        // The slices carry the node's id; they are collected again when next read.
668        self.modifier_slices_dirty.set(true);
669    }
670
671    /// Get this node's ID.
672    pub fn node_id(&self) -> Option<NodeId> {
673        self.id.get()
674    }
675
676    /// Set this node's parent (called when node is added as child).
677    /// Sets both folded_parent (direct) and parent (first non-virtual ancestor for bubbling).
678    pub fn set_parent(&self, parent: NodeId) {
679        self.folded_parent.set(Some(parent));
680        self.parent.set(Some(parent));
681        self.refresh_registry_state();
682    }
683
684    /// Clear this node's parent (called when node is removed from parent).
685    pub fn clear_parent(&self) {
686        self.folded_parent.set(None);
687        self.parent.set(None);
688        self.refresh_registry_state();
689    }
690
691    /// Get this node's parent for dirty flag bubbling (may skip virtual nodes).
692    pub fn parent(&self) -> Option<NodeId> {
693        self.parent.get()
694    }
695
696    /// Get this node's direct parent (may be a virtual node).
697    pub fn folded_parent(&self) -> Option<NodeId> {
698        self.folded_parent.get()
699    }
700
701    /// Returns true if this is a virtual node (transparent container for subcomposition).
702    pub fn is_virtual(&self) -> bool {
703        self.is_virtual
704    }
705
706    pub(crate) fn cache_handles(&self) -> LayoutNodeCacheHandles {
707        self.cache.clone()
708    }
709
710    pub fn resolved_modifiers(&self) -> ResolvedModifiers {
711        self.resolved_modifiers
712    }
713
714    pub fn modifier_capabilities(&self) -> NodeCapabilities {
715        self.modifier_capabilities
716    }
717
718    /// Whether this node's modifier chain makes it the root of a separate
719    /// window. Its parent lays out as if it had no size and its parent's
720    /// scene skips it; its own scene starts here.
721    pub fn is_window_root(&self) -> bool {
722        self.modifier_capabilities
723            .contains(NodeCapabilities::WINDOW_ROOT)
724    }
725
726    pub fn modifier_child_capabilities(&self) -> NodeCapabilities {
727        self.modifier_child_capabilities
728    }
729
730    pub fn set_debug_modifiers(&mut self, enabled: bool) {
731        self.debug_modifiers.set(enabled);
732        self.modifier_chain.set_debug_logging(enabled);
733    }
734
735    pub fn debug_modifiers_enabled(&self) -> bool {
736        self.debug_modifiers.get()
737    }
738
739    pub fn modifier_locals_handle(&self) -> ModifierLocalsHandle {
740        self.modifier_chain.modifier_locals_handle()
741    }
742
743    pub fn has_layout_modifier_nodes(&self) -> bool {
744        self.modifier_capabilities
745            .contains(NodeCapabilities::LAYOUT)
746    }
747
748    pub fn has_draw_modifier_nodes(&self) -> bool {
749        self.modifier_capabilities.contains(NodeCapabilities::DRAW)
750    }
751
752    pub fn has_pointer_input_modifier_nodes(&self) -> bool {
753        self.modifier_capabilities
754            .contains(NodeCapabilities::POINTER_INPUT)
755    }
756
757    pub fn has_semantics_modifier_nodes(&self) -> bool {
758        self.modifier_capabilities
759            .contains(NodeCapabilities::SEMANTICS)
760    }
761
762    pub fn has_focus_modifier_nodes(&self) -> bool {
763        self.modifier_capabilities.contains(NodeCapabilities::FOCUS)
764    }
765
766    fn refresh_registry_state(&self) {
767        if let (Some(id), Some(owner_context_id)) = (self.id.get(), self.owner_context_id.get()) {
768            let parent = self.parent();
769            let capabilities = self.modifier_child_capabilities();
770            let modifier_locals = self.modifier_locals_handle();
771            let _ = crate::render_state::with_layout_node_registry_by_app_context(
772                owner_context_id,
773                |registry| {
774                    registry.update_entry(id, parent, capabilities, modifier_locals);
775                },
776            );
777        }
778    }
779
780    pub fn modifier_slices_snapshot(&self) -> Rc<ModifierNodeSlices> {
781        if self.modifier_slices_dirty.get() {
782            self.update_modifier_slices_cache();
783        }
784        self.modifier_slices_snapshot.borrow().clone()
785    }
786
787    /// Returns a clone of the current layout state.
788    pub fn layout_state(&self) -> LayoutState {
789        self.layout_state.borrow().clone()
790    }
791
792    /// Returns the measured size of this node.
793    pub fn measured_size(&self) -> Size {
794        self.layout_state.borrow().size
795    }
796
797    /// Returns the position of this node relative to its parent.
798    pub fn position(&self) -> Point {
799        self.layout_state.borrow().position
800    }
801
802    /// Returns true if this node has been placed in the current layout pass.
803    pub fn is_placed(&self) -> bool {
804        self.layout_state.borrow().is_placed
805    }
806
807    /// Updates the measured size of this node. Called during measurement.
808    /// [`LayoutState::set_size`] self-reports actual changes to the scene
809    /// phase.
810    pub fn set_measured_size(&self, size: Size) {
811        self.layout_state.borrow_mut().set_size(size);
812    }
813
814    /// Updates the position of this node. Called during placement.
815    /// [`LayoutState::place`] self-reports actual moves to the scene phase.
816    pub fn set_position(&self, position: Point) {
817        self.layout_state.borrow_mut().place(position);
818    }
819
820    /// Records the content offset (e.g. from padding).
821    pub fn set_content_offset(&self, offset: Point) {
822        self.layout_state.borrow_mut().content_offset = offset;
823    }
824
825    /// Clears the is_placed flag. Called at the start of a layout pass.
826    pub fn clear_placed(&self) {
827        self.layout_state.borrow_mut().is_placed = false;
828    }
829
830    pub fn semantics_configuration(&self) -> Option<SemanticsConfiguration> {
831        crate::modifier::collect_semantics_from_chain(self.modifier_chain.chain())
832    }
833
834    /// Whether this node's modifiers make it modal or hidden.
835    pub fn semantics_reach(&self) -> cranpose_foundation::SemanticsReach {
836        if let Some(reach) = self.semantics_reach.get() {
837            return reach;
838        }
839        let reach = crate::modifier::semantics_reach_of_chain(self.modifier_chain.chain());
840        self.semantics_reach.set(Some(reach));
841        reach
842    }
843
844    pub(crate) fn modifier_chain(&self) -> &ModifierChainHandle {
845        &self.modifier_chain
846    }
847
848    /// Access the text field modifier node (if present) with a mutable callback.
849    ///
850    /// This is used for keyboard event dispatch to text fields.
851    /// Returns `None` if no text field modifier is found in the chain.
852    pub fn with_text_field_modifier_mut<R>(
853        &mut self,
854        f: impl FnMut(&mut crate::TextFieldModifierNode) -> R,
855    ) -> Option<R> {
856        self.modifier_chain.with_text_field_modifier_mut(f)
857    }
858
859    /// Returns a handle to the shared layout state.
860    /// Used by layout system to update state without borrowing the Applier.
861    pub fn layout_state_handle(&self) -> Rc<RefCell<LayoutState>> {
862        self.layout_state.clone()
863    }
864
865    pub(crate) fn layout_runtime_state_handle(&self) -> Rc<RefCell<LayoutRuntimeState>> {
866        self.layout_runtime_state.clone()
867    }
868
869    #[cfg(test)]
870    pub(crate) fn layout_runtime_debug_stats(&self) -> LayoutRuntimeDebugStats {
871        self.layout_runtime_state.borrow().debug_stats()
872    }
873}
874impl Clone for LayoutNode {
875    fn clone(&self) -> Self {
876        let mut node = Self {
877            #[cfg(feature = "inspection")]
878            source_trace: self.source_trace.clone(),
879            modifier: self.modifier.clone(),
880            modifier_chain: ModifierChainHandle::new(),
881            resolved_modifiers: ResolvedModifiers::default(),
882            modifier_capabilities: self.modifier_capabilities,
883            modifier_child_capabilities: self.modifier_child_capabilities,
884            measure_policy: self.measure_policy.clone(),
885            density: self.density,
886            children: self.children.clone(),
887            cache: self.cache.clone(),
888            needs_measure: Cell::new(self.needs_measure.get()),
889            needs_layout: Cell::new(self.needs_layout.get()),
890            needs_semantics: Cell::new(self.needs_semantics.get()),
891            semantics_reach: Cell::new(None),
892            needs_redraw: Cell::new(self.needs_redraw.get()),
893            needs_pointer_pass: Cell::new(self.needs_pointer_pass.get()),
894            needs_focus_sync: Cell::new(self.needs_focus_sync.get()),
895            parent: Cell::new(self.parent.get()),
896            folded_parent: Cell::new(self.folded_parent.get()),
897            id: Cell::new(None),
898            owner_context_id: Cell::new(None),
899            debug_modifiers: Cell::new(self.debug_modifiers.get()),
900            is_virtual: self.is_virtual,
901            virtual_children_count: Cell::new(self.virtual_children_count.get()),
902            modifier_slices_snapshot: RefCell::new(Rc::default()),
903            modifier_slices_dirty: Cell::new(true),
904            layout_state: self.layout_state.clone(),
905            layout_runtime_state: self.layout_runtime_state.clone(),
906        };
907        node.sync_modifier_chain();
908        node
909    }
910}
911
912impl Node for LayoutNode {
913    fn mount(&mut self) {
914        let (chain, mut context) = self.modifier_chain.chain_and_context_mut();
915        chain.repair_chain();
916        chain.attach_nodes(&mut *context);
917    }
918
919    fn unmount(&mut self) {
920        self.modifier_chain.chain_mut().detach_nodes();
921    }
922
923    fn set_node_id(&mut self, id: NodeId) {
924        LayoutNode::set_node_id(self, id);
925    }
926
927    fn insert_child(&mut self, child: NodeId) -> bool {
928        if self.children.contains(&child) {
929            return false;
930        }
931        if is_virtual_node(child) {
932            let count = self.virtual_children_count.get();
933            self.virtual_children_count.set(count + 1);
934        }
935        self.children.push(child);
936        self.cache.clear();
937        self.mark_needs_measure();
938        true
939    }
940
941    fn remove_child(&mut self, child: NodeId) -> bool {
942        let before = self.children.len();
943        self.children.retain(|&id| id != child);
944        let removed = self.children.len() < before;
945        if removed {
946            if is_virtual_node(child) {
947                let count = self.virtual_children_count.get();
948                if count > 0 {
949                    self.virtual_children_count.set(count - 1);
950                }
951            }
952            self.cache.clear();
953            self.mark_needs_measure();
954        }
955        removed
956    }
957
958    fn move_child(&mut self, from: usize, to: usize) {
959        if from == to || from >= self.children.len() {
960            return;
961        }
962        let child = self.children.remove(from);
963        let target = to.min(self.children.len());
964        self.children.insert(target, child);
965        self.cache.clear();
966        self.mark_needs_measure();
967    }
968
969    fn update_children(&mut self, children: &[NodeId]) {
970        self.children.clear();
971        self.children.extend_from_slice(children);
972        self.cache.clear();
973        self.mark_needs_measure();
974    }
975
976    fn collect_children_into(&self, out: &mut smallvec::SmallVec<[NodeId; 8]>) {
977        out.clear();
978        out.extend_from_slice(&self.children);
979    }
980
981    fn on_attached_to_parent(&mut self, parent: NodeId) {
982        self.set_parent(parent);
983    }
984
985    fn on_removed_from_parent(&mut self) {
986        self.clear_parent();
987    }
988
989    fn parent(&self) -> Option<NodeId> {
990        self.parent.get()
991    }
992
993    fn mark_needs_layout(&self) {
994        self.needs_layout.set(true);
995    }
996
997    fn needs_layout(&self) -> bool {
998        self.needs_layout.get()
999    }
1000
1001    fn mark_needs_measure(&self) {
1002        self.needs_measure.set(true);
1003        self.needs_layout.set(true);
1004    }
1005
1006    fn needs_measure(&self) -> bool {
1007        self.needs_measure.get()
1008    }
1009
1010    fn mark_needs_semantics(&self) {
1011        self.needs_semantics.set(true);
1012        self.semantics_reach.set(None);
1013    }
1014
1015    fn needs_semantics(&self) -> bool {
1016        self.needs_semantics.get()
1017    }
1018
1019    fn set_parent_for_bubbling(&mut self, parent: NodeId) {
1020        if self.parent.get().is_none() {
1021            self.parent.set(Some(parent));
1022        }
1023    }
1024
1025    fn recycle_key(&self) -> Option<TypeId> {
1026        Some(TypeId::of::<Self>())
1027    }
1028
1029    fn recycle_pool_limit(&self) -> Option<usize> {
1030        Some(RECYCLED_LAYOUT_NODE_POOL_LIMIT)
1031    }
1032
1033    fn prepare_for_recycle(&mut self) {
1034        *self = Self::new_recycled_shell(self.is_virtual);
1035    }
1036
1037    fn rehouse_for_recycle(&self) -> Option<Box<dyn cranpose_core::Node>> {
1038        Some(Box::new(Self::new_recycled_shell(self.is_virtual)))
1039    }
1040
1041    fn rehouse_for_live_compaction(&mut self) -> Option<Box<dyn cranpose_core::Node>> {
1042        let mut previous = std::mem::replace(self, Self::new_recycled_shell(self.is_virtual));
1043        let node_id = previous.id.replace(None);
1044        let parent = previous.parent.get();
1045        let folded_parent = previous.folded_parent.get();
1046        let debug_modifiers = previous.debug_modifiers.get();
1047        let needs_measure = previous.needs_measure.get();
1048        let needs_layout = previous.needs_layout.get();
1049        let needs_semantics = previous.needs_semantics.get();
1050        let needs_redraw = previous.needs_redraw.get();
1051        let needs_pointer_pass = previous.needs_pointer_pass.get();
1052        let needs_focus_sync = previous.needs_focus_sync.get();
1053        let virtual_children_count = previous.virtual_children_count.get();
1054        let children = previous.children.to_vec();
1055        let modifier = previous.modifier.rehouse_for_live_compaction();
1056        let measure_policy = previous.measure_policy.clone();
1057        let layout_state = previous.layout_state.clone();
1058        let layout_runtime_state = previous.layout_runtime_state.clone();
1059
1060        previous.modifier_chain.chain_mut().detach_nodes();
1061
1062        let mut compact = Self::new_with_virtual(modifier, measure_policy, previous.is_virtual);
1063        compact.children = children;
1064        #[cfg(feature = "inspection")]
1065        {
1066            compact.source_trace = previous.source_trace.clone();
1067        }
1068        compact.parent.set(parent);
1069        compact.folded_parent.set(folded_parent);
1070        compact.id.set(node_id);
1071        compact.debug_modifiers.set(debug_modifiers);
1072        compact.needs_measure.set(needs_measure);
1073        compact.needs_layout.set(needs_layout);
1074        compact.needs_semantics.set(needs_semantics);
1075        compact.needs_redraw.set(needs_redraw);
1076        compact.needs_pointer_pass.set(needs_pointer_pass);
1077        compact.needs_focus_sync.set(needs_focus_sync);
1078        compact.virtual_children_count.set(virtual_children_count);
1079        compact.layout_state = layout_state;
1080        compact.layout_runtime_state = layout_runtime_state;
1081        compact.sync_modifier_chain();
1082        if let Some(id) = node_id {
1083            let owner_context_id = register_layout_node(id, &compact);
1084            compact.owner_context_id.set(Some(owner_context_id));
1085        }
1086
1087        Some(Box::new(compact))
1088    }
1089}
1090
1091impl Drop for LayoutNode {
1092    fn drop(&mut self) {
1093        if let (Some(id), Some(owner_context_id)) = (self.id.get(), self.owner_context_id.get()) {
1094            unregister_layout_node(owner_context_id, id);
1095        }
1096    }
1097}
1098
1099const MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY: usize = 128;
1100const VIRTUAL_NODE_ID_START: NodeId = 0xC0000000;
1101
1102#[cfg(test)]
1103#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
1104struct LayoutNodeRegistryDebugStats {
1105    len: usize,
1106    capacity: usize,
1107}
1108
1109struct LayoutNodeRegistryEntry {
1110    parent: Option<NodeId>,
1111    modifier_child_capabilities: NodeCapabilities,
1112    modifier_locals: ModifierLocalsHandle,
1113    is_virtual: bool,
1114}
1115
1116pub(crate) struct LayoutNodeRegistryState {
1117    entries: RefCell<HashMap<NodeId, LayoutNodeRegistryEntry>>,
1118    virtual_node_id_counter: Cell<NodeId>,
1119}
1120
1121impl LayoutNodeRegistryState {
1122    pub(crate) fn new() -> Self {
1123        Self {
1124            entries: RefCell::new(HashMap::new()),
1125            virtual_node_id_counter: Cell::new(VIRTUAL_NODE_ID_START),
1126        }
1127    }
1128
1129    fn register(&self, id: NodeId, node: &LayoutNode) {
1130        self.entries.borrow_mut().insert(
1131            id,
1132            LayoutNodeRegistryEntry {
1133                parent: node.parent(),
1134                modifier_child_capabilities: node.modifier_child_capabilities(),
1135                modifier_locals: node.modifier_locals_handle(),
1136                is_virtual: node.is_virtual(),
1137            },
1138        );
1139    }
1140
1141    fn unregister(&self, id: NodeId) {
1142        let mut entries = self.entries.borrow_mut();
1143        entries.remove(&id);
1144        let should_shrink = (entries.len() <= MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY
1145            && entries.capacity() > MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY)
1146            || entries.capacity()
1147                > entries
1148                    .len()
1149                    .max(MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY)
1150                    .saturating_mul(4);
1151        if should_shrink {
1152            let retained = entries
1153                .len()
1154                .max(MIN_RETAINED_LAYOUT_NODE_REGISTRY_CAPACITY);
1155            let mut rebuilt = HashMap::new();
1156            rebuilt.reserve(retained);
1157            rebuilt.extend(entries.drain());
1158            *entries = rebuilt;
1159        }
1160    }
1161
1162    fn update_entry(
1163        &self,
1164        id: NodeId,
1165        parent: Option<NodeId>,
1166        modifier_child_capabilities: NodeCapabilities,
1167        modifier_locals: ModifierLocalsHandle,
1168    ) {
1169        if let Some(entry) = self.entries.borrow_mut().get_mut(&id) {
1170            entry.parent = parent;
1171            entry.modifier_child_capabilities = modifier_child_capabilities;
1172            entry.modifier_locals = modifier_locals;
1173        }
1174    }
1175
1176    #[cfg(test)]
1177    fn stats(&self) -> LayoutNodeRegistryDebugStats {
1178        let entries = self.entries.borrow();
1179        LayoutNodeRegistryDebugStats {
1180            len: entries.len(),
1181            capacity: entries.capacity(),
1182        }
1183    }
1184
1185    fn is_virtual_node(&self, id: NodeId) -> bool {
1186        self.entries
1187            .borrow()
1188            .get(&id)
1189            .is_some_and(|entry| entry.is_virtual)
1190    }
1191
1192    fn allocate_virtual_node_id(&self) -> NodeId {
1193        let id = self.virtual_node_id_counter.get();
1194        self.virtual_node_id_counter.set(id.wrapping_add(1));
1195        id
1196    }
1197
1198    fn resolve_modifier_local_from_parent_chain(
1199        &self,
1200        start: Option<NodeId>,
1201        token: &ModifierLocalToken,
1202    ) -> Option<ResolvedModifierLocal> {
1203        let mut current = start;
1204        while let Some(parent_id) = current {
1205            let (next_parent, resolved) = {
1206                let entries = self.entries.borrow();
1207                if let Some(entry) = entries.get(&parent_id) {
1208                    let resolved = if entry
1209                        .modifier_child_capabilities
1210                        .contains(NodeCapabilities::MODIFIER_LOCALS)
1211                    {
1212                        entry
1213                            .modifier_locals
1214                            .borrow()
1215                            .resolve(token)
1216                            .map(|value| value.with_source(ModifierLocalSource::Ancestor))
1217                    } else {
1218                        None
1219                    };
1220                    (entry.parent, resolved)
1221                } else {
1222                    (None, None)
1223                }
1224            };
1225            if let Some(value) = resolved {
1226                return Some(value);
1227            }
1228            current = next_parent;
1229        }
1230        None
1231    }
1232}
1233
1234pub(crate) fn register_layout_node(
1235    id: NodeId,
1236    node: &LayoutNode,
1237) -> crate::render_state::AppContextId {
1238    let owner_context_id = crate::render_state::current_app_context_id();
1239    let _ = crate::render_state::with_layout_node_registry_by_app_context(
1240        owner_context_id,
1241        |registry| {
1242            registry.register(id, node);
1243        },
1244    );
1245    owner_context_id
1246}
1247
1248pub(crate) fn unregister_layout_node(
1249    owner_context_id: crate::render_state::AppContextId,
1250    id: NodeId,
1251) {
1252    let _ = crate::render_state::with_layout_node_registry_by_app_context(
1253        owner_context_id,
1254        |registry| {
1255            registry.unregister(id);
1256        },
1257    );
1258}
1259
1260#[cfg(test)]
1261fn layout_node_registry_stats() -> LayoutNodeRegistryDebugStats {
1262    crate::render_state::with_layout_node_registry(LayoutNodeRegistryState::stats)
1263}
1264
1265pub(crate) fn is_virtual_node(id: NodeId) -> bool {
1266    crate::render_state::with_layout_node_registry(|registry| registry.is_virtual_node(id))
1267}
1268
1269pub(crate) fn allocate_virtual_node_id() -> NodeId {
1270    crate::render_state::with_layout_node_registry(
1271        LayoutNodeRegistryState::allocate_virtual_node_id,
1272    )
1273}
1274
1275fn resolve_modifier_local_from_parent_chain(
1276    start: Option<NodeId>,
1277    token: &ModifierLocalToken,
1278) -> Option<ResolvedModifierLocal> {
1279    crate::render_state::with_layout_node_registry(|registry| {
1280        registry.resolve_modifier_local_from_parent_chain(start, token)
1281    })
1282}
1283
1284#[cfg(test)]
1285#[path = "tests/layout_node_tests.rs"]
1286mod tests;
cranpose_ui/widgets/nodes/layout_node.rs

cranpose_ui/widgets/nodes/
layout_node.rs
