[Tree widget]: change how categories handle their visibility on next

[JonasDov]

Phases 3b and 3d. of #1678.
In addition: changed model visibility to always use includeOnlyIfCategoryOfTopMostElement: true (previously only if isAlwaysDrawnExclusive mode), since top-most categories now correctly determine visibility of nested children in differentcategories.

[Copilot]

Pull request overview

Updates tree-widget visibility computation to better account for descendant elements whose categories differ from their ancestors, and aligns model/category visibility calculations with “top-most category” semantics.

Changes:

• Always compute model visibility using only categories of top-most elements (includeOnlyIfCategoryOfTopMostElement: true) and rely on descendant-category grouping for correctness.
• Refactor always/never-drawn-based visibility to group descendant counts by the descendants’ actual categories and compute visibility per visible/hidden group.
• Update visibility tests to expect “all-visible” outcomes for cross-category descendant scenarios; adjust test cache mock behavior.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
packages/itwin/tree-widget/src/tree-widget-react/components/trees/common/internal/visibility/BaseVisibilityHelper.ts	Refactors visibility computation to use top-most categories and grouped descendant-category logic; updates change flows to account for cross-category descendants.
packages/itwin/tree-widget/src/test/trees/models-tree/Utils.ts	Updates fake IDs cache getDescendantsCounts mock used by tests.
packages/itwin/tree-widget/src/test/trees/models-tree/internal/ModelsTreeVisibilityHandler.test.ts	Updates expectations for model/category/element visibility in “child element category differs from parent’s” scenarios.

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[github-actions]

Tree-Widget Next benchmark

Benchmark suite	Current: c4f6b1e	Previous: b618ede	Deviation	Status
models tree 50k 3D elements search > get search paths	1170 ms	1207 ms	-3.07%	〰️
models tree 50k 3D elements search > get search paths (P95 of main thread blocks)	53 ms	58 ms	-8.62%	〰️
models tree 50k 3D elements search > load hierarchy from search paths	104792 ms	117082 ms	-10.50%	✅
models tree 50k 3D elements search > load hierarchy from search paths (P95 of main thread blocks)	32 ms	33 ms	-3.03%	〰️
models tree 50k categories > collect nodes	2855 ms	3016 ms	-5.34%	〰️
models tree 50k categories > collect nodes (P95 of main thread blocks)	127 ms	169 ms	-24.85%	〰️
models tree 50k categories > validate initial visibility	1911 ms	2072 ms	-7.77%	〰️
models tree 50k categories > validate initial visibility (P95 of main thread blocks)	0 ms	0 ms	0%	🟰
models tree 50k categories > change visibility	217 ms	87 ms	149.43%	🚨
models tree 50k categories > change visibility (P95 of main thread blocks)	56 ms	76 ms	-26.32%	〰️
models tree 50k categories > validate changed visibility	3637 ms	3647 ms	-0.27%	〰️
models tree 50k categories > validate changed visibility (P95 of main thread blocks)	28 ms	39 ms	-28.21%	〰️
models tree 50k 3D elements > collect nodes	41176 ms	46645 ms	-11.72%	✅
models tree 50k 3D elements > collect nodes (P95 of main thread blocks)	69 ms	76 ms	-9.21%	〰️
models tree 50k 3D elements > validate initial visibility	1478 ms	1748 ms	-15.45%	✅
models tree 50k 3D elements > validate initial visibility (P95 of main thread blocks)	23 ms	0 ms	2300%	〰️
models tree 50k 3D elements > change model visibility	103 ms	21 ms	390.48%	🚨
models tree 50k 3D elements > change model visibility (P95 of main thread blocks)	0 ms	0 ms	0%	🟰
models tree 50k 3D elements > validate changed model visibility	1988 ms	3216 ms	-38.18%	✅
models tree 50k 3D elements > validate changed model visibility (P95 of main thread blocks)	0 ms	24 ms	-100%	〰️
models tree 50k 3D elements > change category node visibility	490 ms	505 ms	-2.97%	〰️
models tree 50k 3D elements > change category node visibility (P95 of main thread blocks)	57 ms	59 ms	-3.39%	〰️
models tree 50k 3D elements > validate changed category visibility	1355 ms	1931 ms	-29.83%	✅
models tree 50k 3D elements > validate changed category visibility (P95 of main thread blocks)	0 ms	0 ms	0%	🟰
models tree 50k 3D elements > validate per-model category override	1329 ms	1874 ms	-29.08%	✅
models tree 50k 3D elements > validate per-model category override (P95 of main thread blocks)	0 ms	0 ms	0%	🟰
models tree 50k 3D elements > change element visibility	33 ms	33 ms	0%	🟰
models tree 50k 3D elements > change element visibility (P95 of main thread blocks)	0 ms	0 ms	0%	🟰
models tree 50k 3D elements > validate changed element visibility	2126 ms	2616 ms	-18.73%	✅
models tree 50k 3D elements > validate changed element visibility (P95 of main thread blocks)	67 ms	67 ms	0%	🟰
models tree 50k 3D child elements with different categories > collect nodes	41435 ms	46646 ms	-11.17%	✅
models tree 50k 3D child elements with different categories > collect nodes (P95 of main thread blocks)	76 ms	68 ms	11.76%	〰️
models tree 50k 3D child elements with different categories > validate initial visibility	1447 ms	1677 ms	-13.71%	✅
models tree 50k 3D child elements with different categories > validate initial visibility (P95 of main thread blocks)	30 ms	0 ms	3000%	〰️
models tree 50k 3D child elements with different categories > change visibility	52 ms	53 ms	-1.89%	〰️
models tree 50k 3D child elements with different categories > change visibility (P95 of main thread blocks)	0 ms	0 ms	0%	🟰
models tree 50k 3D child elements with different categories > validate changed visibility	2546 ms	3803 ms	-33.05%	✅
models tree 50k 3D child elements with different categories > validate changed visibility (P95 of main thread blocks)	86 ms	82 ms	4.88%	〰️
categories tree 50k subCategories search > get search paths	1743 ms	1888 ms	-7.68%	〰️
categories tree 50k subCategories search > get search paths (P95 of main thread blocks)	40 ms	44 ms	-9.09%	〰️
categories tree 50k subCategories search > load hierarchy from search paths	5371 ms	5657 ms	-5.06%	〰️
categories tree 50k subCategories search > load hierarchy from search paths (P95 of main thread blocks)	51 ms	55 ms	-7.27%	〰️
categories tree 50k subCategories > collect nodes	5699 ms	6112 ms	-6.76%	〰️
categories tree 50k subCategories > collect nodes (P95 of main thread blocks)	42 ms	49 ms	-14.29%	〰️
categories tree 50k subCategories > validate initial visibility	1188 ms	1190 ms	-0.17%	〰️
categories tree 50k subCategories > validate initial visibility (P95 of main thread blocks)	26 ms	27 ms	-3.70%	〰️
categories tree 50k subCategories > change visibility	340 ms	370 ms	-8.11%	〰️
categories tree 50k subCategories > change visibility (P95 of main thread blocks)	24 ms	37 ms	-35.14%	〰️
categories tree 50k subCategories > validate changed visibility	1067 ms	1083 ms	-1.48%	〰️
categories tree 50k subCategories > validate changed visibility (P95 of main thread blocks)	32 ms	44 ms	-27.27%	〰️
categories tree 50k categories > collect nodes	2424 ms	2520 ms	-3.81%	〰️
categories tree 50k categories > collect nodes (P95 of main thread blocks)	123 ms	136 ms	-9.56%	〰️
categories tree 50k categories > validate initial visibility	5087 ms	5378 ms	-5.41%	〰️
categories tree 50k categories > validate initial visibility (P95 of main thread blocks)	128 ms	117 ms	9.40%	〰️
categories tree 50k categories > change visibility	772 ms	685 ms	12.70%	🚨
categories tree 50k categories > change visibility (P95 of main thread blocks)	62 ms	61 ms	1.64%	〰️
categories tree 50k categories > validate changed visibility	4865 ms	5001 ms	-2.72%	〰️
categories tree 50k categories > validate changed visibility (P95 of main thread blocks)	35 ms	46 ms	-23.91%	〰️
classifications tree 50k classifications search > get search paths	2106 ms	2159 ms	-2.45%	〰️
classifications tree 50k classifications search > get search paths (P95 of main thread blocks)	128 ms	152 ms	-15.79%	〰️
classifications tree 50k classifications search > load hierarchy from search paths	64416 ms	73053 ms	-11.82%	✅
classifications tree 50k classifications search > load hierarchy from search paths (P95 of main thread blocks)	0 ms	0 ms	0%	🟰
classifications tree 50k classifications > collect nodes	35123 ms	39556 ms	-11.21%	✅
classifications tree 50k classifications > collect nodes (P95 of main thread blocks)	76 ms	93 ms	-18.28%	〰️
classifications tree 50k classifications > validate initial visibility	3463 ms	3821 ms	-9.37%	〰️
classifications tree 50k classifications > validate initial visibility (P95 of main thread blocks)	66 ms	89 ms	-25.84%	〰️
classifications tree 50k classifications > change visibility	34 ms	30 ms	13.33%	〰️
classifications tree 50k classifications > change visibility (P95 of main thread blocks)	0 ms	0 ms	0%	🟰
classifications tree 50k classifications > validate changed visibility	3911 ms	4151 ms	-5.78%	〰️
classifications tree 50k classifications > validate changed visibility (P95 of main thread blocks)	101 ms	104 ms	-2.88%	〰️

This comment was automatically generated by workflow using github-action-benchmark.

[grigasp]

Did you look at the performance regressions? The following seem worth having a look at:

Benchmark suite	Current: 1d284b8	Previous: b618ede	Deviation	Status
models tree 50k categories > change visibility	1372 ms	87 ms	1477.01%	🚨
models tree 50k 3D child elements with different categories > validate changed visibility (P95 of main thread blocks)	219 ms	82 ms	167.07%	🚨
categories tree 50k categories > change visibility	1676 ms	685 ms	144.67%	🚨
classifications tree 50k classifications > validate changed visibility	5835 ms	4151 ms	40.57%	🚨

[JonasDov]

Did you look at the performance regressions? The following seem worth having a look at:

Benchmark suite Current: 1d284b8 Previous: b618ede Deviation Status
models tree 50k categories > change visibility 1372 ms 87 ms 1477.01% 🚨
models tree 50k 3D child elements with different categories > validate changed visibility (P95 of main thread blocks) 219 ms 82 ms 167.07% 🚨
categories tree 50k categories > change visibility 1676 ms 685 ms 144.67% 🚨
classifications tree 50k classifications > validate changed visibility 5835 ms 4151 ms 40.57% 🚨

Adjusted implementation, a few things:

1. BatchingCache.ts - Replaced shareReplay(1) observable with an event based sharing mechanism. Instead of tracking subscribers in an array, the completion is notified using BeEvent. This removes rxjs arrRemove (O(n²)) cleanup for removing subscriptions.
2. Similarly added subscribeAll helper (uses a plain array for subscription tracking), which is used when changing descendants visibility. Previously RxJS's from + mergeMap was used, which internally uses arrRemove.
3. Changed get/change element visibility, so it does not request children count when element does not have children.
4. Added additional information to ElementModelCategoriesCache which stores which categories have indirect children. (small modification to existing query). This is used:
   4.1. When getting category visibility, first a check is made to see if category does not have indirect children AND if the opposide A/N drawn set is empty. If that is the case, descendants counts is not requested. (opposite set: set different from category default visibility).
   4.2. When changing category visbility, first check if it does not have indirect children. If that is the case, child counts are not requested.

This improved the performance (at least in current perf tests) without adding much overhead IMO. Now performance is very similar to what it was before these changes.

[Copilot]

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 2 comments.