TableView: first-class Reactor control + a 36-page gallery mirroring TableViewSamples (POC)

[DDancingDeath]

Status: draft / proof-of-concept. Self-contained under samples/, gated OFF in shared CI, x64-only. No change to any existing Reactor project's every-PR build.

What this adds

A first-class Reactor (MVU) control for the native split-binary WinUI Microsoft.UI.Xaml.Controls.TableView (shipped in Microsoft.UI.Xaml.Controls.Advanced.dll), plus a 36-page gallery in Reactor.TestApp that mirrors the native TableViewSamples gallery — every page rendering for real (cells + headers + colored pills/chips/stoplight tints).

1. The consumable control — Reactor.Controls.TableView

Any Reactor consumer can drop in TableView(items, columns) in pure C#. It is reconciled by a real TableViewHandler (mount/update/unmount on a pooled control), not a XAML island:

• Text + template columns (CellStyle.Text/Pill/Chip/Tint) via a cell-template bridge + value converter.
• Sort + filter honoring the control's consumer-owned re-shape contract: header clicks raise Sorted/Filtered; the handler re-orders/-filters the bound ObservableCollection from a master snapshot (columns get a SortMemberPath automatically).
• Selection (mode + unit + gutter, OnSelectionChanged), frozen leading/trailing, grid lines, headers visibility, column resize/reorder, hierarchy (HierarchicalItems + HierarchicalChildrenPath + ExpandFirstLevel), row banding, RTL, and an OnControlReady hook to drive imperative APIs (SortByColumn, SelectAll, AutoSizeColumn, ExpandAllGroups, …).
• Stretch-to-fill layout; live updates work in place (an observable row model raises PropertyChanged so bound tint cells re-run their converter without a re-bind).

2. The gallery — first-class, mirrors the reference

Reactor.TestApp gets a TableView section: a NavigationView shell with the reference's grouped sections (Quick start / Columns / Rows & cells / Styling / Power user / Performance / About) and all 36 pages. Each page has the reference SamplePresenter chrome: heading + description + a "Try it" InfoBar + an interactive Options panel (combos/toggles/radios/sliders/buttons + live Status readouts) + the live table + a collapsible "Source code (C#)" section showing the page's key Reactor usage.

How it renders in a code-only host

The dev-framework-built satellite renders blank in a framework-dependent host. Fixes:

• WindowsAppSDKSelfContained=true when the TableView path is on (the activation ABI must match) — the key fix that makes the body realize.
• Register the satellite's XAML metadata provider once, merge its embedded Style/theme closure into Application.Resources exactly once (two copies access-violate the next Frame.Navigate), assign the default Style explicitly, and install a DispatcherQueueSynchronizationContext so the control's realization continuations resume on the UI thread.

Native binaries (both flavors, x64-only)

The satellite is checked in as both flavors and selected by sample $(Configuration):

• native\fre\ — fre (free/optimized) → Release builds, for performance.
• native\chk\ — chk (checked/asserts) → Debug builds, for debugging.

Built from the separate-binary control PR (advanced-binary-poc-v2), which folds in the canonical Advanced control branch.

CI safety

The TableView projects are not in Reactor.slnx; IncludeTableView defaults OFF in shared CI (GITHUB_ACTIONS) and on non-x64, so every existing Reactor PR build stays byte-identical. An on-demand workflow (tableview-control.yml) builds + best-effort UIA-validates the integration.

Review feedback addressed

• Metadata provider now registered exactly once (cached instance + guard) regardless of caller.
• Layout sizing respects framework modifiers: element Height is nullable (written only when explicitly set, else .Height()/Stretch win); the vestigial element-level MinWidth was removed.
• TableView path is x64-only: IncludeTableView auto-off on non-x64 + a build-time guard; the control package restricted to x64 (the native asset is win-x64 only).

[Copilot]

Pull request overview

This PR adds a proof-of-concept “first-class” Reactor control wrapper for the native split-binary WinUI Microsoft.UI.Xaml.Controls.TableView (from Microsoft.UI.Xaml.Controls.Advanced.dll), plus a gated integration/demo in Reactor.TestApp and an on-demand GitHub Actions workflow to build/self-check it without impacting every-PR CI.

Changes:

• Introduces Reactor.Controls.TableView (element + V1 handler + factories) and embeds the control’s style/theme closure so it can render in code-only Reactor hosts.
• Adds a gated “TableView” tab to Reactor.TestApp, including WinRT activation manifest + PRI string merge to satisfy the native control’s localized string lookup.
• Adds a CsWinRT projection project and an on-demand workflow/script to build and (best-effort) validate UIA rendering.

Reviewed changes

Copilot reviewed 26 out of 28 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
samples/TableView.Projection/TableView.Projection.csproj	CsWinRT projection project for the satellite control winmd.
samples/Reactor.TestApp/TableViewStrings/Resources.resw	Localized strings required by native TableView (merged into PRI).
samples/Reactor.TestApp/TableViewStrings/merge-tableview-strings.ps1	Post-build PRI merge script for TestApp.
samples/Reactor.TestApp/tableview-control-selftest.ps1	On-demand build + best-effort UIA render self-test script.
samples/Reactor.TestApp/Reactor.TestApp.csproj	Gated IncludeTableView wiring, references, native DLL content, PRI merge target.
samples/Reactor.TestApp/GlobalUsings.TableView.cs	Alias to avoid SortDirection ambiguity with the projection.
samples/Reactor.TestApp/Demos/TableViewControlDemo.cs	New TestApp demo tab consuming the control as a library user would.
samples/Reactor.TestApp/app.manifest	WinRT activation manifest mapping runtime classes to Advanced.dll.
samples/Reactor.TestApp/App.cs	Adds conditional TableView tab + default tab selection when enabled.
samples/Reactor.Controls.TableView/TableViewStyles.cs	Registers metadata provider + merges embedded style/theme closure + applies style.
samples/Reactor.Controls.TableView/TableViewHandler.cs	V1 element handler (mount/update/unmount, columns, items, selection event).
samples/Reactor.Controls.TableView/TableViewElement.cs	New Reactor element record + column definition for TableView.
samples/Reactor.Controls.TableView/Styles/07_TableView.xaml	Embedded default style/template for TableView/TableViewRow.
samples/Reactor.Controls.TableView/Styles/06_EditableContentPresenter.xaml	Embedded template for a TableView primitive.
samples/Reactor.Controls.TableView/Styles/05_SortIndicator.xaml	Embedded template for sort indicator primitive.
samples/Reactor.Controls.TableView/Styles/04_MarqueeSelector_themeresources.xaml	Theme resources for marquee selection.
samples/Reactor.Controls.TableView/Styles/03_SortIndicator_themeresources.xaml	Theme resources for sort indicator + badge.
samples/Reactor.Controls.TableView/Styles/02_TableView_themeresources.xaml	Theme resources for TableView surface/metrics + keyed styles.
samples/Reactor.Controls.TableView/Styles/01_TabularSurfaces_themeresources.xaml	Shared tabular-surface theme tokens embedded with the control.
samples/Reactor.Controls.TableView/Reactor.Controls.TableView.csproj	Packable control library project + embeds styles + packs native/targets artifacts.
samples/Reactor.Controls.TableView/Factories.cs	Factories + handler registration via ControlRegistry.
samples/Reactor.Controls.TableView/build/Resources.resw	Packaged strings for consumers (merged during build via targets).
samples/Reactor.Controls.TableView/build/Microsoft.UI.Reactor.TableView.targets	Consumer build targets (manifest + PRI string merge).
samples/Reactor.Controls.TableView/build/merge-tableview-strings.ps1	Packaged PRI merge script for consumers.
samples/Reactor.Controls.TableView/build/app.manifest	Packaged WinRT activation manifest for consumers.
.github/workflows/tableview-control.yml	On-demand workflow to build/self-test the gated TableView integration.

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[DDancingDeath]

Thanks for the review. Addressed all of it in 07944e1f (verified: build 0/0, 36/36 pages no-crash, CI-OFF Reactor.slnx 0/0):

Inline comments

1. Metadata provider registered per-call → now registered exactly once (cached instance + double-checked-lock guard); both EnsureInit() and Factories funnel through the guarded path.
   2–4. Height/MinWidth element props fighting Element.Modifiers → element Height is now nullable and the handler writes tv.Height only when it's explicitly set (otherwise .Height()/.MinHeight() modifiers or Stretch win). Removed the vestigial element-level MinWidth (consumers use the .MinWidth() modifier).
2. ARM64 would deploy the x64 DLL → IncludeTableView now auto-defaults off on non-x64, plus a build-time _TableViewArchGuard that fails early if it's forced on another arch.
3. Package Platforms x64;ARM64 but only win-x64 native asset → restricted the control package to <Platforms>x64</Platforms> for this POC.

From a deeper self-review (also fixed in 07944e1f)

• ItemsSource contract: the handler snapshotted the consumer's collection, so in-place add/remove/move on a bound ObservableCollection was invisible (e.g. the RowReorder page's "Move 0→3 (API)" was a no-op). The handler now subscribes to the source's INotifyCollectionChanged and re-syncs the master snapshot (re-applying the active sort/filter), unsubscribing on rebind + unmount. Verified "Move 0→3" now reorders the rows.
• Virtualization page re-materialized 10k–50k rows + re-bound every render (snapping scroll back) → now caches the dataset by size. Showcase passes an explicit tableHeight so Flat + 1000 rows stays virtualized.

This remains a draft / self-contained POC (gated OFF in shared CI, x64-only), so it doesn't touch any existing Reactor project's every-PR build.