# XCEditor Feature Colocation And Framework Boundary Refactor Plan

## Status

Completed on 2026-04-30.

This document is now the final closure record for the product-layer refactor, not a
pending migration checklist.

## Goal

Eliminate the old editor product split where:

- feature UI lived under `Product/Content`
- feature registration lived under `Product/Modules`
- reusable hosted-content contracts lived under `Product/Hosting`

That structure fragmented ownership, hid real runtime boundaries, and kept the
registry layer fatter than its name suggested.

## Final Architecture

```text
editor/src/Product/
  Commands/
  Core/
  Effects/
  Features/
    Utility/
      AddComponent/
        AddComponentPanel.*
        AddComponentUtilityFeature.*
      ColorPicker/
        ColorPickerPanel.*
        ColorPickerUtilityFeature.*
    Workspace/
      Console/
        ConsolePanel.*
        ConsoleWorkspaceFeature.*
      Game/
        GameViewportController.*
        GameViewportFeature.*
        GameWorkspaceFeature.*
      Hierarchy/
        HierarchyModel.*
        HierarchyPanel.*
        HierarchyWorkspaceFeature.*
      Inspector/
        Components/*
        InspectorPanel.*
        InspectorPresentationModel.*
        InspectorSubject.*
        InspectorWorkspaceFeature.*
      Project/
        ProjectPanel.*
        ProjectWorkspaceFeature.*
      Scene/
        SceneEditCommandRoute.*
        SceneViewportController.*
        SceneViewportFeature.*
        SceneViewportSceneOverlay.*
        SceneViewportSession.*
        SceneViewportToolOverlay.*
        SceneViewportTransformGizmo.*
        SceneViewportTransformGizmoSupport.*
        SceneWorkspaceFeature.*
  Framework/
    UtilityWindow/
      EditorUtilityWindowContent.h
    Workspace/
      EditorWorkspaceHostedContent.h
      EditorWorkspaceHostedContentSet.h/.cpp
  Registry/
    EditorProductRegistry.h/.cpp
  Rendering/
  Runtime/
    Diagnostics/
    Features/
      EditorFeatureComposition.h/.cpp
    Shell/
    Store/
    Windowing/
  Services/
  State/
  Support/
```

## Final Rules

- `Features/*` owns feature identity, feature-local registration metadata, and feature
  implementation together.
- `Framework/*` owns only stable host-facing contracts and generic hosted-content
  containers.
- `Registry/*` owns only descriptor types, lookup, and validation.
- `Runtime/Features/*` owns runtime feature composition and content instantiation.
- no central `EditorWorkspacePanelIds.h` pool exists; workspace feature identity now
  lives in the owning feature headers.
- obsolete `Product/Content`, `Product/Modules`, and `Product/Hosting` trees do not
  exist anymore.

## What Was Closed

### 1. Framework Boundary

- `Product/Hosting` was replaced by `Product/Framework`.
- hosted-content contracts were split into:
  - `EditorWorkspaceHostedContent.h`
  - `EditorWorkspaceHostedContentSet.h/.cpp`
  - `EditorUtilityWindowContent.h`

### 2. Feature Colocation

- all workspace feature registration files now sit beside their owning feature UI.
- all utility feature registration files now sit beside their owning utility content.
- feature IDs were pulled back into feature-owned headers instead of a centralized
  workspace panel id table.

### 3. Thin Registry

- `EditorProductModuleRegistry` was replaced by `EditorProductRegistry`.
- public registration API terminology now uses `Feature`, not `Module`.
- runtime-specific composition was removed from `Registry` and moved into:
  - `Product/Runtime/Features/EditorFeatureComposition.*`

### 4. Physical Cleanup

- `Product/Content` was removed.
- `Product/Modules` was removed.
- `Product/Hosting` was removed.
- old include paths and old product registration entry points were removed from the
  build.

## Validation

Validated during the refactor on 2026-04-30 with repeated build and smoke cycles.

Latest validation commands:

- `cmake --build build --config Debug --target XCEditor`
- smoke test with:
  - `XCUIEDITOR_SMOKE_TEST=1`
  - `XCUIEDITOR_SMOKE_TEST_DURATION_SECONDS=12`

Latest observed smoke result:

- `EXIT_CODE=0`
- `DURATION_SECONDS=14.25`

## Marker Gate

Final marker audit on 2026-04-30 found a single pending marker file:

- `20260430-154622-394.dog`

That file was deleted only after:

1. obsolete product trees were physically removed
2. registry responsibilities were reduced to descriptor/lookup/validation only
3. feature identity ownership was moved back into feature-owned headers
4. the latest build succeeded
5. the latest 12-second smoke test exited cleanly

Current marker status:

- no `.dog` files remain in the workspace

## Completion Criteria

The refactor is closed because all of the following are true:

1. `Product/Framework` replaced `Product/Hosting`.
2. `Product/Features` replaced `Product/Content` and absorbed feature-local
   registration.
3. `Product/Registry` replaced `EditorProductModuleRegistry`.
4. feature behavior and feature registration are physically co-located.
5. feature identity is no longer stored in a global workspace panel id pool.
6. the registry is thin and feature-agnostic.
7. runtime feature assembly lives under `Runtime/Features`.
8. the latest `XCEditor` build passed.
9. the latest 12-second smoke test passed.
10. the `.dog` marker gate was processed after items 1-9 were satisfied.