XCEngine/docs/plan/XCUI_Phase_Status_2026-04-05.md

XCUI Phase Status 2026-04-05

Scope

Current execution stays inside the XCUI module and new_editor. Old editor replacement is explicitly out of scope for this phase.

Latest Checkpoint

• Phase 1 sandbox batch committed and pushed as 67a28bd (Add XCUI new editor sandbox phase 1).
• Current work has moved into Phase 2: filling the three-layer XCUI structure instead of replacing the old editor.

Three-Layer Status

1. Common Core

• UI::DrawData, input event types, focus routing, style/theme resolution are in active use.
• UIDocumentCompiler was restored to a stable buildable baseline after a broken parallel schema attempt corrupted the file.
• Build-system hardening for MSVC/PDB output paths has started in root CMake, engine/CMakeLists.txt, new_editor/CMakeLists.txt, and tests/NewEditor/CMakeLists.txt.
• Shared engine-side XCUI runtime scaffolding is now present under engine/include/XCEngine/UI/Runtime and engine/src/UI/Runtime.
• Core regression coverage now includes UIContext, layout, style, and runtime screen-player tests through core_ui_tests.

Current gap:

• Schema/validation is not yet landed in a stable form.
• Shared widget/runtime instantiation is still thin and mostly editor-side.
• Common widget primitives are still incomplete: multiline text editing, tree/list virtualization, property-grid composition, and native image/source-rect level APIs.

2. Runtime/Game Layer

• Runtime-side XCUI is still shallow.
• The main concrete progress here is that the retained-mode demo runtime now supports a real TextField input path with UTF-8 text entry and backspace handling.
• This proves that the runtime-facing layer is no longer limited to static cards/buttons.
• Engine-side runtime ownership is no longer zero: UIScreenPlayer and UISystem now define a minimal shared runtime contract for loading a screen document, ticking it with input, and collecting UI::UIDrawData.

Current gap:

• No real game-facing screen host, menu stack, HUD stack, or shared runtime widget library yet.
• The new runtime layer still needs a real XCUI document host implementation instead of the current host-facing contract only.

3. Editor Layer

• new_editor remains the isolated XCUI sandbox.
• Native hosted preview is working as RHI offscreen surface -> ImGui shell texture embed.
• XCUI Demo remains the long-lived effect and behavior testbed.
• LayoutLab now includes a ScrollView prototype and a more editor-like three-column authored layout.
• Panel diagnostics were expanded to clearly separate preview/runtime/input state and native vs legacy paths.
• XCNewEditor builds successfully to build/new_editor/bin/Debug/XCNewEditor.exe.

Current gap:

• The shell is still ImGui-hosted.
• Editor-specialized widgets are still incomplete: tree, list virtualization, property grid, toolbar/menu, text area, icon atlas widgets.

Validated This Phase

• new_editor_xcui_demo_runtime_tests: 6/6
• new_editor_xcui_layout_lab_runtime_tests: 5/5
• new_editor_xcui_rhi_command_compiler_tests: 6/6
• new_editor_xcui_rhi_render_backend_tests: 5/5
• XCNewEditor Debug target builds successfully
• core_ui_tests: 20/20

Landed This Phase

• Demo runtime TextField with UTF-8 text insertion, caret state, and backspace.
• Demo authored resources updated to exercise the input field.
• LayoutLab ScrollView prototype with clipping and hover rejection outside clipped content.
• RHI image path improvements:
  • clipped image UV adjustment
  • mirrored image UV preservation
  • external texture binding reuse
  • per-batch scissor application
• new_editor panel/shell diagnostics improvements for hosted preview state.
• XCUI asset document loading changed to prefer direct source compilation before ResourceManager fallback for the sandbox path, fixing the LayoutLab crash.

Phase Risks Still Open

• Schema/validation work must be restarted cleanly after the corrupted parallel attempt.
• ScrollView is still authored/static; no wheel-driven scrolling or virtualization yet.
• Image widgets still do not have source-rect/atlas-subregion level API in the high-level draw command model.
• Editor shell still depends on ImGui as host chrome.

Next Phase

1. Re-open common-layer schema/validation on a clean baseline and land the smallest stable version.
2. Expand runtime/game-layer ownership from UIScreenPlayer/UISystem into a real XCUI document host plus menu/HUD stack patterns.
3. Add next editor-facing widgets: TextArea, list/tree, property-style sections.
4. Move more diagnostics and shell affordances into XCUI-owned editor-layer surfaces instead of only ImGui HUDs.
5. Continue phased validation, commit, push, and plan refresh after each stable batch.