25 KiB
XCUI Editor Agent Guide
This file documents the mandatory editor architecture for agents working under
editor/. It is an architecture contract, not just a description of whatever
the current checkout happens to contain.
If this file conflicts with editor/CMakeLists.txt or the real directory tree,
the target-shape rules in this file win. Fix the code or CMake to match these
rules unless the user explicitly asks to change the architecture contract.
Build Shape
The important production targets are:
XCUIEditorLib: reusable XCEditor framework code fromeditor/srcandeditor/include/XCEditor, including the reusable window authority, synchronization planner, and presentation projection underXCEditor/Windowing.XCUIEditorApp: concrete editor executable. Its output name isXCEngine.
XCUIEditorLib is the only production static library allowed under
editor/. All app-side code under editor/app, including Windowing,
Platform, Rendering, Composition, Features, and UtilityWindows, must
compile into XCUIEditorApp unless the code belongs in XCUIEditorLib.
Do not create, restore, or keep app-internal static library targets. Names such
as XCUIEditorAppWindowing, XCUIEditorAppCore, XCUIEditorAppLib, and
XCUIEditorHost are forbidden production target boundaries. If any of these
targets exist in CMake, treat them as stale build debt and remove them as part
of the boundary cleanup.
There is now a narrow public editor/include/XCEditor/Windowing layer for the
generic window authority model, synchronization plan/planner, and presentation
projection. App-specific window orchestration remains under
editor/app/Windowing, render host contracts remain under
editor/app/Rendering/Host, the concrete D3D12 renderer remains under
editor/app/Rendering/D3D12, and the concrete Win32 host remains under
editor/app/Platform/Win32.
Layering
Use these ownership boundaries when changing code:
editor/include/XCEditorandeditor/src: reusable editor framework. Keep this layer independent from app state, Win32, D3D12 host code, andApp::*types.editor/include/XCEditor/Windowingandeditor/src/Windowing: reusable window authority, validation, synchronization planning, commit, and presentation projection. Keep this layer generic and free of app content, host runtime, native platform, and rendering details.editor/app/Composition,Commands,Features,Project,Scene,State,System,UtilityWindows: editor product semantics.editor/app/Windowing/Content,Coordinator,Frame,Host,Runtime: app window orchestration, content ownership, frame driving, frame transfer, and per-window runtime state. Keep this layer backend-neutral; it may depend oneditor/app/Rendering/Hostcontracts, but not concrete render backends.editor/app/Platform/Win32: native window, message dispatch, input, lifecycle, chrome, HWND ownership, Win32 diagnostics, concrete native render surface adapters, and native host adapter behavior.editor/app/Rendering/Host: app rendering contracts consumed by app windowing and app content, including the render-runtime factory interface.editor/app/Rendering/D3D12: concrete D3D12 window renderer, UI renderer, texture host, text system, render loop, render-runtime adapter, and render-runtime factory.
The semantic dependency direction should remain:
XCEditor framework
<- editor app semantics
<- app windowing runtime / rendering host contracts
<- application composition root / concrete Win32 and rendering adapters
Startup Flow
The application starts through:
app/main.cpp
-> RunXCUIEditorApp
-> Application::Run
-> Application::Initialize
The primary workspace window is initialized through:
EditorContext::BuildWorkspaceController()
-> EditorWindowSystem::BootstrapPrimaryWindow(...)
-> EditorWindowManager::CreateWorkspaceWindow(...)
-> EditorWindowContentFactory::CreateWorkspaceContentController(...)
-> EditorWindowRenderRuntimeFactory::CreateWindowRenderRuntime()
-> EditorWindowRuntimeController(EditorContext, contentController, renderRuntime)
-> EditorWindowInstance(runtimeController)
-> EditorWindowHostRuntime::CreateHostWindow(windowInstance, ...)
-> Win32 EditorWindow native peer
Keep authoritative window bootstrap in EditorWindowSystem; do not move it
back into the Win32 host.
Frame Runtime Ownership
EditorWindowManager owns steady-state frame iteration and the immediate-frame
callbacks used by native paint, resize, maximize/restore, and chrome actions.
The Win32 host may request a frame through EditorWindowHostCoordinator, but it
must not own the editor frame loop or fetch EditorContext.
EditorWindowRuntimeController lives under editor/app/Windowing/Runtime.
App windowing creates it from EditorContext plus a workspace or utility
content controller plus a backend-neutral EditorWindowRenderRuntime, then
wraps it in app-owned EditorWindowInstance. The Win32 host receives the
instance only as an EditorHostWindow owner/native-peer binding; it must not
store or call EditorWindowRuntimeController directly, create content
controllers, or receive EditorContext.
Concrete renderer selection is composed above both app windowing and the native
host. Application creates the current
D3D12EditorWindowRenderRuntimeFactory and passes it into
EditorWindowManager; app windowing asks the factory for backend-neutral
Rendering::Host::EditorWindowRenderRuntime instances. EditorWindowInstance
owns runtime controllers that already contain their render runtime; the Win32
host must not create concrete render backends or own render runtimes.
EditorWindowRuntimeController may call
EditorWindowRenderRuntime, UiTextureHost, and ViewportRenderHost, but it
must not include Rendering/D3D12 headers, windows.h, or HWND types.
The host contract direction is:
EditorWindowManager / coordinators
-> ask EditorWindowRenderRuntimeFactory for EditorWindowRenderRuntime
-> create EditorWindowRuntimeController
-> wrap it in app-owned EditorWindowInstance
-> EditorWindowHostRuntime::CreateHostWindow(windowInstance, ...)
-> Win32 EditorWindow owns HWND/input/chrome and supplies native snapshots
-> EditorWindowInstance renders from snapshots and returns native frame commands
The native peer contract for frame/runtime data is data-shaped. Native render
surface creation crosses through EditorNativeWindowRuntimeSurface, which
carries an abstract Rendering::Host::EditorWindowRenderRuntimeSurface rather
than a raw HWND/void*; per-frame native facts cross through
EditorNativeWindowFrameSnapshot; frame-side native effects cross back through
EditorNativeWindowFrameCommands. Do not add one-off native-peer getters for
normal frame data such as HWND, render size, DPI, pending input, cursor point,
workspace bounds, title-bar mode, or cursor application. Extend the
snapshot/command structs when the frame contract needs new data.
Window Authority Model
EditorWindowSystem owns the authoritative UIEditorWindowWorkspaceSet through
EditorWindowWorkspaceStore.
Normal per-frame workspace edits now use direct writes into that authoritative state:
EditorWorkspaceWindowContentController::UpdateAndAppend(...)
-> EditorWindowSystem::TryBuildLiveWindowWorkspaceController(windowId, ...)
-> UIEditorWorkspaceController::BindToState(...)
-> workspace operations mutate the bound authoritative workspace/session
The old normal path is obsolete:
snapshot diff
-> workspaceMutation frame request
-> coordinator
-> synchronization plan
-> commit
Do not reintroduce workspaceMutation as the steady-state route for ordinary
layout, tab, visibility, or active-panel edits inside an existing workspace
window.
Cross-window create, update, close, and destroyed-window reconciliation still use the planner/coordinator flow:
target UIEditorWindowWorkspaceSet
-> EditorWindowSystem::BuildPlanForWindowSet(...)
-> EditorWindowWorkspaceCoordinator::ApplySynchronizationPlan(...)
-> EditorWindowSystem::CommitSynchronizationPlan(...)
EditorWindowWorkspaceCoordinator::RefreshWindowPresentation(...) refreshes
each workspace window projection from authoritative state. Presentation should
follow authority; it should not become a second source of truth.
Frame Transfer Requests
EditorWindowFrameTransferRequests is only for host-side or cross-window side
effects that cannot be represented as direct in-window workspace edits.
Current request fields are:
workspace.beginGlobalTabDragworkspace.detachPanelutility.openUtilityWindow
There is no workspace.workspaceMutation field in the current frame transfer
contract. Treat any doc, comment, or test name that says otherwise as stale.
Window Categories
Workspace and utility windows share the native host path but use distinct content controllers.
- Workspace windows use
EditorWorkspaceWindowContentController. - Utility windows use
EditorUtilityWindowContentController. - App windowing creates content through
EditorWindowContentFactory. - App windowing wraps content in
EditorWindowRuntimeController, then owns that runtime throughEditorWindowInstance. - The concrete host creates a native peer for an existing app-owned
EditorHostWindow; it does not receive or validate runtime controllers.
Utility windows are descriptor driven through EditorUtilityWindowDescriptor,
EditorUtilityWindowRegistry, and CreateEditorUtilityWindowPanel(...).
Register new utility windows there rather than hard-coding them in Win32 host
logic. Utility descriptors may express native host semantics such as
EditorWindowNativeShellRole::ToolWindow, but they must not include
windows.h or encode Win32 style constants such as WS_EX_* or WS_*.
Modification Rules
- First decide whether the change belongs to XCEditor framework, app semantics, app windowing, Win32 host, or rendering host.
- Keep public framework headers free of
App::*, Win32, and D3D12 host types. - Keep
editor/include/XCEditorandeditor/srcfree ofwindows.h, HWND, Win32 exception types such as_EXCEPTION_POINTERS, and DbgHelp/StackWalk code. Win32 crash stack capture belongs undereditor/app/Platform/Win32; framework trace code only writes platform-neutral trace records. - Do not add
editor/appas an include directory forXCUIEditorLib. App-only services must cross into framework code through framework-owned interfaces and app-side adapters. - Do not compile
${XCUI_EDITOR_SHARED_SOURCES}directly intoXCUIEditorApp; the executable should consume shared framework code throughXCUIEditorLib. - Do not add any app-internal static library targets under
editor/. The only editor static library target isXCUIEditorLib. - Do not compile
editor/app/Windowingas a standalone library target. It is an app source ownership boundary only, and should compile intoXCUIEditorApp. - Use
editor/include/XCEditor/Windowingandeditor/src/Windowingfor generic window authority, synchronization, validation, and presentation projection. - Use
editor/app/Windowingfor app-specific window runtime semantics, content, frame transfer, host contracts, runtime controllers, and coordinators. - Use
editor/app/Rendering/Hostfor renderer-facing contracts that app windowing or app content may consume, includingEditorWindowRenderRuntimeFactory. - Use
editor/app/Rendering/D3D12for concrete D3D12 renderer ownership, swap-chain/present/capture details, UI texture/text/render systems, and the D3D12EditorWindowRenderRuntimeimplementation and factory. - Use
editor/app/Platform/Win32only for native host behavior and message integration. Win32 code may request frames through the host coordinator; it must not own the editor frame loop, exposeEditorContext, or create concrete render backends. It may create concrete Win32 render surface adapter objects that implementRendering::Host::EditorWindowRenderRuntimeSurface. - Do not let
editor/app/WindowingincludePlatform/Win32headers. - Do not let
editor/app/WindowingincludeRendering/D3D12headers,windows.h, or HWND types. It should consume concrete rendering only throughRendering::Host::EditorWindowRenderRuntimeandRendering::Host::EditorWindowRenderRuntimeFactory, and it must pass native render surfaces only as abstractEditorWindowRenderRuntimeSurfaceobjects. - Do not let
editor/app/Platform/Win32includeRendering/D3D12headers or implement render-runtime factory methods on the native host interfaces. - Do not let app semantics such as
UtilityWindowsencode Win32 style bits. Use semantic host policy fields, and map those semantics toWS_*constants inside the Win32 host. - Do not spread D3D12 host types into app windowing content, coordinator, frame-transfer, runtime-controller, or public host-contract headers.
- Do not let Win32 host code create workspace or utility content directly.
It should receive an app-owned
EditorHostWindow/EditorWindowInstancecreated by app windowing, not anEditorWindowRuntimeController. - Keep
EditorWindowNativePeerframe/runtime communication data-shaped: useEditorNativeWindowRuntimeSurface,EditorNativeWindowFrameSnapshot,EditorNativeWindowFrameCommands, and small metrics snapshots instead of exposing individual HWND, DPI, size, input, cursor, or title-bar getters to app windowing.EditorNativeWindowRuntimeSurfacemust not expose a raw native handle field. - Do not let Win32 host code call
EditorWindowRuntimeControlleror directly drive editor runtime frames. Native messages may request immediate frames throughEditorWindowHostCoordinator; app windowing owns the render/update step. - Use direct authoritative workspace binding for ordinary in-window workspace mutations.
- Use synchronization plans for operations that create, close, replace, or reconcile workspace windows.
- Use frame transfer requests only for host-side or cross-window effects.
Current Architecture Debt
The highest-value windowing boundary has been hardened: XCUIEditorLib now
owns the reusable window authority, synchronization planner, workspace store,
and presentation projection under XCEditor/Windowing. App windowing remains
a source ownership boundary under editor/app/Windowing; it is not allowed to
be a separate production library target. The Win32 host is the concrete native
adapter and creates native host windows for app-owned EditorWindowInstance
objects supplied by app windowing.
The framework/app compile boundary is also enforced. XCUIEditorLib does not
receive editor/app includes, and XCUIEditorApp does not directly compile
the shared framework sources. When framework UI code needs app-provided data
such as loaded icons, expose a framework-owned interface and adapt it in app
composition code.
The top-level target debt is any app-internal static library target left in
the build. XCUIEditorLib must remain the only editor static library. If CMake
defines targets such as XCUIEditorAppWindowing, XCUIEditorAppCore,
XCUIEditorAppLib, or XCUIEditorHost, remove those target boundaries and
compile their app-side sources into XCUIEditorApp.
The main windowing debt that was previously in the Win32 host has been cut:
frame iteration, immediate frame driving, content-controller construction, and
EditorContext ownership now live in app windowing. EditorWindowHostCoordinator
does not expose GetEditorContext(), and the native host receives an
app-owned EditorWindowInstance rather than raw workspace/utility content or a
runtime controller.
The native-peer ownership cut has also been made: EditorWindowManager owns
EditorWindowInstance objects, each instance owns its
EditorWindowRuntimeController, and editor/app/Platform/Win32/Windowing
EditorWindow is a native peer for HWND/input/chrome/message integration. The
Win32 platform code must stay free of
Windowing/Runtime/EditorWindowRuntimeController.h.
The native frame contract cut has also been made: frame/runtime initialization
no longer crosses the boundary through granular native-peer getters such as
HWND, DPI, size, input, cursor, workspace bounds, and title-bar mode. Win32
captures those native facts into EditorNativeWindowRuntimeSurface and
EditorNativeWindowFrameSnapshot; app windowing renders from the snapshot and
returns native side effects through EditorNativeWindowFrameCommands.
EditorNativeWindowRuntimeSurface carries an abstract render surface object,
not a raw HWND or erased void*.
The renderer ownership cut has also been made: app windowing no longer owns the
concrete D3D12 window render loop or Win32 surface setup.
EditorWindowRuntimeController consumes a backend-neutral
Rendering::Host::EditorWindowRenderRuntime, and EditorWindowManager receives
a backend-neutral Rendering::Host::EditorWindowRenderRuntimeFactory. The
current D3D12 factory is composed in Application, not in the Win32 host. The
current D3D12 runtime may recognize the concrete Win32 render surface adapter,
but app windowing must only traffic in the abstract rendering-host surface type.
The platform-boundary cut has also been made: XCUIEditorLib trace code is
platform-neutral, and Win32 exception/DbgHelp stack capture lives under
editor/app/Platform/Win32/Diagnostics. Utility-window descriptors express
native shell intent with semantic host policy values rather than Win32 style
bits; the Win32 host maps those semantics to WS_* constants.
The remaining promotion debt is the app runtime surface and host contract
vocabulary itself.
editor/app/Windowing is still app-internal and may depend on app semantics
such as EditorContext, EditorShellRuntime, utility window descriptors, and
product-specific content. This app-internal dependency is a directory-level
ownership detail only; it must not become a separate static library boundary.
Do not promote host interfaces, frame transfer, runtime controllers, content
controllers, or render-runtime contracts to XCEditor until they are generic
enough to expose. Do not move frame ownership back into
editor/app/Platform/Win32, do not move concrete renderer ownership back into
editor/app/Windowing, and do not move renderer factory ownership back into
the Win32 host.
Do not take another library-boundary architecture cut just to keep carving this
area. After the native-peer and native-frame-contract cuts, the next default
improvement should be boundary guardrails, such as checks that keep
editor/app/Windowing free of Rendering/D3D12, Platform/Win32,
windows.h, HWND types, raw native render handles, and one-off native-peer
frame getters; keep app semantics free of Win32 WS_* constants; keep
editor/include/XCEditor and editor/src free of Win32 diagnostics and
exception types; and keep editor/app/Platform/Win32 free of Rendering/D3D12
and Windowing/Runtime/EditorWindowRuntimeController.h. Consider another
structural source-directory cut only when there is concrete pressure, such as
another native host, another render backend, or headless editor/window tests;
do not satisfy that pressure by adding another production static library.
Validation
Default editor validation is only the app build plus the 12-second smoke run:
cmake --build build --config Debug --target editor_ui_smoke_targets
build\tests\UI\Editor\smoke\Debug\editor_ui_smoke_runner.exe build\editor\Debug\XCEngine.exe
Do not run editor_windowing_phase1_tests, editor_ui_tests, or broader test
targets by default. Run them only when the user explicitly asks for them or a
separate targeted change makes them necessary.
The runner sets XCUIEDITOR_SMOKE_TEST_DURATION_SECONDS=12, waits for the
editor to launch, lets the app auto-exit, and treats a clean editor exit as
success.
Recommended Reading
Start with these files for editor/windowing work:
editor/CMakeLists.txteditor/app/Bootstrap/Application.*editor/app/Composition/EditorContext.*editor/app/Composition/EditorShellRuntime.*editor/include/XCEditor/Workspace/UIEditorWorkspaceController.heditor/src/Workspace/UIEditorWorkspaceController.cppeditor/include/XCEditor/Windowing/System/EditorWindowSystem.heditor/include/XCEditor/Windowing/System/EditorWindowSynchronizationPlan.heditor/include/XCEditor/Windowing/System/EditorWindowSynchronizationPlanner.heditor/include/XCEditor/Windowing/Presentation/EditorWorkspaceWindowProjection.heditor/include/XCEditor/Windowing/Presentation/EditorWindowPresentationPolicy.heditor/src/Windowing/System/EditorWindowSystem.cppeditor/src/Windowing/System/EditorWindowWorkspaceStore.*editor/src/Windowing/System/EditorWindowSynchronizationPlanner.cppeditor/src/Windowing/Presentation/EditorWindowPresentationPolicy.cppeditor/app/Windowing/Host/EditorWindowHostInterfaces.heditor/app/Windowing/Content/EditorWindowContentController.heditor/app/Windowing/Content/EditorWindowContentFactory.*editor/app/Windowing/Content/EditorWorkspaceWindowContentController.*editor/app/Windowing/Frame/EditorWindowFrameOrchestrator.*editor/app/Windowing/Frame/EditorWindowTransferRequests.heditor/app/Windowing/Runtime/EditorWindowRuntimeController.*editor/app/Windowing/Runtime/EditorWindowScreenshotController.*editor/app/Windowing/EditorWindowInstance.*editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.*editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.*editor/app/Windowing/EditorWindowManager.*editor/app/Rendering/Host/EditorWindowRenderRuntime.heditor/app/Rendering/D3D12/D3D12EditorWindowRenderRuntime.*editor/app/Platform/Win32/Diagnostics/Win32CrashTrace.*editor/app/Platform/Win32/Windowing/Win32EditorWindowRenderRuntimeSurface.heditor/app/Platform/Win32/Windowing/EditorWindow.*editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.*editor/app/Platform/Win32/Windowing/EditorWindowMessageDispatcher.*tests/UI/Editor/smoke/CMakeLists.txt
Recent Cuts
- The framework-to-app icon dependency is sealed:
UIEditorShellComposeuses the framework-ownedUIEditorShellIconResolver, and the app adaptsBuiltInIconsinEditorShellDrawComposer. - The framework/app compile boundary is sealed:
XCUIEditorLibdoes not receiveeditor/appincludes,XCUIEditorAppdoes not directly compile${XCUI_EDITOR_SHARED_SOURCES}, and the app consumes framework code throughXCUIEditorLib. - The reusable window authority core lives in the framework:
EditorWindowSystem, synchronization planning, workspace store, and presentation projection are undereditor/include/XCEditor/Windowingandeditor/src/Windowing. - App windowing owns the runtime cut: content controllers,
EditorWindowRuntimeController, frame driving, frame transfer, host contracts, andEditorWindowManagerare undereditor/app/Windowingas an app source directory, not as a standalone library target; Win32 remains the native adapter and no longer exposesEditorContext. - The native-peer ownership cut is sealed: app windowing now owns live
EditorWindowInstanceobjects, those instances ownEditorWindowRuntimeController, and Win32EditorWindowonly owns the native peer side for HWND/input/chrome/message work.CreateHostWindow(...)binds a native peer to an existingEditorHostWindow; it does not receive a runtime controller. - The native frame contract cut is sealed: app windowing consumes
EditorNativeWindowRuntimeSurfaceandEditorNativeWindowFrameSnapshotinstead of calling granular native-peer getters for frame/runtime data, and Win32 applies frame side effects throughEditorNativeWindowFrameCommands. Runtime surface creation carries an abstractRendering::Host::EditorWindowRenderRuntimeSurface, not a raw HWND/void*. - The concrete renderer cut is sealed: app windowing consumes
Rendering::Host::EditorWindowRenderRuntimeandRendering::Host::EditorWindowRenderRuntimeFactory, while the current D3D12 implementation and factory live undereditor/app/Rendering/D3D12. The factory is composed inApplication;editor/app/Windowingshould stay free ofRendering/D3D12,windows.h, and HWND types, andeditor/app/Platform/Win32should stay free ofRendering/D3D12. - The Win32 platform-boundary cut is sealed: framework runtime trace code no
longer includes Win32/DbgHelp or exposes
_EXCEPTION_POINTERS; Win32 crash stack capture lives undereditor/app/Platform/Win32/Diagnostics; utility window descriptors use semantic native host policies instead ofWS_*constants. - The production target shape is sealed:
XCUIEditorLibis the only editor static library, and all app-side source directories compile intoXCUIEditorApp. - Default validation remains the editor app build plus the 12-second smoke run; run broader windowing/unit targets only for targeted coverage.