Seal editor host content binding boundary

editor/AGENTS.md

@@ -51,9 +51,10 @@ Use these ownership boundaries when changing code:
 - `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
-  on `editor/app/Rendering/Host` contracts, but not concrete render backends.
+  app window orchestration, content ownership, host-facing content binding
+  contracts, frame driving, frame transfer, and per-window runtime state. Keep
+  this layer backend-neutral; it may depend on `editor/app/Rendering/Host`
+  contracts, 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.
@@ -148,6 +149,13 @@ 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.
 
+Host-visible content binding interfaces live under
+`editor/app/Windowing/Host`, not `editor/app/Windowing/Content`. The native
+host may consume small binding contracts such as
+`EditorWindowInputFeedbackBinding`, `EditorWindowTitleBarBinding`, and
+`EditorWindowDockHostBinding`; it must not include the content-controller
+header or couple to concrete workspace/utility content controllers.
+
 ## Window Authority Model
 
 `EditorWindowSystem` owns the authoritative `UIEditorWindowWorkspaceSet` through
@@ -247,8 +255,8 @@ logic. Utility descriptors may express native host semantics such as
   generic window authority, synchronization, validation, and presentation
   projection.
 - Use `editor/app/Windowing` for app-specific window runtime semantics,
-  content, frame transfer, host contracts, runtime controllers, and
-  coordinators.
+  content, frame transfer, host contracts, host-visible content binding
+  interfaces, runtime controllers, and coordinators.
 - Use `editor/app/Rendering/Host` for renderer-facing contracts that app
   windowing or app content may consume, including
   `EditorWindowRenderRuntimeFactory`.
@@ -276,6 +284,10 @@ logic. Utility descriptors may express native host semantics such as
 - Do not let Win32 host code create workspace or utility content directly.
   It should receive an app-owned `EditorHostWindow`/`EditorWindowInstance`
   created by app windowing, not an `EditorWindowRuntimeController`.
+- Do not let `editor/app/Platform/Win32` include
+  `Windowing/Content/EditorWindowContentController.h`. Host-visible content
+  state must cross through `Windowing/Host/EditorWindowContentBindings.h` and
+  `Windowing/Host/EditorWindowHostInterfaces.h`.
 - Keep `EditorWindowNativePeer` frame/runtime communication data-shaped:
   use `EditorNativeWindowRuntimeSurface`, `EditorNativeWindowFrameSnapshot`,
   `EditorNativeWindowFrameCommands`, and small metrics snapshots instead of
@@ -352,6 +364,12 @@ platform-neutral, and Win32 exception/DbgHelp stack capture lives under
 native shell intent with semantic host policy values rather than Win32 style
 bits; the Win32 host maps those semantics to `WS_*` constants.
 
+The host/content binding cut has also been made: host-visible content binding
+contracts live in `editor/app/Windowing/Host/EditorWindowContentBindings.h`.
+`editor/app/Windowing/Content/EditorWindowContentController.h` owns concrete
+content-controller contracts, while the Win32 native host consumes only the
+small host binding interfaces exposed from `Windowing/Host`.
+
 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
@@ -373,10 +391,12 @@ improvement should be boundary guardrails, such as checks that keep
 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.
+and `Windowing/Runtime/EditorWindowRuntimeController.h`; keep
+`editor/app/Platform/Win32` free of
+`Windowing/Content/EditorWindowContentController.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
 
@@ -414,6 +434,7 @@ Start with these files for editor/windowing work:
 - `editor/src/Windowing/System/EditorWindowWorkspaceStore.*`
 - `editor/src/Windowing/System/EditorWindowSynchronizationPlanner.cpp`
 - `editor/src/Windowing/Presentation/EditorWindowPresentationPolicy.cpp`
+- `editor/app/Windowing/Host/EditorWindowContentBindings.h`
 - `editor/app/Windowing/Host/EditorWindowHostInterfaces.h`
 - `editor/app/Windowing/Content/EditorWindowContentController.h`
 - `editor/app/Windowing/Content/EditorWindowContentFactory.*`
@@ -477,6 +498,9 @@ Start with these files for editor/windowing work:
   stack capture lives under `editor/app/Platform/Win32/Diagnostics`; utility
   window descriptors use semantic native host policies instead of `WS_*`
   constants.
+- The host/content binding cut is sealed: native host-visible content binding
+  contracts live under `editor/app/Windowing/Host`, and Win32 code consumes
+  `EditorWindowContentBindings.h` instead of the content-controller contract.
 - The production target shape is sealed: `XCUIEditorLib` is the only editor
   static library, and all app-side source directories compile into
   `XCUIEditorApp`.

editor/app/Platform/Win32/Chrome/EditorWindowChromeController.cpp

@@ -2,7 +2,7 @@
 
 #include "Platform/Win32/Windowing/EditorWindow.h"
 #include "Platform/Win32/Windowing/EditorWindowSupport.h"
-#include "Windowing/Content/EditorWindowContentController.h"
+#include "Windowing/Host/EditorWindowContentBindings.h"
 #include "Windowing/Host/EditorWindowHostCoordinator.h"
 
 #include <XCEditor/Foundation/UIEditorTheme.h>

editor/app/Platform/Win32/Windowing/EditorWindow.cpp

@@ -5,7 +5,7 @@
 #include "Platform/Win32/Windowing/EditorWindowSupport.h"
 #include "Platform/Win32/Windowing/Win32EditorWindowRenderRuntimeSurface.h"
 #include "Platform/Win32/Runtime/EditorWindowInputController.h"
-#include "Windowing/Content/EditorWindowContentController.h"
+#include "Windowing/Host/EditorWindowContentBindings.h"
 #include <XCEditor/Docking/UIEditorDockHostTransfer.h>
 #include <XCEditor/Foundation/UIEditorRuntimeTrace.h>
 #include <XCEditor/Shell/UIEditorShellInteraction.h>

editor/app/Platform/Win32/Windowing/EditorWindowMessageDispatcher.cpp

@@ -5,7 +5,7 @@
 #include "Platform/Win32/Runtime/EditorWindowInputController.h"
 #include "Platform/Win32/Windowing/EditorWindow.h"
 #include "Platform/Win32/Windowing/EditorWindowPointerCapture.h"
-#include "Windowing/Content/EditorWindowContentController.h"
+#include "Windowing/Host/EditorWindowContentBindings.h"
 #include "Windowing/Host/EditorWindowHostCoordinator.h"
 
 #include <cstdint>

editor/app/Windowing/Content/EditorWindowContentController.h

@@ -1,12 +1,10 @@
 #pragma once
 
 #include "Windowing/Frame/EditorWindowTransferRequests.h"
+#include "Windowing/Host/EditorWindowContentBindings.h"
 
-#include <XCEditor/Docking/UIEditorDockHostTransfer.h>
 #include <XCEditor/Foundation/UIEditorTextMeasurement.h>
-#include <XCEditor/Windowing/Presentation/EditorWorkspaceWindowProjection.h>
 
-#include <cstdint>
 #include <filesystem>
 #include <optional>
 #include <string>
@@ -35,10 +33,6 @@ namespace XCEngine::UI::Editor {
 struct UIEditorShellInteractionFrame;
 struct UIEditorShellInteractionState;
 
-namespace Widgets {
-struct UIEditorDockHostDropPreviewState;
-}
-
 } // namespace XCEngine::UI::Editor
 
 namespace XCEngine::UI::Editor::Rendering::Host {
@@ -52,12 +46,6 @@ namespace XCEngine::UI::Editor::App {
 
 class EditorContext;
 
-enum class EditorWindowContentCursorKind : std::uint8_t {
-    Arrow = 0,
-    ResizeEW,
-    ResizeNS,
-};
-
 struct EditorWindowContentCapabilities {
     bool workspace = false;
     bool dockHost = false;
@@ -67,51 +55,6 @@ struct EditorWindowContentCapabilities {
     bool utilityPanel = false;
 };
 
-class EditorWindowWorkspaceBinding {
-public:
-    virtual ~EditorWindowWorkspaceBinding() = default;
-
-    virtual const EditorWorkspaceWindowProjection* TryGetWorkspaceProjection() const = 0;
-    virtual void RefreshWorkspaceProjection(EditorWorkspaceWindowProjection projection) = 0;
-};
-
-class EditorWindowDockHostBinding {
-public:
-    virtual ~EditorWindowDockHostBinding() = default;
-
-    virtual void SetExternalDockHostDropPreview(
-        const Widgets::UIEditorDockHostDropPreviewState& preview) = 0;
-    virtual void ClearExternalDockHostDropPreview() = 0;
-    virtual bool TryResolveDockTabDragHotspot(
-        std::string_view nodeId,
-        std::string_view panelId,
-        const ::XCEngine::UI::UIPoint& point,
-        ::XCEngine::UI::UIPoint& outHotspot) const = 0;
-    virtual UIEditorDockHostTabDropTarget ResolveDockTabDropTarget(
-        const ::XCEngine::UI::UIPoint& point) const = 0;
-};
-
-class EditorWindowInputFeedbackBinding {
-public:
-    virtual ~EditorWindowInputFeedbackBinding() = default;
-
-    virtual bool HasHostedContentCapture() const = 0;
-    virtual bool HasShellInteractiveCapture() const = 0;
-    virtual bool HasInteractiveCapture() const = 0;
-    virtual EditorWindowContentCursorKind GetHostedContentCursorKind() const = 0;
-    virtual EditorWindowContentCursorKind GetDockCursorKind() const = 0;
-};
-
-class EditorWindowTitleBarBinding {
-public:
-    virtual ~EditorWindowTitleBarBinding() = default;
-
-    virtual bool ShouldUseDetachedTitleBarTabStrip() const = 0;
-    virtual std::string ResolveTabStripTitleText(std::string_view fallbackTitle) const = 0;
-    virtual std::string ResolveDetachedWindowTitleText(
-        std::string_view fallbackWindowTitle) const = 0;
-};
-
 struct EditorWindowContentInitializationContext {
     const std::filesystem::path& repoRoot;
     EditorContext& editorContext;

editor/app/Windowing/EditorWindowInstance.cpp

@@ -1,7 +1,7 @@
 #include "Windowing/EditorWindowInstance.h"
 
 #include "Support/StringEncoding.h"
-#include "Windowing/Content/EditorWindowContentController.h"
+#include "Windowing/Host/EditorWindowContentBindings.h"
 #include "Windowing/Runtime/EditorWindowRuntimeController.h"
 
 #include <XCEditor/Docking/UIEditorDockHostTransfer.h>

editor/app/Windowing/Host/EditorWindowContentBindings.h

@@ -0,0 +1,77 @@
+#pragma once
+
+#include <XCEditor/Docking/UIEditorDockHostTransfer.h>
+#include <XCEditor/Windowing/Presentation/EditorWorkspaceWindowProjection.h>
+
+#include <cstdint>
+#include <string>
+#include <string_view>
+
+namespace XCEngine::UI {
+
+struct UIPoint;
+
+} // namespace XCEngine::UI
+
+namespace XCEngine::UI::Editor {
+
+namespace Widgets {
+struct UIEditorDockHostDropPreviewState;
+}
+
+} // namespace XCEngine::UI::Editor
+
+namespace XCEngine::UI::Editor::App {
+
+enum class EditorWindowContentCursorKind : std::uint8_t {
+    Arrow = 0,
+    ResizeEW,
+    ResizeNS,
+};
+
+class EditorWindowWorkspaceBinding {
+public:
+    virtual ~EditorWindowWorkspaceBinding() = default;
+
+    virtual const EditorWorkspaceWindowProjection* TryGetWorkspaceProjection() const = 0;
+    virtual void RefreshWorkspaceProjection(EditorWorkspaceWindowProjection projection) = 0;
+};
+
+class EditorWindowDockHostBinding {
+public:
+    virtual ~EditorWindowDockHostBinding() = default;
+
+    virtual void SetExternalDockHostDropPreview(
+        const Widgets::UIEditorDockHostDropPreviewState& preview) = 0;
+    virtual void ClearExternalDockHostDropPreview() = 0;
+    virtual bool TryResolveDockTabDragHotspot(
+        std::string_view nodeId,
+        std::string_view panelId,
+        const ::XCEngine::UI::UIPoint& point,
+        ::XCEngine::UI::UIPoint& outHotspot) const = 0;
+    virtual UIEditorDockHostTabDropTarget ResolveDockTabDropTarget(
+        const ::XCEngine::UI::UIPoint& point) const = 0;
+};
+
+class EditorWindowInputFeedbackBinding {
+public:
+    virtual ~EditorWindowInputFeedbackBinding() = default;
+
+    virtual bool HasHostedContentCapture() const = 0;
+    virtual bool HasShellInteractiveCapture() const = 0;
+    virtual bool HasInteractiveCapture() const = 0;
+    virtual EditorWindowContentCursorKind GetHostedContentCursorKind() const = 0;
+    virtual EditorWindowContentCursorKind GetDockCursorKind() const = 0;
+};
+
+class EditorWindowTitleBarBinding {
+public:
+    virtual ~EditorWindowTitleBarBinding() = default;
+
+    virtual bool ShouldUseDetachedTitleBarTabStrip() const = 0;
+    virtual std::string ResolveTabStripTitleText(std::string_view fallbackTitle) const = 0;
+    virtual std::string ResolveDetachedWindowTitleText(
+        std::string_view fallbackWindowTitle) const = 0;
+};
+
+} // namespace XCEngine::UI::Editor::App