Fix UI document host input integration build

engine/include/XCEngine/UI/Runtime/UIScreenDocumentHost.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <XCEngine/UI/Input/UIInputDispatcher.h>
 #include <XCEngine/UI/Runtime/UIScreenTypes.h>
 
 #include <cstdint>
@@ -22,6 +23,20 @@ public:
 
 class UIDocumentScreenHost final : public IUIScreenDocumentHost {
 public:
+    struct InputDebugSnapshot {
+        std::uint64_t totalPointerEventCount = 0u;
+        UIPoint pointerPosition = {};
+        bool pointerInsideViewport = false;
+        std::string hoveredStateKey = {};
+        std::string focusedStateKey = {};
+        std::string activeStateKey = {};
+        std::string captureStateKey = {};
+        std::string lastEventType = {};
+        std::string lastTargetStateKey = {};
+        std::string lastTargetKind = {};
+        std::string lastResult = {};
+    };
+
     struct ScrollDebugSnapshot {
         std::uint64_t totalWheelEventCount = 0u;
         std::uint64_t handledWheelEventCount = 0u;
@@ -42,10 +57,20 @@ public:
     UIScreenFrameResult BuildFrame(
         const UIScreenDocument& document,
         const UIScreenFrameInput& input) override;
+    const InputDebugSnapshot& GetInputDebugSnapshot() const;
     const ScrollDebugSnapshot& GetScrollDebugSnapshot() const;
 
 private:
+    struct PointerState {
+        UIPoint position = {};
+        bool hasPosition = false;
+        bool insideViewport = false;
+    };
+
+    UIInputDispatcher m_inputDispatcher;
     std::unordered_map<std::string, float> m_verticalScrollOffsets = {};
+    PointerState m_pointerState = {};
+    InputDebugSnapshot m_inputDebugSnapshot = {};
     ScrollDebugSnapshot m_scrollDebugSnapshot = {};
 };