Add XCUI core scroll view validation in new_editor

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

@@ -2,6 +2,10 @@
 
 #include <XCEngine/UI/Runtime/UIScreenTypes.h>
 
+#include <cstdint>
+#include <string>
+#include <unordered_map>
+
 namespace XCEngine {
 namespace UI {
 namespace Runtime {
@@ -18,10 +22,31 @@ public:
 
 class UIDocumentScreenHost final : public IUIScreenDocumentHost {
 public:
+    struct ScrollDebugSnapshot {
+        std::uint64_t totalWheelEventCount = 0u;
+        std::uint64_t handledWheelEventCount = 0u;
+        UIPoint lastPointerPosition = {};
+        UIRect lastViewportRect = {};
+        UIRect primaryViewportRect = {};
+        float lastWheelDelta = 0.0f;
+        float lastOverflow = 0.0f;
+        float lastOffsetBefore = 0.0f;
+        float lastOffsetAfter = 0.0f;
+        float primaryOverflow = 0.0f;
+        std::string lastTargetStateKey = {};
+        std::string primaryTargetStateKey = {};
+        std::string lastResult = {};
+    };
+
     UIScreenLoadResult LoadScreen(const UIScreenAsset& asset) override;
     UIScreenFrameResult BuildFrame(
         const UIScreenDocument& document,
         const UIScreenFrameInput& input) override;
+    const ScrollDebugSnapshot& GetScrollDebugSnapshot() const;
+
+private:
+    std::unordered_map<std::string, float> m_verticalScrollOffsets = {};
+    ScrollDebugSnapshot m_scrollDebugSnapshot = {};
 };
 
 } // namespace Runtime