Add XCUI command routing and widget state models

engine/include/XCEngine/UI/Widgets/UIKeyboardNavigationModel.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <cstddef>
+
+namespace XCEngine {
+namespace UI {
+namespace Widgets {
+
+class UIKeyboardNavigationModel {
+public:
+    static constexpr std::size_t InvalidIndex = static_cast<std::size_t>(-1);
+
+    std::size_t GetItemCount() const;
+    bool SetItemCount(std::size_t itemCount);
+    bool ClampToItemCount();
+
+    bool HasCurrentIndex() const;
+    std::size_t GetCurrentIndex() const;
+    bool SetCurrentIndex(std::size_t index, bool updateAnchor = true);
+    bool ClearCurrentIndex();
+
+    bool HasSelectionAnchor() const;
+    std::size_t GetSelectionAnchorIndex() const;
+    bool SetSelectionAnchorIndex(std::size_t index);
+    bool ClearSelectionAnchor();
+
+    bool MoveNext();
+    bool MovePrevious();
+    bool MoveHome();
+    bool MoveEnd();
+
+private:
+    std::size_t m_itemCount = 0;
+    std::size_t m_currentIndex = InvalidIndex;
+    std::size_t m_selectionAnchorIndex = InvalidIndex;
+};
+
+} // namespace Widgets
+} // namespace UI
+} // namespace XCEngine

engine/include/XCEngine/UI/Widgets/UIPropertyEditModel.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <string>
+
+namespace XCEngine {
+namespace UI {
+namespace Widgets {
+
+class UIPropertyEditModel {
+public:
+    bool HasActiveEdit() const;
+    const std::string& GetActiveFieldId() const;
+    const std::string& GetStagedValue() const;
+    bool IsDirty() const;
+
+    bool BeginEdit(std::string fieldId, std::string initialValue);
+    bool UpdateStagedValue(std::string stagedValue);
+    bool CommitEdit(
+        std::string* outFieldId = nullptr,
+        std::string* outCommittedValue = nullptr);
+    bool CancelEdit();
+
+private:
+    std::string m_activeFieldId = {};
+    std::string m_baselineValue = {};
+    std::string m_stagedValue = {};
+    bool m_dirty = false;
+};
+
+} // namespace Widgets
+} // namespace UI
+} // namespace XCEngine