Add XCUI expansion state and coverage tests

engine/src/UI/Widgets/UIEditorCollectionPrimitives.cpp

@@ -64,6 +64,7 @@ bool UsesUIEditorCollectionPrimitiveColumnLayout(UIEditorCollectionPrimitiveKind
 bool IsUIEditorCollectionPrimitiveHoverable(UIEditorCollectionPrimitiveKind kind) {
     return kind == UIEditorCollectionPrimitiveKind::TreeItem ||
         kind == UIEditorCollectionPrimitiveKind::ListItem ||
+        kind == UIEditorCollectionPrimitiveKind::PropertySection ||
         kind == UIEditorCollectionPrimitiveKind::FieldRow;
 }
 

engine/src/UI/Widgets/UIExpansionModel.cpp

@@ -0,0 +1,57 @@
+#include <XCEngine/UI/Widgets/UIExpansionModel.h>
+
+#include <utility>
+
+namespace XCEngine {
+namespace UI {
+namespace Widgets {
+
+bool UIExpansionModel::HasExpandedItems() const {
+    return !m_expandedIds.empty();
+}
+
+std::size_t UIExpansionModel::GetExpandedCount() const {
+    return m_expandedIds.size();
+}
+
+bool UIExpansionModel::IsExpanded(std::string_view id) const {
+    return m_expandedIds.contains(std::string(id));
+}
+
+bool UIExpansionModel::SetExpanded(std::string itemId, bool expanded) {
+    return expanded
+        ? Expand(std::move(itemId))
+        : Collapse(std::move(itemId));
+}
+
+bool UIExpansionModel::Expand(std::string itemId) {
+    return m_expandedIds.insert(std::move(itemId)).second;
+}
+
+bool UIExpansionModel::Collapse(std::string itemId) {
+    return m_expandedIds.erase(itemId) > 0u;
+}
+
+bool UIExpansionModel::ToggleExpanded(std::string itemId) {
+    const auto it = m_expandedIds.find(itemId);
+    if (it != m_expandedIds.end()) {
+        m_expandedIds.erase(it);
+        return true;
+    }
+
+    m_expandedIds.insert(std::move(itemId));
+    return true;
+}
+
+bool UIExpansionModel::Clear() {
+    if (m_expandedIds.empty()) {
+        return false;
+    }
+
+    m_expandedIds.clear();
+    return true;
+}
+
+} // namespace Widgets
+} // namespace UI
+} // namespace XCEngine