add convenience filter method for session model top items

GUI/coregui/Models/SessionModel.h

@@ -97,6 +97,8 @@ public:
     //! Returns first item in list of topItems
     template <typename T = SessionItem> T* topItem() const;
     template <typename T = SessionItem> QVector<T*> topItems() const;
+    template <typename T = SessionItem>
+    QVector<T*> topItems(std::function<bool(const T&)> accept) const;
 
     virtual void initFrom(SessionModel* model, SessionItem* parent);
     SessionItem* rootItem() const;
@@ -156,6 +158,21 @@ template <typename T> QVector<T*> SessionModel::topItems() const
     return result;
 }
 
+template <typename T> QVector<T*> SessionModel::topItems(std::function<bool(const T&)> accept) const
+{
+    QVector<T*> result;
+
+    QModelIndex parentIndex;
+    for (int i_row = 0; i_row < rowCount(parentIndex); ++i_row) {
+        QModelIndex itemIndex = index(i_row, 0, parentIndex);
+        if (auto item = dynamic_cast<T*>(itemForIndex(itemIndex)))
+            if (accept(*item))
+                result.push_back(item);
+    }
+
+    return result;
+}
+
 inline bool SessionModel::setHeaderData(int, Qt::Orientation, const QVariant&, int)
 {
     return false;