3 files changed, 127 insertions, 0 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt
index dc62b75..04af853 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -146,6 +146,7 @@ ADD_LIBRARY(ousia_core
 	src/core/model/Index
 	src/core/model/Node
 	src/core/model/Project
+	src/core/model/RootNode
 	src/core/model/Style
 	src/core/model/Typesystem
 	src/core/parser/Parser
diff --git a/src/core/model/RootNode.cpp b/src/core/model/RootNode.cpp
new file mode 100644
index 0000000..fa05c36
--- /dev/null
+++ b/src/core/model/RootNode.cpp
@@ -0,0 +1,41 @@
+/*
+    Ousía
+    Copyright (C) 2014, 2015  Benjamin Paaßen, Andreas Stöckel
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <core/common/RttiBuilder.hpp>
+
+#include "RootNode.hpp"
+
+namespace ousia {
+
+void RootNode::import(Handle<Node> node)
+{
+	if (!node->type().isOneOf(doGetImportTypes())) {
+		throw OusiaException(
+		    std::string("Node with type ") + node->type().name +
+		    std::string(" cannot be imported in a ") + type().name);
+	}
+	doImport(node);
+}
+
+RttiSet RootNode::getImportTypes() { return doGetImportTypes(); }
+
+namespace RttiTypes {
+const Rtti RootNode = RttiBuilder<ousia::RootNode>("RootNode").parent(&Node);
+}
+}
+
diff --git a/src/core/model/RootNode.hpp b/src/core/model/RootNode.hpp
new file mode 100644
index 0000000..1ed72f1
--- /dev/null
+++ b/src/core/model/RootNode.hpp
@@ -0,0 +1,85 @@
+/*
+    Ousía
+    Copyright (C) 2014, 2015  Benjamin Paaßen, Andreas Stöckel
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file RootNode.hpp
+ *
+ * Defines a base class for Nodes that may act as a root and thus are capable of
+ * importing other nodes.
+ *
+ * @author Andreas Stöckel (astoecke@techfk.uni-bielefeld.de)
+ */
+
+#ifndef _OUSIA_ROOT_NODE_HPP_
+#define _OUSIA_ROOT_NODE_HPP_
+
+#include "Node.hpp"
+
+namespace ousia {
+
+/**
+ * The RootNode class represents a Node that may be a Root node (such as
+ * Documents, Typesystems and Domains). Root nodes have the property, that the
+ * allow importing/referencing other Nodes.
+ */
+class RootNode : public Node {
+protected:
+	/**
+	 * Imports the given node. The node was checked to be one of the supported
+	 * types.
+	 *
+	 * @param node is the node that should be imported.
+	 */
+	virtual void doImport(Handle<Node> node) = 0;
+
+	/**
+	 * Should return a set of types that can be imported by this Node.
+	 *
+	 * @return a set of Node types that may be imported by this Node.
+	 */
+	virtual RttiSet doGetImportTypes() = 0;
+
+public:
+	using Node::Node;
+
+	/**
+	 * Tries to import the given node. Throws an exception if the node is not of
+	 * the supported types.
+	 *
+	 * @param node is the node that should be imported.
+	 */
+	void import(Handle<Node> node);
+
+	/**
+	 * Returns a set of types that can be imported by this Node.
+	 *
+	 * @return a set of types that can be imported.
+	 */
+	RttiSet getImportTypes();
+};
+
+namespace RttiTypes {
+/**
+ * Rtti descriptor for the RootNode class.
+ */
+extern const Rtti RootNode;
+}
+}
+
+#endif /* _OUSIA_ROOT_NODE_HPP_ */
+