Add key viewer
diff --git a/src/key-tree-model.hpp b/src/key-tree-model.hpp
new file mode 100644
index 0000000..4cb72ce
--- /dev/null
+++ b/src/key-tree-model.hpp
@@ -0,0 +1,80 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2014, Regents of the University of California,
+ *
+ * This file is part of NFD Control Center.  See AUTHORS.md for complete list of NFD
+ * authors and contributors.
+ *
+ * NFD Control Center 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.
+ *
+ * NFD Control Center 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 NFD
+ * Control Center, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NDN_NCC_KEY_TREE_MODEL_HPP
+#define NDN_NCC_KEY_TREE_MODEL_HPP
+
+#include <QAbstractItemModel>
+#include <QModelIndex>
+#include <QVariant>
+
+namespace ndn {
+namespace ncc {
+
+class KeyTreeItem;
+
+class KeyTreeModel : public QAbstractItemModel
+{
+  Q_OBJECT
+
+public:
+  explicit
+  KeyTreeModel(QObject* parent = 0);
+
+  ~KeyTreeModel();
+
+  void
+  clear();
+
+  void
+  addChild(KeyTreeItem* child);
+
+  QVariant
+  name(const QModelIndex& index, int role) const;
+
+  QVariant
+  data(const QModelIndex& index, int role) const Q_DECL_OVERRIDE;
+
+  Qt::ItemFlags
+  flags(const QModelIndex& index) const Q_DECL_OVERRIDE;
+
+  QVariant
+  headerData(int section, Qt::Orientation orientation,
+             int role = Qt::DisplayRole) const Q_DECL_OVERRIDE;
+
+  QModelIndex
+  index(int row, int column, const QModelIndex& parent = QModelIndex()) const Q_DECL_OVERRIDE;
+
+  QModelIndex
+  parent(const QModelIndex& index) const Q_DECL_OVERRIDE;
+
+  int
+  rowCount(const QModelIndex& parent = QModelIndex()) const Q_DECL_OVERRIDE;
+
+  int
+  columnCount(const QModelIndex& parent = QModelIndex()) const Q_DECL_OVERRIDE;
+
+private:
+  KeyTreeItem* m_rootItem;
+};
+
+} // namespace ncc
+} // namespace ndn
+
+#endif // NDN_NCC_KEY_TREE_MODEL_HPP