From a3f87785f5bec1d7a8b7d5f460fb09a78dabc4ca Mon Sep 17 00:00:00 2001
From: Denes Matetelki <denes.matetelki@gmail.com>
Date: Tue, 14 Jun 2011 11:45:41 +0200
Subject: [PATCH] last node cannot be deleted

---
 graphwidget.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/graphwidget.cpp b/graphwidget.cpp
index cec0084..3f06f5d 100644
--- a/graphwidget.cpp
+++ b/graphwidget.cpp
@@ -331,6 +331,14 @@ void GraphWidget::keyPressEvent(QKeyEvent *event)
 
          if (m_activeNode)
          {
+             if (m_nodeList.size()==1)
+             {
+                 dynamic_cast<MainWindow *>(m_parent)->getStatusBar()->showMessage(
+                             tr("Last node cannot be deleted."),
+                             5000); // millisec
+                  break;
+             }
+
              if (m_hintNode==m_activeNode)
                  m_hintNode=0;