Graph panel ingores rotate (shift + mouse drag)

I was working with a graph panel. There were some input, switching between modes, adding and collapsing nodes and so on. And suddenly the panel started to ignore shift + mouse drag event. Drag without shift works normally - the graph is moved. But when I try to rotate it with shift + mouse drag nothing happens. And plenty of stack traces is written to the stderr. They all are identical and complains about Null Pointer Exception.
I could not reproduce this behabior. Newly created graph panels works normally.
- Code: Select all
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at org.wandora.application.gui.topicpanels.graphpanel.mousetools.RotateMouseTool.mouseDragged(RotateMouseTool.java:73)
at org.wandora.application.gui.topicpanels.graphpanel.MouseToolManager.dispatchEvent(MouseToolManager.java:138)
at org.wandora.application.gui.topicpanels.graphpanel.MouseToolManager.processEvent(MouseToolManager.java:151)
at org.wandora.application.gui.topicpanels.graphpanel.MouseToolManager.mouseDragged(MouseToolManager.java:198)
at org.wandora.application.gui.topicpanels.graphpanel.TopicMapGraphPanel.mouseDragged(TopicMapGraphPanel.java:1215)
at java.awt.Component.processMouseMotionEvent(Component.java:6564)
at javax.swing.JComponent.processMouseMotionEvent(JComponent.java:3330)
at java.awt.Component.processEvent(Component.java:6285)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4872)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4509)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:740)
at java.awt.EventQueue.access$300(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:699)
at java.awt.EventQueue$3.run(EventQueue.java:697)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:713)
at java.awt.EventQueue$4.run(EventQueue.java:711)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:710)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
I could not reproduce this behabior. Newly created graph panels works normally.