Nullpointerexception

When I put run.args.extra=-J-Dnetbeans.winsys.hideEmptyDocArea=true in my project.properties I got a NullPointerException (NPE) at startup. I though it was a bug and I reported it but then I realized that I got the NPE because I had removed/hidden also the editor.wsmode in my layer.xml ... ... <folder name="Windows2"> <folder name="Modes"> <folder name="editor_hidden"/> <file name="editor.wsmode_hidden"/> </folder> </folder> ... ... As soon as I removed those entries from the layer.xml hideEmptyDocAre worked perfectly.

If you’re getting a NullPointerException stacktrace like the one below while using the Netbeans Visual Library to create your own GraphScene, check that your adding your widgets propertly to scene. A good idea is to use LayerWidgets, declaring them in the constructor of your GraphScene: mainLayer = new LayerWidget(this); addChild(mainLayer); connectionLayer = new LayerWidget(this); addChild(connectionLayer); and then add the widgets to those layers in attachNodeWidget and attachEdgeWidget: @Override protected Widget attachNodeWidget(String node) { LabelWidget w = new LabelWidget(this, node); w.setBorder(BORDER4); w.getActions().addAction(createSelectAction()); w.getActions().addAction(createObjectHoverAction()); w.getActions().addAction(ActionFactory.createMoveAction()); this.mainLayer.addChild(w); return w; } @Override protected Widget attachEdgeWidget(String edge) { ConnectionWidget w = new ConnectionWidget(this); w.setTargetAnchorShape(AnchorShape.TRIANGLE_FILLED); this.connectionLayer.addChild(w); return w; } The stacktrace: ...