public class ExampleView extends ViewPart   { ... public void createPartControl(Composite parent)   { // define a grid layout   GridLayout layout = new GridLayout();   layout.numColumns = 1;   layout.marginHeight = 0;   layout.marginWidth = 0; l  ayout.horizontalSpacing = 0;   layout.verticalSpacing = 1;   parent.setLayout(layout);   // create widgets createActionBar(parent);   createTree(parent);   // add context menu and listeners  viewer.addDoubleClickListener(this); viewer.addSelectionChangedListener(openAction);   // register viewer so actions respond to selection getSite().setSelectionPRovider(viewer);   hookContextMenu();   }  private void createTree(Composite parent)   {   viewer = new TreeViewer(parent, SWT.SINGLE  SWT.H_SCROLL  SWT.V_SCROLL  SWT.BORDER);  viewer.setContentProvider(new ExampleViewContentProvider()); viewer.setLabelProvider  (new ExampleViewLabelProvider());   viewer.setSorter(new ViewerSorter());   viewer.setInput(ModelManager.getExampleModel());   viewer.getControl().setLayoutData(new GridData(GridData.FILL_BOTH));   } ... }