gistfile1.java

public void createPartControl(Composite parent) {
	Tree myTree = new Tree(parent, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);
	myTree.setHeaderVisible(true);

	myTreeViewer = new TreeViewer(executionTree);
	myTreeViewer.setLabelProvider(new MyLabelProvider());
	myTreeViewer.setContentProvider(new ContentProvider());
	myTreeViewer..setInput(MyDataStore.getInstance());


	MyDataStore.addObserver(new Observer() {
		@Override
		public void update(Observable o, Object arg) {
			Display.getDefault().asyncExec(new Runnable() {
				public void run() {
					myTreeViewer.refresh();
				}
			});
		}
	}
}