Description George C. Hetrick 2003-05-15 09:43:16 EDT

In the program below, tree nodes are correctly reported as collapsed when they 
are first created, but if they are opened and closed, their state is reported 
incorrectly.

package bugs;

import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.ITreeViewerListener;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.TreeExpansionEvent;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class BugReport {
	private static ITreeContentProvider contentProvider =
		new MyContentProvider();
	private static MyLabelProvider labelProvider = new MyLabelProvider();
	private static TreeViewer treeViewer;

	private static String root = "root";
	private static String one = "one";
	private static String two = "two";
	private static String three = "three";

	static class MyLabelProvider
		extends LabelProvider
		implements ITreeViewerListener {
		public String getText(Object element) {
			return ((String) element)
				+ ((treeViewer.getExpandedState(element))
					? ":expanded"
					: ":closed");
		}
		public void treeCollapsed(TreeExpansionEvent event) {
			event.getTreeViewer().update(event.getElement(), null);
		}

		public void treeExpanded(TreeExpansionEvent event) {
			event.getTreeViewer().update(event.getElement(), null);
		}
	};

	static class MyContentProvider implements ITreeContentProvider {
		public Object[] getChildren(Object parentElement) {
			if (parentElement.equals(root))
				return new Object[] { one };
			if (parentElement.equals(one))
				return new Object[] { two };
			if (parentElement.equals(two))
				return new Object[] { three };
			return new Object[0];
		}

		public Object getParent(Object element) {
			if (element.equals(one))
				return root;
			if (element.equals(two))
				return one;
			if (element.equals(three))
				return two;
			return null;
		}

		public boolean hasChildren(Object element) {
			return element != three;
		}

		public Object[] getElements(Object inputElement) {
			return getChildren(inputElement);
		}

		public void dispose() {}

		public void inputChanged(
			Viewer viewer,
			Object oldInput,
			Object newInput) {
			}
	};

	public static void main(String[] args) {
		final Display display = Display.getDefault();
		Shell shell = new Shell(display, SWT.TITLE | SWT.ICON | 
SWT.CLOSE);
		shell.setLayout(new FillLayout());
		treeViewer = new TreeViewer(shell);
		treeViewer.addTreeListener(labelProvider);
		treeViewer.setContentProvider(contentProvider);
		treeViewer.setLabelProvider(labelProvider);
		treeViewer.setInput(root);
		shell.open();

		// start the event loop. We stop when the user has done
		// something to dispose our window.
		//
		while (!shell.isDisposed()) {
			if (!display.readAndDispatch())
				display.sleep();
		}
		display.dispose();
	}

}