Attachment 220635 Details for Bug 388628 – Code reproducing the problem

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Code reproducing the problem

LazyTreeViewerGetSelectionNPE.java (text/x-java), 4.09 KB, created by Missing name

on 2012-09-02 12:38:26 EDT

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Filename:

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Creator: Missing name

Created: 2012-09-02 12:38:26 EDT

Size: 4.09 KB

patch

obsolete

>package swt;
>
>import java.util.HashMap;
>import java.util.Map;
>
>import org.eclipse.jface.viewers.ILazyTreeContentProvider;
>import org.eclipse.jface.viewers.OwnerDrawLabelProvider;
>import org.eclipse.jface.viewers.TreeViewer;
>import org.eclipse.jface.viewers.Viewer;
>import org.eclipse.jface.viewers.ViewerCell;
>import org.eclipse.swt.SWT;
>import org.eclipse.swt.events.SelectionAdapter;
>import org.eclipse.swt.events.SelectionEvent;
>import org.eclipse.swt.layout.FillLayout;
>import org.eclipse.swt.widgets.Button;
>import org.eclipse.swt.widgets.Display;
>import org.eclipse.swt.widgets.Event;
>import org.eclipse.swt.widgets.Shell;
>
>public class LazyTreeViewerGetSelectionNPE {
>	
>	private static class Element {
>		final String name;
>		final Element parent;
>
>		Element (Element parent, String name) {
>			this.parent = parent;
>			this.name = name;
>		}
>		String getName() {
>			return name;
>		}
>		@Override
>		public String toString() {
>			return (parent == null ? "" : parent.toString()) + "/" + getName();
>		}
>		@Override
>		public boolean equals(Object o) {
>			if ( ! (o instanceof Element)) return false;
>			Element other = (Element) o;
>			return other.name.equals(name) && 
>					(other.parent == null && parent == null ||
>					other.parent != null && other.parent.equals(parent));
>		}
>		@Override
>		public int hashCode() {
>			return (parent == null ? 0 : parent.hashCode()) ^ 
>					name.hashCode();
>		}
>	}
>
>	private static Map<Element, Integer> element2nChildren = 
>			new HashMap<Element, Integer>();
>
>	private static class ContentProvider implements ILazyTreeContentProvider {
>		private final TreeViewer viewer;
>
>		public ContentProvider(TreeViewer viewer) {
>			this.viewer = viewer;
>		}
>		public void dispose() {
>		}
>
>		public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
>		}
>
>		public void updateElement(Object parent, int index) {
>			Element element = new Element(
>					(Element) parent, String.valueOf(index));
>			viewer.replace(parent, index, element);
>			updateChildCount(element);
>		}
>
>		public void updateChildCount(Object element, int currentChildCount) {
>			updateChildCount(element);
>		}
>		
>		private void updateChildCount(Object element) {
>			int nChildren = element2nChildren.containsKey(element)
>					? element2nChildren.get(element)
>					: 0;
>			viewer.setChildCount(element, nChildren);
>		}
>
>		public Object getParent(Object element) {
>			return ((Element)element).parent;
>		}
>		
>	}
>
>	private static class ODLabelProvider extends OwnerDrawLabelProvider {
>		@Override
>		public void update(ViewerCell cell) {
>			cell.setText(((Element)cell.getElement()).toString());
>		}
>
>		@Override
>		protected void measure(Event event, Object element) {
>		}
>
>		@Override
>		protected void paint(Event event, Object element) {
>		}
>	}
>	
>	public static void main (String [] args) {
>		final Display display = new Display();
>		final Shell shell = new Shell(display);
>
>		final TreeViewer viewer = new TreeViewer(shell, SWT.VIRTUAL);
>		viewer.setContentProvider(new ContentProvider(viewer));
>		viewer.setLabelProvider(new ODLabelProvider());
>		// Using a non-owner-draw LabelProvider works around the bug
>		//viewer.setLabelProvider(new LabelProvider());
>		
>		viewer.setUseHashlookup(true);
>		
>		final Element root = new Element(null, "root");
>		element2nChildren.put(root, 2);
>		element2nChildren.put(new Element(root,"1"), 1);
>		
>		viewer.setInput(root);
>
>		Button button = new Button(shell, SWT.NONE);
>		button.setText("Remove second item");
>		button.addSelectionListener(new SelectionAdapter() {
>			@Override
>			public void widgetSelected(SelectionEvent e) {
>				element2nChildren.put(root,1);
>
>				// calling collapseAll works around this bug
>				//viewer.collapseAll();
>				
>				// removing the selection programmatically doesn't help:
>				//viewer.setSelection(TreeSelection.EMPTY);
>				
>				viewer.refresh(root);
>			};
>		});
>
>		shell.setLayout(new FillLayout());
>		shell.layout();
>		shell.open ();
>		while (!shell.isDisposed ()) {
>			if (!display.readAndDispatch ()) display.sleep ();
>		}
>		display.dispose ();
>	}
>
>}

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Attachments on bug 388628: 220635