Bug 161805 [Viewers] JFace TreeViewer collapses node when sibbling removed
3.2 1. Use the Eclipse Wizard to produce a plugin with a tree viewer view. 2. Paste the modified SampleView.java - this looks like the left part of the attached screenshot 3. Click on the top node Parent1 and type - 4. TreeViewer.remove is called to remove Parent 1. TreeViewer.refresh is called - this looks like the right part of the attached screenshot Wrong: node Parent 4 is now collapsed. Expectation Parent 4 is still expanded. Is there any workaround? Am I misusing your API? Note. The snippet is almost identical to the code generated by PDE for plugin / view / Tree Viewer. Here is the extra code in createPartControl: viewer.getTree().addKeyListener(new KeyListener() { public void keyReleased(KeyEvent e) { // TODO Auto-generated method stub } public void keyPressed(KeyEvent e) { if (e.character == '-') { TreeParent parent = (TreeParent) ((IStructuredSelection)viewer.getSelection()).toArray()[0]; parent.getParent().removeChild(parent); viewer.refresh(); } if (e.character == '+') { TreeParent parent = (TreeParent) ((IStructuredSelection)viewer.getSelection()).toArray()[0]; parent.addChild(new TreeParent(new Date().toString())); } } });
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* </p>
	 * 
	 * @param elementOrTreePath
	 *            the element or path
	 * @return <code>true</code> if the tree node representing the given
	 *         element can be expanded, or <code>false</code> if not
	 */
	public boolean isExpandable(Object elementOrTreePath) {
		Object element;
		TreePath path;
		if (elementOrTreePath instanceof TreePath) {
			path = (TreePath) elementOrTreePath;
			element = path.getLastSegment();
		} else {
			element = elementOrTreePath;
			path = null;
		}
		IContentProvider cp = getContentProvider();
		if (cp instanceof ITreePathContentProvider) {
			ITreePathContentProvider tpcp = (ITreePathContentProvider) cp;
			if (path == null) {
				
				Widget w = findItem(element);
				if (w instanceof Item) {
					Item item = (Item) w;
					path = getTreePathFromItem(item);
				}
				if (path == null) {
					path = new TreePath(new Object[] { element });
				}