Bug 156537 [Viewers] Virtual tree viewer does not populate with initial children
I20060830-1650 When a tree viewer is created with the SWT.Vitrual flag and uses an ILazyTreeContentProvider, the viewew does not populate with the initial children in the model. The method TreeViewer.createChildren(Widget) only updates existing items if the parent (root)element has been mapped to data, and does not query the content provider for the number of children it has. Attached is a sample plug-in showing the problem. The tree "model" looks like this: root one two three When the input is set to the viewer ("root") a call is made to "createChildren", but the content provider is never used.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
}
			return tpcp.hasChildren(path);
		}
		if (cp instanceof ITreeContentProvider) {
			ITreeContentProvider tcp = (ITreeContentProvider) cp;
			return tcp.hasChildren(element);
		}
		return false;
	}
	/**
	 * Return whether the given element is expandable.
	 * 
	 * @param item
	 *            the tree item for the element
	 * @param parentPath
	 *            the parent path if it is knwon or <code>null</code> if it
	 *            needs to be determines
	 * @param element
	 *            the element
	 * @return whether the given element is expandable
	 */
	private boolean isExpandable(Item item, TreePath parentPath, Object element) {
		if (isTreePathContentProvider()) {
			TreePath path;
			if (parentPath != null) {
				path = parentPath.createChildPath(element);
			} else {
				path = getTreePathFromItem(item);
			}
			ITreePathContentProvider cp = (ITreePathContentProvider) getContentProvider();