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
protected Widget doFindItem(Object element) {
		
		Object root = getRoot();
		if (root == null) {
			return null;
		}
		Item[] items = getChildren(getControl());
		if (items != null) {
			for (int i = 0; i < items.length; i++) {
				Widget o = internalFindItem(items[i], element);
				if (o != null) {
					return o;
				}
			}
		}
		return null;
	}
	/**
	 * Copies the attributes of the given element into the given SWT item.
	 * 
	 * @param item
	 *            the SWT item
	 * @param element
	 *            the element
	 */
	protected abstract void doUpdateItem(Item item, Object element);
	
	protected void doUpdateItem(Widget widget, Object element, boolean fullMap) {
		if (widget instanceof Item) {