Bug 122756 [Viewers] Support for TreePath based content providers
Now that the JFace tree viewer supports the notion of a tree path, it would be benefitial if this information was made available to content providers and label providers. The particular scenario that requires this is team views that include change sets. A view can display multiple change sets and a single model element may be included in multiple change sets. In 3.2, we are using the common navigator framework to allow model providers to display their models in a team operation. Having a tree path based content provider would allow the logical model display to be intermixed with change sets. Without this support, team providers would most likely need to support two views, one which shows resources and change sets and another that shows the effects of the operation on the logical model.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
Assert.isNotNull(parentElement);
        assertElementsNotNull(childElements);
        Widget[] widgets = findItems(parentElement);
        
        if (widgets.length == 0)
            return;
		for (int i = 0; i < widgets.length; i++) {
			internalAdd(widgets[i], parentElement, childElements);
		}        
    }
	/**
     * Adds the given child elements to this viewer as children of the given
     * parent element.
     * <p>
     * EXPERIMENTAL.  Not to be used except by JDT.
     * This method was added to support JDT's explorations
     * into grouping by working sets, which requires viewers to support multiple 
     * equal elements.  See bug 76482 for more details.  This support will
     * likely be removed in Eclipse 3.2 in favour of proper support for
     * multiple equal elements. 
     * </p>
     *
     * @param widget 
     *           the widget for the parent element
     * @param parentElement
     *           the parent element
     * @param childElements
     *           the child elements to add
     * @since 3.1
     */