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
*/
    protected void fireTreeExpanded(final TreeExpansionEvent event) {
        Object[] listeners = treeListeners.getListeners();
        for (int i = 0; i < listeners.length; ++i) {
            final ITreeViewerListener l = (ITreeViewerListener) listeners[i];
            SafeRunnable.run(new SafeRunnable() {
                public void run() {
                    l.treeExpanded(event);
                }
            });
        }
    }
    /**
     * Returns the auto-expand level.
     * 
     * @return non-negative level, or <code>ALL_LEVELS</code> if all levels
     *         of the tree are expanded automatically
     * @see #setAutoExpandLevel
     */
    public int getAutoExpandLevel() {
        return expandToLevel;
    }
    /**
     * Returns the SWT child items for the given SWT widget.
     * 
     * @param widget
     *           the widget
     * @return the child items
     */
    protected abstract Item[] getChildren(Widget widget);