Bug 84314 [Viewers] Need to allow mapping elements to multiple widgets/items
One of the projects I am working on is using an essentially graph structured dependancy model and we use TableTreeViewer for browsing (drilling down) through this graph. The nature of the model is such that the same model element can occur in multiple positions (paths) of the three. Current implementation of the TreeViewer and TableTreeViewer do not support such one-to-many mapping of model elements to widgets, leading to loads of unnecessary overhead to enshure that correct items will get updated. Suggestion: Element -> Item mapper should allow returning of more than one item per model element that is associated with this element.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
*/
    public void removeTreeListener(ITreeViewerListener listener) {
        treeListeners.remove(listener);
    }
    
    public void reveal(Object element) {
        Assert.isNotNull(element);
        Widget w = internalExpand(element, true);
        if (w instanceof Item)
            showItem((Item) w);
    }
    /**
     * Returns the rightmost visible descendent of the given item. Returns the
     * item itself if it has no children.
     * 
     * @param item
     *           the item to compute the descendent of
     * @return the rightmost visible descendent or the item iself if it has no
     *         children
     */
    private Item rightMostVisibleDescendent(Item item) {
        Item[] children = getItems(item);
        if (getExpanded(item) && children != null && children.length > 0) {
            return rightMostVisibleDescendent(children[children.length - 1]);
        }
        return item;
    }
    
    public Item scrollDown(int x, int y) {
        Item current = getItem(x, y);