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
protected void addSelectionListener(Control control,
            SelectionListener listener) {
        
    }
    /**
     * Adds a listener for expand and collapse events in this viewer. Has no
     * effect if an identical listener is already registered.
     * 
     * @param listener
     *           a tree viewer listener
     */
    public void addTreeListener(ITreeViewerListener listener) {
        treeListeners.add(listener);
    }
    /**
     * Adds the given SWT tree listener to the given SWT control.
     * 
     * @param control
     *           the SWT control
     * @param listener
     *           the SWT tree listener
     */
    protected abstract void addTreeListener(Control control,
            TreeListener listener);
    
    protected void associate(Object element, Item item) {
        Object data = item.getData();
        if (data != null && data != element && equals(data, element)) {