Bug 159550 [Viewers] Deprecate TableTreeViewer
The underlying SWT-controls of TableTreeViewer (TableTree,TableTreeItem,TableTreeEditor) are deprecated and so should TableTreeViewer I think.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TableTreeViewer.java
/* (non-Javadoc)
     * Method declared on StructuredViewer.
     */
    protected Item getItem(int x, int y) {
        
        return getTableTree().getTable().getItem(
                getTableTree().toControl(new Point(x, y)));
    }
    /* (non-Javadoc)
     * Method declared on AbstractTreeViewer.
     */
    protected int getItemCount(Control widget) {
        return ((TableTree) widget).getItemCount();
    }
    /* (non-Javadoc)
     * Method declared on AbstractTreeViewer.
     */
    protected int getItemCount(Item item) {
        return ((TableTreeItem) item).getItemCount();
    }
    /* (non-Javadoc)
     * Method declared on AbstractTreeViewer.
     */
    protected org.eclipse.swt.widgets.Item[] getItems(
            org.eclipse.swt.widgets.Item item) {
        return ((TableTreeItem) item).getItems();
    }
    /**
     * The table tree viewer implementation of this <code>Viewer</code> framework
     * method returns the label provider, which in the case of table tree