getSite().setSelectionProvider( this );

public void fireSelectionChanged()
{
    final SelectionChangedEvent event = new SelectionChangedEvent( this, new StructuredSelection( this  ) );
    Object[] listeners = selectionChangedListeners.getListeners();
    for (int i = 0; i < listeners.length; ++i)
    {
        final ISelectionChangedListener l = (ISelectionChangedListener) listeners[i];
        SafeRunnable.run(new SafeRunnable() {
            public void run() {
                l.selectionChanged( event );
            }
        });
    }
}