Bug 136256 Enhance the message builder
Please see the spec attached in 133995 for detail.
UI/org.eclipse.birt.report.designer.ui.lib.explorer/src/org/eclipse/birt/report/designer/ui/lib/explorer/LibraryExplorerTreeViewPage.java
/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.validators.IValidationListener#elementValidated(org.eclipse.birt.report.model.api.DesignElementHandle,
	 *      org.eclipse.birt.report.model.api.validators.ValidationEvent)
	 */
	public void elementValidated( DesignElementHandle targetElement,
			ValidationEvent ev )
	{
		treeViewer.refresh( );
	}
	private void refreshRoot( )
	{
		treeViewer.setInput( libraryProvider.getLibraries( ) );
	}
	public void setLibraryProvider( ILibraryProvider provider )
	{
		this.libraryProvider = provider;
	}
	public void preferenceChange( PreferenceChangeEvent event )
	{
		if ( ReportPlugin.LIBRARY_PREFERENCE.equals( event.getKey( ) ) )
			Display.getDefault( ).asyncExec( new Runnable( ) {
				public void run( )
				{
					refreshRoot( );
				}
			} );
	}
}