Bug 175664 [Mac] Unexpected internal exception occurs when invoke expression builder
Description: There are two problems: 1. "fx" button (Click this button to invoke Expression Builder) could not be displayed correctly, nothing displayed in the button. 2. Click on the button, an unexpected internal exception occurs. Version:2.2.0.v20070205 Steps to reproduce: 1.Insert a Data item to the layout. Click "fx" button to invoke the expression builder, although on Mac "fx" button could not display correctly. Error log: Argument cannot be null Plug-in Provider: Eclipse.org Plug-in Name: BIRT Designer UI Plug-in ID: org.eclipse.birt.report.designer.ui Error Code: Error.GUIException.invokedByUnexpectedException Error Message:Argument cannot be null
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/util/UIUtil.java
* Returns the name for the file
	 * 
	 * @param filePath
	 *            the full path of the file
	 * @return Returns the name of the file
	 */
	public static String getSimpleFileName( String filePath )
	{
		return new File( filePath ).getName( );
	}
	/**
	 * Returns the namespace of the library for inculde
	 * 
	 * @param handle
	 *            the module handle to include the library
	 * @param libraryPath
	 *            the full path of the library file to include
	 * @return the namespace used to include, or null if the user cancels this
	 *         operator
	 */
	private static String getLibraryNamespace( ModuleHandle handle,
			String libraryPath )
	{
		String namespace = getSimpleFileName( libraryPath ).split( "\\." )[0]; 
		if ( handle.getLibrary( namespace ) != null )
		{
			ImportLibraryDialog dialog = new ImportLibraryDialog( namespace );
			if ( dialog.open( ) == Dialog.OK )
			{
				namespace = (String) dialog.getResult( );