Bug 122869 Drag a parameter from data explorer view into a table in library, a new parameter is created automatically.
Description:Drag a parameter from data explorer view into a table in library, a new parameter is created automatically. Steps to reproduce: 1. Add a cascading parameter and a table in a library file. 2. Drag a parameter from data explorer view into a table cell in layout editor. 3. Find that a new parameter was added in data explorer view automatically.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ExpressionBuilder.java
CompositeRuler ruler = new CompositeRuler( );
		ruler.addDecorator( 0, new LineNumberRulerColumn( ) );
		sourceViewer = new SourceViewer( composite, ruler, SWT.H_SCROLL
				| SWT.V_SCROLL );
		JSSyntaxContext context = new JSSyntaxContext( );
		try
		{
			context.setVariable( IReportGraphicConstants.REPORT_KEY_WORD,
					IReportDesign.class ); 
		}
		catch ( ClassNotFoundException e )
		{
		}
		sourceViewer.configure( new JSSourceViewerConfiguration( context ) );
		
		
		
		if ( expression != null )
		{
			JSEditorInput editorInput = new JSEditorInput( expression );
			JSDocumentProvider documentProvider = new JSDocumentProvider( );
			try
			{
				documentProvider.connect( editorInput );
			}
			catch ( CoreException e )
			{
				ExceptionHandler.handle( e );
			}
			IDocument document = documentProvider.getDocument( editorInput );