String sExpr = serviceprovider.invoke( IUIServiceProvider.COMMAND_EXPRESSION, txtDefinition.getText( ), oContext, sTitle );
String sExpr = context.getUIServiceProvider( ) .invoke( IUIServiceProvider.COMMAND_EXPRESSION, txtDefinition.getText( ), context.getExtendedItem( ), sTitle );
	public void widgetSelected( SelectionEvent e )	{		if ( e.getSource( ).equals( btnBuilder ) )		{			try			{				String sExpr = serviceprovider.invoke( IUIServiceProvider.COMMAND_EXPRESSION,						txtDefinition.getText( ),						oContext,						sTitle );				txtDefinition.setText( sExpr );				query.setDefinition( sExpr );			}			catch ( ChartException e1 )			{				WizardBase.displayException( e1 );			}		}		else if ( e.getSource( ).equals( btnRuleEditor ) )		{			RuleEditorDialog editor = new RuleEditorDialog( cmpTop.getShell( ),					(Query) EcoreUtil.copy( query ),					sTitle );			if ( !editor.wasCancelled( ) )			{				query.getRules( ).addAll( editor.getRules( ) );			}		}		else if ( e.getSource( ).equals( btnFormatEditor ) )		{			FormatSpecifier formatspecifier = seriesdefinition.getFormatSpecifier( );			FormatSpecifierDialog editor = new FormatSpecifierDialog( cmpTop.getShell( ),					formatspecifier,					sTitle );			if ( !editor.wasCancelled( ) )			{				if ( editor.getFormatSpecifier( ) == null )				{					seriesdefinition.eUnset( DataPackage.eINSTANCE.getSeriesDefinition_FormatSpecifier( ) );				}				else				{					seriesdefinition.setFormatSpecifier( editor.getFormatSpecifier( ) );				}			}		}	}