Bug 202891 NPE throws out when click on data item in layout[0001]
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dialogs/BindingDialogHelper.java
setDataFieldExpression( getBinding( ).getExpression( ) );
			}
			else
			{
				setName( getBinding( ).getName( ) );
				setDisplayName( getBinding( ).getDisplayName( ) );
				setTypeSelect( DATA_TYPE_CHOICE_SET.findChoice( getBinding( ).getDataType( ) )
						.getDisplayName( ) );
				setDataFieldExpression( getBinding( ).getExpression( ) );
			}
		}
		if ( !isCreate )
		{
			if ( isRef )
			{
				this.cmbName.setEnabled( false );
			}
			else
			{
				this.txtName.setEnabled( false );
			}
		}
		if ( isAggregate( ) )
		{
			initFunction( );
			initDataFields( );
			initFilter( );
			initGroups( );
		}
		validate( );