if (editor instanceof PHPStructuredEditor) {
PHPStructuredEditor phpEditor = (PHPStructuredEditor) editor;
if (phpEditor.getSourceViwerConfiguration().getClass() == PHPStructuredTextViewerConfiguration.class) {
phpFoldingProvider = new StructuredTextFoldingProviderPHP();
phpFoldingProvider.install(viewer);
} else {
fProjectionListener = new ProjectionListener(viewer);
fEditor = (PHPStructuredEditor) editor;