code: private void toggleReadOnly() {
  		allFiles.setReadOnly(!allFiles.isReadOnly());
  		imageFiles.setReadOnly(!imageFiles.isReadOnly());
  		textFiles.setReadOnly(!textFiles.isReadOnly());
  		pdfFiles.setReadOnly(!pdfFiles.isReadOnly());
  	}
docs: Toggles the readonly state off all file widgets in the example.