code: public void setFilter(String filter) {
  		if(filter == null || filter.length() == 0 ) {
  			this.filter = null;
  		} else {
  			this.filter = filter;
  		}
  		
  		// Reload the list of files.
  		this.loadFolder(this.currentFolder);
  	}
docs: Set a regular expression to filter the files that can be selected.
  
  @param filter A regular expression.