code: func ThemeNames() []string {
  	var str []string
  	str = append(str, defaultTheme)
  
  	path := themeManager.themePath
  	if path == "" {
  		path = "." + string(os.PathSeparator)
  	}
  	files, err := ioutil.ReadDir(path)
  	if err != nil {
  		panic("Failed to read theme directory: " + themeManager.themePath)
  	}
  
  	for _, f := range files {
  		name := f.Name()
  		if !f.IsDir() && strings.HasSuffix(name, themeSuffix) {
  			str = append(str, strings.TrimSuffix(name, themeSuffix))
  		}
  	}
  
  	return str
  }
docs: // ThemeNames returns the list of short theme names (file names)