package main import ( "fmt" "tea" ) type Model int func main() { p := tea.NewProgram(0, update, view) p.Start() } func update(msg tea.Msg, model tea.Model) (tea.Model, tea.Cmd) { m, _ := model.(Model) switch msg := msg.(type) { case tea.KeyPressMsg: switch msg { case "j": m += 1 if m > 3 { m = 3 } case "k": m -= 1 if m < 0 { m = 0 } case "q": return m, tea.Quit } } return m, nil } func view(model tea.Model) string { m, _ := model.(Model) choices := fmt.Sprintf( "%s\n%s\n%s\n%s", checkbox("Plant carrots", m == 0), checkbox("Go to the market", m == 1), checkbox("Read something", m == 2), checkbox("See friends", m == 3), ) return fmt.Sprintf( "What to do today?\n\n%s.\n\n(press j/k to select or q to quit)", choices, ) } func checkbox(label string, checked bool) string { check := " " if checked { check = "x" } return fmt.Sprintf("[%s] %s", check, label) }