diff --git a/README.md b/README.md index 960723d..743ecc5 100644 --- a/README.md +++ b/README.md @@ -41,14 +41,14 @@ We'll start by defining our package and import some libraries. Our only external import will be the Bubble Tea library, which we'll call `tea` for short. ```go - package main +package main - import ( - "fmt" - "os" +import ( + "fmt" + "os" - tea "github.com/charmbracelet/bubbletea" - ) + tea "github.com/charmbracelet/bubbletea" +) ``` Bubble Tea programs are comprised of a **model** that describes the application @@ -64,11 +64,11 @@ So let's start by defining our model which will store our application's state. It can be any type, but a `struct` usually makes the most sense. ```go - type model struct { - choices []string // items on the to-do list - cursor int // which to-do list item our cursor is pointing at - selected map[int]struct{} // which to-do items are selected - } +type model struct { + choices []string // items on the to-do list + cursor int // which to-do list item our cursor is pointing at + selected map[int]struct{} // which to-do items are selected +} ``` ### The Initialization Function @@ -80,21 +80,21 @@ don't need to do any I/O, so for the command we'll just return `nil`, which translates to "no command." ```go - func initialize() (tea.Model, tea.Cmd) { - m := model{ +func initialize() (tea.Model, tea.Cmd) { + m := model{ - // Our to-do list is just a grocery list - choices: []string{"Buy carrots", "Buy celery", "Buy kohlrabi"}, + // Our to-do list is just a grocery list + choices: []string{"Buy carrots", "Buy celery", "Buy kohlrabi"}, - // A map which indicates which choices are selected. We're using - // the map like a mathematical set. The keys refer to the indexes - // of the `choices` slice, above. - selected: make(map[int]struct{}), - } - - // Return the model and `nil`, which means "no I/O right now, please." - return m, nil + // A map which indicates which choices are selected. We're using + // the map like a mathematical set. The keys refer to the indexes + // of the `choices` slice, above. + selected: make(map[int]struct{}), } + + // Return the model and `nil`, which means "no I/O right now, please." + return m, nil +} ``` ### The Update Function @@ -118,49 +118,49 @@ For now, we'll just deal with `tea.KeyMsg` messages, which are automatically sent to the update function when keys are pressed. ```go - func update(msg tea.Msg, mdl tea.Model) (tea.Model, tea.Cmd) { - m, _ := mdl.(model) +func update(msg tea.Msg, mdl tea.Model) (tea.Model, tea.Cmd) { + m, _ := mdl.(model) - switch msg := msg.(type) { + switch msg := msg.(type) { - // Is it a key press? - case tea.KeyMsg: + // Is it a key press? + case tea.KeyMsg: - // Cool, what was the actual key pressed? - switch msg.String() { + // Cool, what was the actual key pressed? + switch msg.String() { - // These keys should exit the program. - case "ctrl+c", "q": - return m, tea.Quit + // These keys should exit the program. + case "ctrl+c", "q": + return m, tea.Quit - // The "up" and "k" keys move the cursor up - case "up", "k": - if m.cursor > 0 { - m.cursor-- - } + // The "up" and "k" keys move the cursor up + case "up", "k": + if m.cursor > 0 { + m.cursor-- + } - // The "down" and "j" keys move the cursor down - case "down", "j": - if m.cursor < len(m.choices)-1 { - m.cursor++ - } + // The "down" and "j" keys move the cursor down + case "down", "j": + if m.cursor < len(m.choices)-1 { + m.cursor++ + } - // The "enter" key and the spacebar (a literal space) toggle - // the selected state for the item that the cursor is pointing at. - case "enter", " ": - _, ok := m.selected[m.cursor] - if ok { - delete(m.selected, m.cursor) - } else { - m.selected[m.cursor] = struct{}{} - } + // The "enter" key and the spacebar (a literal space) toggle + // the selected state for the item that the cursor is pointing at. + case "enter", " ": + _, ok := m.selected[m.cursor] + if ok { + delete(m.selected, m.cursor) + } else { + m.selected[m.cursor] = struct{}{} } } - - // Return the updated model to the Bubble Tea runtime for processing. - // Note that we're not returning a command. - return m, nil } + + // Return the updated model to the Bubble Tea runtime for processing. + // Note that we're not returning a command. + return m, nil +} ``` You may have noticed that "ctrl+c" and "q" above return a `tea.Quit` command @@ -178,37 +178,37 @@ to worry about redraw logic and stuff like that. Bubble Tea takes care of it for you. ```go - func view(mdl tea.Model) string { - m, _ := mdl.(model) +func view(mdl tea.Model) string { + m, _ := mdl.(model) - // The header - s := "What should we buy at the market?\n\n" + // The header + s := "What should we buy at the market?\n\n" - // Iterate over our choices - for i, choice := range m.choices { + // Iterate over our choices + for i, choice := range m.choices { - // Is the cursor pointing at this choice? - cursor := " " // no cursor - if m.cursor == i { - cursor = ">" // cursor! - } - - // Is this choice selected? - checked := " " // not selected - if _, ok := m.selected[i]; ok { - checked = "x" // selected! - } - - // Render the row - s += fmt.Sprintf("%s [%s] %s\n", cursor, checked, choice) + // Is the cursor pointing at this choice? + cursor := " " // no cursor + if m.cursor == i { + cursor = ">" // cursor! } - // The footer - s += "\nPress q to quit.\n" + // Is this choice selected? + checked := " " // not selected + if _, ok := m.selected[i]; ok { + checked = "x" // selected! + } - // Send the UI for rendering - return s + // Render the row + s += fmt.Sprintf("%s [%s] %s\n", cursor, checked, choice) } + + // The footer + s += "\nPress q to quit.\n" + + // Send the UI for rendering + return s +} ``` ### All Together Now @@ -217,13 +217,13 @@ The last step is to simply run our program. We pass our functions to `tea.NewProgram` and let it rip: ```go - func main() { - p := tea.NewProgram(initialize, update, view) - if err := p.Start(); err != nil { - fmt.Printf("Alas, there's been an error: %v", err) - os.Exit(1) - } +func main() { + p := tea.NewProgram(initialize, update, view) + if err := p.Start(); err != nil { + fmt.Printf("Alas, there's been an error: %v", err) + os.Exit(1) } +} ``` ### What's Next?