trying_out_go/shopping.go

108 lines
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2023-10-16 12:44:08 -04:00
package main
import (
"fmt"
"os"
tea "github.com/charmbracelet/bubbletea"
)
type shoppingModel struct {
choices []string // items on the shopping list
cursor int // which shopping list item our cursor is pointing at
selected map[int]struct{} // which shopping items are selected
}
func initialModel() shoppingModel {
return shoppingModel{
// Our shopping list is 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{}),
}
}
func (m shoppingModel) Init() tea.Cmd {
// Just return `nil`, which means "no I/O right now, please."
return nil
}
func (m shoppingModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
switch msg := msg.(type) {
// Is it a key press?
case tea.KeyMsg:
// Cool, what was the actual key pressed?
switch msg.String() {
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 "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{}{}
}
}
}
// Return the updated shoppingModel to the Bubble Tea runtime for processing.
// Note that we're not returning a command.
return m, nil
}
func (m shoppingModel) View() string {
// The header
s := "What should we buy at the market? \n\n"
// 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)
}
// The footer
s += "\nPress q to quit.\n"
// Send the UI for rendering
return s
}
func shopping() {
p := tea.NewProgram(initialModel())
if _, err := p.Run(); err != nil {
fmt.Printf("Alas, there's been an error: %v", err)
os.Exit(1)
}
}