gum/choose/choose.go

// Package choose provides an interface to choose one option from a given list
// of options. The options can be provided as (new-line separated) stdin or a
// list of arguments.
//
// It is different from the filter command as it does not provide a fuzzy
// finding input, so it is best used for smaller lists of options.
//
// Let's pick from a list of gum flavors:
//
//   $ gum choose "Strawberry" "Banana" "Cherry"
//
package choose

import (
	"fmt"
	"io"

	"github.com/charmbracelet/bubbles/list"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

type model struct {
	choice            string
	height            int
	indicator         string
	indicatorStyle    lipgloss.Style
	itemStyle         lipgloss.Style
	items             []item
	list              list.Model
	options           []string
	quitting          bool
	selectedItemStyle lipgloss.Style
}

type item string

func (i item) FilterValue() string { return "" }

type itemDelegate struct {
	indicator         string
	indicatorStyle    lipgloss.Style
	itemStyle         lipgloss.Style
	selectedItemStyle lipgloss.Style
}

func (d itemDelegate) Height() int                               { return 1 }
func (d itemDelegate) Spacing() int                              { return 0 }
func (d itemDelegate) Update(msg tea.Msg, m *list.Model) tea.Cmd { return nil }
func (d itemDelegate) Render(w io.Writer, m list.Model, index int, listItem list.Item) {
	i, ok := listItem.(item)
	if !ok {
		return
	}

	str := fmt.Sprintf("%s", i)

	fn := d.itemStyle.Render
	if index == m.Index() {
		fn = func(s string) string {
			return d.indicatorStyle.Render(d.indicator) + d.selectedItemStyle.Render(s)
		}
	}

	fmt.Fprintf(w, fn(str))
}

func (m model) Init() tea.Cmd { return nil }

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		m.list.SetWidth(msg.Width)
		return m, nil

	case tea.KeyMsg:
		switch keypress := msg.String(); keypress {
		case "ctrl+c":
			m.quitting = true
			return m, tea.Quit

		case "enter":
			m.quitting = true
			i, ok := m.list.SelectedItem().(item)
			if ok {
				m.choice = string(i)
			}
			return m, tea.Quit
		}
	}

	var cmd tea.Cmd
	m.list, cmd = m.list.Update(msg)
	return m, cmd
}

func (m model) View() string {
	if m.quitting {
		return ""
	}
	return m.list.View()
}

func clamp(min, max, val int) int {
	if val < min {
		return min
	}
	if val > max {
		return max
	}
	return val
}