an example

cmd/main.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+func main() {
+	p := tea.NewProgram(itashi.initialModel())
+	if _, err := p.Run(); err != nil {
+		fmt.Printf("Alas, there's been an error: %v", err)
+		os.Exit(1)
+	}
+}

go.mod

@@ -1,3 +1,23 @@
 module git.aetherial.dev/aeth/itashi
 
 go 1.22.3
+
+require (
+	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
+	github.com/charmbracelet/bubbletea v0.26.2 // indirect
+	github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f // indirect
+	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
+	github.com/mattn/go-isatty v0.0.18 // indirect
+	github.com/mattn/go-localereader v0.0.1 // indirect
+	github.com/mattn/go-runewidth v0.0.15 // indirect
+	github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 // indirect
+	github.com/muesli/cancelreader v0.2.2 // indirect
+	github.com/muesli/reflow v0.3.0 // indirect
+	github.com/muesli/termenv v0.15.2 // indirect
+	github.com/rivo/uniseg v0.4.6 // indirect
+	golang.org/x/crypto v0.23.0 // indirect
+	golang.org/x/sync v0.7.0 // indirect
+	golang.org/x/sys v0.20.0 // indirect
+	golang.org/x/term v0.20.0 // indirect
+	golang.org/x/text v0.15.0 // indirect
+)

go.sum

@@ -0,0 +1,41 @@
+github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiErDT4WkJ2k=
+github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
+github.com/charmbracelet/bubbletea v0.26.2 h1:Eeb+n75Om9gQ+I6YpbCXQRKHt5Pn4vMwusQpwLiEgJQ=
+github.com/charmbracelet/bubbletea v0.26.2/go.mod h1:6I0nZ3YHUrQj7YHIHlM8RySX4ZIthTliMY+W8X8b+Gs=
+github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f h1:Y/CXytFA4m6baUTXGLOoWe4PQhGxaX0KpnayAqC48p4=
+github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f/go.mod h1:vw97MGsxSvLiUE2X8qFplwetxpGLQrlU1Q9AUEIzCaM=
+github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY=
+github.com/lucasb-eyer/go-colorful v1.2.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
+github.com/mattn/go-isatty v0.0.18 h1:DOKFKCQ7FNG2L1rbrmstDN4QVRdS89Nkh85u68Uwp98=
+github.com/mattn/go-isatty v0.0.18/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mattn/go-localereader v0.0.1 h1:ygSAOl7ZXTx4RdPYinUpg6W99U8jWvWi9Ye2JC/oIi4=
+github.com/mattn/go-localereader v0.0.1/go.mod h1:8fBrzywKY7BI3czFoHkuzRoWE9C+EiG4R1k4Cjx5p88=
+github.com/mattn/go-runewidth v0.0.12/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
+github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZgg3U=
+github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 h1:ZK8zHtRHOkbHy6Mmr5D264iyp3TiX5OmNcI5cIARiQI=
+github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6/go.mod h1:CJlz5H+gyd6CUWT45Oy4q24RdLyn7Md9Vj2/ldJBSIo=
+github.com/muesli/cancelreader v0.2.2 h1:3I4Kt4BQjOR54NavqnDogx/MIoWBFa0StPA8ELUXHmA=
+github.com/muesli/cancelreader v0.2.2/go.mod h1:3XuTXfFS2VjM+HTLZY9Ak0l6eUKfijIfMUZ4EgX0QYo=
+github.com/muesli/reflow v0.3.0 h1:IFsN6K9NfGtjeggFP+68I4chLZV2yIKsXJFNZ+eWh6s=
+github.com/muesli/reflow v0.3.0/go.mod h1:pbwTDkVPibjO2kyvBQRBxTWEEGDGq0FlB1BIKtnHY/8=
+github.com/muesli/termenv v0.15.2 h1:GohcuySI0QmI3wN8Ok9PtKGkgkFIk7y6Vpb5PvrY+Wo=
+github.com/muesli/termenv v0.15.2/go.mod h1:Epx+iuz8sNs7mNKhxzH4fWXGNpZwUaJKRS1noLXviQ8=
+github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.4.6 h1:Sovz9sDSwbOz9tgUy8JpT+KgCkPYJEN/oYzlJiYTNLg=
+github.com/rivo/uniseg v0.4.6/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
+golang.org/x/crypto v0.23.0 h1:dIJU/v2J8Mdglj/8rJ6UUOM3Zc9zLZxVZwwxMooUSAI=
+golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
+golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
+golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sys v0.0.0-20210809222454-d867a43fc93e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
+golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.20.0 h1:VnkxpohqXaOBYJtBmEppKUG6mXpi+4O6purfc2+sMhw=
+golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
+golang.org/x/text v0.3.8 h1:nAL+RVCQ9uMn3vJZbV+MRnydTJFPf8qqY42YiA6MrqY=
+golang.org/x/text v0.3.8/go.mod h1:E6s5w1FMmriuDzIBO73fBruAKo1PCIq6d2Q6DHfQ8WQ=
+golang.org/x/text v0.15.0 h1:h1V/4gjBv8v9cjcR6+AR5+/cIYK5N/WAgiv4xlsEtAk=
+golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=

pkg/userinterface.go

@@ -0,0 +1,104 @@
+// localizing all of the functions required to construct the user interface
+
+package itashi
+
+import (
+	"fmt"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+type model struct {
+	choices  []string
+	cursor   int
+	selected map[int]struct{}
+}
+
+func initialModel() model {
+	return model{
+		// Our to-do 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 model) Init() tea.Cmd {
+	// Just return `nil`, which means "no I/O right now, please."
+	return nil
+}
+
+func (m model) 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() {
+
+		// 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 "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 model to the Bubble Tea runtime for processing.
+	// Note that we're not returning a command.
+	return m, nil
+}
+
+func (m model) 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
+}