First pass at text input

examples/input/main.go

@@ -0,0 +1,68 @@
+package main
+
+// A simple program that counts down from 5 and then exits.
+
+import (
+	"fmt"
+	"log"
+	"tea"
+
+	"tea/input"
+)
+
+type model struct {
+	input input.Model
+}
+
+type tickMsg struct{}
+
+func main() {
+	tea.UseSysLog("tea")
+
+	p := tea.NewProgram(
+		model{
+			input: input.DefaultModel(),
+		},
+		update,
+		view,
+		nil,
+		//[]tea.Sub{input.Blink},
+	)
+
+	if err := p.Start(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func update(msg tea.Msg, mdl tea.Model) (tea.Model, tea.Cmd) {
+	var cmd tea.Cmd
+
+	m, _ := mdl.(model)
+
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch msg.String() {
+		case "break":
+			fallthrough
+		case "esc":
+			return m, tea.Quit
+		}
+
+	case input.CursorBlinkMsg:
+		return input.Update(msg, m.input)
+	}
+
+	m.input, cmd = input.Update(msg, m.input)
+	return m, cmd
+}
+
+func view(mdl tea.Model) string {
+	m, _ := mdl.(model)
+	help := "(esc to exit)"
+
+	return fmt.Sprintf(
+		"What’s your favorite Pokémon?\n\n%s\n\n%s",
+		input.View(m.input),
+		help,
+	)
+}

input/input.go

@@ -0,0 +1,66 @@
+package input
+
+import (
+	"log"
+	"tea"
+	"time"
+)
+
+type Model struct {
+	Prompt       string
+	Value        string
+	Cursor       string
+	HiddenCursor string
+	Blink        bool
+	BlinkSpeed   time.Duration
+}
+
+type CursorBlinkMsg struct{}
+
+func DefaultModel() Model {
+	return Model{
+		Prompt:       "> ",
+		Value:        "",
+		Cursor:       "█",
+		HiddenCursor: " ",
+		Blink:        false,
+		BlinkSpeed:   time.Second,
+	}
+}
+
+func Update(msg tea.Msg, model tea.Model) (Model, tea.Cmd) {
+	m, _ := model.(Model)
+
+	log.Printf("msg: %v\n", msg)
+	switch msg := msg.(type) {
+
+	case tea.KeyMsg:
+		switch msg.Type {
+		case tea.KeyBackspace:
+			m.Value = m.Value[:len(m.Value)-1]
+		case tea.KeyRune:
+			m.Value = m.Value + msg.String()
+		}
+
+	case CursorBlinkMsg:
+		m.Blink = !m.Blink
+	}
+
+	return m, nil
+}
+
+func View(model tea.Model) string {
+	m, _ := model.(Model)
+	cursor := m.Cursor
+	//if m.Blink {
+	//cursor = m.HiddenCursor
+	//}
+	return m.Prompt + m.Value + cursor
+}
+
+func Blink(model tea.Model) tea.Msg {
+	//m, _ := model.(Model)
+	//time.Sleep(m.BlinkSpeed)
+	time.Sleep(time.Second)
+	return CursorBlinkMsg{}
+}