docs(example): add textarea dynamic height example

Author: meowgorithm

examples/dynamic-textarea/main.go

@@ -0,0 +1,91 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"strings"
+
+	"charm.land/bubbles/v2/textarea"
+	tea "charm.land/bubbletea/v2"
+)
+
+func main() {
+	p := tea.NewProgram(initialModel())
+	if _, err := p.Run(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+type model struct {
+	textarea textarea.Model
+}
+
+func initialModel() model {
+	ti := textarea.New()
+	ti.Placeholder = "Schnrr..."
+	ti.ShowLineNumbers = true
+	ti.DynamicHeight = true
+	ti.MinHeight = 3
+	ti.MaxHeight = 15
+	ti.MaxContentHeight = 20
+	ti.SetWidth(60)
+	ti.SetVirtualCursor(false)
+	ti.Focus()
+
+	return model{textarea: ti}
+}
+
+func (m model) Init() tea.Cmd {
+	return tea.Batch(textarea.Blink, tea.RequestBackgroundColor)
+}
+
+func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	var cmds []tea.Cmd
+	var cmd tea.Cmd
+
+	switch msg := msg.(type) {
+	case tea.BackgroundColorMsg:
+		m.textarea.SetStyles(textarea.DefaultStyles(msg.IsDark()))
+	case tea.KeyPressMsg:
+		switch msg.String() {
+		case "ctrl+c":
+			return m, tea.Quit
+		}
+	}
+
+	m.textarea, cmd = m.textarea.Update(msg)
+	cmds = append(cmds, cmd)
+	return m, tea.Batch(cmds...)
+}
+
+func (m model) statusView() string {
+	return fmt.Sprintf(
+		"\nHeight: %d · Lines: %d · Cursor: (%d, %d) · Scroll: %.0f%%",
+		m.textarea.Height(),
+		m.textarea.LineCount(),
+		m.textarea.Line(),
+		m.textarea.Column(),
+		m.textarea.ScrollPercent()*100,
+	)
+}
+
+func (m model) View() tea.View {
+	const gap = "\n"
+
+	var c *tea.Cursor
+	if !m.textarea.VirtualCursor() {
+		c = m.textarea.Cursor()
+		c.Y += 1 // account for gap
+	}
+
+	f := gap
+	f += strings.Join([]string{
+		m.textarea.View(),
+		m.statusView(),
+		"\n(ctrl+c to quit)",
+	}, "\n")
+
+	v := tea.NewView(f)
+	v.Cursor = c
+	return v
+}