Backport: Fix prevent duplicate content on window resize in chat example to v2-exp

examples/chat/main.go

@@ -5,23 +5,29 @@ package main
 
 import (
 	"fmt"
-	"os"
+	"log"
 	"strings"
 
-	"charm.land/bubbles/v2/cursor"
-	"charm.land/bubbles/v2/textarea"
-	"charm.land/bubbles/v2/viewport"
-	tea "charm.land/bubbletea/v2"
-	"charm.land/lipgloss/v2"
+	"github.com/charmbracelet/bubbles/textarea"
+	"github.com/charmbracelet/bubbles/viewport"
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
 )
 
+const gap = "\n\n"
+
 func main() {
 	p := tea.NewProgram(initialModel())
+
 	if _, err := p.Run(); err != nil {
-		fmt.Fprintf(os.Stderr, "Oof: %v\n", err)
+		log.Fatal(err)
 	}
 }
 
+type (
+	errMsg error
+)
+
 type model struct {
 	viewport    viewport.Model
 	messages    []string
@@ -33,7 +39,6 @@ type model struct {
 func initialModel() model {
 	ta := textarea.New()
 	ta.Placeholder = "Send a message..."
-	ta.SetVirtualCursor(false)
 	ta.Focus()
 
 	ta.Prompt = "┃ "
@@ -43,17 +48,13 @@ func initialModel() model {
 	ta.SetHeight(3)
 
 	// Remove cursor line styling
-	s := ta.Styles()
-	s.Focused.CursorLine = lipgloss.NewStyle()
-	ta.SetStyles(s)
+	ta.FocusedStyle.CursorLine = lipgloss.NewStyle()
 
 	ta.ShowLineNumbers = false
 
-	vp := viewport.New(viewport.WithWidth(30), viewport.WithHeight(5))
+	vp := viewport.New(30, 5)
 	vp.SetContent(`Welcome to the chat room!
 Type a message and press Enter to send.`)
-	vp.KeyMap.Left.SetEnabled(false)
-	vp.KeyMap.Right.SetEnabled(false)
 
 	ta.KeyMap.InsertNewline.SetEnabled(false)
 
@@ -71,53 +72,56 @@ func (m model) Init() tea.Cmd {
 }
 
 func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	var (
+		tiCmd tea.Cmd
+		vpCmd tea.Cmd
+	)
+
 	switch msg := msg.(type) {
 	case tea.WindowSizeMsg:
-		m.viewport.SetWidth(msg.Width)
+		m.viewport.Width = msg.Width
 		m.textarea.SetWidth(msg.Width)
-		m.viewport.SetHeight(msg.Height - m.textarea.Height())
+		m.viewport.Height = msg.Height - m.textarea.Height() - lipgloss.Height(gap)
 
 		if len(m.messages) > 0 {
 			// Wrap content before setting it.
-			m.viewport.SetContent(lipgloss.NewStyle().Width(m.viewport.Width()).Render(strings.Join(m.messages, "\n")))
+			m.viewport.SetContent(lipgloss.NewStyle().Width(m.viewport.Width).Render(strings.Join(m.messages, "\n")))
 		}
 		m.viewport.GotoBottom()
-	case tea.KeyPressMsg:
-		switch msg.String() {
-		case "ctrl+c", "esc":
+		m.textarea, tiCmd = m.textarea.Update(msg)
+		m.viewport, vpCmd = m.viewport.Update(msg)
+	case tea.KeyMsg:
+		m.textarea, tiCmd = m.textarea.Update(msg)
+		m.viewport, vpCmd = m.viewport.Update(msg)
+		switch msg.Type {
+		case tea.KeyCtrlC, tea.KeyEsc:
 			fmt.Println(m.textarea.Value())
 			return m, tea.Quit
-		case "enter":
+		case tea.KeyEnter:
 			m.messages = append(m.messages, m.senderStyle.Render("You: ")+m.textarea.Value())
-			m.viewport.SetContent(lipgloss.NewStyle().Width(m.viewport.Width()).Render(strings.Join(m.messages, "\n")))
+			m.viewport.SetContent(lipgloss.NewStyle().Width(m.viewport.Width).Render(strings.Join(m.messages, "\n")))
 			m.textarea.Reset()
 			m.viewport.GotoBottom()
-			return m, nil
-		default:
-			// Send all other keypresses to the textarea.
-			var cmd tea.Cmd
-			m.textarea, cmd = m.textarea.Update(msg)
-			return m, cmd
 		}
 
-	case cursor.BlinkMsg:
-		// Textarea should also process cursor blinks.
-		var cmd tea.Cmd
-		m.textarea, cmd = m.textarea.Update(msg)
-		return m, cmd
+	// We handle errors just like any other message
+	case errMsg:
+		m.err = msg
+		return m, nil
+
+	default:
+		m.textarea, tiCmd = m.textarea.Update(msg)
+		m.viewport, vpCmd = m.viewport.Update(msg)
 	}
 
-	return m, nil
+	return m, tea.Batch(tiCmd, vpCmd)
 }
 
-func (m model) View() tea.View {
-	viewportView := m.viewport.View()
-	v := tea.NewView(viewportView + "\n" + m.textarea.View())
-	c := m.textarea.Cursor()
-	if c != nil {
-		c.Y += lipgloss.Height(viewportView)
-	}
-	v.Cursor = c
-	v.AltScreen = true
-	return v
+func (m model) View() string {
+	return fmt.Sprintf(
+		"%s%s%s",
+		m.viewport.View(),
+		gap,
+		m.textarea.View(),
+	)
 }