When a large update is performed, it will cause a flash.

[yorukot]

Describe the bug
When a large update is performed, it will cause a flash.

Setup

• OS: Fedora
• Shell: zsh
• Terminal Emulator: kitty
• Terminal Multiplexer: zellij

To Reproduce
Steps to reproduce the behavior:

1. go run main.go
2. Press Tab to let tui update
3. See error

Source Code

package main

import (
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
	"log"
	"math/rand"
	"strings"
)

type sessionState uint

const (
	timerView sessionState = iota
	spinnerView
)

var (
	modelStyle = lipgloss.NewStyle().
			Width(80).
			Height(35).
			Align(lipgloss.Center, lipgloss.Center).
			BorderStyle(lipgloss.HiddenBorder()).
			Background(lipgloss.Color("#4B4B4B"))

	focusedModelStyle = lipgloss.NewStyle().
				Width(80).
				Height(35).
				Align(lipgloss.Center, lipgloss.Center).
				BorderStyle(lipgloss.NormalBorder()).
				BorderForeground(lipgloss.Color("69")).
				Background(lipgloss.Color("#4B4B4B"))
)

type mainModel struct {
	state sessionState
}

func newModel() mainModel {
	m := mainModel{}
	return m
}

func (m mainModel) Init() tea.Cmd {
	return tea.Batch()
}

func (m mainModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmds []tea.Cmd
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "ctrl+c", "q":
			return m, tea.Quit
		case "tab":
			if m.state == timerView {
				m.state = spinnerView
			} else {
				m.state = timerView
			}
		}
	}
	return m, tea.Batch(cmds...)
}

func (m mainModel) View() string {
	var s string
	example1 := strings.Repeat("AAAA", 760)
	example2 := strings.Repeat("Test", 760)
	example := []string{example1, example2}
	if m.state == timerView {
		s += lipgloss.JoinHorizontal(lipgloss.Top, focusedModelStyle.Render(example[rand.Intn(2)]), modelStyle.Render(example[rand.Intn(2)]))
	} else {
		s += lipgloss.JoinHorizontal(lipgloss.Top, modelStyle.Render(example[rand.Intn(2)]), focusedModelStyle.Render(example[rand.Intn(2)]))
	}
	return s
}

func main() {
	p := tea.NewProgram(newModel(), tea.WithAltScreen())

	if _, err := p.Run(); err != nil {
		log.Fatal(err)
	}
}

Expected behavior
Normal update without flash

Screenshots
https://github.com/charmbracelet/bubbletea/assets/107802416/4f6337cb-2d4b-44b4-ade1-c31b7866ceef

Additional context
yorukot/superfile#122

[meowgorithm]

Hi! No ETA yet but we're actually working on a new renderer right now to addresses this very issue.