Bubble Tea WindowSizeMsg/Viewport Example

go.mod

module example

go 1.16

require (
	github.com/charmbracelet/bubbles v0.7.7
	github.com/charmbracelet/bubbletea v0.13.2
)

go.sum

github.com/atotto/clipboard v0.1.2/go.mod h1:ZY9tmq7sm5xIbd9bOK4onWV4S6X0u6GY7Vn0Yu86PYI=
github.com/charmbracelet/bubbles v0.7.7 h1:eVsAYiAJskifXaqHpPzbOZS1srMaTnuiTazC6uukBbA=
github.com/charmbracelet/bubbles v0.7.7/go.mod h1:5WX1sSSjNCgCrzvRMN/z23HxvWaa+AI16Ch0KPZPeDs=
github.com/charmbracelet/bubbletea v0.13.1/go.mod h1:tp9tr9Dadh0PLhgiwchE5zZJXm5543JYjHG9oY+5qSg=
github.com/charmbracelet/bubbletea v0.13.2 h1:fSOx3q0/VbA3ChWeiNcUsNeNysD9FFWD1tZypShBuCQ=
github.com/charmbracelet/bubbletea v0.13.2/go.mod h1:okqaA5VF0aSpEZ2HB+L/cxVw2HthIDZ1dmWoRZs8/4g=
github.com/charmbracelet/lipgloss v0.1.2/go.mod h1:5D8zradw52m7QmxRF6QgwbwJi9je84g8MkWiGN07uKg=
github.com/containerd/console v1.0.1 h1:u7SFAJyRqWcG6ogaMAx3KjSTy1e3hT9QxqX7Jco7dRc=
github.com/containerd/console v1.0.1/go.mod h1:XUsP6YE/mKtz6bxc+I8UiKKTP04qjQL4qcS3XoQ5xkw=
github.com/google/goterm v0.0.0-20190703233501-fc88cf888a3f/go.mod h1:nOFQdrUlIlx6M6ODdSpBj1NVA+VgLC6kmw60mkw34H4=
github.com/lucasb-eyer/go-colorful v1.0.3/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
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 v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
github.com/mattn/go-runewidth v0.0.10/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
github.com/mattn/go-runewidth v0.0.12 h1:Y41i/hVW3Pgwr8gV+J23B9YEY0zxjptBuCWEaxmAOow=
github.com/mattn/go-runewidth v0.0.12/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
github.com/muesli/reflow v0.2.1-0.20210115123740-9e1d0d53df68 h1:y1p/ycavWjGT9FnmSjdbWUlLGvcxrY0Rw3ATltrxOhk=
github.com/muesli/reflow v0.2.1-0.20210115123740-9e1d0d53df68/go.mod h1:Xk+z4oIWdQqJzsxyjgl3P22oYZnHdZ8FFTHAQQt5BMQ=
github.com/muesli/termenv v0.7.2/go.mod h1:ct2L5N2lmix82RaY3bMWwVu/jUFc9Ule0KGDCiKYPh8=
github.com/muesli/termenv v0.8.1 h1:9q230czSP3DHVpkaPDXGp0TOfAwyjyYwXlUCQxQSaBk=
github.com/muesli/termenv v0.8.1/go.mod h1:kzt/D/4a88RoheZmwfqorY3A+tnsSMA9HJC/fQSFKo0=
github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20201012173705-84dcc777aaee/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897 h1:pLI5jrR7OSLijeIDcmRxNmw2api+jEfxLoykJVice/E=
golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20200916030750-2334cc1a136f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4 h1:myAQVi0cGEoqQVR5POX+8RR2mrocKqNN1hmeMqhX27k=
golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

main.go

package main

import (
	"fmt"
	"os"

	"github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
)

type model struct {
	ready bool
	vp    viewport.Model
}

func (m model) Init() tea.Cmd {
	return tea.EnterAltScreen
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {

	case tea.WindowSizeMsg:
		m.vp.Width = msg.Width
		m.vp.Height = msg.Height
		m.ready = true

	case tea.KeyMsg:
		switch msg.String() {
		case "q", "esc", "ctrl+c":
			return m, tea.Quit

		case "down", "j":
			m.vp.LineDown(1)

		case "up", "k":
			m.vp.LineUp(1)
		}
	}

	return m, nil
}

func (m model) View() string {
	if !m.ready {
		return "Loading..."
	}

	return m.vp.View()
}

func main() {
	var content string
	for i := 0; i < 300; i++ {
		content += fmt.Sprintf("%03d\n", i)
	}

	m := model{}
	m.vp.SetContent(content)

	if err := tea.NewProgram(m).Start(); err != nil {
		fmt.Println("Error running program:", err)
		os.Exit(1)
	}
}