glow/ui/pager.go

562 lines
14 KiB
Go

package ui
import (
"fmt"
"log"
"math"
"strings"
"time"
"github.com/charmbracelet/bubbles/spinner"
"github.com/charmbracelet/bubbles/textinput"
"github.com/charmbracelet/bubbles/viewport"
tea "github.com/charmbracelet/bubbletea"
"github.com/charmbracelet/charm"
"github.com/charmbracelet/charm/ui/common"
"github.com/charmbracelet/glamour"
runewidth "github.com/mattn/go-runewidth"
"github.com/muesli/reflow/ansi"
te "github.com/muesli/termenv"
)
const (
maxDocumentWidth = 120
statusBarHeight = 1
gray = "#333333"
yellowGreen = "#ECFD65"
fuschia = "#EE6FF8"
mintGreen = "#89F0CB"
darkGreen = "#1C8760"
noteHeadingText = " Set Memo "
notePromptText = " > "
pagerStashIcon = "🔒"
)
var (
pagerHelpHeight = strings.Count(pagerHelpView(pagerModel{}, 0), "\n")
noteHeading = te.String(noteHeadingText).
Foreground(common.Cream.Color()).
Background(common.Green.Color()).
String()
statusBarBg = common.NewColorPair("#242424", "#E6E6E6")
statusBarNoteFg = common.NewColorPair("#7D7D7D", "#656565")
// Styling functions.
statusBarScrollPosStyle = newStyle(common.NewColorPair("#5A5A5A", "#949494").String(), statusBarBg.String())
statusBarNoteStyle = newStyle(statusBarNoteFg.String(), statusBarBg.String())
statusBarHelpStyle = newStyle(statusBarNoteFg.String(), common.NewColorPair("#323232", "#DCDCDC").String())
statusBarStashDotStyle = newStyle(common.Green.String(), statusBarBg.String())
statusBarMessageStyle = newStyle(mintGreen, darkGreen)
statusBarMessageStashDotStyle = newStyle(mintGreen, darkGreen)
statusBarMessageScrollPosStyle = newStyle(mintGreen, darkGreen)
statusBarMessageHelpStyle = newStyle("#B6FFE4", common.Green.String())
helpViewStyle = newStyle(statusBarNoteFg.String(), common.NewColorPair("#1B1B1B", "#f2f2f2").String())
)
// Create a new termenv styling function.
func newStyle(fg, bg string) func(string) string {
return te.Style{}.
Foreground(te.ColorProfile().Color(fg)).
Background(te.ColorProfile().Color(bg)).
Styled
}
// MSG
type contentRenderedMsg string
type noteSavedMsg *charm.Markdown
type stashSuccessMsg markdown
type stashErrMsg struct {
err error
}
func (s stashErrMsg) Error() string {
return s.err.Error()
}
// MODEL
type pagerState int
const (
pagerStateBrowse pagerState = iota
pagerStateSetNote
pagerStateStashing
pagerStateStashSuccess
pagerStateStatusMessage
)
type pagerModel struct {
cc *charm.Client
viewport viewport.Model
state pagerState
glamourStyle string
width int
height int
showHelp bool
textInput textinput.Model
spinner spinner.Model
statusMessage string
statusMessageTimer *time.Timer
// Current document being rendered, sans-glamour rendering. We cache
// it here so we can re-render it on resize.
currentDocument markdown
// Newly stashed markdown. We store it here temporarily so we can replace
// currentDocument above after a stash.
stashedDocument *markdown
}
func newPagerModel(glamourStyle string) pagerModel {
// Init viewport
vp := viewport.Model{}
vp.YPosition = 0
vp.HighPerformanceRendering = config.HighPerformancePager
// Init text input UI for notes/memos
ti := textinput.NewModel()
ti.Prompt = te.String(notePromptText).
Foreground(te.ColorProfile().Color(gray)).
Background(te.ColorProfile().Color(yellowGreen)).
String()
ti.TextColor = gray
ti.BackgroundColor = yellowGreen
ti.CursorColor = fuschia
ti.CharLimit = noteCharacterLimit
ti.Focus()
sp := spinner.NewModel()
sp.ForegroundColor = statusBarNoteFg.String()
sp.BackgroundColor = statusBarBg.String()
sp.HideFor = time.Millisecond * 50
sp.MinimumLifetime = time.Millisecond * 180
return pagerModel{
state: pagerStateBrowse,
glamourStyle: glamourStyle,
textInput: ti,
viewport: vp,
spinner: sp,
}
}
func (m *pagerModel) setSize(w, h int) {
m.width = w
m.height = h
m.viewport.Width = w
m.viewport.Height = h - statusBarHeight
m.textInput.Width = w - len(noteHeadingText) - len(notePromptText) - 1
if m.showHelp {
m.viewport.Height -= (statusBarHeight + pagerHelpHeight)
}
}
func (m *pagerModel) setContent(s string) {
m.viewport.SetContent(s)
}
func (m *pagerModel) toggleHelp() {
m.showHelp = !m.showHelp
m.setSize(m.width, m.height)
if m.viewport.PastBottom() {
m.viewport.GotoBottom()
}
}
// Perform stuff that needs to happen after a successful markdown stash. Note
// that the the returned command should be sent back the through the pager
// update function.
func (m *pagerModel) showStatusMessage(statusMessage string) tea.Cmd {
// Show a success message to the user
m.state = pagerStateStatusMessage
m.statusMessage = statusMessage
if m.statusMessageTimer != nil {
m.statusMessageTimer.Stop()
}
m.statusMessageTimer = time.NewTimer(statusMessageTimeout)
return waitForStatusMessageTimeout(pagerContext, m.statusMessageTimer)
}
func (m *pagerModel) unload() {
if m.showHelp {
m.toggleHelp()
}
if m.statusMessageTimer != nil {
m.statusMessageTimer.Stop()
}
m.state = pagerStateBrowse
m.viewport.SetContent("")
m.viewport.YOffset = 0
m.textInput.Reset()
}
// UPDATE
func pagerUpdate(msg tea.Msg, m pagerModel) (pagerModel, tea.Cmd) {
var (
cmd tea.Cmd
cmds []tea.Cmd
)
switch msg := msg.(type) {
case tea.KeyMsg:
switch m.state {
case pagerStateSetNote:
switch msg.String() {
case "esc":
m.state = pagerStateBrowse
return m, nil
case "enter":
var cmd tea.Cmd
if m.textInput.Value() != m.currentDocument.Note { // don't update if the note didn't change
m.currentDocument.Note = m.textInput.Value() // update optimistically
cmd = saveDocumentNote(m.cc, m.currentDocument.ID, m.currentDocument.Note)
}
m.state = pagerStateBrowse
m.textInput.Reset()
return m, cmd
}
default:
switch msg.String() {
case "q", "esc":
if m.state != pagerStateBrowse {
m.state = pagerStateBrowse
return m, nil
}
case "home", "g":
m.viewport.GotoTop()
if m.viewport.HighPerformanceRendering {
cmds = append(cmds, viewport.Sync(m.viewport))
}
case "end", "G":
m.viewport.GotoBottom()
if m.viewport.HighPerformanceRendering {
cmds = append(cmds, viewport.Sync(m.viewport))
}
case "m":
isStashed := m.currentDocument.markdownType == stashedMarkdown ||
m.currentDocument.markdownType == convertedMarkdown
// Users can only set the note on user-stashed markdown
if !isStashed {
break
}
m.state = pagerStateSetNote
// Stop the timer for hiding a status message since changing
// the state above will have cleared it.
if m.statusMessageTimer != nil {
m.statusMessageTimer.Stop()
}
// Pre-populate note with existing value
if m.textInput.Value() == "" {
m.textInput.SetValue(m.currentDocument.Note)
m.textInput.CursorEnd()
}
return m, textinput.Blink(m.textInput)
case "s":
// Stash a local document
if m.state != pagerStateStashing && m.currentDocument.markdownType == localMarkdown {
m.state = pagerStateStashing
m.spinner.Start()
cmds = append(
cmds,
stashDocument(m.cc, m.currentDocument),
spinner.Tick(m.spinner),
)
}
case "?":
m.toggleHelp()
if m.viewport.HighPerformanceRendering {
cmds = append(cmds, viewport.Sync(m.viewport))
}
}
}
case spinner.TickMsg:
if m.state == pagerStateStashing || m.spinner.Visible() {
newSpinnerModel, cmd := spinner.Update(msg, m.spinner)
m.spinner = newSpinnerModel
cmds = append(cmds, cmd)
} else if m.state == pagerStateStashSuccess && !m.spinner.Visible() {
m.state = pagerStateBrowse
m.currentDocument = *m.stashedDocument
m.stashedDocument = nil
cmd := m.showStatusMessage("Stashed!")
cmds = append(cmds, cmd)
}
// Glow has rendered the content
case contentRenderedMsg:
m.setContent(string(msg))
if m.viewport.HighPerformanceRendering {
cmds = append(cmds, viewport.Sync(m.viewport))
}
// We've reveived terminal dimensions, either for the first time or
// after a resize
case tea.WindowSizeMsg:
return m, renderWithGlamour(m, m.currentDocument.Body)
case stashSuccessMsg:
// Stashing was successful. Convert the loaded document to a stashed
// one and show a status message. Note that we're also handling this
// message in the main update function where we're adding this stashed
// item to the stash listing.
m.state = pagerStateStashSuccess
if !m.spinner.Visible() {
m.state = pagerStateBrowse
m.currentDocument = markdown(msg)
cmd := m.showStatusMessage("Stashed!")
cmds = append(cmds, cmd)
} else {
md := markdown(msg)
m.stashedDocument = &md
}
case stashErrMsg:
// TODO
case statusMessageTimeoutMsg:
// Hide the status message bar
m.state = pagerStateBrowse
}
switch m.state {
case pagerStateSetNote:
m.textInput, cmd = textinput.Update(msg, m.textInput)
cmds = append(cmds, cmd)
default:
m.viewport, cmd = viewport.Update(msg, m.viewport)
cmds = append(cmds, cmd)
}
return m, tea.Batch(cmds...)
}
// VIEW
func pagerView(m pagerModel) string {
var b strings.Builder
fmt.Fprint(&b, viewport.View(m.viewport)+"\n")
// Footer
switch m.state {
case pagerStateSetNote:
pagerSetNoteView(&b, m)
default:
pagerStatusBarView(&b, m)
}
if m.showHelp {
fmt.Fprint(&b, pagerHelpView(m, m.width))
}
return b.String()
}
func pagerStatusBarView(b *strings.Builder, m pagerModel) {
const (
minPercent float64 = 0.0
maxPercent float64 = 1.0
percentToStringMagnitude float64 = 100.0
)
var (
isStashed bool = m.currentDocument.markdownType == stashedMarkdown || m.currentDocument.markdownType == convertedMarkdown
showStatusMessage bool = m.state == pagerStateStatusMessage
)
// Logo
logo := glowLogoView(" Glow ")
// Scroll percent
percent := math.Max(minPercent, math.Min(maxPercent, m.viewport.ScrollPercent()))
scrollPercent := fmt.Sprintf(" %3.f%% ", percent*percentToStringMagnitude)
if showStatusMessage {
scrollPercent = statusBarMessageScrollPosStyle(scrollPercent)
} else {
scrollPercent = statusBarScrollPosStyle(scrollPercent)
}
// "Help" note
var helpNote string
if showStatusMessage {
helpNote = statusBarMessageHelpStyle(" ? Help ")
} else {
helpNote = statusBarHelpStyle(" ? Help ")
}
// Status indicator; spinner or stash dot
var statusIndicator string
if m.state == pagerStateStashing || m.state == pagerStateStashSuccess {
if m.spinner.Visible() {
statusIndicator = statusBarNoteStyle(" ") + spinner.View(m.spinner)
}
} else if isStashed && showStatusMessage {
statusIndicator = statusBarMessageStashDotStyle(" " + pagerStashIcon)
} else if isStashed {
statusIndicator = statusBarStashDotStyle(" " + pagerStashIcon)
}
// Note
var note string
if showStatusMessage {
note = "Stashed!"
} else {
note = m.currentDocument.Note
if len(note) == 0 {
note = "(No memo)"
}
}
note = truncate(" "+note+" ", max(0,
m.width-
ansi.PrintableRuneWidth(logo)-
ansi.PrintableRuneWidth(statusIndicator)-
ansi.PrintableRuneWidth(scrollPercent)-
ansi.PrintableRuneWidth(helpNote),
))
if showStatusMessage {
note = statusBarMessageStyle(note)
} else {
note = statusBarNoteStyle(note)
}
// Empty space
padding := max(0,
m.width-
ansi.PrintableRuneWidth(logo)-
ansi.PrintableRuneWidth(statusIndicator)-
ansi.PrintableRuneWidth(note)-
ansi.PrintableRuneWidth(scrollPercent)-
ansi.PrintableRuneWidth(helpNote),
)
emptySpace := strings.Repeat(" ", padding)
if showStatusMessage {
emptySpace = statusBarMessageStyle(emptySpace)
} else {
emptySpace = statusBarNoteStyle(emptySpace)
}
fmt.Fprintf(b, "%s%s%s%s%s%s",
logo,
statusIndicator,
note,
emptySpace,
scrollPercent,
helpNote,
)
}
func pagerSetNoteView(b *strings.Builder, m pagerModel) {
fmt.Fprint(b, noteHeading)
fmt.Fprint(b, textinput.View(m.textInput))
}
func pagerHelpView(m pagerModel, width int) (s string) {
col1 := [...]string{
"g/home go to top",
"G/end go to bottom",
"",
"m set memo",
"esc back to files",
"q quit",
}
if m.currentDocument.markdownType != stashedMarkdown {
col1[4] = "s stash this document"
}
s += "\n"
s += "k/↑ up " + col1[0] + "\n"
s += "j/↓ down " + col1[1] + "\n"
s += "j/↓ down " + col1[2] + "\n"
s += "b/pgup page up " + col1[3] + "\n"
s += "f/pgdn page down " + col1[4] + "\n"
s += "u ½ page up " + col1[5] + "\n"
s += "d ½ page down"
s = indent(s, 2)
// Fill up empty cells with spaces for background coloring
if width > 0 {
lines := strings.Split(s, "\n")
for i := 0; i < len(lines); i++ {
l := runewidth.StringWidth(lines[i])
n := max(width-l, 0)
lines[i] += strings.Repeat(" ", n)
}
s = strings.Join(lines, "\n")
}
return helpViewStyle(s)
}
// COMMANDS
func renderWithGlamour(m pagerModel, md string) tea.Cmd {
return func() tea.Msg {
s, err := glamourRender(m, md)
if err != nil {
if debug {
log.Println("error rendering with Glamour:", err)
}
return errMsg{err}
}
return contentRenderedMsg(s)
}
}
// This is where the magic happens.
func glamourRender(m pagerModel, markdown string) (string, error) {
if !config.GlamourEnabled {
return markdown, nil
}
// initialize glamour
var gs glamour.TermRendererOption
if m.glamourStyle == "auto" {
gs = glamour.WithAutoStyle()
} else {
gs = glamour.WithStylePath(m.glamourStyle)
}
width := max(0, min(maxDocumentWidth, m.viewport.Width))
r, err := glamour.NewTermRenderer(
gs,
glamour.WithWordWrap(width),
)
if err != nil {
return "", err
}
out, err := r.Render(markdown)
if err != nil {
return "", err
}
// trim lines
lines := strings.Split(out, "\n")
var content string
for i, s := range lines {
content += strings.TrimSpace(s)
// don't add an artificial newline after the last split
if i+1 < len(lines) {
content += "\n"
}
}
return content, nil
}