Stanislav N. aka pztrn
19b5ef3d9f
Well, doing "git add ." not from repository's root is a bad idea. Updated chroma dependency, added more languages to syntax highlighting.
393 lines
11 KiB
Go
393 lines
11 KiB
Go
package html
|
|
|
|
import (
|
|
"fmt"
|
|
"html"
|
|
"io"
|
|
"sort"
|
|
"strings"
|
|
|
|
"github.com/alecthomas/chroma"
|
|
)
|
|
|
|
// Option sets an option of the HTML formatter.
|
|
type Option func(f *Formatter)
|
|
|
|
// Standalone configures the HTML formatter for generating a standalone HTML document.
|
|
func Standalone() Option { return func(f *Formatter) { f.standalone = true } }
|
|
|
|
// ClassPrefix sets the CSS class prefix.
|
|
func ClassPrefix(prefix string) Option { return func(f *Formatter) { f.prefix = prefix } }
|
|
|
|
// WithClasses emits HTML using CSS classes, rather than inline styles.
|
|
func WithClasses() Option { return func(f *Formatter) { f.Classes = true } }
|
|
|
|
// TabWidth sets the number of characters for a tab. Defaults to 8.
|
|
func TabWidth(width int) Option { return func(f *Formatter) { f.tabWidth = width } }
|
|
|
|
// PreventSurroundingPre prevents the surrounding pre tags around the generated code
|
|
func PreventSurroundingPre() Option { return func(f *Formatter) { f.preventSurroundingPre = true } }
|
|
|
|
// WithLineNumbers formats output with line numbers.
|
|
func WithLineNumbers() Option {
|
|
return func(f *Formatter) {
|
|
f.lineNumbers = true
|
|
}
|
|
}
|
|
|
|
// LineNumbersInTable will, when combined with WithLineNumbers, separate the line numbers
|
|
// and code in table td's, which make them copy-and-paste friendly.
|
|
func LineNumbersInTable() Option {
|
|
return func(f *Formatter) {
|
|
f.lineNumbersInTable = true
|
|
}
|
|
}
|
|
|
|
// HighlightLines higlights the given line ranges with the Highlight style.
|
|
//
|
|
// A range is the beginning and ending of a range as 1-based line numbers, inclusive.
|
|
func HighlightLines(ranges [][2]int) Option {
|
|
return func(f *Formatter) {
|
|
f.highlightRanges = ranges
|
|
sort.Sort(f.highlightRanges)
|
|
}
|
|
}
|
|
|
|
// BaseLineNumber sets the initial number to start line numbering at. Defaults to 1.
|
|
func BaseLineNumber(n int) Option {
|
|
return func(f *Formatter) {
|
|
f.baseLineNumber = n
|
|
}
|
|
}
|
|
|
|
// New HTML formatter.
|
|
func New(options ...Option) *Formatter {
|
|
f := &Formatter{
|
|
baseLineNumber: 1,
|
|
}
|
|
for _, option := range options {
|
|
option(f)
|
|
}
|
|
return f
|
|
}
|
|
|
|
// Formatter that generates HTML.
|
|
type Formatter struct {
|
|
standalone bool
|
|
prefix string
|
|
Classes bool // Exported field to detect when classes are being used
|
|
preventSurroundingPre bool
|
|
tabWidth int
|
|
lineNumbers bool
|
|
lineNumbersInTable bool
|
|
highlightRanges highlightRanges
|
|
baseLineNumber int
|
|
}
|
|
|
|
type highlightRanges [][2]int
|
|
|
|
func (h highlightRanges) Len() int { return len(h) }
|
|
func (h highlightRanges) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
|
|
func (h highlightRanges) Less(i, j int) bool { return h[i][0] < h[j][0] }
|
|
|
|
func (f *Formatter) Format(w io.Writer, style *chroma.Style, iterator chroma.Iterator) (err error) {
|
|
defer func() {
|
|
if perr := recover(); perr != nil {
|
|
err = perr.(error)
|
|
}
|
|
}()
|
|
return f.writeHTML(w, style, iterator.Tokens())
|
|
}
|
|
|
|
func brightenOrDarken(colour chroma.Colour, factor float64) chroma.Colour {
|
|
if colour.Brightness() < 0.5 {
|
|
return colour.Brighten(factor)
|
|
}
|
|
return colour.Brighten(-factor)
|
|
}
|
|
|
|
// Ensure that style entries exist for highlighting, etc.
|
|
func (f *Formatter) restyle(style *chroma.Style) (*chroma.Style, error) {
|
|
builder := style.Builder()
|
|
bg := builder.Get(chroma.Background)
|
|
// If we don't have a line highlight colour, make one that is 10% brighter/darker than the background.
|
|
if !style.Has(chroma.LineHighlight) {
|
|
highlight := chroma.StyleEntry{Background: bg.Background}
|
|
highlight.Background = brightenOrDarken(highlight.Background, 0.1)
|
|
builder.AddEntry(chroma.LineHighlight, highlight)
|
|
}
|
|
// If we don't have line numbers, use the text colour but 20% brighter/darker
|
|
if !style.Has(chroma.LineNumbers) {
|
|
text := chroma.StyleEntry{Colour: bg.Colour}
|
|
text.Colour = brightenOrDarken(text.Colour, 0.5)
|
|
builder.AddEntry(chroma.LineNumbers, text)
|
|
builder.AddEntry(chroma.LineNumbersTable, text)
|
|
}
|
|
return builder.Build()
|
|
}
|
|
|
|
// We deliberately don't use html/template here because it is two orders of magnitude slower (benchmarked).
|
|
//
|
|
// OTOH we need to be super careful about correct escaping...
|
|
func (f *Formatter) writeHTML(w io.Writer, style *chroma.Style, tokens []chroma.Token) (err error) { // nolint: gocyclo
|
|
style, err = f.restyle(style)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
css := f.styleToCSS(style)
|
|
if !f.Classes {
|
|
for t, style := range css {
|
|
css[t] = compressStyle(style)
|
|
}
|
|
}
|
|
if f.standalone {
|
|
fmt.Fprint(w, "<html>\n")
|
|
if f.Classes {
|
|
fmt.Fprint(w, "<style type=\"text/css\">\n")
|
|
f.WriteCSS(w, style)
|
|
fmt.Fprintf(w, "body { %s; }\n", css[chroma.Background])
|
|
fmt.Fprint(w, "</style>")
|
|
}
|
|
fmt.Fprintf(w, "<body%s>\n", f.styleAttr(css, chroma.Background))
|
|
}
|
|
|
|
wrapInTable := f.lineNumbers && f.lineNumbersInTable
|
|
|
|
lines := chroma.SplitTokensIntoLines(tokens)
|
|
lineDigits := len(fmt.Sprintf("%d", len(lines)))
|
|
highlightIndex := 0
|
|
|
|
if wrapInTable {
|
|
// List line numbers in its own <td>
|
|
fmt.Fprintf(w, "<div%s>\n", f.styleAttr(css, chroma.Background))
|
|
fmt.Fprintf(w, "<table%s><tr>", f.styleAttr(css, chroma.LineTable))
|
|
fmt.Fprintf(w, "<td%s>\n", f.styleAttr(css, chroma.LineTableTD))
|
|
if !f.preventSurroundingPre {
|
|
fmt.Fprintf(w, "<pre%s>", f.styleAttr(css, chroma.Background))
|
|
}
|
|
for index := range lines {
|
|
line := f.baseLineNumber + index
|
|
highlight, next := f.shouldHighlight(highlightIndex, line)
|
|
if next {
|
|
highlightIndex++
|
|
}
|
|
if highlight {
|
|
fmt.Fprintf(w, "<span%s>", f.styleAttr(css, chroma.LineHighlight))
|
|
}
|
|
|
|
fmt.Fprintf(w, "<span%s>%*d\n</span>", f.styleAttr(css, chroma.LineNumbersTable), lineDigits, line)
|
|
|
|
if highlight {
|
|
fmt.Fprintf(w, "</span>")
|
|
}
|
|
}
|
|
if !f.preventSurroundingPre {
|
|
fmt.Fprint(w, "</pre>")
|
|
}
|
|
fmt.Fprint(w, "</td>\n")
|
|
fmt.Fprintf(w, "<td%s>\n", f.styleAttr(css, chroma.LineTableTD))
|
|
}
|
|
|
|
if !f.preventSurroundingPre {
|
|
fmt.Fprintf(w, "<pre%s>", f.styleAttr(css, chroma.Background))
|
|
}
|
|
highlightIndex = 0
|
|
for index, tokens := range lines {
|
|
// 1-based line number.
|
|
line := f.baseLineNumber + index
|
|
highlight, next := f.shouldHighlight(highlightIndex, line)
|
|
if next {
|
|
highlightIndex++
|
|
}
|
|
if highlight {
|
|
fmt.Fprintf(w, "<span%s>", f.styleAttr(css, chroma.LineHighlight))
|
|
}
|
|
|
|
if f.lineNumbers && !wrapInTable {
|
|
fmt.Fprintf(w, "<span%s>%*d</span>", f.styleAttr(css, chroma.LineNumbers), lineDigits, line)
|
|
}
|
|
|
|
for _, token := range tokens {
|
|
html := html.EscapeString(token.String())
|
|
attr := f.styleAttr(css, token.Type)
|
|
if attr != "" {
|
|
html = fmt.Sprintf("<span%s>%s</span>", attr, html)
|
|
}
|
|
fmt.Fprint(w, html)
|
|
}
|
|
if highlight {
|
|
fmt.Fprintf(w, "</span>")
|
|
}
|
|
}
|
|
|
|
if !f.preventSurroundingPre {
|
|
fmt.Fprint(w, "</pre>")
|
|
}
|
|
|
|
if wrapInTable {
|
|
fmt.Fprint(w, "</td></tr></table>\n")
|
|
fmt.Fprint(w, "</div>\n")
|
|
}
|
|
|
|
if f.standalone {
|
|
fmt.Fprint(w, "\n</body>\n")
|
|
fmt.Fprint(w, "</html>\n")
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (f *Formatter) shouldHighlight(highlightIndex, line int) (bool, bool) {
|
|
next := false
|
|
for highlightIndex < len(f.highlightRanges) && line > f.highlightRanges[highlightIndex][1] {
|
|
highlightIndex++
|
|
next = true
|
|
}
|
|
if highlightIndex < len(f.highlightRanges) {
|
|
hrange := f.highlightRanges[highlightIndex]
|
|
if line >= hrange[0] && line <= hrange[1] {
|
|
return true, next
|
|
}
|
|
}
|
|
return false, next
|
|
}
|
|
|
|
func (f *Formatter) class(t chroma.TokenType) string {
|
|
for t != 0 {
|
|
if cls, ok := chroma.StandardTypes[t]; ok {
|
|
if cls != "" {
|
|
return f.prefix + cls
|
|
}
|
|
return ""
|
|
}
|
|
t = t.Parent()
|
|
}
|
|
if cls := chroma.StandardTypes[t]; cls != "" {
|
|
return f.prefix + cls
|
|
}
|
|
return ""
|
|
}
|
|
|
|
func (f *Formatter) styleAttr(styles map[chroma.TokenType]string, tt chroma.TokenType) string {
|
|
if f.Classes {
|
|
cls := f.class(tt)
|
|
if cls == "" {
|
|
return ""
|
|
}
|
|
return string(fmt.Sprintf(` class="%s"`, cls))
|
|
}
|
|
if _, ok := styles[tt]; !ok {
|
|
tt = tt.SubCategory()
|
|
if _, ok := styles[tt]; !ok {
|
|
tt = tt.Category()
|
|
if _, ok := styles[tt]; !ok {
|
|
return ""
|
|
}
|
|
}
|
|
}
|
|
return fmt.Sprintf(` style="%s"`, styles[tt])
|
|
}
|
|
|
|
func (f *Formatter) tabWidthStyle() string {
|
|
if f.tabWidth != 0 && f.tabWidth != 8 {
|
|
return fmt.Sprintf("; -moz-tab-size: %[1]d; -o-tab-size: %[1]d; tab-size: %[1]d", f.tabWidth)
|
|
}
|
|
return ""
|
|
}
|
|
|
|
// WriteCSS writes CSS style definitions (without any surrounding HTML).
|
|
func (f *Formatter) WriteCSS(w io.Writer, style *chroma.Style) error {
|
|
css := f.styleToCSS(style)
|
|
// Special-case background as it is mapped to the outer ".chroma" class.
|
|
if _, err := fmt.Fprintf(w, "/* %s */ .%schroma { %s }\n", chroma.Background, f.prefix, css[chroma.Background]); err != nil {
|
|
return err
|
|
}
|
|
// Special-case code column of table to expand width.
|
|
if f.lineNumbers && f.lineNumbersInTable {
|
|
if _, err := fmt.Fprintf(w, "/* %s */ .%schroma .%s:last-child { width: 100%%; }",
|
|
chroma.LineTableTD, f.prefix, f.class(chroma.LineTableTD)); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
tts := []int{}
|
|
for tt := range css {
|
|
tts = append(tts, int(tt))
|
|
}
|
|
sort.Ints(tts)
|
|
for _, ti := range tts {
|
|
tt := chroma.TokenType(ti)
|
|
if tt == chroma.Background {
|
|
continue
|
|
}
|
|
styles := css[tt]
|
|
if _, err := fmt.Fprintf(w, "/* %s */ .%schroma .%s { %s }\n", tt, f.prefix, f.class(tt), styles); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (f *Formatter) styleToCSS(style *chroma.Style) map[chroma.TokenType]string {
|
|
classes := map[chroma.TokenType]string{}
|
|
bg := style.Get(chroma.Background)
|
|
// Convert the style.
|
|
for t := range chroma.StandardTypes {
|
|
entry := style.Get(t)
|
|
if t != chroma.Background {
|
|
entry = entry.Sub(bg)
|
|
}
|
|
if entry.IsZero() {
|
|
continue
|
|
}
|
|
classes[t] = StyleEntryToCSS(entry)
|
|
}
|
|
classes[chroma.Background] += f.tabWidthStyle()
|
|
lineNumbersStyle := "margin-right: 0.4em; padding: 0 0.4em 0 0.4em;"
|
|
// All rules begin with default rules followed by user provided rules
|
|
classes[chroma.LineNumbers] = lineNumbersStyle + classes[chroma.LineNumbers]
|
|
classes[chroma.LineNumbersTable] = lineNumbersStyle + classes[chroma.LineNumbersTable]
|
|
classes[chroma.LineHighlight] = "display: block; width: 100%;" + classes[chroma.LineHighlight]
|
|
classes[chroma.LineTable] = "border-spacing: 0; padding: 0; margin: 0; border: 0; width: auto; overflow: auto; display: block;" + classes[chroma.LineTable]
|
|
classes[chroma.LineTableTD] = "vertical-align: top; padding: 0; margin: 0; border: 0;" + classes[chroma.LineTableTD]
|
|
return classes
|
|
}
|
|
|
|
// StyleEntryToCSS converts a chroma.StyleEntry to CSS attributes.
|
|
func StyleEntryToCSS(e chroma.StyleEntry) string {
|
|
styles := []string{}
|
|
if e.Colour.IsSet() {
|
|
styles = append(styles, "color: "+e.Colour.String())
|
|
}
|
|
if e.Background.IsSet() {
|
|
styles = append(styles, "background-color: "+e.Background.String())
|
|
}
|
|
if e.Bold == chroma.Yes {
|
|
styles = append(styles, "font-weight: bold")
|
|
}
|
|
if e.Italic == chroma.Yes {
|
|
styles = append(styles, "font-style: italic")
|
|
}
|
|
if e.Underline == chroma.Yes {
|
|
styles = append(styles, "text-decoration: underline")
|
|
}
|
|
return strings.Join(styles, "; ")
|
|
}
|
|
|
|
// Compress CSS attributes - remove spaces, transform 6-digit colours to 3.
|
|
func compressStyle(s string) string {
|
|
parts := strings.Split(s, ";")
|
|
out := []string{}
|
|
for _, p := range parts {
|
|
p = strings.Join(strings.Fields(p), " ")
|
|
p = strings.Replace(p, ": ", ":", 1)
|
|
if strings.Contains(p, "#") {
|
|
c := p[len(p)-6:]
|
|
if c[0] == c[1] && c[2] == c[3] && c[4] == c[5] {
|
|
p = p[:len(p)-6] + c[0:1] + c[2:3] + c[4:5]
|
|
}
|
|
}
|
|
out = append(out, p)
|
|
}
|
|
return strings.Join(out, ";")
|
|
}
|