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mirror of https://github.com/danog/blackfriday.git synced 2024-12-11 17:09:38 +01:00
blackfriday/latex.go
2016-04-01 15:37:21 +03:00

332 lines
7.1 KiB
Go

//
// Blackfriday Markdown Processor
// Available at http://github.com/russross/blackfriday
//
// Copyright © 2011 Russ Ross <russ@russross.com>.
// Distributed under the Simplified BSD License.
// See README.md for details.
//
//
//
// LaTeX rendering backend
//
//
package blackfriday
import "bytes"
// Latex is a type that implements the Renderer interface for LaTeX output.
//
// Do not create this directly, instead use the LatexRenderer function.
type Latex struct {
w HTMLWriter
}
// LatexRenderer creates and configures a Latex object, which
// satisfies the Renderer interface.
//
// flags is a set of LATEX_* options ORed together (currently no such options
// are defined).
func LatexRenderer(flags int) Renderer {
var writer HTMLWriter
return &Latex{
w: writer,
}
}
func (r *Latex) Write(b []byte) (int, error) {
return r.w.Write(b)
}
// render code chunks using verbatim, or listings if we have a language
func (r *Latex) BlockCode(text []byte, lang string) {
if lang == "" {
r.w.WriteString("\n\\begin{verbatim}\n")
} else {
r.w.WriteString("\n\\begin{lstlisting}[language=")
r.w.WriteString(lang)
r.w.WriteString("]\n")
}
r.w.Write(text)
if lang == "" {
r.w.WriteString("\n\\end{verbatim}\n")
} else {
r.w.WriteString("\n\\end{lstlisting}\n")
}
}
func (r *Latex) TitleBlock(text []byte) {
}
func (r *Latex) BlockQuote(text []byte) {
r.w.WriteString("\n\\begin{quotation}\n")
r.w.Write(text)
r.w.WriteString("\n\\end{quotation}\n")
}
func (r *Latex) BlockHtml(text []byte) {
// a pretty lame thing to do...
r.w.WriteString("\n\\begin{verbatim}\n")
r.w.Write(text)
r.w.WriteString("\n\\end{verbatim}\n")
}
func (r *Latex) BeginHeader(level int, id string) {
switch level {
case 1:
r.w.WriteString("\n\\section{")
case 2:
r.w.WriteString("\n\\subsection{")
case 3:
r.w.WriteString("\n\\subsubsection{")
case 4:
r.w.WriteString("\n\\paragraph{")
case 5:
r.w.WriteString("\n\\subparagraph{")
case 6:
r.w.WriteString("\n\\textbf{")
}
}
func (r *Latex) EndHeader(level int, id string, header []byte) {
r.w.WriteString("}\n")
}
func (r *Latex) HRule() {
r.w.WriteString("\n\\HRule\n")
}
func (r *Latex) BeginList(flags ListType) {
if flags&ListTypeOrdered != 0 {
r.w.WriteString("\n\\begin{enumerate}\n")
} else {
r.w.WriteString("\n\\begin{itemize}\n")
}
}
func (r *Latex) EndList(flags ListType) {
if flags&ListTypeOrdered != 0 {
r.w.WriteString("\n\\end{enumerate}\n")
} else {
r.w.WriteString("\n\\end{itemize}\n")
}
}
func (r *Latex) ListItem(text []byte, flags ListType) {
r.w.WriteString("\n\\item ")
r.w.Write(text)
}
func (r *Latex) BeginParagraph() {
r.w.WriteString("\n")
}
func (r *Latex) EndParagraph() {
r.w.WriteString("\n")
}
func (r *Latex) Table(header []byte, body []byte, columnData []CellAlignFlags) {
r.w.WriteString("\n\\begin{tabular}{")
for _, elt := range columnData {
switch elt {
case TableAlignmentLeft:
r.w.WriteByte('l')
case TableAlignmentRight:
r.w.WriteByte('r')
default:
r.w.WriteByte('c')
}
}
r.w.WriteString("}\n")
r.w.Write(header)
r.w.WriteString(" \\\\\n\\hline\n")
r.w.Write(body)
r.w.WriteString("\n\\end{tabular}\n")
}
func (r *Latex) TableRow(text []byte) {
r.w.WriteString(" \\\\\n")
r.w.Write(text)
}
func (r *Latex) TableHeaderCell(out *bytes.Buffer, text []byte, align CellAlignFlags) {
if out.Len() > 0 {
out.WriteString(" & ")
}
out.Write(text)
}
func (r *Latex) TableCell(out *bytes.Buffer, text []byte, align CellAlignFlags) {
if out.Len() > 0 {
out.WriteString(" & ")
}
out.Write(text)
}
// TODO: this
func (r *Latex) BeginFootnotes() {
}
// TODO: this
func (r *Latex) EndFootnotes() {
}
func (r *Latex) FootnoteItem(name, text []byte, flags ListType) {
}
func (r *Latex) AutoLink(link []byte, kind LinkType) {
r.w.WriteString("\\href{")
if kind == LinkTypeEmail {
r.w.WriteString("mailto:")
}
r.w.Write(link)
r.w.WriteString("}{")
r.w.Write(link)
r.w.WriteString("}")
}
func (r *Latex) CodeSpan(text []byte) {
r.w.WriteString("\\texttt{")
r.escapeSpecialChars(text)
r.w.WriteString("}")
}
func (r *Latex) DoubleEmphasis(text []byte) {
r.w.WriteString("\\textbf{")
r.w.Write(text)
r.w.WriteString("}")
}
func (r *Latex) Emphasis(text []byte) {
r.w.WriteString("\\textit{")
r.w.Write(text)
r.w.WriteString("}")
}
func (r *Latex) Image(link []byte, title []byte, alt []byte) {
if bytes.HasPrefix(link, []byte("http://")) || bytes.HasPrefix(link, []byte("https://")) {
// treat it like a link
r.w.WriteString("\\href{")
r.w.Write(link)
r.w.WriteString("}{")
r.w.Write(alt)
r.w.WriteString("}")
} else {
r.w.WriteString("\\includegraphics{")
r.w.Write(link)
r.w.WriteString("}")
}
}
func (r *Latex) LineBreak() {
r.w.WriteString(" \\\\\n")
}
func (r *Latex) Link(link []byte, title []byte, content []byte) {
r.w.WriteString("\\href{")
r.w.Write(link)
r.w.WriteString("}{")
r.w.Write(content)
r.w.WriteString("}")
}
func (r *Latex) RawHtmlTag(tag []byte) {
}
func (r *Latex) TripleEmphasis(text []byte) {
r.w.WriteString("\\textbf{\\textit{")
r.w.Write(text)
r.w.WriteString("}}")
}
func (r *Latex) StrikeThrough(text []byte) {
r.w.WriteString("\\sout{")
r.w.Write(text)
r.w.WriteString("}")
}
// TODO: this
func (r *Latex) FootnoteRef(ref []byte, id int) {
}
func needsBackslash(c byte) bool {
for _, r := range []byte("_{}%$&\\~#") {
if c == r {
return true
}
}
return false
}
func (r *Latex) escapeSpecialChars(text []byte) {
for i := 0; i < len(text); i++ {
// directly copy normal characters
org := i
for i < len(text) && !needsBackslash(text[i]) {
i++
}
if i > org {
r.w.Write(text[org:i])
}
// escape a character
if i >= len(text) {
break
}
r.w.WriteByte('\\')
r.w.WriteByte(text[i])
}
}
func (r *Latex) Entity(entity []byte) {
// TODO: convert this into a unicode character or something
r.w.Write(entity)
}
func (r *Latex) NormalText(text []byte) {
r.escapeSpecialChars(text)
}
// header and footer
func (r *Latex) DocumentHeader() {
r.w.WriteString("\\documentclass{article}\n")
r.w.WriteString("\n")
r.w.WriteString("\\usepackage{graphicx}\n")
r.w.WriteString("\\usepackage{listings}\n")
r.w.WriteString("\\usepackage[margin=1in]{geometry}\n")
r.w.WriteString("\\usepackage[utf8]{inputenc}\n")
r.w.WriteString("\\usepackage{verbatim}\n")
r.w.WriteString("\\usepackage[normalem]{ulem}\n")
r.w.WriteString("\\usepackage{hyperref}\n")
r.w.WriteString("\n")
r.w.WriteString("\\hypersetup{colorlinks,%\n")
r.w.WriteString(" citecolor=black,%\n")
r.w.WriteString(" filecolor=black,%\n")
r.w.WriteString(" linkcolor=black,%\n")
r.w.WriteString(" urlcolor=black,%\n")
r.w.WriteString(" pdfstartview=FitH,%\n")
r.w.WriteString(" breaklinks=true,%\n")
r.w.WriteString(" pdfauthor={Blackfriday Markdown Processor v")
r.w.WriteString(VERSION)
r.w.WriteString("}}\n")
r.w.WriteString("\n")
r.w.WriteString("\\newcommand{\\HRule}{\\rule{\\linewidth}{0.5mm}}\n")
r.w.WriteString("\\addtolength{\\parskip}{0.5\\baselineskip}\n")
r.w.WriteString("\\parindent=0pt\n")
r.w.WriteString("\n")
r.w.WriteString("\\begin{document}\n")
}
func (r *Latex) DocumentFooter() {
r.w.WriteString("\n\\end{document}\n")
}
func (r *Latex) Render(ast *Node) []byte {
return nil
}