//
// 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 {
}
// 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 {
return &Latex{}
}
func (options *Latex) GetFlags() int {
return 0
}
// render code chunks using verbatim, or listings if we have a language
func (options *Latex) BlockCode(out *bytes.Buffer, text []byte, lang string) {
if lang == "" {
out.WriteString("\n\\begin{verbatim}\n")
} else {
out.WriteString("\n\\begin{lstlisting}[language=")
out.WriteString(lang)
out.WriteString("]\n")
}
out.Write(text)
if lang == "" {
out.WriteString("\n\\end{verbatim}\n")
} else {
out.WriteString("\n\\end{lstlisting}\n")
}
}
func (options *Latex) TitleBlock(out *bytes.Buffer, text []byte) {
}
func (options *Latex) BlockQuote(out *bytes.Buffer, text []byte) {
out.WriteString("\n\\begin{quotation}\n")
out.Write(text)
out.WriteString("\n\\end{quotation}\n")
}
func (options *Latex) BlockHtml(out *bytes.Buffer, text []byte) {
// a pretty lame thing to do...
out.WriteString("\n\\begin{verbatim}\n")
out.Write(text)
out.WriteString("\n\\end{verbatim}\n")
}
func (options *Latex) Header(out *bytes.Buffer, text func() bool, level int, id string) {
marker := out.Len()
switch level {
case 1:
out.WriteString("\n\\section{")
case 2:
out.WriteString("\n\\subsection{")
case 3:
out.WriteString("\n\\subsubsection{")
case 4:
out.WriteString("\n\\paragraph{")
case 5:
out.WriteString("\n\\subparagraph{")
case 6:
out.WriteString("\n\\textbf{")
}
if !text() {
out.Truncate(marker)
return
}
out.WriteString("}\n")
}
func (options *Latex) HRule(out *bytes.Buffer) {
out.WriteString("\n\\HRule\n")
}
func (options *Latex) List(out *bytes.Buffer, text func() bool, flags int) {
marker := out.Len()
if flags&LIST_TYPE_ORDERED != 0 {
out.WriteString("\n\\begin{enumerate}\n")
} else {
out.WriteString("\n\\begin{itemize}\n")
}
if !text() {
out.Truncate(marker)
return
}
if flags&LIST_TYPE_ORDERED != 0 {
out.WriteString("\n\\end{enumerate}\n")
} else {
out.WriteString("\n\\end{itemize}\n")
}
}
func (options *Latex) ListItem(out *bytes.Buffer, text []byte, flags int) {
out.WriteString("\n\\item ")
out.Write(text)
}
func (options *Latex) Paragraph(out *bytes.Buffer, text func() bool) {
marker := out.Len()
out.WriteString("\n")
if !text() {
out.Truncate(marker)
return
}
out.WriteString("\n")
}
func (options *Latex) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int) {
out.WriteString("\n\\begin{tabular}{")
for _, elt := range columnData {
switch elt {
case TABLE_ALIGNMENT_LEFT:
out.WriteByte('l')
case TABLE_ALIGNMENT_RIGHT:
out.WriteByte('r')
default:
out.WriteByte('c')
}
}
out.WriteString("}\n")
out.Write(header)
out.WriteString(" \\\\\n\\hline\n")
out.Write(body)
out.WriteString("\n\\end{tabular}\n")
}
func (options *Latex) TableRow(out *bytes.Buffer, text []byte) {
if out.Len() > 0 {
out.WriteString(" \\\\\n")
}
out.Write(text)
}
func (options *Latex) TableHeaderCell(out *bytes.Buffer, text []byte, align int) {
if out.Len() > 0 {
out.WriteString(" & ")
}
out.Write(text)
}
func (options *Latex) TableCell(out *bytes.Buffer, text []byte, align int) {
if out.Len() > 0 {
out.WriteString(" & ")
}
out.Write(text)
}
// TODO: this
func (options *Latex) Footnotes(out *bytes.Buffer, text func() bool) {
}
func (options *Latex) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int) {
}
func (options *Latex) AutoLink(out *bytes.Buffer, link []byte, kind int) {
out.WriteString("\\href{")
if kind == LINK_TYPE_EMAIL {
out.WriteString("mailto:")
}
out.Write(link)
out.WriteString("}{")
out.Write(link)
out.WriteString("}")
}
func (options *Latex) CodeSpan(out *bytes.Buffer, text []byte) {
out.WriteString("\\texttt{")
escapeSpecialChars(out, text)
out.WriteString("}")
}
func (options *Latex) DoubleEmphasis(out *bytes.Buffer, text []byte) {
out.WriteString("\\textbf{")
out.Write(text)
out.WriteString("}")
}
func (options *Latex) Emphasis(out *bytes.Buffer, text []byte) {
out.WriteString("\\textit{")
out.Write(text)
out.WriteString("}")
}
func (options *Latex) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte) {
if bytes.HasPrefix(link, []byte("http://")) || bytes.HasPrefix(link, []byte("https://")) {
// treat it like a link
out.WriteString("\\href{")
out.Write(link)
out.WriteString("}{")
out.Write(alt)
out.WriteString("}")
} else {
out.WriteString("\\includegraphics{")
out.Write(link)
out.WriteString("}")
}
}
func (options *Latex) LineBreak(out *bytes.Buffer) {
out.WriteString(" \\\\\n")
}
func (options *Latex) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
out.WriteString("\\href{")
out.Write(link)
out.WriteString("}{")
out.Write(content)
out.WriteString("}")
}
func (options *Latex) RawHtmlTag(out *bytes.Buffer, tag []byte) {
}
func (options *Latex) TripleEmphasis(out *bytes.Buffer, text []byte) {
out.WriteString("\\textbf{\\textit{")
out.Write(text)
out.WriteString("}}")
}
func (options *Latex) StrikeThrough(out *bytes.Buffer, text []byte) {
out.WriteString("\\sout{")
out.Write(text)
out.WriteString("}")
}
// TODO: this
func (options *Latex) FootnoteRef(out *bytes.Buffer, ref []byte, id int) {
}
func needsBackslash(c byte) bool {
for _, r := range []byte("_{}%$&\\~#") {
if c == r {
return true
}
}
return false
}
func escapeSpecialChars(out *bytes.Buffer, 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 {
out.Write(text[org:i])
}
// escape a character
if i >= len(text) {
break
}
out.WriteByte('\\')
out.WriteByte(text[i])
}
}
func (options *Latex) Entity(out *bytes.Buffer, entity []byte) {
// TODO: convert this into a unicode character or something
out.Write(entity)
}
func (options *Latex) NormalText(out *bytes.Buffer, text []byte) {
escapeSpecialChars(out, text)
}
// header and footer
func (options *Latex) DocumentHeader(out *bytes.Buffer) {
out.WriteString("\\documentclass{article}\n")
out.WriteString("\n")
out.WriteString("\\usepackage{graphicx}\n")
out.WriteString("\\usepackage{listings}\n")
out.WriteString("\\usepackage[margin=1in]{geometry}\n")
out.WriteString("\\usepackage[utf8]{inputenc}\n")
out.WriteString("\\usepackage{verbatim}\n")
out.WriteString("\\usepackage[normalem]{ulem}\n")
out.WriteString("\\usepackage{hyperref}\n")
out.WriteString("\n")
out.WriteString("\\hypersetup{colorlinks,%\n")
out.WriteString(" citecolor=black,%\n")
out.WriteString(" filecolor=black,%\n")
out.WriteString(" linkcolor=black,%\n")
out.WriteString(" urlcolor=black,%\n")
out.WriteString(" pdfstartview=FitH,%\n")
out.WriteString(" breaklinks=true,%\n")
out.WriteString(" pdfauthor={Blackfriday Markdown Processor v")
out.WriteString(VERSION)
out.WriteString("}}\n")
out.WriteString("\n")
out.WriteString("\\newcommand{\\HRule}{\\rule{\\linewidth}{0.5mm}}\n")
out.WriteString("\\addtolength{\\parskip}{0.5\\baselineskip}\n")
out.WriteString("\\parindent=0pt\n")
out.WriteString("\n")
out.WriteString("\\begin{document}\n")
}
func (options *Latex) DocumentFooter(out *bytes.Buffer) {
out.WriteString("\n\\end{document}\n")
}
