1// 2// Blackfriday Markdown Processor 3// Available at http://github.com/russross/blackfriday 4// 5// Copyright © 2011 Russ Ross <russ@russross.com>. 6// Distributed under the Simplified BSD License. 7// See README.md for details. 8// 9 10// 11// 12// LaTeX rendering backend 13// 14// 15 16package blackfriday 17 18import ( 19 "bytes" 20 "strings" 21) 22 23// Latex is a type that implements the Renderer interface for LaTeX output. 24// 25// Do not create this directly, instead use the LatexRenderer function. 26type Latex struct { 27} 28 29// LatexRenderer creates and configures a Latex object, which 30// satisfies the Renderer interface. 31// 32// flags is a set of LATEX_* options ORed together (currently no such options 33// are defined). 34func LatexRenderer(flags int) Renderer { 35 return &Latex{} 36} 37 38func (options *Latex) GetFlags() int { 39 return 0 40} 41 42// render code chunks using verbatim, or listings if we have a language 43func (options *Latex) BlockCode(out *bytes.Buffer, text []byte, info string) { 44 if info == "" { 45 out.WriteString("\n\\begin{verbatim}\n") 46 } else { 47 lang := strings.Fields(info)[0] 48 out.WriteString("\n\\begin{lstlisting}[language=") 49 out.WriteString(lang) 50 out.WriteString("]\n") 51 } 52 out.Write(text) 53 if info == "" { 54 out.WriteString("\n\\end{verbatim}\n") 55 } else { 56 out.WriteString("\n\\end{lstlisting}\n") 57 } 58} 59 60func (options *Latex) TitleBlock(out *bytes.Buffer, text []byte) { 61 62} 63 64func (options *Latex) BlockQuote(out *bytes.Buffer, text []byte) { 65 out.WriteString("\n\\begin{quotation}\n") 66 out.Write(text) 67 out.WriteString("\n\\end{quotation}\n") 68} 69 70func (options *Latex) BlockHtml(out *bytes.Buffer, text []byte) { 71 // a pretty lame thing to do... 72 out.WriteString("\n\\begin{verbatim}\n") 73 out.Write(text) 74 out.WriteString("\n\\end{verbatim}\n") 75} 76 77func (options *Latex) Header(out *bytes.Buffer, text func() bool, level int, id string) { 78 marker := out.Len() 79 80 switch level { 81 case 1: 82 out.WriteString("\n\\section{") 83 case 2: 84 out.WriteString("\n\\subsection{") 85 case 3: 86 out.WriteString("\n\\subsubsection{") 87 case 4: 88 out.WriteString("\n\\paragraph{") 89 case 5: 90 out.WriteString("\n\\subparagraph{") 91 case 6: 92 out.WriteString("\n\\textbf{") 93 } 94 if !text() { 95 out.Truncate(marker) 96 return 97 } 98 out.WriteString("}\n") 99} 100 101func (options *Latex) HRule(out *bytes.Buffer) { 102 out.WriteString("\n\\HRule\n") 103} 104 105func (options *Latex) List(out *bytes.Buffer, text func() bool, flags int) { 106 marker := out.Len() 107 if flags&LIST_TYPE_ORDERED != 0 { 108 out.WriteString("\n\\begin{enumerate}\n") 109 } else { 110 out.WriteString("\n\\begin{itemize}\n") 111 } 112 if !text() { 113 out.Truncate(marker) 114 return 115 } 116 if flags&LIST_TYPE_ORDERED != 0 { 117 out.WriteString("\n\\end{enumerate}\n") 118 } else { 119 out.WriteString("\n\\end{itemize}\n") 120 } 121} 122 123func (options *Latex) ListItem(out *bytes.Buffer, text []byte, flags int) { 124 out.WriteString("\n\\item ") 125 out.Write(text) 126} 127 128func (options *Latex) Paragraph(out *bytes.Buffer, text func() bool) { 129 marker := out.Len() 130 out.WriteString("\n") 131 if !text() { 132 out.Truncate(marker) 133 return 134 } 135 out.WriteString("\n") 136} 137 138func (options *Latex) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int) { 139 out.WriteString("\n\\begin{tabular}{") 140 for _, elt := range columnData { 141 switch elt { 142 case TABLE_ALIGNMENT_LEFT: 143 out.WriteByte('l') 144 case TABLE_ALIGNMENT_RIGHT: 145 out.WriteByte('r') 146 default: 147 out.WriteByte('c') 148 } 149 } 150 out.WriteString("}\n") 151 out.Write(header) 152 out.WriteString(" \\\\\n\\hline\n") 153 out.Write(body) 154 out.WriteString("\n\\end{tabular}\n") 155} 156 157func (options *Latex) TableRow(out *bytes.Buffer, text []byte) { 158 if out.Len() > 0 { 159 out.WriteString(" \\\\\n") 160 } 161 out.Write(text) 162} 163 164func (options *Latex) TableHeaderCell(out *bytes.Buffer, text []byte, align int) { 165 if out.Len() > 0 { 166 out.WriteString(" & ") 167 } 168 out.Write(text) 169} 170 171func (options *Latex) TableCell(out *bytes.Buffer, text []byte, align int) { 172 if out.Len() > 0 { 173 out.WriteString(" & ") 174 } 175 out.Write(text) 176} 177 178// TODO: this 179func (options *Latex) Footnotes(out *bytes.Buffer, text func() bool) { 180 181} 182 183func (options *Latex) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int) { 184 185} 186 187func (options *Latex) AutoLink(out *bytes.Buffer, link []byte, kind int) { 188 out.WriteString("\\href{") 189 if kind == LINK_TYPE_EMAIL { 190 out.WriteString("mailto:") 191 } 192 out.Write(link) 193 out.WriteString("}{") 194 out.Write(link) 195 out.WriteString("}") 196} 197 198func (options *Latex) CodeSpan(out *bytes.Buffer, text []byte) { 199 out.WriteString("\\texttt{") 200 escapeSpecialChars(out, text) 201 out.WriteString("}") 202} 203 204func (options *Latex) DoubleEmphasis(out *bytes.Buffer, text []byte) { 205 out.WriteString("\\textbf{") 206 out.Write(text) 207 out.WriteString("}") 208} 209 210func (options *Latex) Emphasis(out *bytes.Buffer, text []byte) { 211 out.WriteString("\\textit{") 212 out.Write(text) 213 out.WriteString("}") 214} 215 216func (options *Latex) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte) { 217 if bytes.HasPrefix(link, []byte("http://")) || bytes.HasPrefix(link, []byte("https://")) { 218 // treat it like a link 219 out.WriteString("\\href{") 220 out.Write(link) 221 out.WriteString("}{") 222 out.Write(alt) 223 out.WriteString("}") 224 } else { 225 out.WriteString("\\includegraphics{") 226 out.Write(link) 227 out.WriteString("}") 228 } 229} 230 231func (options *Latex) LineBreak(out *bytes.Buffer) { 232 out.WriteString(" \\\\\n") 233} 234 235func (options *Latex) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) { 236 out.WriteString("\\href{") 237 out.Write(link) 238 out.WriteString("}{") 239 out.Write(content) 240 out.WriteString("}") 241} 242 243func (options *Latex) RawHtmlTag(out *bytes.Buffer, tag []byte) { 244} 245 246func (options *Latex) TripleEmphasis(out *bytes.Buffer, text []byte) { 247 out.WriteString("\\textbf{\\textit{") 248 out.Write(text) 249 out.WriteString("}}") 250} 251 252func (options *Latex) StrikeThrough(out *bytes.Buffer, text []byte) { 253 out.WriteString("\\sout{") 254 out.Write(text) 255 out.WriteString("}") 256} 257 258// TODO: this 259func (options *Latex) FootnoteRef(out *bytes.Buffer, ref []byte, id int) { 260 261} 262 263func needsBackslash(c byte) bool { 264 for _, r := range []byte("_{}%$&\\~#") { 265 if c == r { 266 return true 267 } 268 } 269 return false 270} 271 272func escapeSpecialChars(out *bytes.Buffer, text []byte) { 273 for i := 0; i < len(text); i++ { 274 // directly copy normal characters 275 org := i 276 277 for i < len(text) && !needsBackslash(text[i]) { 278 i++ 279 } 280 if i > org { 281 out.Write(text[org:i]) 282 } 283 284 // escape a character 285 if i >= len(text) { 286 break 287 } 288 out.WriteByte('\\') 289 out.WriteByte(text[i]) 290 } 291} 292 293func (options *Latex) Entity(out *bytes.Buffer, entity []byte) { 294 // TODO: convert this into a unicode character or something 295 out.Write(entity) 296} 297 298func (options *Latex) NormalText(out *bytes.Buffer, text []byte) { 299 escapeSpecialChars(out, text) 300} 301 302// header and footer 303func (options *Latex) DocumentHeader(out *bytes.Buffer) { 304 out.WriteString("\\documentclass{article}\n") 305 out.WriteString("\n") 306 out.WriteString("\\usepackage{graphicx}\n") 307 out.WriteString("\\usepackage{listings}\n") 308 out.WriteString("\\usepackage[margin=1in]{geometry}\n") 309 out.WriteString("\\usepackage[utf8]{inputenc}\n") 310 out.WriteString("\\usepackage{verbatim}\n") 311 out.WriteString("\\usepackage[normalem]{ulem}\n") 312 out.WriteString("\\usepackage{hyperref}\n") 313 out.WriteString("\n") 314 out.WriteString("\\hypersetup{colorlinks,%\n") 315 out.WriteString(" citecolor=black,%\n") 316 out.WriteString(" filecolor=black,%\n") 317 out.WriteString(" linkcolor=black,%\n") 318 out.WriteString(" urlcolor=black,%\n") 319 out.WriteString(" pdfstartview=FitH,%\n") 320 out.WriteString(" breaklinks=true,%\n") 321 out.WriteString(" pdfauthor={Blackfriday Markdown Processor v") 322 out.WriteString(VERSION) 323 out.WriteString("}}\n") 324 out.WriteString("\n") 325 out.WriteString("\\newcommand{\\HRule}{\\rule{\\linewidth}{0.5mm}}\n") 326 out.WriteString("\\addtolength{\\parskip}{0.5\\baselineskip}\n") 327 out.WriteString("\\parindent=0pt\n") 328 out.WriteString("\n") 329 out.WriteString("\\begin{document}\n") 330} 331 332func (options *Latex) DocumentFooter(out *bytes.Buffer) { 333 out.WriteString("\n\\end{document}\n") 334} 335