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)
 21
 22// Latex is a type that implements the Renderer interface for LaTeX output.
 23//
 24// Do not create this directly, instead use the LatexRenderer function.
 25type Latex struct {
 26	w HtmlWriter
 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	var writer HtmlWriter
 36	return &Latex{
 37		w: writer,
 38	}
 39}
 40
 41func (r *Latex) Write(b []byte) (int, error) {
 42	return r.w.Write(b)
 43}
 44
 45func (r *Latex) GetFlags() HtmlFlags {
 46	return 0
 47}
 48
 49// render code chunks using verbatim, or listings if we have a language
 50func (r *Latex) BlockCode(text []byte, lang string) {
 51	if lang == "" {
 52		r.w.WriteString("\n\\begin{verbatim}\n")
 53	} else {
 54		r.w.WriteString("\n\\begin{lstlisting}[language=")
 55		r.w.WriteString(lang)
 56		r.w.WriteString("]\n")
 57	}
 58	r.w.Write(text)
 59	if lang == "" {
 60		r.w.WriteString("\n\\end{verbatim}\n")
 61	} else {
 62		r.w.WriteString("\n\\end{lstlisting}\n")
 63	}
 64}
 65
 66func (r *Latex) TitleBlock(text []byte) {
 67
 68}
 69
 70func (r *Latex) BlockQuote(text []byte) {
 71	r.w.WriteString("\n\\begin{quotation}\n")
 72	r.w.Write(text)
 73	r.w.WriteString("\n\\end{quotation}\n")
 74}
 75
 76func (r *Latex) BlockHtml(text []byte) {
 77	// a pretty lame thing to do...
 78	r.w.WriteString("\n\\begin{verbatim}\n")
 79	r.w.Write(text)
 80	r.w.WriteString("\n\\end{verbatim}\n")
 81}
 82
 83func (r *Latex) BeginHeader(level int, id string) {
 84	switch level {
 85	case 1:
 86		r.w.WriteString("\n\\section{")
 87	case 2:
 88		r.w.WriteString("\n\\subsection{")
 89	case 3:
 90		r.w.WriteString("\n\\subsubsection{")
 91	case 4:
 92		r.w.WriteString("\n\\paragraph{")
 93	case 5:
 94		r.w.WriteString("\n\\subparagraph{")
 95	case 6:
 96		r.w.WriteString("\n\\textbf{")
 97	}
 98}
 99
100func (r *Latex) EndHeader(level int, id string, header []byte) {
101	r.w.WriteString("}\n")
102}
103
104func (r *Latex) HRule() {
105	r.w.WriteString("\n\\HRule\n")
106}
107
108func (r *Latex) BeginList(flags ListType) {
109	if flags&ListTypeOrdered != 0 {
110		r.w.WriteString("\n\\begin{enumerate}\n")
111	} else {
112		r.w.WriteString("\n\\begin{itemize}\n")
113	}
114}
115
116func (r *Latex) EndList(flags ListType) {
117	if flags&ListTypeOrdered != 0 {
118		r.w.WriteString("\n\\end{enumerate}\n")
119	} else {
120		r.w.WriteString("\n\\end{itemize}\n")
121	}
122}
123
124func (r *Latex) ListItem(text []byte, flags ListType) {
125	r.w.WriteString("\n\\item ")
126	r.w.Write(text)
127}
128
129func (r *Latex) BeginParagraph() {
130	r.w.WriteString("\n")
131}
132
133func (r *Latex) EndParagraph() {
134	r.w.WriteString("\n")
135}
136
137func (r *Latex) Table(header []byte, body []byte, columnData []int) {
138	r.w.WriteString("\n\\begin{tabular}{")
139	for _, elt := range columnData {
140		switch elt {
141		case TableAlignmentLeft:
142			r.w.WriteByte('l')
143		case TableAlignmentRight:
144			r.w.WriteByte('r')
145		default:
146			r.w.WriteByte('c')
147		}
148	}
149	r.w.WriteString("}\n")
150	r.w.Write(header)
151	r.w.WriteString(" \\\\\n\\hline\n")
152	r.w.Write(body)
153	r.w.WriteString("\n\\end{tabular}\n")
154}
155
156func (r *Latex) TableRow(text []byte) {
157	r.w.WriteString(" \\\\\n")
158	r.w.Write(text)
159}
160
161func (r *Latex) TableHeaderCell(out *bytes.Buffer, text []byte, align int) {
162	if out.Len() > 0 {
163		out.WriteString(" & ")
164	}
165	out.Write(text)
166}
167
168func (r *Latex) TableCell(out *bytes.Buffer, text []byte, align int) {
169	if out.Len() > 0 {
170		out.WriteString(" & ")
171	}
172	out.Write(text)
173}
174
175// TODO: this
176func (r *Latex) BeginFootnotes() {
177}
178
179// TODO: this
180func (r *Latex) EndFootnotes() {
181}
182
183func (r *Latex) FootnoteItem(name, text []byte, flags ListType) {
184
185}
186
187func (r *Latex) AutoLink(link []byte, kind LinkType) {
188	r.w.WriteString("\\href{")
189	if kind == LinkTypeEmail {
190		r.w.WriteString("mailto:")
191	}
192	r.w.Write(link)
193	r.w.WriteString("}{")
194	r.w.Write(link)
195	r.w.WriteString("}")
196}
197
198func (r *Latex) CodeSpan(text []byte) {
199	r.w.WriteString("\\texttt{")
200	r.escapeSpecialChars(text)
201	r.w.WriteString("}")
202}
203
204func (r *Latex) DoubleEmphasis(text []byte) {
205	r.w.WriteString("\\textbf{")
206	r.w.Write(text)
207	r.w.WriteString("}")
208}
209
210func (r *Latex) Emphasis(text []byte) {
211	r.w.WriteString("\\textit{")
212	r.w.Write(text)
213	r.w.WriteString("}")
214}
215
216func (r *Latex) Image(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		r.w.WriteString("\\href{")
220		r.w.Write(link)
221		r.w.WriteString("}{")
222		r.w.Write(alt)
223		r.w.WriteString("}")
224	} else {
225		r.w.WriteString("\\includegraphics{")
226		r.w.Write(link)
227		r.w.WriteString("}")
228	}
229}
230
231func (r *Latex) LineBreak() {
232	r.w.WriteString(" \\\\\n")
233}
234
235func (r *Latex) Link(link []byte, title []byte, content []byte) {
236	r.w.WriteString("\\href{")
237	r.w.Write(link)
238	r.w.WriteString("}{")
239	r.w.Write(content)
240	r.w.WriteString("}")
241}
242
243func (r *Latex) RawHtmlTag(tag []byte) {
244}
245
246func (r *Latex) TripleEmphasis(text []byte) {
247	r.w.WriteString("\\textbf{\\textit{")
248	r.w.Write(text)
249	r.w.WriteString("}}")
250}
251
252func (r *Latex) StrikeThrough(text []byte) {
253	r.w.WriteString("\\sout{")
254	r.w.Write(text)
255	r.w.WriteString("}")
256}
257
258// TODO: this
259func (r *Latex) FootnoteRef(ref []byte, id int) {
260}
261
262func needsBackslash(c byte) bool {
263	for _, r := range []byte("_{}%$&\\~#") {
264		if c == r {
265			return true
266		}
267	}
268	return false
269}
270
271func (r *Latex) escapeSpecialChars(text []byte) {
272	for i := 0; i < len(text); i++ {
273		// directly copy normal characters
274		org := i
275
276		for i < len(text) && !needsBackslash(text[i]) {
277			i++
278		}
279		if i > org {
280			r.w.Write(text[org:i])
281		}
282
283		// escape a character
284		if i >= len(text) {
285			break
286		}
287		r.w.WriteByte('\\')
288		r.w.WriteByte(text[i])
289	}
290}
291
292func (r *Latex) Entity(entity []byte) {
293	// TODO: convert this into a unicode character or something
294	r.w.Write(entity)
295}
296
297func (r *Latex) NormalText(text []byte) {
298	r.escapeSpecialChars(text)
299}
300
301// header and footer
302func (r *Latex) DocumentHeader() {
303	r.w.WriteString("\\documentclass{article}\n")
304	r.w.WriteString("\n")
305	r.w.WriteString("\\usepackage{graphicx}\n")
306	r.w.WriteString("\\usepackage{listings}\n")
307	r.w.WriteString("\\usepackage[margin=1in]{geometry}\n")
308	r.w.WriteString("\\usepackage[utf8]{inputenc}\n")
309	r.w.WriteString("\\usepackage{verbatim}\n")
310	r.w.WriteString("\\usepackage[normalem]{ulem}\n")
311	r.w.WriteString("\\usepackage{hyperref}\n")
312	r.w.WriteString("\n")
313	r.w.WriteString("\\hypersetup{colorlinks,%\n")
314	r.w.WriteString("  citecolor=black,%\n")
315	r.w.WriteString("  filecolor=black,%\n")
316	r.w.WriteString("  linkcolor=black,%\n")
317	r.w.WriteString("  urlcolor=black,%\n")
318	r.w.WriteString("  pdfstartview=FitH,%\n")
319	r.w.WriteString("  breaklinks=true,%\n")
320	r.w.WriteString("  pdfauthor={Blackfriday Markdown Processor v")
321	r.w.WriteString(VERSION)
322	r.w.WriteString("}}\n")
323	r.w.WriteString("\n")
324	r.w.WriteString("\\newcommand{\\HRule}{\\rule{\\linewidth}{0.5mm}}\n")
325	r.w.WriteString("\\addtolength{\\parskip}{0.5\\baselineskip}\n")
326	r.w.WriteString("\\parindent=0pt\n")
327	r.w.WriteString("\n")
328	r.w.WriteString("\\begin{document}\n")
329}
330
331func (r *Latex) DocumentFooter() {
332	r.w.WriteString("\n\\end{document}\n")
333}
334
335func (r *Latex) Render(ast *Node) []byte {
336	return nil
337}