1 /*
2  * pdf.c
3  *
4  * pdf file support for page
5  */
6 
7 #include <u.h>
8 #include <libc.h>
9 #include <draw.h>
10 #include <cursor.h>
11 #include <thread.h>
12 #include <bio.h>
13 #include "page.h"
14 
15 static Image*	pdfdrawpage(Document *d, int page);
16 static char*	pdfpagename(Document*, int);
17 
18 char *pdfprolog =
19 #include "pdfprolog.c"
20 	;
21 
22 Rectangle
23 pdfbbox(GSInfo *gs)
24 {
25 	char *p;
26 	char *f[4];
27 	Rectangle r;
28 
29 	r = Rect(0,0,0,0);
30 	waitgs(gs);
31 	gscmd(gs, "/CropBox knownoget {} {[0 0 0 0]} ifelse PAGE==\n");
32 	p = Brdline(&gs->gsrd, '\n');
33 	p[Blinelen(&gs->gsrd)-1] ='\0';
34 	if(p[0] != '[')
35 		return r;
36 	if(tokenize(p+1, f, 4) != 4)
37 		return r;
38 	r = Rect(atoi(f[0]), atoi(f[1]), atoi(f[2]), atoi(f[3]));
39 	waitgs(gs);
40 	return r;
41 }
42 
43 Document*
44 initpdf(Biobuf *b, int argc, char **argv, uchar *buf, int nbuf)
45 {
46 	Document *d;
47 	PDFInfo *pdf;
48 	char *p;
49 	char *fn;
50 	char fdbuf[20];
51 	int fd;
52 	int i, npage;
53 	Rectangle bbox;
54 
55 	if(argc > 1) {
56 		fprint(2, "can only view one pdf file at a time\n");
57 		return nil;
58 	}
59 
60 	fprint(2, "reading through pdf...\n");
61 	if(b == nil){	/* standard input; spool to disk (ouch) */
62 		fd = spooltodisk(buf, nbuf, &fn);
63 		sprint(fdbuf, "/dev/fd/%d", fd);
64 		b = Bopen(fdbuf, OREAD);
65 		if(b == nil){
66 			fprint(2, "cannot open disk spool file\n");
67 			wexits("Bopen temp");
68 		}
69 	}else
70 		fn = argv[0];
71 
72 	/* sanity check */
73 	Bseek(b, 0, 0);
74 	if(!(p = Brdline(b, '\n')) && !(p = Brdline(b, '\r'))) {
75 		fprint(2, "cannot find end of first line\n");
76 		wexits("initps");
77 	}
78 	if(strncmp(p, "%PDF-", 5) != 0) {
79 		werrstr("not pdf");
80 		return nil;
81 	}
82 
83 	/* setup structures so one free suffices */
84 	p = emalloc(sizeof(*d) + sizeof(*pdf));
85 	d = (Document*) p;
86 	p += sizeof(*d);
87 	pdf = (PDFInfo*) p;
88 
89 	d->extra = pdf;
90 	d->b = b;
91 	d->drawpage = pdfdrawpage;
92 	d->pagename = pdfpagename;
93 	d->fwdonly = 0;
94 	d->type = Tpdf;
95 
96 	if(spawngs(&pdf->gs, "-dDELAYSAFER") < 0)
97 		return nil;
98 
99 	gscmd(&pdf->gs, "%s", pdfprolog);
100 	waitgs(&pdf->gs);
101 
102 	setdim(&pdf->gs, Rect(0,0,0,0), ppi, 0);
103 	gscmd(&pdf->gs, "(%s) (r) file { DELAYSAFER { .setsafe } if } stopped pop pdfopen begin\n", fn);
104 	gscmd(&pdf->gs, "pdfpagecount PAGE==\n");
105 	p = Brdline(&pdf->gs.gsrd, '\n');
106 	if(p == nil) {
107 		if(Blinelen(&pdf->gs.gsrd) > 0) {
108 			fprint(2, "unexpected output (too long) from gs\n");
109 			return nil;
110 		}
111 		fprint(2, "early EOF from gs - is ghostscript installed?\n");
112 		return nil;
113 	}
114 	npage = atoi(p);
115 	if(npage < 1) {
116 		fprint(2, "no pages?\n");
117 		return nil;
118 	}
119 	d->npage = npage;
120 	d->docname = argv[0];
121 
122 	gscmd(&pdf->gs, "Trailer\n");
123 	bbox = pdfbbox(&pdf->gs);
124 
125 	pdf->pagebbox = emalloc(sizeof(Rectangle)*npage);
126 	for(i=0; i<npage; i++) {
127 		gscmd(&pdf->gs, "%d pdfgetpage\n", i+1);
128 		pdf->pagebbox[i] = pdfbbox(&pdf->gs);
129 		if(Dx(pdf->pagebbox[i]) <= 0)
130 			pdf->pagebbox[i] = bbox;
131 	}
132 	return d;
133 }
134 
135 static Image*
136 pdfdrawpage(Document *doc, int page)
137 {
138 	PDFInfo *pdf = doc->extra;
139 	Image *im;
140 
141 	gscmd(&pdf->gs, "%d DoPDFPage\n", page+1);
142 	im = convert(&pdf->gs.g);
143 	if(im == nil) {
144 		fprint(2, "fatal: readimage error %r\n");
145 		wexits("readimage");
146 	}
147 	waitgs(&pdf->gs);
148 	return im;
149 }
150 
151 static char*
152 pdfpagename(Document *d, int page)
153 {
154 	static char str[15];
155 
156 	USED(d);
157 	sprint(str, "p %d", page+1);
158 	return str;
159 }