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