page: implement bookmarks (thanks trav_ for starting it)

add new functions pageaddr() that returns a string describing
the page to be loaded. it is in the form of:

/path/to/file!pagename!subpage!....

one can jump to such a page by calling trywalk(name, addr)
where name and addr get concatinated with ! to form a page
address and then the currently loaded pages are walked up
to the nearest page which is then returned. (or nil when
not found). the remaining address will be set in the global
pagewalk variable.

once pages get loaded (asynchronously), pagewalk1() gets
called again on addpage() and continues the walking up to the
last page.

new program flag -j <addr> was added to jump to a page on
startup.

page address (without filename) can also be supplied in
plumb message with the "addr" attribute.

2 files changed, 180 insertions, 37 deletions

diff --git a/sys/man/1/page b/sys/man/1/page
index 73c280f7c..828b28316 100644
--- a/sys/man/1/page
+++ b/sys/man/1/page
@@ -9,12 +9,13 @@ files
 .B page
 [
 .B -abirPRvVw
-]
-[
+] [
 .B -p
 .I ppi
-]
-[
+] [
+.B -j
+.I addr
+] [
 .IR file ...
 ]
 .SH DESCRIPTION
@@ -96,6 +97,12 @@ to not load any graphics files nor to read
 from standard input but rather to listen
 for ones to load from the plumbing channel.
 .PP
+The
+.B -j
+option with a page address
+.I addr
+jumps to the specified page on startup.
+.PP
 Pressing and holding button 1 permits panning about the page.
 .PP
 Button 2 raises a menu of operations on the current image or the
@@ -126,6 +133,9 @@ Displays the next page.
 .B Prev
 Displays the previous page.
 .TP
+.B Snarf
+Writes the current page address to the snarf buffer.
+.TP
 .B Zerox
 Displays the current image in a new page window. 
 Useful for selecting important pages from large documents.
@@ -179,6 +189,10 @@ page /usr/inferno/icons/*.bit
 Browse the Inferno bitmap library.
 .TP
 .L
+page -j /sys/doc/troff.pdf!7 /sys/doc/troff.pdf
+Jump to page 7 in the troff manual.
+.TP
+.L
 man -t page | page -w
 Preview this manual in a new window.
 .SH "SEE ALSO
diff --git a/sys/src/cmd/page.c b/sys/src/cmd/page.c
index 942519e69..ae646ea00 100644
--- a/sys/src/cmd/page.c
+++ b/sys/src/cmd/page.c
@@ -8,7 +8,8 @@
 
 typedef struct Page Page;
 struct Page {
-	char	*label;
+	char	*name;
+	char	*delim;
 
 	QLock;
 	char	*ext;
@@ -38,6 +39,7 @@ Page *root, *current;
 Page lru;
 QLock pagelock;
 int nullfd;
+char *pagewalk = nil;
 
 enum {
 	MiB	= 1024*1024,
@@ -67,6 +69,7 @@ enum {
 	Cdummy1,
 	Cnext,
 	Cprev,
+	Csnarf,
 	Czerox,
 	Cwrite,
 	Cext,
@@ -90,6 +93,7 @@ struct {
 	[Cdummy1]	"",		0, 0, 0,
 	[Cnext]		"next",		Kright, ' ', '\n', 
 	[Cprev]		"prev",		Kleft, Kbs, 0,
+	[Csnarf]	"snarf",	's', 0, 0,
 	[Czerox]	"zerox",	'z', 0, 0,
 	[Cwrite]	"write",	'w', 0, 0,
 	[Cext]		"ext",		'x', 0, 0,
@@ -124,18 +128,20 @@ Cursor reading = {
 	 0x00, 0x00, 0x01, 0xb6, 0x01, 0xb6, 0x00, 0x00, }
 };
 
+int pagewalk1(Page *p);
 void showpage1(Page *);
 void showpage(Page *);
 void drawpage(Page *);
 Point pagesize(Page *);
 
 Page*
-addpage(Page *up, char *label, int (*popen)(Page *), void *pdata, int fd)
+addpage(Page *up, char *name, int (*popen)(Page *), void *pdata, int fd)
 {
 	Page *p;
 
 	p = mallocz(sizeof(*p), 1);
-	p->label = strdup(label);
+	p->name = strdup(name);
+	p->delim = "!";
  	p->image = nil;
 	p->data = pdata;
 	p->open = popen;
@@ -152,8 +158,11 @@ addpage(Page *up, char *label, int (*popen)(Page *), void *pdata, int fd)
 	}
 	qunlock(&pagelock);
 
-	if(up && current == up)
+	if(up && current == up){
+		if(!pagewalk1(p))
+			return p;
 		showpage1(p);
+	}
 	return p;
 }
 
@@ -265,19 +274,50 @@ pipeline(int fd, char *fmt, ...)
 	close(pfd[0]);
 }
 
-char*
-shortname(char *s)
+static char*
+shortlabel(char *s)
 {
-	char *x;
-
-	while(strlen(s) > 20){
-		if((x = strchr(s, '/')) == nil)
-			break;
-		if(x[1] == 0)
-			break;
-		s = x+1;
+	enum { NR=60 };
+	static char buf[NR*UTFmax];
+	int i, k, l;
+	Rune r;
+
+	l = utflen(s);
+	if(l < NR-2)
+		return s;
+	k = i = 0;
+	while(i < NR/2){
+		k += chartorune(&r, s+k);
+		i++;
 	}
-	return s;
+	strncpy(buf, s, k);
+	strcpy(buf+k, "...");
+	while((l-i) >= NR/2-4){
+		k += chartorune(&r, s+k);
+		i++;
+	}
+	strcat(buf, s+k);
+	return buf;
+}
+
+static char*
+pageaddr1(Page *p, char *s, char *e)
+{
+	if(p == nil || p == root)
+		return s;
+	return seprint(pageaddr1(p->up, s, e), e, "%s%s", p->up->delim, p->name);
+}
+
+/*
+ * returns address string of a page in the form:
+ * /dir/filename!page!subpage!...
+ */
+char*
+pageaddr(Page *p, char *buf, int nbuf)
+{
+	buf[0] = 0;
+	pageaddr1(p, buf, buf+nbuf);
+	return buf;
 }
 
 int
@@ -401,7 +441,7 @@ popenepub(Page *p)
 		while(n > 0 && s[n-1] == '\n')
 			n--;
 		s[n] = 0;
-		addpage(p, shortname(buf), popenfile, strdup(buf), -1);
+		addpage(p, buf, popenfile, strdup(buf), -1);
 	}
 	close(fd);
 	return -1;
@@ -439,7 +479,7 @@ popenpdf(Page *p)
 			"(/fd/3) (w) file "
 			"dup flushfile "
 			"dup (THIS IS NOT AN INFERNO BITMAP\\n) writestring "
-			"flushfile\n", p->label);
+			"flushfile\n", p->name);
 		while((n = read(0, buf, sizeof buf)) > 0){
 			if(memcmp(buf, "THIS IS NOT AN INFERNO BITMAP\n", 30) == 0)
 				break;
@@ -477,6 +517,7 @@ popengs(Page *p)
 	pdf = 0;
 	ifd = p->fd;
 	p->fd = -1;
+	p->open = nil;
 	seek(ifd, 0, 0);
 	if(read(ifd, buf, 5) != 5)
 		goto Err0;
@@ -699,6 +740,7 @@ popenfile(Page *p)
 	p->ext = nil;
 	file = p->data;
 	p->data = nil;
+	p->open = nil;
 	if(fd < 0){
 		if((fd = open(file, OREAD)) < 0){
 		Err0:
@@ -724,7 +766,8 @@ popenfile(Page *p)
 			p->open = popenepub;
 			return p->open(p);
 		}
-
+		if(strcmp(pageaddr(p, buf, sizeof(buf)), file) == 0)
+			p->delim = "/";
 		if((n = dirreadall(fd, &d)) < 0)
 			goto Err1;
 		qsort(d, n, sizeof d[0], dircmp);
@@ -1077,11 +1120,11 @@ drawpage(Page *p)
 		r = rectaddpt(Rpt(ZP, pagesize(p)), addpt(pos, screen->r.min));
 		zoomdraw(screen, r, ZR, paper, i, i->r.min, zoom);
 	} else {
-		r = Rpt(ZP, stringsize(font, p->label));
+		r = Rpt(ZP, stringsize(font, p->name));
 		r = rectaddpt(r, addpt(subpt(divpt(subpt(screen->r.max, screen->r.min), 2),
 			divpt(r.max, 2)), screen->r.min));
 		draw(screen, r, paper, nil, ZP);
-		string(screen, r.min, display->black, ZP, font, p->label);
+		string(screen, r.min, display->black, ZP, font, p->name);
 	}
 	drawframe(r);
 }
@@ -1104,24 +1147,81 @@ translate(Page *p, Point d)
 	drawframe(nr);
 }
 
+int
+pagewalk1(Page *p)
+{
+	char *s;
+	int n;
+
+	if((s = pagewalk) == nil || *s == 0)
+		return 1;
+	n = strlen(p->name);
+	if(n == 0 || strncmp(s, p->name, n) != 0)
+		return 0;
+	if(s[n] == 0){
+		pagewalk = nil;
+		return 1;
+	}
+	if(s[n] == '/' || s[n] == '!'){
+		pagewalk = s + n+1;
+		return 1;
+	}
+	return 0;
+}
+
+Page*
+trywalk(char *name, char *addr)
+{
+	static char buf[NPATH];
+	Page *p, *a;
+
+	pagewalk = nil;
+	memset(buf, 0, sizeof(buf));
+	snprint(buf, sizeof(buf), "%s%s%s",
+		name ? name : "",
+		(name && addr) ? "!" : "", 
+		addr ? addr : "");
+	pagewalk = buf;
+
+	a = nil;
+	if(root){
+		p = root->down;
+	Loop:
+		for(; p; p = p->next)
+			if(pagewalk1(p)){
+				a = p;
+				p = p->down;
+				goto Loop;
+			}
+	}
+	return a;
+}
+
 Page*
 findpage(char *name)
 {
+	static char buf[NPATH], *f[32];
 	Page *p;
 	int n;
 
+	if(name == nil)
+		return nil;
+
 	n = strlen(name);
-	/* look in current document first */
+	/* look in current document */
 	if(current && current->up){
 		for(p = current->up->down; p; p = p->next)
-			if(cistrncmp(p->label, name, n) == 0)
+			if(cistrncmp(p->name, name, n) == 0)
 				return p;
 	}
 	/* look everywhere */
-	for(p = root->down; p; p = nextpage(p))
-		if(cistrncmp(p->label, name, n) == 0)
-			return p;
-	return nil;
+	if(root){
+		for(p = root->down; p; p = nextpage(p))
+			if(cistrncmp(p->name, name, n) == 0)
+				return p;
+	}
+	/* try bookmark */
+	return trywalk(name, nil);
 }
 
 Page*
@@ -1149,8 +1249,9 @@ char*
 pagemenugen(int i)
 {
 	Page *p;
+
 	if(p = pageat(i))
-		return p->label;
+		return shortlabel(p->name);
 	return nil;
 }
 
@@ -1274,7 +1375,7 @@ showext(Page *p)
 
 	if(p->ext == nil)
 		return;
-	snprint(label, sizeof(label), "%s %s", p->ext, p->label);
+	snprint(label, sizeof(label), "%s %s", p->ext, p->name);
 	ps = Pt(0, 0);
 	if(p->image)
 		ps = addpt(subpt(p->image->r.max, p->image->r.min), Pt(24, 24));
@@ -1310,6 +1411,19 @@ showext(Page *p)
 
 
 void
+snarfaddr(Page *p)
+{
+	char buf[NPATH], *s;
+	int fd;
+
+	s = pageaddr(p, buf, sizeof(buf));
+	if((fd = open("/dev/snarf", OWRITE)) >= 0){
+		write(fd, s, strlen(s));
+		close(fd);
+	}
+}
+
+void
 eresized(int new)
 {
 	Page *p;
@@ -1344,7 +1458,7 @@ void drawerr(Display *, char *msg)
 void
 usage(void)
 {
-	fprint(2, "usage: %s [ -iRw ] [ -m mb ] [ -p ppi ] [ file ... ]\n", argv0);
+	fprint(2, "usage: %s [ -iRw ] [ -m mb ] [ -p ppi ] [ -j addr ] [ file ... ]\n", argv0);
 	exits("usage");
 }
 
@@ -1411,11 +1525,11 @@ docmd(int i, Mouse *m)
 		if(current->image){
 			s = nil;
 			if(current->up && current->up != root)
-				s = current->up->label;
+				s = current->up->name;
 			snprint(buf, sizeof(buf), "%s%s%s.bit",
 				s ? s : "",
 				s ? "." : "",
-				current->label);
+				current->name);
 			if(eenter("Write", buf, sizeof(buf), m) > 0){
 				if((fd = create(buf, OWRITE, 0666)) < 0){
 					errstr(buf, sizeof(buf));
@@ -1436,6 +1550,9 @@ docmd(int i, Mouse *m)
 		showext(current);
 		qunlock(current);
 		break;
+	case Csnarf:
+		snarfaddr(current);
+		break;
 	case Cnext:
 		shownext();
 		break;
@@ -1462,6 +1579,8 @@ main(int argc, char *argv[])
 	char *s;
 	int i;
 
+	quotefmtinstall();
+
 	ARGBEGIN {
 	case 'a':
 	case 'v':
@@ -1478,6 +1597,9 @@ main(int argc, char *argv[])
 	case 'i':
 		imode = 1;
 		break;
+	case 'j':
+		trywalk(EARGF(usage()), nil);
+		break;
 	case 'm':
 		imemlimit = atol(EARGF(usage()))*MiB;
 		break;
@@ -1523,10 +1645,11 @@ main(int argc, char *argv[])
 	lru.lprev = &lru;
 	lru.lnext = &lru;
 	current = root = addpage(nil, "", nil, nil, -1);
+	root->delim = "";
 	if(*argv == nil && !imode)
 		addpage(root, "stdin", popenfile, strdup("/fd/0"), -1);
 	for(; *argv; argv++)
-		addpage(root, shortname(*argv), popenfile, strdup(*argv), -1);
+		addpage(root, *argv, popenfile, strdup(*argv), -1);
 
 	for(;;){
 		drawlock(0);
@@ -1615,6 +1738,7 @@ main(int argc, char *argv[])
 		case Eplumb:
 			pm = e.v;
 			if(pm && pm->ndata > 0){
+				Page *j;
 				int fd;
 
 				fd = -1;
@@ -1639,7 +1763,12 @@ main(int argc, char *argv[])
 					sprint(s, "%s/%s", pm->wdir, pm->data);
 					cleanname(s);
 				}
-				showpage(addpage(root, shortname(s), popenfile, s, fd));
+				j = trywalk(s, plumblookup(pm->attr, "addr"));
+				if(j == nil){
+					current = root;
+					j = addpage(root, s, popenfile, s, fd);
+				}
+				showpage(j);
 			}
 		Plumbfree:
 			plumbfree(pm);