replaceing page with npage

1 files changed, 1282 insertions, 0 deletions

diff --git a/sys/src/cmd/page.c b/sys/src/cmd/page.c
new file mode 100644
index 000000000..a0751a5eb
--- /dev/null
+++ b/sys/src/cmd/page.c
@@ -0,0 +1,1282 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <event.h>
+#include <cursor.h>
+#include <keyboard.h>
+#include <plumb.h>
+
+typedef struct Page Page;
+struct Page {
+	char	*label;
+
+	QLock;
+	void	*data;
+	int	(*open)(Page *);
+
+	char	*text;
+	Image	*image;
+	int	fd;
+	int	gen;
+
+	Page	*up;
+	Page	*next;
+	Page	*down;
+	Page	*tail;
+};
+
+int zoom = 1;
+int ppi = 100;
+int imode;
+int newwin;
+int rotate;
+int viewgen;
+int pagegen;
+Point resize, pos;
+Page *root, *current;
+QLock pagelock;
+int nullfd;
+
+char pagespool[] = "/tmp/pagespool.";
+
+enum {
+	NPROC = 4,
+	NAHEAD = 2,
+	NBUF = 8*1024,
+	NPATH = 1024,
+};
+
+char *pagemenugen(int i);
+
+char *menuitems[] = {
+	"orig size",
+	"rotate 90",
+	"upside down",
+	"",
+	"fit width",
+	"fit height",
+	"",
+	"zoom in",
+	"zoom out",
+	"",
+	"next",
+	"prev",
+	"zerox",
+	"",
+	"quit",
+	nil
+};
+
+Menu pagemenu = {
+	nil,
+	pagemenugen,
+	-1,
+};
+
+Menu menu = {
+	menuitems,
+	nil,
+	-1,
+};
+
+Cursor reading = {
+	{-1, -1},
+	{0xff, 0x80, 0xff, 0x80, 0xff, 0x00, 0xfe, 0x00, 
+	 0xff, 0x00, 0xff, 0x80, 0xff, 0xc0, 0xef, 0xe0, 
+	 0xc7, 0xf0, 0x03, 0xf0, 0x01, 0xe0, 0x00, 0xc0, 
+	 0x03, 0xff, 0x03, 0xff, 0x03, 0xff, 0x03, 0xff, },
+	{0x00, 0x00, 0x7f, 0x00, 0x7e, 0x00, 0x7c, 0x00, 
+	 0x7e, 0x00, 0x7f, 0x00, 0x6f, 0x80, 0x47, 0xc0, 
+	 0x03, 0xe0, 0x01, 0xf0, 0x00, 0xe0, 0x00, 0x40, 
+	 0x00, 0x00, 0x01, 0xb6, 0x01, 0xb6, 0x00, 0x00, }
+};
+
+void showpage(Page *);
+void drawpage(Page *);
+Point pagesize(Page *);
+
+Page*
+addpage(Page *up, char *label, int (*popen)(Page *), void *pdata, int fd)
+{
+	Page *p;
+
+	p = mallocz(sizeof(*p), 1);
+	p->label = strdup(label);
+	p->gen = pagegen;
+	p->text = nil;
+	p->image = nil;
+	p->data = pdata;
+	p->open = popen;
+	p->fd = fd;
+
+	p->down = nil;
+	p->tail = nil;
+	p->next = nil;
+
+	qlock(&pagelock);
+	if(p->up = up){
+		if(up->tail == nil)
+			up->down = up->tail = p;
+		else {
+			up->tail->next = p;
+			up->tail = p;
+		}
+	}
+	qunlock(&pagelock);
+
+	if(up && current == up)
+		showpage(p);
+	return p;
+}
+
+void
+resizewin(Point size)
+{
+	int wctl;
+
+	if((wctl = open("/dev/wctl", OWRITE)) < 0)
+		return;
+	/* add rio border */
+	size = addpt(size, Pt(Borderwidth*2, Borderwidth*2));
+	fprint(wctl, "resize -dx %d -dy %d\n", size.x, size.y);
+	close(wctl);
+}
+
+int
+createtmp(ulong id, char *pfx)
+{
+	char nam[64];
+
+	snprint(nam, sizeof nam, "%s%s%.12d%.8lux", pagespool, pfx, getpid(), id ^ 0xcafebabe);
+	return create(nam, OEXCL|ORCLOSE|ORDWR, 0600);
+}
+
+int
+catchnote(void *, char *msg)
+{
+	if(strstr(msg, "sys: write on closed pipe"))
+		return 1;
+	if(strstr(msg, "hangup"))
+		return 1;
+	if(strstr(msg, "alarm"))
+		return 1;
+	return 0;
+}
+
+void
+pipeline(int fd, char *fmt, ...)
+{
+	char buf[128], *argv[4];
+	va_list arg;
+	int pfd[2];
+
+	if(pipe(pfd) < 0){
+	Err:
+		dup(nullfd, fd);
+		return;
+	}
+	switch(rfork(RFPROC|RFFDG|RFREND|RFNOWAIT)){
+	case -1:
+		close(pfd[0]);
+		close(pfd[1]);
+		goto Err;
+	case 0:
+		if(dup(fd, 0)<0)
+			exits("dup");
+		if(dup(pfd[1], 1)<0)
+			exits("dup");
+		close(fd);
+		close(pfd[1]);
+		close(pfd[0]);
+		va_start(arg, fmt);
+		vsnprint(buf, sizeof buf, fmt, arg);
+		va_end(arg);
+
+		argv[0] = "rc";
+		argv[1] = "-c";
+		argv[2] = buf;
+		argv[3] = nil;
+		exec("/bin/rc", argv);
+		sysfatal("exec: %r");
+	}
+	close(pfd[1]);
+	dup(pfd[0], fd);
+	close(pfd[0]);
+}
+
+int
+popenfile(Page*);
+
+int
+popenconv(Page *p)
+{
+	char nam[NPATH];
+	int fd;
+
+	if((fd = dup(p->fd, -1)) < 0){
+		close(p->fd);
+		p->fd = -1;
+		return -1;
+	}
+
+	seek(fd, 0, 0);
+	if(p->data)
+		pipeline(fd, "%s", (char*)p->data);
+
+	/*
+	 * dont keep the file descriptor arround if it can simply
+	 * be reopened.
+	 */
+	fd2path(p->fd, nam, sizeof(nam));
+	if(strncmp(nam, pagespool, strlen(pagespool))){
+		close(p->fd);
+		p->fd = -1;
+		p->data = strdup(nam);
+		p->open = popenfile;
+	}
+
+	return fd;
+}
+
+typedef struct Ghost Ghost;
+struct Ghost
+{
+	QLock;
+
+	int	pin;
+	int	pout;
+	int	pdat;
+};
+
+int
+popenpdf(Page *p)
+{
+	char buf[NBUF];
+	int n, pfd[2];
+	Ghost *gs;
+
+	if(pipe(pfd) < 0)
+		return -1;
+	switch(rfork(RFFDG|RFPROC|RFMEM|RFNOWAIT)){
+	case -1:
+		close(pfd[0]);
+		close(pfd[1]);
+		return -1;
+	case 0:
+		close(pfd[0]);
+		gs = p->data;
+		qlock(gs);
+		fprint(gs->pin, "%s DoPDFPage\n"
+			"(/fd/3) (w) file "
+			"dup flushfile "
+			"dup (THIS IS NOT AN INFERNO BITMAP\\n) writestring "
+			"flushfile\n", p->label);
+		while((n = read(gs->pdat, buf, sizeof buf)) > 0){
+			if(memcmp(buf, "THIS IS NOT AN INFERNO BITMAP\n", 30) == 0)
+				break;
+			if(pfd[1] < 0)
+				continue;
+			if(write(pfd[1], buf, n) != n){
+				close(pfd[1]);
+				pfd[1]=-1;
+			}
+		}
+		qunlock(gs);
+		exits(nil);
+	}
+	close(pfd[1]);
+	return pfd[0];
+}
+
+int
+infernobithdr(char *buf, int n)
+{
+	if(n >= 11){
+		if(memcmp(buf, "compressed\n", 11) == 0)
+			return 1;
+		if(strtochan((char*)buf))
+			return 1;
+		if(memcmp(buf, "          ", 10) == 0 && 
+			'0' <= buf[10] && buf[10] <= '9' &&
+			buf[11] == ' ')
+			return 1;
+	}
+	return 0;
+}
+
+int
+popengs(Page *p)
+{
+	int n, i, pdf, ifd, ofd, pin[2], pout[2], pdat[2];
+	char buf[NBUF], nam[32], *argv[16];
+
+	pdf = 0;
+	ifd = p->fd;
+	p->fd = -1;
+	seek(ifd, 0, 0);
+	if(read(ifd, buf, 5) != 5)
+		goto Err0;
+	seek(ifd, 0, 0);
+	if(memcmp(buf, "%PDF-", 5) == 0)
+		pdf = 1;
+	p->text = strdup(p->label);
+	if(pipe(pin) < 0){
+	Err0:
+		close(ifd);
+		return -1;
+	}
+	if(pipe(pout) < 0){
+	Err1:
+		close(pin[0]);
+		close(pin[1]);
+		goto Err0;
+	}
+	if(pipe(pdat) < 0){
+	Err2:
+		close(pdat[0]);
+		close(pdat[1]);
+		goto Err1;
+	}
+
+	switch(rfork(RFREND|RFPROC|RFFDG|RFNOWAIT)){
+	case -1:
+		goto Err2;
+	case 0:
+		if(pdf){
+			if(dup(pin[1], 0)<0)
+				exits("dup");
+			if(dup(pout[1], 1)<0)
+				exits("dup");
+		} else {
+			if(dup(nullfd, 0)<0)
+				exits("dup");
+			if(dup(nullfd, 1)<0)
+				exits("dup");
+		}
+		if(dup(nullfd, 2)<0)
+			exits("dup");
+		if(dup(pdat[1], 3)<0)
+			exits("dup");
+		if(dup(ifd, 4)<0)
+			exits("dup");
+
+		close(pin[0]);
+		close(pin[1]);
+		close(pout[0]);
+		close(pout[1]);
+		close(pdat[0]);
+		close(pdat[1]);
+		close(ifd);
+
+		if(p->data)
+			pipeline(4, "%s", (char*)p->data);
+
+		argv[0] = "gs";
+		argv[1] = "-q";
+		argv[2] = "-sDEVICE=plan9";
+		argv[3] = "-sOutputFile=/fd/3";
+		argv[4] = "-dBATCH";
+		argv[5] = pdf ? "-dDELAYSAFER" : "-dSAFER";
+		argv[6] = "-dQUIET";
+		argv[7] = "-dTextAlphaBits=4";
+		argv[8] = "-dGraphicsAlphaBits=4";
+		snprint(buf, sizeof buf, "-r%d", ppi);
+		argv[9] = buf;
+		argv[10] = "-dDOINTERPOLATE";
+		argv[11] = pdf ? "-" : "/fd/4";
+		argv[12] = nil;
+		exec("/bin/gs", argv);
+		sysfatal("exec: %r");
+	}
+
+	close(pin[1]);
+	close(pout[1]);
+	close(pdat[1]);
+	close(ifd);
+
+	if(pdf){
+		Ghost *gs;
+		char *prolog =
+			"/PAGEOUT (/fd/1) (w) file def\n"
+			"/PAGE== { PAGEOUT exch write==only PAGEOUT (\\n) writestring PAGEOUT flushfile } def\n"
+			"\n"
+			"/Page null def\n"
+			"/Page# 0 def\n"
+			"/PDFSave null def\n"
+			"/DSCPageCount 0 def\n"
+			"/DoPDFPage {dup /Page# exch store pdfgetpage pdfshowpage } def\n"
+			"\n"
+			"GS_PDF_ProcSet begin\n"
+			"pdfdict begin\n"
+			"(/fd/4) (r) file { DELAYSAFER { .setsafe } if } stopped pop pdfopen begin\n"
+			"\n"
+			"pdfpagecount PAGE==\n";
+
+		n = strlen(prolog);
+		if(write(pin[0], prolog, n) != n)
+			goto Out;
+		if((n = read(pout[0], buf, sizeof(buf)-1)) < 0)
+			goto Out;
+		buf[n] = 0;
+		n = atoi(buf);
+		if(n <= 0){
+			werrstr("no pages");
+			goto Out;
+		}
+		gs = mallocz(sizeof(*gs), 1);
+		gs->pin = pin[0];
+		gs->pout = pout[0];
+		gs->pdat = pdat[0];
+		for(i=1; i<=n; i++){
+			snprint(nam, sizeof nam, "%d", i);
+			addpage(p, nam, popenpdf, gs, -1);
+		}
+
+		/* keep ghostscript arround */
+		return -1;
+	} else {
+		i = 0;
+		ofd = -1;
+		while((n = read(pdat[0], buf, sizeof(buf))) >= 0){
+			if(ofd >= 0 && (n <= 0 || infernobithdr(buf, n))){
+				snprint(nam, sizeof nam, "%d", i);
+				addpage(p, nam, popenconv, nil, ofd);
+				ofd = -1;
+			}
+			if(n <= 0)
+				break;
+			if(ofd < 0){
+				snprint(nam, sizeof nam, "%.4d", ++i);
+				if((ofd = createtmp((ulong)p, nam)) < 0)
+					ofd = dup(nullfd, -1);
+			}
+			if(write(ofd, buf, n) != n)
+				break;
+		}
+		if(ofd >= 0)
+			close(ofd);
+	}
+Out:
+	close(pin[0]);
+	close(pout[0]);
+	close(pdat[0]);
+	return -1;
+}
+
+int
+popenfile(Page *p)
+{
+	char buf[NBUF], *file;
+	int i, n, fd, tfd;
+	Dir *d;
+
+	fd = p->fd;
+	p->fd = -1;
+	file = p->data;
+	if(fd < 0){
+		if((fd = open(file, OREAD)) < 0){
+		Err0:
+			p->data = nil;
+			free(file);
+			return -1;
+		}
+	}
+	seek(fd, 0, 0);
+	if((d = dirfstat(fd)) == nil){
+	Err1:
+		close(fd);
+		goto Err0;
+	}
+	if(d->mode & DMDIR){
+		free(d);
+		d = nil;
+		if((n = dirreadall(fd, &d)) < 0)
+			goto Err1;
+		for(i = 0; i<n; i++)
+			addpage(p, d[i].name, popenfile, smprint("%s/%s", file, d[i].name), -1);
+		free(d);
+		p->text = strdup(p->label);
+		goto Err1;
+	}
+	free(d);
+
+	memset(buf, 0, 32+1);
+	if((n = read(fd, buf, 32)) <= 0)
+		goto Err1;
+
+	p->fd = fd;
+	p->data = nil;
+	p->open = popenconv;
+	if(memcmp(buf, "%PDF-", 5) == 0 || strstr(buf, "%!"))
+		p->open = popengs;
+	else if(memcmp(buf, "x T ", 4) == 0){
+		p->data = "lp -dstdout";
+		p->open = popengs;
+	}
+	else if(memcmp(buf, "\xF7\x02\x01\x83\x92\xC0\x1C;", 8) == 0){
+		p->data = "dvips -Pps -r0 -q1 -f1";
+		p->open = popengs;
+	}
+	else if(memcmp(buf, "\x1F\x8B", 2) == 0){
+		p->data = "gunzip";
+		p->open = popengs;
+	}
+	else if(memcmp(buf, "\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1", 8) == 0){
+		p->data = "doc2ps";
+		p->open = popengs;
+	}
+	else if(memcmp(buf, "GIF", 3) == 0)
+		p->data = "gif -t9";
+	else if(memcmp(buf, "\111\111\052\000", 4) == 0) 
+		p->data = "fb/tiff2pic | fb/3to1 rgbv | fb/pcp -tplan9";
+	else if(memcmp(buf, "\115\115\000\052", 4) == 0)
+		p->data = "fb/tiff2pic | fb/3to1 rgbv | fb/pcp -tplan9";
+	else if(memcmp(buf, "\377\330\377", 3) == 0)
+		p->data = "jpg -t9";
+	else if(memcmp(buf, "\211PNG\r\n\032\n", 3) == 0)
+		p->data = "png -t9";
+	else if(memcmp(buf, "\0PC Research, Inc", 17) == 0)
+		p->data = "aux/g3p9bit -g";
+	else if(memcmp(buf, "TYPE=ccitt-g31", 14) == 0)
+		p->data = "aux/g3p9bit -g";
+	else if(memcmp(buf, "II*", 3) == 0)
+		p->data = "aux/g3p9bit -g";
+	else if(memcmp(buf, "TYPE=", 5) == 0)
+		p->data = "fb/3to1 rgbv |fb/pcp -tplan9";
+	else if(buf[0] == 'P' && '0' <= buf[1] && buf[1] <= '9')
+		p->data = "ppm -t9";
+	else if(memcmp(buf, "BM", 2) == 0)
+		p->data = "bmp -t9";
+	else if(infernobithdr(buf, n))
+		p->data = nil;
+	else {
+		werrstr("unknown image format");
+		goto Err1;
+	}
+
+	if(seek(fd, 0, 0) < 0)
+		goto Noseek;
+	if((i = read(fd, buf+n, n)) < 0)
+		goto Err1;
+	if(i != n || memcmp(buf, buf+n, i)){
+		n += i;
+	Noseek:
+		if((tfd = createtmp((ulong)p, "file")) < 0)
+			goto Err1;
+		while(n > 0){
+			if(write(tfd, buf, n) != n)
+				goto Err2;
+			if((n = read(fd, buf, sizeof(buf))) < 0)
+				goto Err2;
+		}
+		if(dup(tfd, fd) < 0){
+		Err2:
+			close(tfd);
+			goto Err1;
+		}
+		close(tfd);
+	}
+	free(file);
+	return p->open(p);
+}
+
+Page*
+nextpage(Page *p)
+{
+	if(p){
+		if(p->down)
+			return p->down;
+		if(p->next)
+			return p->next;
+		if(p->up)
+			return p->up->next;
+	}
+	return nil;
+}
+
+Page*
+prevpage(Page *x)
+{
+	Page *p, *t;
+
+	if(x){
+		for(p = root->down; p; p = t)
+			if((t = nextpage(p)) == x)
+				return p;
+	}
+	return nil;
+}
+
+int
+openpage(Page *p)
+{
+	int fd;
+
+	fd = -1;
+	if(p->open == nil || (fd = p->open(p)) < 0)
+		p->open = nil;
+	else {
+		if(rotate)
+			pipeline(fd, "rotate -r %d", rotate);
+		if(resize.x)
+			pipeline(fd, "resize -x %d", resize.x);
+		else if(resize.y)
+			pipeline(fd, "resize -y %d", resize.y);
+	}
+	return fd;
+}
+
+void
+loadpage(Page *p)
+{
+	int fd;
+
+	if(p->open && p->image == nil && p->text == nil){
+		if((fd = openpage(p)) >= 0){
+			pagegen++;
+			p->image = readimage(display, fd, 1);
+			close(fd);
+		}
+		if(p->image == nil && p->text == nil)
+			p->text = smprint("%s: %r", p->label);
+	}
+	p->gen = pagegen;
+}
+
+void
+unloadpage(Page *p)
+{
+	if(p->open){
+		if(p->text)
+			free(p->text);
+		p->text = nil;
+		if(p->image){
+			lockdisplay(display);
+			freeimage(p->image);
+			unlockdisplay(display);
+		}
+		p->image = nil;
+	}
+}
+
+void
+unloadpages(int age)
+{
+	Page *p;
+
+	for(p = root->down; p; p = nextpage(p)){
+		if(age == 0)	/* synchronous flush */
+			qlock(p);
+		else if(!canqlock(p))
+			continue;
+		if((pagegen - p->gen) >= age)
+			unloadpage(p);
+		qunlock(p);
+	}
+}
+
+void
+loadpages(Page *p, int ahead, int oviewgen)
+{
+	int i;
+
+	ahead++;	/* load at least one */
+	unloadpages(ahead*2);
+	for(i = 0; i < ahead && p; p = nextpage(p), i++){
+		if(viewgen != oviewgen)
+			break;
+		if(canqlock(p)){
+			loadpage(p);
+			if(viewgen != oviewgen){
+				unloadpage(p);
+				qunlock(p);
+				break;
+			}
+			if(p == current){
+				Point size;
+
+				esetcursor(nil);
+				size = pagesize(p);
+				if(size.x && size.y && newwin){
+					newwin = 0;
+					resizewin(size);
+				}
+				lockdisplay(display);
+				drawpage(p);
+				unlockdisplay(display);
+			}
+			qunlock(p);
+		}
+	}
+}
+
+/*
+ * A draw operation that touches only the area contained in bot but not in top.
+ * mp and sp get aligned with bot.min.
+ */
+static void
+gendrawdiff(Image *dst, Rectangle bot, Rectangle top, 
+	Image *src, Point sp, Image *mask, Point mp, int op)
+{
+	Rectangle r;
+	Point origin;
+	Point delta;
+
+	USED(op);
+
+	if(Dx(bot)*Dy(bot) == 0)
+		return;
+
+	/* no points in bot - top */
+	if(rectinrect(bot, top))
+		return;
+
+	/* bot - top ≡ bot */
+	if(Dx(top)*Dy(top)==0 || rectXrect(bot, top)==0){
+		gendrawop(dst, bot, src, sp, mask, mp, op);
+		return;
+	}
+
+	origin = bot.min;
+	/* split bot into rectangles that don't intersect top */
+	/* left side */
+	if(bot.min.x < top.min.x){
+		r = Rect(bot.min.x, bot.min.y, top.min.x, bot.max.y);
+		delta = subpt(r.min, origin);
+		gendrawop(dst, r, src, addpt(sp, delta), mask, addpt(mp, delta), op);
+		bot.min.x = top.min.x;
+	}
+
+	/* right side */
+	if(bot.max.x > top.max.x){
+		r = Rect(top.max.x, bot.min.y, bot.max.x, bot.max.y);
+		delta = subpt(r.min, origin);
+		gendrawop(dst, r, src, addpt(sp, delta), mask, addpt(mp, delta), op);
+		bot.max.x = top.max.x;
+	}
+
+	/* top */
+	if(bot.min.y < top.min.y){
+		r = Rect(bot.min.x, bot.min.y, bot.max.x, top.min.y);
+		delta = subpt(r.min, origin);
+		gendrawop(dst, r, src, addpt(sp, delta), mask, addpt(mp, delta), op);
+		bot.min.y = top.min.y;
+	}
+
+	/* bottom */
+	if(bot.max.y > top.max.y){
+		r = Rect(bot.min.x, top.max.y, bot.max.x, bot.max.y);
+		delta = subpt(r.min, origin);
+		gendrawop(dst, r, src, addpt(sp, delta), mask, addpt(mp, delta), op);
+		bot.max.y = top.max.y;
+	}
+}
+
+void
+zoomdraw(Image *d, Rectangle r, Rectangle top, Image *s, Point sp, int f)
+{
+	int w, x, y;
+	Image *t;
+	Point a;
+
+	if(f <= 1){
+		gendrawdiff(d, r, top, s, sp, nil, ZP, S);
+		return;
+	}
+	a = ZP;
+	if(r.min.x < d->r.min.x){
+		sp.x += (d->r.min.x - r.min.x)/f;
+		a.x = (d->r.min.x - r.min.x)%f;
+		r.min.x = d->r.min.x;
+	}
+	if(r.min.y < d->r.min.y){
+		sp.y += (d->r.min.y - r.min.y)/f;
+		a.y = (d->r.min.y - r.min.y)%f;
+		r.min.y = d->r.min.y;
+	}
+	rectclip(&r, d->r);
+	w = s->r.max.x - sp.x;
+	if(w > Dx(r))
+		w = Dx(r);
+	t = allocimage(display, Rect(r.min.x, r.min.y, r.min.x+w, r.max.y), s->chan, 0, DNofill);
+	if(t == nil)
+		return;
+	for(y=r.min.y; y<r.max.y; y++){
+		draw(t, Rect(r.min.x, y, r.min.x+w, y+1), s, nil, sp);
+		if(++a.y == zoom){
+			a.y = 0;
+			sp.y++;
+		}
+	}
+	sp = r.min;
+	for(x=r.min.x; x<r.max.x; x++){
+		gendrawdiff(d, Rect(x, r.min.y, x+1, r.max.y), top, t, sp, nil, ZP, S);
+		if(++a.x == f){
+			a.x = 0;
+			sp.x++;
+		}
+	}
+	freeimage(t);
+}
+
+Point
+pagesize(Page *p)
+{
+	return p->image ? mulpt(subpt(p->image->r.max, p->image->r.min), zoom) : ZP;
+}
+
+void
+drawpage(Page *p)
+{
+	Rectangle r;
+	Image *i;
+
+	if((i = p->image) == nil){
+		char *s;
+
+		if((s = p->text) == nil)
+			s = "...";
+		r.min = ZP;
+		r.max = stringsize(font, p->text);
+		r = rectaddpt(r, addpt(subpt(divpt(subpt(screen->r.max, screen->r.min), 2), divpt(r.max, 2)),
+			screen->r.min));
+		draw(screen, r, display->white, nil, ZP);
+		string(screen, r.min, display->black, ZP, font, s);
+	} else {
+		r = rectaddpt(Rpt(ZP, pagesize(p)), addpt(pos, screen->r.min));
+		zoomdraw(screen, r, ZR, i, i->r.min, zoom);
+	}
+	gendrawdiff(screen, screen->r, r, display->white, ZP, nil, ZP, S);
+	border(screen, r, -Borderwidth, display->black, ZP);
+	flushimage(display, 1);
+}
+
+void
+translate(Page *p, Point d)
+{
+	Rectangle r, or, nr;
+	Image *i;
+
+	i = p->image;
+	if((i==0) || (d.x==0 && d.y==0))
+		return;
+	r = rectaddpt(Rpt(ZP, pagesize(p)), addpt(pos, screen->r.min));
+	pos = addpt(pos, d);
+	nr = rectaddpt(r, d);
+	or = r;
+	rectclip(&or, screen->r);
+	draw(screen, rectaddpt(or, d), screen, nil, or.min);
+	zoomdraw(screen, nr, rectaddpt(or, d), i, i->r.min, zoom);
+	gendrawdiff(screen, screen->r, nr, display->white, ZP, nil, ZP, S);
+	border(screen, nr, -Borderwidth, display->black, ZP);
+	flushimage(display, 1);
+}
+
+Page*
+findpage(char *name)
+{
+	Page *p;
+	int n;
+
+	n = strlen(name);
+	/* look in current document first */
+	if(current && current->up){
+		for(p = current->up->down; p; p = p->next)
+			if(cistrncmp(p->label, 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;
+}
+
+Page*
+pageat(int i)
+{
+	Page *p;
+
+	for(p = root->down; i > 0 && p; p = nextpage(p))
+		i--;
+	return i ? nil : p;
+}
+
+int
+pageindex(Page *x)
+{
+	Page *p;
+	int i;
+
+	for(i = 0, p = root->down; p && p != x; p = nextpage(p))
+		i++;
+	return (p == x) ? i : -1;
+}
+
+char*
+pagemenugen(int i)
+{
+	Page *p;
+	if(p = pageat(i))
+		return p->label;
+	return nil;
+}
+
+void
+showpage(Page *p)
+{
+	static int nproc;
+	int oviewgen;
+
+	if(p == nil)
+		return;
+	esetcursor(&reading);
+	current = p;
+	oviewgen = viewgen;
+	if(++nproc > NPROC)
+		if(waitpid() > 0)
+			nproc--;
+	switch(rfork(RFPROC|RFMEM)){
+	case -1:
+		sysfatal("rfork: %r");
+	case 0:
+		loadpages(p, NAHEAD, oviewgen);
+		exits(nil);
+	}
+}
+
+void
+zerox(Page *p)
+{
+	char nam[64], *argv[4];
+	int fd;
+
+	if(p == nil)
+		return;
+	esetcursor(&reading);
+	qlock(p);
+	if((fd = openpage(p)) < 0)
+		goto Out;
+	if(rfork(RFREND|RFFDG|RFPROC|RFENVG|RFNOTEG|RFNOWAIT) == 0){
+		dup(fd, 0);
+		close(fd);
+
+		snprint(nam, sizeof nam, "/bin/%s", argv0);
+		argv[0] = argv0;
+		argv[1] = "-w";
+		argv[2] = nil;
+		exec(nam, argv);
+		sysfatal("exec: %r");
+	}
+	close(fd);
+Out:
+	qunlock(p);
+	esetcursor(nil);
+}
+
+void
+eresized(int new)
+{
+	Page *p;
+
+	lockdisplay(display);
+	if(new && getwindow(display, Refnone) == -1)
+		sysfatal("getwindow: %r");
+	if(p = current){
+		if(canqlock(p)){
+			drawpage(p);
+			qunlock(p);
+		}
+	}
+	unlockdisplay(display);
+}
+
+void killcohort(void)
+{
+	int i;
+	for(i=0;i!=3;i++){	/* It's a long way to the kitchen */
+		postnote(PNGROUP, getpid(), "kill");
+		sleep(1);
+	}
+}
+
+void drawerr(Display *, char *msg)
+{
+	sysfatal("draw: %s", msg);
+}
+
+char*
+shortname(char *s)
+{
+	char *x;
+	if(x = strrchr(s, '/'))
+		if(x[1] != 0)
+			return x+1;
+	return s;
+}
+
+void
+usage(void)
+{
+	fprint(2, "usage: %s [ -iRw ] [ -p ppi ] [ file ... ]\n", argv0);
+	exits("usage");
+}
+
+void
+main(int argc, char *argv[])
+{
+	enum { Eplumb = 4 };
+	char jump[32];
+	Plumbmsg *pm;
+	Point o;
+	Mouse m;
+	Event e;
+	char *s;
+	int i;
+
+	ARGBEGIN {
+	case 'a':
+	case 'v':
+	case 'V':
+	case 'P':
+		break;
+	case 'R':
+		newwin = -1;
+		break;
+	case 'w':
+		newwin = 1;
+		break;
+	case 'i':
+		imode = 1;
+		break;
+	case 'p':
+		ppi = atoi(EARGF(usage()));
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	/*
+	 * so that we can stop all subprocesses with a note,
+	 * and to isolate rendezvous from other processes
+	 */
+	rfork(RFNOTEG|RFNAMEG|RFREND);
+	atexit(killcohort);
+	atnotify(catchnote, 1);
+	if(newwin > 0){
+		s = smprint("-pid %d", getpid());
+		if(newwindow(s) < 0)
+			sysfatal("newwindow: %r");
+		free(s);
+	}
+	initdraw(drawerr, nil, argv0);
+	display->locking = 1;
+	unlockdisplay(display);
+	einit(Ekeyboard|Emouse);
+	eplumb(Eplumb, "image");
+	nullfd = open("/dev/null", ORDWR);
+	current = root = addpage(nil, "root", nil, nil, -1);
+
+	if(*argv == nil && !imode)
+		addpage(root, "stdin", popenfile, strdup("/fd/0"), -1);
+	for(; *argv; argv++)
+		addpage(root, shortname(*argv), popenfile, strdup(*argv), -1);
+
+	jump[0] = 0;
+	for(;;){
+		i=event(&e);
+		switch(i){
+		case Emouse:
+			lockdisplay(display);
+			m = e.mouse;
+			if(m.buttons & 1){
+				if(current == nil || !canqlock(current))
+					goto Unlock;
+				for(;;) {
+					o = m.xy;
+					m = emouse();
+					if((m.buttons & 1) == 0)
+						break;
+					translate(current, subpt(m.xy, o));
+				}
+				qunlock(current);
+				goto Unlock;
+			}
+			if(m.buttons & 2){
+				i = emenuhit(2, &m, &menu);
+				if(i < 0 || i >= nelem(menuitems) || menuitems[i]==nil)
+					goto Unlock;
+				s = menuitems[i];
+				if(strcmp(s, "orig size")==0){
+					pos = ZP;
+					zoom = 1;
+					resize = ZP;
+					rotate = 0;
+				Unload:
+					viewgen++;
+					unlockdisplay(display);
+					esetcursor(&reading);
+					unloadpages(0);
+					showpage(current);
+					continue;
+				}
+				if(strncmp(s, "rotate ", 7)==0){
+					rotate += atoi(s+7);
+					rotate %= 360;
+					goto Unload;
+				}
+				if(strcmp(s, "upside down")==0){
+					rotate += 180;
+					goto Unload;
+				}
+				if(strcmp(s, "fit width")==0){
+					pos = ZP;
+					zoom = 1;
+					resize = subpt(screen->r.max, screen->r.min);
+					resize.y = 0;
+					goto Unload;
+				}
+				if(strcmp(s, "fit height")==0){
+					pos = ZP;
+					zoom = 1;
+					resize = subpt(screen->r.max, screen->r.min);
+					resize.x = 0;
+					goto Unload;
+				}
+				if(strncmp(s, "zoom", 4)==0){
+					if(current && canqlock(current)){
+						o = subpt(m.xy, screen->r.min);
+						if(strstr(s, "in")){
+							if(zoom < 0x40000000){
+								zoom *= 2;
+								pos =  addpt(mulpt(subpt(pos, o), 2), o);
+							}
+						}else{
+							if(zoom > 1){
+								zoom /= 2;
+								pos =  addpt(divpt(subpt(pos, o), 2), o);
+							}
+						}
+						drawpage(current);
+						qunlock(current);
+					}
+				}
+				unlockdisplay(display);
+				if(strcmp(s, "next")==0)
+					showpage(nextpage(current));
+				if(strcmp(s, "prev")==0)
+					showpage(prevpage(current));
+				if(strcmp(s, "zerox")==0)
+					zerox(current);
+				if(strcmp(s, "quit")==0)
+					exits(0);
+				continue;
+			}
+			if(m.buttons & 4){
+				if(root->down == nil)
+					goto Unlock;
+				pagemenu.lasthit = pageindex(current);
+				i = emenuhit(3, &m, &pagemenu);
+				unlockdisplay(display);
+				if(i != -1)
+					showpage(pageat(i));
+				continue;
+			}
+		Unlock:
+			unlockdisplay(display);
+			break;
+		case Ekeyboard:
+			switch(e.kbdc){
+			case 'q':
+			case Kdel:
+			case Keof:
+				exits(0);
+			case Kup:
+				if(current == nil || !canqlock(current))
+					break;
+				lockdisplay(display);
+				if(pos.y < 0){
+					translate(current, Pt(0, Dy(screen->r)/2));
+					unlockdisplay(display);
+					qunlock(current);
+					continue;
+				}
+				unlockdisplay(display);
+				qunlock(current);
+				if(prevpage(current))
+					pos.y = 0;
+			case '-':
+			case Kbs:
+			case Kleft:
+				showpage(prevpage(current));
+				break;
+			case Kdown:
+				if(current == nil || !canqlock(current))
+					break;
+				o = addpt(pos, pagesize(current));
+				lockdisplay(display);
+				if(o.y > Dy(screen->r)){
+					translate(current, Pt(0, -Dy(screen->r)/2));
+					unlockdisplay(display);
+					qunlock(current);
+					continue;
+				}
+				unlockdisplay(display);
+				qunlock(current);
+				if(nextpage(current))
+					pos.y = 0;
+			case '\n':
+				if(jump[0]){
+					showpage(findpage(jump));
+					jump[0] = 0;
+					break;
+				}
+			case ' ':
+			case Kright:
+				showpage(nextpage(current));
+				break;
+			default:
+				i = strlen(jump);
+				if(i+1 < sizeof(jump)){
+					jump[i] = e.kbdc;
+					jump[i+1] = 0;
+				}
+			}
+			break;
+		case Eplumb:
+			pm = e.v;
+			if(pm && pm->ndata > 0){
+				int fd;
+
+				fd = -1;
+				s = plumblookup(pm->attr, "action");
+				if(s && strcmp(s, "quit")==0)
+					exits(0);
+				if(s && strcmp(s, "showdata")==0){
+					static ulong plumbid;
+
+					if((fd = createtmp(plumbid++, "plumb")) < 0){
+						fprint(2, "plumb: createtmp: %r\n");
+						goto Plumbfree;
+					}
+					s = malloc(NPATH);
+					if(fd2path(fd, s, NPATH) < 0){
+						close(fd);
+						goto Plumbfree;
+					}
+					write(fd, pm->data, pm->ndata);
+				}else if(pm->data[0] == '/'){
+					s = strdup(pm->data);
+				}else{
+					s = malloc(strlen(pm->wdir)+1+pm->ndata+1);
+					sprint(s, "%s/%s", pm->wdir, pm->data);
+					cleanname(s);
+				}
+				showpage(addpage(root, shortname(s), popenfile, s, fd));
+			}
+		Plumbfree:
+			plumbfree(pm);
+			break;
+		}
+	}
+}