acme: shift button 3 for reverse search

An experiment. Let's see if it's any good.
Also document the Mac conventions in devdraw(3).

man/man1/0intro.1

@@ -99,6 +99,11 @@ The argument is one of
 \fL'\fIxmin ymin xmax ymax\fL'\fR,
 \fRor
 \fIxmin\fL,\fIymin\fL,\fIxmax\fL,\fIymax\fR.
+See
+.MR devdraw (1)
+and
+.MR keyboard (7)
+for details about typing and clicking in graphical applications.
 .PP
 The
 .MR plumber (4)

man/man1/acme.1

@@ -588,6 +588,9 @@ not just
 or
 .BR 127 .
 (There is an easier way to locate literal text; see below.)
+If shift is held down during the selection or click,
+any leading regular expression search defaults to
+searching backward in the text instead of forward.
 .PP
 If the text is a file name followed by a colon and an address,
 .I acme
@@ -608,6 +611,8 @@ moved there.  Thus, to search for occurrences of a word in a file,
 just click button 3 on the word.  Because of the rule of using the
 selection as the button 3 action, subsequent clicks will find subsequent
 occurrences without moving the mouse.
+If shift is held down during the selection or click,
+the search looks backward in the file.
 .PP
 In all these actions, the mouse motion is not done if the text is a null string
 within a non-null selected string in the tag, so that (for example) complex regular expressions

man/man1/devdraw.1

@@ -10,19 +10,71 @@ invoked via
 .I Devdraw
 serves a custom graphics protocol and is the only program
 that talks directly to X window servers.
-On Macintosh, setting
-.BI devdrawretina
-to
-.BI 1
-will cause
-.I devdraw
-to use all available physical pixels on a retina display.
+.PP
+.SS "Apple macOS
+.PP
+On macOS, because a laptop trackpad click only has one button (the trackpad itself)
+Option-click is button 2, and Command-click is button 3.
+While the main mouse button is held down,
+Control, Option, and Command serve as simulated buttons 1, 2, 3 for chording in
+.MR acme (4) .
+For example, the 1-3 pasting chord in acme can be executed by
+highlighting text while holding down the trackpad button
+and then, while still holding down the button, pressing the Command key.
+.PP
+As usual, buttons 4 and 5 represent a scroll wheel.
+Two-finger scrolling on the trackpad sends those button events.
+.PP
+Holding down shift while clicking adds 5 to the button number.
+For example, Command-Click is button 3, so Command-Shift-Click is button 8.
+Most programs do not respond to those buttons; one notable exception is
+.MR acme (1) ,
+which interprets button 8 (shifted button 3) as a reverse search.
+.PP
+Typing Command-F toggles full screen mode.
+.PP
+.I Devdraw
+automatically detects high-resolution (retina) displays.
+For debugging, typing Command-R toggles retina mode.
+.PP
+Other than the special cases mentioned above,
+holding down Command while typing a character
+.B Kcmd
+(0xF100)
+plus that character.
+Some programs (notably
+.IR acme (1))
+recognize standard keyboard shortcuts such as
+Command-Z (undo), Command-Shift-Z (redo),
+Command-X (cut), and Command-V (paste).
+.SS "X Windows
+.PP
+On Unix systems, Control-click is mouse button 2,
+and Alt-click is mouse button 3.
+While the main mouse button is held down,
+Control and Alt serve as simulated buttons 2, 3 for chording in
+.MR acme (4) .
+For example, the 1-3 pasting chord in acme can be executed by
+highlighting text while holding down the trackpad button
+and then, while still holding down the button, pressing the Alt key.
+.PP
+Because the Control and Alt keys have other meanings
+(see
+.MR keyboard (7)
+for the Alt key's meaning)
+and there is no third modifier key like on the Mac,
+there is no way to type
+.B Kcmd
+variants,
+so there is no access to keyboard shortcuts for
+undo, redo, cut, and paste.
 .SH SOURCE
 .B \*9/src/cmd/devdraw
 .SH "SEE ALSO
 .MR draw (3) ,
 .MR drawfcall (3) ,
-.MR graphics (3)
+.MR graphics (3) ,
+.MR keyboard (7)
 .SH BUGS
 .I Devdraw
 should probably present a standard 9P server

man/man4/acme.4

@@ -361,6 +361,10 @@ for text inserted to the tag,
 for a button 3 action in the body,
 .B l
 for a button 3 action in the tag,
+.B R
+for a shifted button 3 action in the body,
+.B r
+for a shifted button 3 action in the tag,
 .B X
 for a button 2 action in the body, and
 .B x

man/man7/keyboard.7

@@ -62,16 +62,11 @@ Any rune can be typed using a compose key followed by several
 other keys.
 The compose key is also generally near the lower right of the main key area:
 the
-.B NUM PAD
-key on the Gnot, the
-.B Alternate
-key on the Next, the
-.B Compose
-key on the SLC, the
 .B Option
-key on the Magnum, and either
+key on the Mac
+and the
 .B Alt
-key on the PC.
+key on Unix systems.
 To type a single rune with the value specified by
 a given four-digit hexadecimal number,
 type the compose key,

src/cmd/9term/9term.c

@@ -1,4 +1,5 @@
 #include <u.h>
+#include <pwd.h>
 #include <signal.h>
 #include <libc.h>
 #include <ctype.h>
@@ -56,7 +57,7 @@ threadmaybackground(void)
 void
 threadmain(int argc, char *argv[])
 {
-	char *p;
+	char *p, *env;
 
 	rfork(RFNOTEG);
 	font = nil;
@@ -64,6 +65,25 @@ threadmain(int argc, char *argv[])
 	mainpid = getpid();
 	messagesize = 8192;
 
+	threadmaybackground();
+
+	env = getenv("__CFBundleIdentifier");
+	if(env != nil && strcmp(env, "com.swtch.9term") == 0) {
+		// Being invoked as $PLAN9/mac/9term.app.
+		// Set $SHELL and daemonize to let parent exit.
+		// This makes sure that each click on 9term
+		// brings up a new window.
+		extern void _threaddaemonize(void);
+		struct passwd *pw;
+
+		unsetenv("__CFBundleIdentifier");
+		pw = getpwuid(getuid());
+		if(pw != nil && pw->pw_shell != nil)
+			setenv("SHELL", pw->pw_shell, 1);
+		loginshell = TRUE;
+		//_threaddaemonize();
+	}
+
 	ARGBEGIN{
 	default:
 		usage();

src/cmd/acme/acme.c

@@ -518,6 +518,7 @@ mousethread(void *v)
 	Mouse m;
 	char *act;
 	enum { MResize, MMouse, MPlumb, MWarnings, NMALT };
+	enum { Shift = 5 };
 	static Alt alts[NMALT+1];
 
 	USED(v);
@@ -661,9 +662,9 @@ mousethread(void *v)
 				}else if(m.buttons & 2){
 					if(textselect2(t, &q0, &q1, &argt))
 						execute(t, q0, q1, FALSE, argt);
-				}else if(m.buttons & 4){
+				}else if(m.buttons & (4|(4<<Shift))){
 					if(textselect3(t, &q0, &q1))
-						look3(t, q0, q1, FALSE);
+						look3(t, q0, q1, FALSE, (m.buttons&(4<<Shift))!=0);
 				}
 				if(w)
 					winunlock(w);
@@ -770,7 +771,7 @@ waitthread(void *v)
 					pids = p;
 				}
 			}else{
-				if(search(t, c->name, c->nname)){
+				if(search(t, c->name, c->nname, FALSE)){
 					textdelete(t, t->q0, t->q1, TRUE);
 					textsetselect(t, 0, 0);
 				}

src/cmd/acme/addr.c

@@ -172,7 +172,7 @@ regexp(uint showerr, Text *t, Range lim, Range r, Rune *pat, int dir, int *found
 }
 
 Range
-address(uint showerr, Text *t, Range lim, Range ar, void *a, uint q0, uint q1, int (*getc)(void*, uint),  int *evalp, uint *qp)
+address(uint showerr, Text *t, Range lim, Range ar, void *a, uint q0, uint q1, int (*getc)(void*, uint),  int *evalp, uint *qp, int reverse)
 {
 	int dir, size, npat;
 	int prevc, c, nc, n;
@@ -183,6 +183,8 @@ address(uint showerr, Text *t, Range lim, Range ar, void *a, uint q0, uint q1, i
 	r = ar;
 	q = q0;
 	dir = None;
+	if(reverse)
+		dir = Back;
 	size = Line;
 	c = 0;
 	while(q < q1){
@@ -201,7 +203,7 @@ address(uint showerr, Text *t, Range lim, Range ar, void *a, uint q0, uint q1, i
 			if(q>=q1 && t!=nil && t->file!=nil)	/* rhs defaults to $ */
 				r.q1 = t->file->b.nc;
 			else{
-				nr = address(showerr, t, lim, ar, a, q, q1, getc, evalp, &q);
+				nr = address(showerr, t, lim, ar, a, q, q1, getc, evalp, &q, FALSE);
 				r.q1 = nr.q1;
 			}
 			*qp = q;

src/cmd/acme/dat.h

@@ -454,6 +454,7 @@ struct Expand
 	int	nname;
 	char	*bname;
 	int	jump;
+	int	reverse;
 	union{
 		Text	*at;
 		Rune	*ar;

src/cmd/acme/exec.c

@@ -280,13 +280,14 @@ getarg(Text *argt, int doaddr, int dofile, Rune **rp, int *nrp)
 	Expand e;
 	char *a;
 
+	memset(&e, 0, sizeof e);
 	*rp = nil;
 	*nrp = 0;
 	if(argt == nil)
 		return nil;
 	a = nil;
 	textcommit(argt, TRUE);
-	if(expand(argt, argt->q0, argt->q1, &e)){
+	if(expand(argt, argt->q0, argt->q1, &e, FALSE)){
 		free(e.bname);
 		if(e.nname && dofile){
 			e.name = runerealloc(e.name, e.nname+1);
@@ -1083,7 +1084,7 @@ look(Text *et, Text *t, Text *argt, int _0, int _1, Rune *arg, int narg)
 	if(et && et->w){
 		t = &et->w->body;
 		if(narg > 0){
-			search(t, arg, narg);
+			search(t, arg, narg, FALSE);
 			return;
 		}
 		getarg(argt, FALSE, FALSE, &r, &n);
@@ -1092,7 +1093,7 @@ look(Text *et, Text *t, Text *argt, int _0, int _1, Rune *arg, int narg)
 			r = runemalloc(n);
 			bufread(&t->file->b, t->q0, r, n);
 		}
-		search(t, r, n);
+		search(t, r, n, FALSE);
 		free(r);
 	}
 }

src/cmd/acme/fns.h

@@ -63,8 +63,8 @@ void	fontx(Text*, Text*, Text*, int, int, Rune*, int);
 #define isalnum acmeisalnum
 int	isalnum(Rune);
 void	execute(Text*, uint, uint, int, Text*);
-int	search(Text*, Rune*, uint);
-void	look3(Text*, uint, uint, int);
+int	search(Text*, Rune*, uint, int);
+void	look3(Text*, uint, uint, int, int);
 void	editcmd(Text*, Rune*, uint);
 uint	min(uint, uint);
 uint	max(uint, uint);
@@ -85,11 +85,11 @@ int		isregexc(int);
 void *emalloc(uint);
 void *erealloc(void*, uint);
 char	*estrdup(char*);
-Range		address(uint, Text*, Range, Range, void*, uint, uint, int (*)(void*, uint),  int*, uint*);
+Range		address(uint, Text*, Range, Range, void*, uint, uint, int (*)(void*, uint),  int*, uint*, int);
 int		rxexecute(Text*, Rune*, uint, uint, Rangeset*);
 int		rxbexecute(Text*, uint, Rangeset*);
 Window*	makenewwindow(Text *t);
-int	expand(Text*, uint, uint, Expand*);
+int	expand(Text*, uint, uint, Expand*, int);
 Rune*	skipbl(Rune*, int, int*);
 Rune*	findbl(Rune*, int, int*);
 char*	edittext(Window*, int, Rune*, int);

src/cmd/acme/look.c

@@ -80,7 +80,7 @@ startplumbing(void)
 
 
 void
-look3(Text *t, uint q0, uint q1, int external)
+look3(Text *t, uint q0, uint q1, int external, int reverse)
 {
 	int n, c, f, expanded;
 	Text *ct;
@@ -94,7 +94,7 @@ look3(Text *t, uint q0, uint q1, int external)
 	ct = seltext;
 	if(ct == nil)
 		seltext = t;
-	expanded = expand(t, q0, q1, &e);
+	expanded = expand(t, q0, q1, &e, reverse);
 	if(!external && t->w!=nil && t->w->nopen[QWevent]>0){
 		/* send alphanumeric expansion to external client */
 		if(expanded == FALSE)
@@ -109,6 +109,8 @@ look3(Text *t, uint q0, uint q1, int external)
 		c = 'l';
 		if(t->what == Body)
 			c = 'L';
+		if(reverse)
+			c += 'R' - 'L';
 		n = q1-q0;
 		if(n <= EVENTSIZE){
 			r = runemalloc(n);
@@ -203,12 +205,17 @@ look3(Text *t, uint q0, uint q1, int external)
 		ct = &t->w->body;
 		if(t->w != ct->w)
 			winlock(ct->w, 'M');
-		if(t == ct)
-			textsetselect(ct, e.q1, e.q1);
+		if(t == ct) {
+			uint q;
+			q = e.q1;
+			if(reverse)
+				q = e.q0;
+			textsetselect(ct, q, q);
+		}
 		n = e.q1 - e.q0;
 		r = runemalloc(n);
 		bufread(&t->file->b, e.q0, r, n);
-		if(search(ct, r, n) && e.jump)
+		if(search(ct, r, n, reverse) && e.jump)
 			moveto(mousectl, addpt(frptofchar(&ct->fr, ct->fr.p0), Pt(4, ct->fr.font->height-4)));
 		if(t->w != ct->w)
 			winunlock(ct->w);
@@ -241,6 +248,7 @@ plumblook(Plumbmsg *m)
 		warning(nil, "insanely long file name (%d bytes) in plumb message (%.32s...)\n", m->ndata, m->data);
 		return;
 	}
+	memset(&e, 0, sizeof e);
 	e.q0 = 0;
 	e.q1 = 0;
 	if(m->data[0] == '\0')
@@ -303,11 +311,11 @@ plumbshow(Plumbmsg *m)
 }
 
 int
-search(Text *ct, Rune *r, uint n)
+search(Text *ct, Rune *r, uint n, int reverse)
 {
-	uint q, nb, maxn;
+	uint nb, maxn;
 	int around;
-	Rune *s, *b, *c;
+	Rune *s, *b;
 
 	if(n==0 || n>ct->file->b.nc)
 		return FALSE;
@@ -321,55 +329,111 @@ search(Text *ct, Rune *r, uint n)
 	nb = 0;
 	b[nb] = 0;
 	around = 0;
-	q = ct->q1;
-	for(;;){
-		if(q >= ct->file->b.nc){
-			q = 0;
-			around = 1;
-			nb = 0;
-			b[nb] = 0;
-		}
-		if(nb > 0){
-			c = runestrchr(b, r[0]);
-			if(c == nil){
-				q += nb;
+	if(reverse){
+		uint q1;
+		q1 = ct->q0; // q1 is (past) end of text being searched.
+		for(;;){
+			if(q1 <= 0){
+				q1 = ct->file->b.nc;
+				around = 1;
 				nb = 0;
 				b[nb] = 0;
-				if(around && q>=ct->q1)
-					break;
-				continue;
 			}
-			q += (c-b);
-			nb -= (c-b);
-			b = c;
-		}
-		/* reload if buffer covers neither string nor rest of file */
-		if(nb<n && nb!=ct->file->b.nc-q){
-			nb = ct->file->b.nc-q;
-			if(nb >= maxn)
-				nb = maxn-1;
-			bufread(&ct->file->b, q, s, nb);
-			b = s;
-			b[nb] = '\0';
-		}
-		/* this runeeq is fishy but the null at b[nb] makes it safe */
-		if(runeeq(b, n, r, n)==TRUE){
-			if(ct->w){
-				textshow(ct, q, q+n, 1);
-				winsettag(ct->w);
-			}else{
-				ct->q0 = q;
-				ct->q1 = q+n;
+			if(nb > 0){
+				Rune *c;
+				for(c=b+nb; c>b; c--)
+					if(c[-1] == r[n-1])
+						break;
+				if(c == b) {
+					q1 -= nb;
+					nb = 0;
+					b[nb] = 0;
+					if(around && q1 <= 0)
+						break;
+					continue;
+				}
+				q1 -= nb - (c - b);
+				nb = c - b;
 			}
-			seltext = ct;
-			fbuffree(s);
-			return TRUE;
+			/* reload if buffer covers neither string nor beginning of file */
+			if(nb<n && nb!=q1){
+				nb = q1;
+				if(nb >= maxn)
+					nb = maxn-1;
+				bufread(&ct->file->b, q1-nb, s, nb);
+				b = s;
+				b[nb] = '\0';
+			}
+			if(runeeq(b+nb-n, n, r, n)==TRUE){
+				if(ct->w){
+					textshow(ct, q1-n, q1, 1);
+					winsettag(ct->w);
+				}else{
+					ct->q0 = q1-n;
+					ct->q1 = q1;
+				}
+				seltext = ct;
+				fbuffree(s);
+				return TRUE;
+			}
+			q1--;
+			nb--;
+			if(around && q1 <= 0)
+				break;
+		}
+	}else{
+		uint q;
+		q = ct->q1;
+		for(;;){
+			if(q >= ct->file->b.nc){
+				q = 0;
+				around = 1;
+				nb = 0;
+				b[nb] = 0;
+			}
+			if(nb > 0){
+				Rune *c;
+				c = runestrchr(b, r[0]);
+				if(c == nil){
+					q += nb;
+					nb = 0;
+					b[nb] = 0;
+					if(around && q>=ct->q1)
+						break;
+					continue;
+				}
+				q += (c-b);
+				nb -= (c-b);
+				b = c;
+			}
+			/* reload if buffer covers neither string nor rest of file */
+			if(nb<n && nb!=ct->file->b.nc-q){
+				nb = ct->file->b.nc-q;
+				if(nb >= maxn)
+					nb = maxn-1;
+				bufread(&ct->file->b, q, s, nb);
+				b = s;
+				b[nb] = '\0';
+			}
+			/* this runeeq is fishy but the null at b[nb] makes it safe */
+			if(runeeq(b, n, r, n)==TRUE){
+				if(ct->w){
+					textshow(ct, q, q+n, 1);
+					winsettag(ct->w);
+				}else{
+					ct->q0 = q;
+					ct->q1 = q+n;
+				}
+				seltext = ct;
+				fbuffree(s);
+				return TRUE;
+			}
+			--nb;
+			b++;
+			q++;
+			if(around && q>=ct->q1)
+				break;
 		}
-		--nb;
-		b++;
-		q++;
-		if(around && q>=ct->q1)
-			break;
 	}
 	fbuffree(s);
 	return FALSE;
@@ -526,7 +590,7 @@ texthas(Text *t, uint q0, Rune *r)
 }
 
 int
-expandfile(Text *t, uint q0, uint q1, Expand *e)
+expandfile(Text *t, uint q0, uint q1, Expand *e, int reverse)
 {
 	int i, n, nname, colon, eval;
 	uint amin, amax;
@@ -570,6 +634,11 @@ expandfile(Text *t, uint q0, uint q1, Expand *e)
 						break;
 			}else
 				amax = t->file->b.nc;
+		if(colon != q0)
+			reverse = FALSE;
+	}else if(reverse){
+		if(textreadc(t, q0) != ':')
+			reverse = FALSE;
 	}
 	amin = amax;
 	e->q0 = q0;
@@ -643,12 +712,16 @@ expandfile(Text *t, uint q0, uint q1, Expand *e)
 	}
 
   Isfile:
+  print("isfile reverse=%d colon=%d q0=%d\n", reverse, colon, q0);
 	e->name = r;
 	e->nname = nname;
 	e->u.at = t;
 	e->a0 = amin+1;
+	e->reverse = reverse;
 	eval = FALSE;
-	address(TRUE, nil, range(-1,-1), range(0,0), t, e->a0, amax, tgetc, &eval, (uint*)&e->a1);
+	// Note: address is repeated in openfile when
+	// expandfile returns to expand returns to look3.
+	address(TRUE, nil, range(-1,-1), range(0,0), t, e->a0, amax, tgetc, &eval, (uint*)&e->a1, e->reverse);
 	return TRUE;
 
    Isntfile:
@@ -657,7 +730,7 @@ expandfile(Text *t, uint q0, uint q1, Expand *e)
 }
 
 int
-expand(Text *t, uint q0, uint q1, Expand *e)
+expand(Text *t, uint q0, uint q1, Expand *e, int reverse)
 {
 	memset(e, 0, sizeof *e);
 	e->agetc = tgetc;
@@ -670,7 +743,7 @@ expand(Text *t, uint q0, uint q1, Expand *e)
 			e->jump = FALSE;
 	}
 
-	if(expandfile(t, q0, q1, e))
+	if(expandfile(t, q0, q1, e, reverse))
 		return TRUE;
 
 	if(q0 == q1){
@@ -806,7 +879,7 @@ openfile(Text *t, Expand *e)
 		eval = FALSE;
 	else{
 		eval = TRUE;
-		r = address(TRUE, t, range(-1,-1), range(t->q0, t->q1), e->u.at, e->a0, e->a1, e->agetc, &eval, &dummy);
+		r = address(TRUE, t, range(-1,-1), range(t->q0, t->q1), e->u.at, e->a0, e->a1, e->agetc, &eval, &dummy, e->reverse);
 		if(r.q0 > r.q1) {
 			eval = FALSE;
 			warning(nil, "addresses out of order\n");

src/cmd/acme/xfid.c

@@ -486,7 +486,7 @@ xfidwrite(Xfid *x)
 		t = &w->body;
 		wincommit(w, t);
 		eval = TRUE;
-		a = address(FALSE, t, w->limit, w->addr, r, 0, nr, rgetc, &eval, (uint*)&nb);
+		a = address(FALSE, t, w->limit, w->addr, r, 0, nr, rgetc, &eval, (uint*)&nb, FALSE);
 		free(r);
 		if(nb < nr){
 			respond(x, &fc, Ebadaddr);
@@ -900,7 +900,11 @@ xfideventwrite(Xfid *x, Window *w)
 			break;
 		case 'l':
 		case 'L':
-			look3(t, q0, q1, TRUE);
+			look3(t, q0, q1, TRUE, FALSE);
+			break;
+		case 'r':
+		case 'R':
+			look3(t, q0, q1, TRUE, TRUE);
 			break;
 		default:
 			qunlock(&row.lk);

src/cmd/devdraw/mac-screen.m

@@ -631,12 +631,17 @@ rpc_resizewindow(Client *c, Rectangle r)
 	b = [NSEvent pressedMouseButtons];
 	b = (b&~6) | (b&4)>>1 | (b&2)<<1;
 	if(b){
+		int x;
+		x = 0;
 		if(m & ~omod & NSEventModifierFlagControl)
-			b |= 1;
+			x = 1;
 		if(m & ~omod & NSEventModifierFlagOption)
-			b |= 2;
+			x = 2;
 		if(m & ~omod & NSEventModifierFlagCommand)
-			b |= 4;
+			x = 4;
+		if(m & NSEventModifierFlagShift)
+			x <<= 5;
+		b |= x;
 		[self sendmouse:b];
 	}else if(m & ~omod & NSEventModifierFlagOption)
 		gfx_keystroke(self.client, Kalt);
@@ -701,6 +706,8 @@ rpc_resizewindow(Client *c, Rectangle r)
 		}else
 		if(m & NSEventModifierFlagCommand)
 			b = 4;
+		if(m & NSEventModifierFlagShift)
+			b <<= 5;
 	}
 	[self sendmouse:b];
 }