Add scrollback and universal scroll

-.rej

@@ -0,0 +1,71 @@
+--- config.def.h
++++ config.def.h
+@@ -120,6 +120,8 @@ static const char *colorname[] = {
+ 	/* more colors can be added after 255 to use with DefaultXX */
+ 	"#cccccc",
+ 	"#555555",
++	"black",
++	"gray90",
+ };
+ 
+ 
+@@ -127,9 +129,10 @@ static const char *colorname[] = {
+  * Default colors (colorname index)
+  * foreground, background, cursor, reverse cursor
+  */
+-unsigned int defaultfg = 7;
+-unsigned int defaultbg = 0;
+-static unsigned int defaultcs = 256;
++
++unsigned int defaultbg = 258;
++unsigned int defaultfg = 259;
++unsigned int defaultcs = 256;
+ static unsigned int defaultrcs = 257;
+ 
+ /*
+--- st.c
++++ st.c
+@@ -1877,6 +1877,36 @@ strhandle(void)
+ 				}
+ 			}
+ 			return;
++		case 10: /* set foreground color */
++			if (narg < 2)
++				break;
++
++			p = strescseq.args[1];
++			if (xsetcolorname(defaultfg, p))
++				fprintf(stderr, "erresc: invalid foreground color %d\n", p);
++			else
++				redraw();
++			break;
++		case 11: /* set background color */
++			if (narg < 2)
++				break;
++
++			p = strescseq.args[1];
++			if (xsetcolorname(defaultbg, p))
++				fprintf(stderr, "erresc: invalid background color %d\n", p);
++			else
++				redraw();
++			break;
++		case 12: /* set cursor color */
++			if (narg < 2)
++				break;
++
++			p = strescseq.args[1];
++			if (xsetcolorname(defaultcs, p))
++				fprintf(stderr, "erresc: invalid cursor color %d\n", p);
++			else
++				redraw();
++			break;
+ 		case 4: /* color set */
+ 			if (narg < 3)
+ 				break;
+--- st.h
++++ st.h
+@@ -123,3 +123,4 @@ extern char *termname;
+ extern unsigned int tabspaces;
+ extern unsigned int defaultfg;
+ extern unsigned int defaultbg;
++extern unsigned int defaultcs;

.gitignore

@@ -2,3 +2,4 @@
 
 *.swp
 *.swo
+*.o

.pc/st-universcroll-0.8.4.diff

@@ -0,0 +1,90 @@
+From 9726b1e58352126252412e101432e64d46fc51ca Mon Sep 17 00:00:00 2001
+From: Dennis Lee <dennis@dennislee.xyz>
+Date: Sun, 28 Jun 2020 23:01:03 -0700
+Subject: [PATCH] universcroll: mouse wheel only scroll in all modes
+
+Scroll normally via scroll(1), without Shift, when outside of
+`MODE_ALTSCREEN`. Inside an alt screen, continue to scroll normally
+without Shift; in this mode, your scrolling is automatically translated
+into ^Y and ^E. It just werks!
+
+Based on the existing mouse-altscreen patch
+https://st.suckless.org/patches/scrollback/
+adapted for st(1) 0.8.4 and scroll(1).
+---
+ config.def.h | 10 +++++-----
+ st.c         |  5 +++++
+ st.h         |  1 +
+ x.c          |  2 ++
+ 4 files changed, 13 insertions(+), 5 deletions(-)
+
+diff --git a/config.def.h b/config.def.h
+index 6f05dce..62e87da 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -173,11 +173,11 @@ static uint forcemousemod = ShiftMask;
+  * Beware that overloading Button1 will disable the selection.
+  */
+ static MouseShortcut mshortcuts[] = {
+-	/* mask                 button   function        argument       release */
+-	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
+-	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
++	/* mask                 button   function        argument      release alt */
++	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},           1 },
++	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\033[5;2~"}, 0, -1 },
+ 	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
+-	{ ShiftMask,            Button5, ttysend,        {.s = "\033[6;2~"} },
++	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\033[6;2~"}, 0, -1 },
+ 	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },
+ };
+
+diff --git a/st.c b/st.c
+index 76b7e0d..1f65453 100644
+--- a/st.c
++++ b/st.c
+@@ -1047,6 +1047,11 @@ tnew(int col, int row)
+ 	treset();
+ }
+
++int tisaltscr(void)
++{
++	return IS_SET(MODE_ALTSCREEN);
++}
++
+ void
+ tswapscreen(void)
+ {
+diff --git a/st.h b/st.h
+index 3d351b6..39cc054 100644
+--- a/st.h
++++ b/st.h
+@@ -87,6 +87,7 @@ void sendbreak(const Arg *);
+ void toggleprinter(const Arg *);
+
+ int tattrset(int);
++int tisaltscr(void);
+ void tnew(int, int);
+ void tresize(int, int);
+ void tsetdirtattr(int);
+diff --git a/x.c b/x.c
+index 210f184..210dde9 100644
+--- a/x.c
++++ b/x.c
+@@ -34,6 +34,7 @@ typedef struct {
+ 	void (*func)(const Arg *);
+ 	const Arg arg;
+ 	uint  release;
++	int  altscrn;  /* 0: don't care, -1: not alt screen, 1: alt screen */
+ } MouseShortcut;
+
+ typedef struct {
+@@ -446,6 +447,7 @@ mouseaction(XEvent *e, uint release)
+ 	for (ms = mshortcuts; ms < mshortcuts + LEN(mshortcuts); ms++) {
+ 		if (ms->release == release &&
+ 		    ms->button == e->xbutton.button &&
++		    (!ms->altscrn || (ms->altscrn == (tisaltscr() ? 1 : -1))) &&
+ 		    (match(ms->mod, state) ||  /* exact or forced */
+ 		     match(ms->mod, state & ~forcemousemod))) {
+ 			ms->func(&(ms->arg));
+--
+2.27.0

config.def.h

@@ -178,11 +178,11 @@ static uint forcemousemod = ShiftMask;
  * Beware that overloading Button1 will disable the selection.
  */
 static MouseShortcut mshortcuts[] = {
-	/* mask                 button   function        argument       release */
-	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
-	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
+	/* mask                 button   function        argument      release alt */
+	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},           1 },
+	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\033[5;2~"}, 0, -1 },
 	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
-	{ ShiftMask,            Button5, ttysend,        {.s = "\033[6;2~"} },
+	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\033[6;2~"}, 0, -1 },
 	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },
 };
 
@@ -205,6 +205,8 @@ static Shortcut shortcuts[] = {
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
 	{ MODKEY,               XK_l,           copyurl,        {.i =  0} },
+	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
+	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
 };
 
 /*

config.def.h.orig

@@ -205,6 +205,8 @@ static Shortcut shortcuts[] = {
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
 	{ MODKEY,               XK_l,           copyurl,        {.i =  0} },
+	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
+	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
 };
 
 /*

config.h

@@ -54,7 +54,7 @@ int allowwindowops = 0;
  * low minlatency will tear/flicker more, as it can "detect" idle too early.
  */
 static double minlatency = 22;
-static double maxlatency = 66;
+static double maxlatency = 44;
 
 /*
  * blinking timeout (set to 0 to disable blinking) for the terminal blinking
@@ -94,7 +94,7 @@ char *termname = "st-256color";
 unsigned int tabspaces = 8;
 
 /* bg opacity */
-float alpha = 0.5, alphaUnfocused = 0.3;
+float alpha = 0.8, alphaUnfocused = 0.3;
 
 /* Terminal colors (16 first used in escape sequence) */
 static const char *colorname[] = {
@@ -129,8 +129,8 @@ static const char *colorname[] = {
  */
 unsigned int defaultfg = 7;
 unsigned int defaultbg = 0;
-static unsigned int defaultcs = 256;
-static unsigned int defaultrcs = 257;
+unsigned int defaultcs = 256;
+unsigned int defaultrcs = 257;
 unsigned int bg = 16, bgUnfocused = 16;
 
 /*
@@ -176,9 +176,9 @@ static uint forcemousemod = ShiftMask;
 static MouseShortcut mshortcuts[] = {
 	/* mask                 button   function        argument       release */
 	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
-	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
+	{ XK_NO_MOD,           Button4, ttysend,        {.s = "\033[5;2~"}, 0, -1 },
 	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
-	{ ShiftMask,            Button5, ttysend,        {.s = "\033[6;2~"} },
+	{ XK_NO_MOD,           Button5, ttysend,        {.s = "\033[6;2~"}, 0, -1 },
 	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },
 };
 
@@ -200,7 +200,9 @@ static Shortcut shortcuts[] = {
 	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
-	{ MODKEY,               XK_l,           copyurl,        {.i =  0} },
+	{ MODKEY|ShiftMask,               XK_l,           copyurl,        {.i =  0} },
+	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
+	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
 };
 
 /*

st-osc10-20210106-9c4b3f4.diff

@@ -0,0 +1,91 @@
+From 9c4b3f40e07dd1d6dd94fa733b7853aff7f4b8fc Mon Sep 17 00:00:00 2001
+From: Raheman Vaiya <r.vaiya@gmail.com>
+Date: Sat, 16 Jan 2021 18:18:07 -0500
+Subject: [PATCH] Add proper OSC 10/11 support.
+
+---
+ config.def.h |  9 ++++++---
+ st.c         | 30 ++++++++++++++++++++++++++++++
+ st.h         |  1 +
+ 3 files changed, 37 insertions(+), 3 deletions(-)
+
+diff --git a/config.def.h b/config.def.h
+index 6f05dce..9bb22a5 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -120,6 +120,8 @@ static const char *colorname[] = {
+ 	/* more colors can be added after 255 to use with DefaultXX */
+ 	"#cccccc",
+ 	"#555555",
++	"black",
++	"gray90",
+ };
+ 
+ 
+@@ -127,9 +129,10 @@ static const char *colorname[] = {
+  * Default colors (colorname index)
+  * foreground, background, cursor, reverse cursor
+  */
+-unsigned int defaultfg = 7;
+-unsigned int defaultbg = 0;
+-static unsigned int defaultcs = 256;
++
++unsigned int defaultbg = 258;
++unsigned int defaultfg = 259;
++unsigned int defaultcs = 256;
+ static unsigned int defaultrcs = 257;
+ 
+ /*
+diff --git a/st.c b/st.c
+index abbbe4b..6a57d89 100644
+--- a/st.c
++++ b/st.c
+@@ -1877,6 +1877,36 @@ strhandle(void)
+ 				}
+ 			}
+ 			return;
++		case 10: /* set foreground color */
++			if (narg < 2)
++				break;
++
++			p = strescseq.args[1];
++			if (xsetcolorname(defaultfg, p))
++				fprintf(stderr, "erresc: invalid foreground color %d\n", p);
++			else
++				redraw();
++			break;
++		case 11: /* set background color */
++			if (narg < 2)
++				break;
++
++			p = strescseq.args[1];
++			if (xsetcolorname(defaultbg, p))
++				fprintf(stderr, "erresc: invalid background color %d\n", p);
++			else
++				redraw();
++			break;
++		case 12: /* set cursor color */
++			if (narg < 2)
++				break;
++
++			p = strescseq.args[1];
++			if (xsetcolorname(defaultcs, p))
++				fprintf(stderr, "erresc: invalid cursor color %d\n", p);
++			else
++				redraw();
++			break;
+ 		case 4: /* color set */
+ 			if (narg < 3)
+ 				break;
+diff --git a/st.h b/st.h
+index 3d351b6..054366d 100644
+--- a/st.h
++++ b/st.h
+@@ -123,3 +123,4 @@ extern char *termname;
+ extern unsigned int tabspaces;
+ extern unsigned int defaultfg;
+ extern unsigned int defaultbg;
++extern unsigned int defaultcs;
+-- 
+2.20.1
+

st.c

@@ -1056,6 +1056,11 @@ tnew(int col, int row)
 	treset();
 }
 
+int tisaltscr(void)
+{
+	return IS_SET(MODE_ALTSCREEN);
+}
+
 void
 tswapscreen(void)
 {

st.c.orig

@@ -35,6 +35,7 @@
 #define ESC_ARG_SIZ   16
 #define STR_BUF_SIZ   ESC_BUF_SIZ
 #define STR_ARG_SIZ   ESC_ARG_SIZ
+#define HISTSIZE      2000
 
 /* macros */
 #define IS_SET(flag)		((term.mode & (flag)) != 0)
@@ -42,6 +43,9 @@
 #define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
 #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
 #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
+#define TLINE(y)		((y) < term.scr ? term.hist[((y) + term.histi - \
+				term.scr + HISTSIZE + 1) % HISTSIZE] : \
+				term.line[(y) - term.scr])
 
 enum term_mode {
 	MODE_WRAP        = 1 << 0,
@@ -115,6 +119,9 @@ typedef struct {
 	int col;      /* nb col */
 	Line *line;   /* screen */
 	Line *alt;    /* alternate screen */
+	Line hist[HISTSIZE]; /* history buffer */
+	int histi;    /* history index */
+	int scr;      /* scroll back */
 	int *dirty;   /* dirtyness of lines */
 	TCursor c;    /* cursor */
 	int ocx;      /* old cursor col */
@@ -184,8 +191,8 @@ static void tnewline(int);
 static void tputtab(int);
 static void tputc(Rune);
 static void treset(void);
-static void tscrollup(int, int);
-static void tscrolldown(int, int);
+static void tscrollup(int, int, int);
+static void tscrolldown(int, int, int);
 static void tsetattr(int *, int);
 static void tsetchar(Rune, Glyph *, int, int);
 static void tsetdirt(int, int);
@@ -413,10 +420,10 @@ tlinelen(int y)
 {
 	int i = term.col;
 
-	if (term.line[y][i - 1].mode & ATTR_WRAP)
+	if (TLINE(y)[i - 1].mode & ATTR_WRAP)
 		return i;
 
-	while (i > 0 && term.line[y][i - 1].u == ' ')
+	while (i > 0 && TLINE(y)[i - 1].u == ' ')
 		--i;
 
 	return i;
@@ -525,7 +532,7 @@ selsnap(int *x, int *y, int direction)
 		 * Snap around if the word wraps around at the end or
 		 * beginning of a line.
 		 */
-		prevgp = &term.line[*y][*x];
+		prevgp = &TLINE(*y)[*x];
 		prevdelim = ISDELIM(prevgp->u);
 		for (;;) {
 			newx = *x + direction;
@@ -540,14 +547,14 @@ selsnap(int *x, int *y, int direction)
 					yt = *y, xt = *x;
 				else
 					yt = newy, xt = newx;
-				if (!(term.line[yt][xt].mode & ATTR_WRAP))
+				if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
 					break;
 			}
 
 			if (newx >= tlinelen(newy))
 				break;
 
-			gp = &term.line[newy][newx];
+			gp = &TLINE(newy)[newx];
 			delim = ISDELIM(gp->u);
 			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
 					|| (delim && gp->u != prevgp->u)))
@@ -568,14 +575,14 @@ selsnap(int *x, int *y, int direction)
 		*x = (direction < 0) ? 0 : term.col - 1;
 		if (direction < 0) {
 			for (; *y > 0; *y += direction) {
-				if (!(term.line[*y-1][term.col-1].mode
+				if (!(TLINE(*y-1)[term.col-1].mode
 						& ATTR_WRAP)) {
 					break;
 				}
 			}
 		} else if (direction > 0) {
 			for (; *y < term.row-1; *y += direction) {
-				if (!(term.line[*y][term.col-1].mode
+				if (!(TLINE(*y)[term.col-1].mode
 						& ATTR_WRAP)) {
 					break;
 				}
@@ -606,13 +613,13 @@ getsel(void)
 		}
 
 		if (sel.type == SEL_RECTANGULAR) {
-			gp = &term.line[y][sel.nb.x];
+			gp = &TLINE(y)[sel.nb.x];
 			lastx = sel.ne.x;
 		} else {
-			gp = &term.line[y][sel.nb.y == y ? sel.nb.x : 0];
+			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
 			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
 		}
-		last = &term.line[y][MIN(lastx, linelen-1)];
+		last = &TLINE(y)[MIN(lastx, linelen-1)];
 		while (last >= gp && last->u == ' ')
 			--last;
 
@@ -847,6 +854,9 @@ void
 ttywrite(const char *s, size_t n, int may_echo)
 {
 	const char *next;
+	Arg arg = (Arg) { .i = term.scr };
+
+	kscrolldown(&arg);
 
 	if (may_echo && IS_SET(MODE_ECHO))
 		twrite(s, n, 1);
@@ -1058,13 +1068,53 @@ tswapscreen(void)
 }
 
 void
-tscrolldown(int orig, int n)
+kscrolldown(const Arg* a)
+{
+	int n = a->i;
+
+	if (n < 0)
+		n = term.row + n;
+
+	if (n > term.scr)
+		n = term.scr;
+
+	if (term.scr > 0) {
+		term.scr -= n;
+		selscroll(0, -n);
+		tfulldirt();
+	}
+}
+
+void
+kscrollup(const Arg* a)
+{
+	int n = a->i;
+
+	if (n < 0)
+		n = term.row + n;
+
+	if (term.scr <= HISTSIZE-n) {
+		term.scr += n;
+		selscroll(0, n);
+		tfulldirt();
+	}
+}
+
+void
+tscrolldown(int orig, int n, int copyhist)
 {
 	int i;
 	Line temp;
 
 	LIMIT(n, 0, term.bot-orig+1);
 
+	if (copyhist) {
+		term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
+		temp = term.hist[term.histi];
+		term.hist[term.histi] = term.line[term.bot];
+		term.line[term.bot] = temp;
+	}
+
 	tsetdirt(orig, term.bot-n);
 	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
 
@@ -1074,17 +1124,28 @@ tscrolldown(int orig, int n)
 		term.line[i-n] = temp;
 	}
 
-	selscroll(orig, n);
+	if (term.scr == 0)
+		selscroll(orig, n);
 }
 
 void
-tscrollup(int orig, int n)
+tscrollup(int orig, int n, int copyhist)
 {
 	int i;
 	Line temp;
 
 	LIMIT(n, 0, term.bot-orig+1);
 
+	if (copyhist) {
+		term.histi = (term.histi + 1) % HISTSIZE;
+		temp = term.hist[term.histi];
+		term.hist[term.histi] = term.line[orig];
+		term.line[orig] = temp;
+	}
+
+	if (term.scr > 0 && term.scr < HISTSIZE)
+		term.scr = MIN(term.scr + n, HISTSIZE-1);
+
 	tclearregion(0, orig, term.col-1, orig+n-1);
 	tsetdirt(orig+n, term.bot);
 
@@ -1094,7 +1155,8 @@ tscrollup(int orig, int n)
 		term.line[i+n] = temp;
 	}
 
-	selscroll(orig, -n);
+	if (term.scr == 0)
+		selscroll(orig, -n);
 }
 
 void
@@ -1123,7 +1185,7 @@ tnewline(int first_col)
 	int y = term.c.y;
 
 	if (y == term.bot) {
-		tscrollup(term.top, 1);
+		tscrollup(term.top, 1, 1);
 	} else {
 		y++;
 	}
@@ -1288,14 +1350,14 @@ void
 tinsertblankline(int n)
 {
 	if (BETWEEN(term.c.y, term.top, term.bot))
-		tscrolldown(term.c.y, n);
+		tscrolldown(term.c.y, n, 0);
 }
 
 void
 tdeleteline(int n)
 {
 	if (BETWEEN(term.c.y, term.top, term.bot))
-		tscrollup(term.c.y, n);
+		tscrollup(term.c.y, n, 0);
 }
 
 int32_t
@@ -1732,11 +1794,11 @@ csihandle(void)
 		break;
 	case 'S': /* SU -- Scroll <n> line up */
 		DEFAULT(csiescseq.arg[0], 1);
-		tscrollup(term.top, csiescseq.arg[0]);
+		tscrollup(term.top, csiescseq.arg[0], 0);
 		break;
 	case 'T': /* SD -- Scroll <n> line down */
 		DEFAULT(csiescseq.arg[0], 1);
-		tscrolldown(term.top, csiescseq.arg[0]);
+		tscrolldown(term.top, csiescseq.arg[0], 0);
 		break;
 	case 'L': /* IL -- Insert <n> blank lines */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -2240,7 +2302,7 @@ eschandle(uchar ascii)
 		return 0;
 	case 'D': /* IND -- Linefeed */
 		if (term.c.y == term.bot) {
-			tscrollup(term.top, 1);
+			tscrollup(term.top, 1, 1);
 		} else {
 			tmoveto(term.c.x, term.c.y+1);
 		}
@@ -2253,7 +2315,7 @@ eschandle(uchar ascii)
 		break;
 	case 'M': /* RI -- Reverse index */
 		if (term.c.y == term.top) {
-			tscrolldown(term.top, 1);
+			tscrolldown(term.top, 1, 1);
 		} else {
 			tmoveto(term.c.x, term.c.y-1);
 		}
@@ -2463,7 +2525,7 @@ twrite(const char *buf, int buflen, int show_ctrl)
 void
 tresize(int col, int row)
 {
-	int i;
+	int i, j;
 	int minrow = MIN(row, term.row);
 	int mincol = MIN(col, term.col);
 	int *bp;
@@ -2500,6 +2562,14 @@ tresize(int col, int row)
 	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
 	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
 
+	for (i = 0; i < HISTSIZE; i++) {
+		term.hist[i] = xrealloc(term.hist[i], col * sizeof(Glyph));
+		for (j = mincol; j < col; j++) {
+			term.hist[i][j] = term.c.attr;
+			term.hist[i][j].u = ' ';
+		}
+	}
+
 	/* resize each row to new width, zero-pad if needed */
 	for (i = 0; i < minrow; i++) {
 		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
@@ -2558,7 +2628,7 @@ drawregion(int x1, int y1, int x2, int y2)
 			continue;
 
 		term.dirty[y] = 0;
-		xdrawline(term.line[y], x1, y, x2);
+		xdrawline(TLINE(y), x1, y, x2);
 	}
 }
 
@@ -2579,8 +2649,9 @@ draw(void)
 		cx--;
 
 	drawregion(0, 0, term.col, term.row);
-	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
-			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
+	if (term.scr == 0)
+		xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+				term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
 	term.ocx = cx;
 	term.ocy = term.c.y;
 	xfinishdraw();

st.c.rej

@@ -0,0 +1,323 @@
+--- st.c
++++ st.c
+@@ -35,6 +35,7 @@
+ #define ESC_ARG_SIZ   16
+ #define STR_BUF_SIZ   ESC_BUF_SIZ
+ #define STR_ARG_SIZ   ESC_ARG_SIZ
++#define HISTSIZE      2000
+ 
+ /* macros */
+ #define IS_SET(flag)		((term.mode & (flag)) != 0)
+@@ -42,6 +43,9 @@
+ #define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
+ #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
+ #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
++#define TLINE(y)		((y) < term.scr ? term.hist[((y) + term.histi - \
++				term.scr + HISTSIZE + 1) % HISTSIZE] : \
++				term.line[(y) - term.scr])
+ 
+ enum term_mode {
+ 	MODE_WRAP        = 1 << 0,
+@@ -115,6 +119,9 @@ typedef struct {
+ 	int col;      /* nb col */
+ 	Line *line;   /* screen */
+ 	Line *alt;    /* alternate screen */
++	Line hist[HISTSIZE]; /* history buffer */
++	int histi;    /* history index */
++	int scr;      /* scroll back */
+ 	int *dirty;   /* dirtyness of lines */
+ 	TCursor c;    /* cursor */
+ 	int ocx;      /* old cursor col */
+@@ -184,8 +191,8 @@ static void tnewline(int);
+ static void tputtab(int);
+ static void tputc(Rune);
+ static void treset(void);
+-static void tscrollup(int, int);
+-static void tscrolldown(int, int);
++static void tscrollup(int, int, int);
++static void tscrolldown(int, int, int);
+ static void tsetattr(int *, int);
+ static void tsetchar(Rune, Glyph *, int, int);
+ static void tsetdirt(int, int);
+@@ -414,10 +421,10 @@ tlinelen(int y)
+ {
+ 	int i = term.col;
+ 
+-	if (term.line[y][i - 1].mode & ATTR_WRAP)
++	if (TLINE(y)[i - 1].mode & ATTR_WRAP)
+ 		return i;
+ 
+-	while (i > 0 && term.line[y][i - 1].u == ' ')
++	while (i > 0 && TLINE(y)[i - 1].u == ' ')
+ 		--i;
+ 
+ 	return i;
+@@ -526,7 +533,7 @@ selsnap(int *x, int *y, int direction)
+ 		 * Snap around if the word wraps around at the end or
+ 		 * beginning of a line.
+ 		 */
+-		prevgp = &term.line[*y][*x];
++		prevgp = &TLINE(*y)[*x];
+ 		prevdelim = ISDELIM(prevgp->u);
+ 		for (;;) {
+ 			newx = *x + direction;
+@@ -541,14 +548,14 @@ selsnap(int *x, int *y, int direction)
+ 					yt = *y, xt = *x;
+ 				else
+ 					yt = newy, xt = newx;
+-				if (!(term.line[yt][xt].mode & ATTR_WRAP))
++				if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
+ 					break;
+ 			}
+ 
+ 			if (newx >= tlinelen(newy))
+ 				break;
+ 
+-			gp = &term.line[newy][newx];
++			gp = &TLINE(newy)[newx];
+ 			delim = ISDELIM(gp->u);
+ 			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
+ 					|| (delim && gp->u != prevgp->u)))
+@@ -569,14 +576,14 @@ selsnap(int *x, int *y, int direction)
+ 		*x = (direction < 0) ? 0 : term.col - 1;
+ 		if (direction < 0) {
+ 			for (; *y > 0; *y += direction) {
+-				if (!(term.line[*y-1][term.col-1].mode
++				if (!(TLINE(*y-1)[term.col-1].mode
+ 						& ATTR_WRAP)) {
+ 					break;
+ 				}
+ 			}
+ 		} else if (direction > 0) {
+ 			for (; *y < term.row-1; *y += direction) {
+-				if (!(term.line[*y][term.col-1].mode
++				if (!(TLINE(*y)[term.col-1].mode
+ 						& ATTR_WRAP)) {
+ 					break;
+ 				}
+@@ -607,13 +614,13 @@ getsel(void)
+ 		}
+ 
+ 		if (sel.type == SEL_RECTANGULAR) {
+-			gp = &term.line[y][sel.nb.x];
++			gp = &TLINE(y)[sel.nb.x];
+ 			lastx = sel.ne.x;
+ 		} else {
+-			gp = &term.line[y][sel.nb.y == y ? sel.nb.x : 0];
++			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
+ 			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
+ 		}
+-		last = &term.line[y][MIN(lastx, linelen-1)];
++		last = &TLINE(y)[MIN(lastx, linelen-1)];
+ 		while (last >= gp && last->u == ' ')
+ 			--last;
+ 
+@@ -848,6 +855,9 @@ void
+ ttywrite(const char *s, size_t n, int may_echo)
+ {
+ 	const char *next;
++	Arg arg = (Arg) { .i = term.scr };
++
++	kscrolldown(&arg);
+ 
+ 	if (may_echo && IS_SET(MODE_ECHO))
+ 		twrite(s, n, 1);
+@@ -1059,13 +1069,53 @@ tswapscreen(void)
+ }
+ 
+ void
+-tscrolldown(int orig, int n)
++kscrolldown(const Arg* a)
++{
++	int n = a->i;
++
++	if (n < 0)
++		n = term.row + n;
++
++	if (n > term.scr)
++		n = term.scr;
++
++	if (term.scr > 0) {
++		term.scr -= n;
++		selscroll(0, -n);
++		tfulldirt();
++	}
++}
++
++void
++kscrollup(const Arg* a)
++{
++	int n = a->i;
++
++	if (n < 0)
++		n = term.row + n;
++
++	if (term.scr <= HISTSIZE-n) {
++		term.scr += n;
++		selscroll(0, n);
++		tfulldirt();
++	}
++}
++
++void
++tscrolldown(int orig, int n, int copyhist)
+ {
+ 	int i;
+ 	Line temp;
+ 
+ 	LIMIT(n, 0, term.bot-orig+1);
+ 
++	if (copyhist) {
++		term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
++		temp = term.hist[term.histi];
++		term.hist[term.histi] = term.line[term.bot];
++		term.line[term.bot] = temp;
++	}
++
+ 	tsetdirt(orig, term.bot-n);
+ 	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
+ 
+@@ -1075,17 +1125,28 @@ tscrolldown(int orig, int n)
+ 		term.line[i-n] = temp;
+ 	}
+ 
+-	selscroll(orig, n);
++	if (term.scr == 0)
++		selscroll(orig, n);
+ }
+ 
+ void
+-tscrollup(int orig, int n)
++tscrollup(int orig, int n, int copyhist)
+ {
+ 	int i;
+ 	Line temp;
+ 
+ 	LIMIT(n, 0, term.bot-orig+1);
+ 
++	if (copyhist) {
++		term.histi = (term.histi + 1) % HISTSIZE;
++		temp = term.hist[term.histi];
++		term.hist[term.histi] = term.line[orig];
++		term.line[orig] = temp;
++	}
++
++	if (term.scr > 0 && term.scr < HISTSIZE)
++		term.scr = MIN(term.scr + n, HISTSIZE-1);
++
+ 	tclearregion(0, orig, term.col-1, orig+n-1);
+ 	tsetdirt(orig+n, term.bot);
+ 
+@@ -1095,7 +1156,8 @@ tscrollup(int orig, int n)
+ 		term.line[i+n] = temp;
+ 	}
+ 
+-	selscroll(orig, -n);
++	if (term.scr == 0)
++		selscroll(orig, -n);
+ }
+ 
+ void
+@@ -1124,7 +1186,7 @@ tnewline(int first_col)
+ 	int y = term.c.y;
+ 
+ 	if (y == term.bot) {
+-		tscrollup(term.top, 1);
++		tscrollup(term.top, 1, 1);
+ 	} else {
+ 		y++;
+ 	}
+@@ -1289,14 +1351,14 @@ void
+ tinsertblankline(int n)
+ {
+ 	if (BETWEEN(term.c.y, term.top, term.bot))
+-		tscrolldown(term.c.y, n);
++		tscrolldown(term.c.y, n, 0);
+ }
+ 
+ void
+ tdeleteline(int n)
+ {
+ 	if (BETWEEN(term.c.y, term.top, term.bot))
+-		tscrollup(term.c.y, n);
++		tscrollup(term.c.y, n, 0);
+ }
+ 
+ int32_t
+@@ -1733,11 +1795,11 @@ csihandle(void)
+ 		break;
+ 	case 'S': /* SU -- Scroll <n> line up */
+ 		DEFAULT(csiescseq.arg[0], 1);
+-		tscrollup(term.top, csiescseq.arg[0]);
++		tscrollup(term.top, csiescseq.arg[0], 0);
+ 		break;
+ 	case 'T': /* SD -- Scroll <n> line down */
+ 		DEFAULT(csiescseq.arg[0], 1);
+-		tscrolldown(term.top, csiescseq.arg[0]);
++		tscrolldown(term.top, csiescseq.arg[0], 0);
+ 		break;
+ 	case 'L': /* IL -- Insert <n> blank lines */
+ 		DEFAULT(csiescseq.arg[0], 1);
+@@ -2241,7 +2303,7 @@ eschandle(uchar ascii)
+ 		return 0;
+ 	case 'D': /* IND -- Linefeed */
+ 		if (term.c.y == term.bot) {
+-			tscrollup(term.top, 1);
++			tscrollup(term.top, 1, 1);
+ 		} else {
+ 			tmoveto(term.c.x, term.c.y+1);
+ 		}
+@@ -2254,7 +2316,7 @@ eschandle(uchar ascii)
+ 		break;
+ 	case 'M': /* RI -- Reverse index */
+ 		if (term.c.y == term.top) {
+-			tscrolldown(term.top, 1);
++			tscrolldown(term.top, 1, 1);
+ 		} else {
+ 			tmoveto(term.c.x, term.c.y-1);
+ 		}
+@@ -2464,7 +2526,7 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ void
+ tresize(int col, int row)
+ {
+-	int i;
++	int i, j;
+ 	int minrow = MIN(row, term.row);
+ 	int mincol = MIN(col, term.col);
+ 	int *bp;
+@@ -2501,6 +2563,14 @@ tresize(int col, int row)
+ 	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
+ 	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
+ 
++	for (i = 0; i < HISTSIZE; i++) {
++		term.hist[i] = xrealloc(term.hist[i], col * sizeof(Glyph));
++		for (j = mincol; j < col; j++) {
++			term.hist[i][j] = term.c.attr;
++			term.hist[i][j].u = ' ';
++		}
++	}
++
+ 	/* resize each row to new width, zero-pad if needed */
+ 	for (i = 0; i < minrow; i++) {
+ 		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
+@@ -2559,7 +2629,7 @@ drawregion(int x1, int y1, int x2, int y2)
+ 			continue;
+ 
+ 		term.dirty[y] = 0;
+-		xdrawline(term.line[y], x1, y, x2);
++		xdrawline(TLINE(y), x1, y, x2);
+ 	}
+ }
+ 
+@@ -2580,8 +2650,9 @@ draw(void)
+ 		cx--;
+ 
+ 	drawregion(0, 0, term.col, term.row);
+-	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+-			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
++	if (term.scr == 0)
++		xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
++				term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
+ 	term.ocx = cx;
+ 	term.ocy = term.c.y;
+ 	xfinishdraw();

st.h

@@ -91,6 +91,7 @@ void toggleprinter(const Arg *);
 void copyurl(const Arg *);
 
 int tattrset(int);
+int tisaltscr(void);
 void tnew(int, int);
 void tresize(int, int);
 void tsetdirtattr(int);

st.h.orig

@@ -82,6 +82,8 @@ void redraw(void);
 void tfulldirt(void);
 void draw(void);
 
+void kscrolldown(const Arg *);
+void kscrollup(const Arg *);
 void printscreen(const Arg *);
 void printsel(const Arg *);
 void sendbreak(const Arg *);

st.h.rej

@@ -0,0 +1,7 @@
+--- st.h
++++ st.h
+@@ -123,4 +123,3 @@ extern char *termname;
+ extern unsigned int tabspaces;
+ extern unsigned int defaultfg;
+ extern unsigned int defaultbg;
+-extern unsigned int defaultcs;

x.c

@@ -34,6 +34,7 @@ typedef struct {
 	void (*func)(const Arg *);
 	const Arg arg;
 	uint  release;
+	int  altscrn;  /* 0: don't care, -1: not alt screen, 1: alt screen */
 } MouseShortcut;
 
 typedef struct {
@@ -450,6 +451,7 @@ mouseaction(XEvent *e, uint release)
 	for (ms = mshortcuts; ms < mshortcuts + LEN(mshortcuts); ms++) {
 		if (ms->release == release &&
 		    ms->button == e->xbutton.button &&
+		    (!ms->altscrn || (ms->altscrn == (tisaltscr() ? 1 : -1))) &&
 		    (match(ms->mod, state) ||  /* exact or forced */
 		     match(ms->mod, state & ~forcemousemod))) {
 			ms->func(&(ms->arg));

x.c.orig

@@ -254,6 +254,8 @@ static char *opt_line  = NULL;
 static char *opt_name  = NULL;
 static char *opt_title = NULL;
 
+static int focused = 0;
+
 static int oldbutton = 3; /* button event on startup: 3 = release */
 
 void
@@ -774,35 +776,38 @@ xloadcolor(int i, const char *name, Color *ncolor)
 	return XftColorAllocName(xw.dpy, xw.vis, xw.cmap, name, ncolor);
 }
 
+void
+xloadalpha(void)
+{
+	float const usedAlpha = focused ? alpha : alphaUnfocused;
+	if (opt_alpha) alpha = strtof(opt_alpha, NULL);
+	dc.col[defaultbg].color.alpha = (unsigned short)(0xffff * usedAlpha);
+	dc.col[defaultbg].pixel &= 0x00FFFFFF;
+	dc.col[defaultbg].pixel |= (unsigned char)(0xff * usedAlpha) << 24;
+}
+
 void
 xloadcols(void)
 {
-	int i;
 	static int loaded;
 	Color *cp;
 
-	if (loaded) {
-		for (cp = dc.col; cp < &dc.col[dc.collen]; ++cp)
-			XftColorFree(xw.dpy, xw.vis, xw.cmap, cp);
-	} else {
-		dc.collen = MAX(LEN(colorname), 256);
-		dc.col = xmalloc(dc.collen * sizeof(Color));
+	if (!loaded) {
+		dc.collen = 1 + (defaultbg = MAX(LEN(colorname), 256));
+		dc.col = xmalloc((dc.collen) * sizeof(Color));
 	}
 
-	for (i = 0; i < dc.collen; i++)
+	for (int i = 0; i+1 < dc.collen; ++i)
 		if (!xloadcolor(i, NULL, &dc.col[i])) {
 			if (colorname[i])
 				die("could not allocate color '%s'\n", colorname[i]);
 			else
 				die("could not allocate color %d\n", i);
 		}
+	if (dc.collen) // cannot die, as the color is already loaded.
+		xloadcolor(focused ?bg :bgUnfocused, NULL, &dc.col[defaultbg]);
 
-	/* set alpha value of bg color */
-	if (opt_alpha)
-		alpha = strtof(opt_alpha, NULL);
-	dc.col[defaultbg].color.alpha = (unsigned short)(0xffff * alpha);
-	dc.col[defaultbg].pixel &= 0x00FFFFFF;
-	dc.col[defaultbg].pixel |= (unsigned char)(0xff * alpha) << 24;
+	xloadalpha();
 	loaded = 1;
 }
 
@@ -1747,12 +1752,22 @@ focus(XEvent *ev)
 		xseturgency(0);
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[I", 3, 0);
+		if (!focused) {
+			focused = 1;
+			xloadcols();
+			tfulldirt();
+		}
 	} else {
 		if (xw.ime.xic)
 			XUnsetICFocus(xw.ime.xic);
 		win.mode &= ~MODE_FOCUSED;
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[O", 3, 0);
+		if (focused) {
+			focused = 0;
+			xloadcols();
+			tfulldirt();
+		}
 	}
 }
 
@@ -2059,6 +2074,7 @@ run:
 	XSetLocaleModifiers("");
 	cols = MAX(cols, 1);
 	rows = MAX(rows, 1);
+	defaultbg = MAX(LEN(colorname), 256);
 	tnew(cols, rows);
 	xinit(cols, rows);
 	xsetenv();