Mass screen.c rename/tidy. Add a actual size (ysize) as distinct from display size (now dx,dy). Move functions which work on the displayed area into screen-display.c and tidy. Use macros consistently when accessing screen data (may want to move everything about again later!). This the first step on the road to scrollback.

10 files changed, 617 insertions, 555 deletions

diff --git a/Makefile b/Makefile
index 41dc6ae3..8bbc2ed6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-# $Id: Makefile,v 1.43 2007-11-20 17:01:38 nicm Exp $
+# $Id: Makefile,v 1.44 2007-11-20 21:42:28 nicm Exp $
 
 .SUFFIXES: .c .o .y .h
 .PHONY: clean update-index.html upload-index.html
@@ -16,17 +16,17 @@ DEBUG=
 META?= \002 # C-b
 
 SRCS= tmux.c server.c server-msg.c server-fn.c buffer.c buffer-poll.c status.c \
-      xmalloc.c xmalloc-debug.c input.c input-keys.c screen.c window.c \
-      session.c local.c log.c client.c client-msg.c client-fn.c key-string.c \
-      key-bindings.c resize.c cmd.c cmd-new-session.c cmd-detach-client.c \
-      cmd-list-sessions.c cmd-new-window.c cmd-next-window.c cmd-bind-key.c \
+      xmalloc.c xmalloc-debug.c input.c input-keys.c screen.c screen-display.c \
+      window.c session.c local.c log.c client.c client-msg.c client-fn.c \
+      key-string.c key-bindings.c resize.c cmd.c cmd-new-session.c \
+      cmd-detach-client.c cmd-list-sessions.c cmd-new-window.c cmd-bind-key.c \
       cmd-unbind-key.c cmd-previous-window.c cmd-last-window.c cmd-list-keys.c \
       cmd-set-option.c cmd-rename-window.c cmd-select-window.c \
       cmd-list-windows.c cmd-attach-session.c cmd-send-prefix.c \
       cmd-refresh-client.c cmd-kill-window.c cmd-list-clients.c \
-      cmd-has-session.c cmd-link-window.c cmd-unlink-window.c \
+      cmd-link-window.c cmd-unlink-window.c cmd-next-window.c \
       cmd-swap-window.c cmd-rename-session.c cmd-kill-session.c \
-      cmd-switch-client.c
+      cmd-switch-client.c cmd-has-session.c 
 
 CC?= cc
 INCDIRS+= -I. -I- -I/usr/local/include
diff --git a/cmd-list-windows.c b/cmd-list-windows.c
index 1340a7ae..c7bd1716 100644
--- a/cmd-list-windows.c
+++ b/cmd-list-windows.c
@@ -1,4 +1,4 @@
-/* $Id: cmd-list-windows.c,v 1.8 2007-11-16 21:12:31 nicm Exp $ */
+/* $Id: cmd-list-windows.c,v 1.9 2007-11-20 21:42:29 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -49,7 +49,7 @@ cmd_list_windows_exec(unused void *ptr, struct cmd_ctx *ctx)
 		w = wl->window;
 		ctx->print(ctx, "%d: %s \"%s\" (%s) [%ux%u]",
 		    wl->idx, w->name, w->screen.title, ttyname(w->fd),
-		    w->screen.sx, w->screen.sy);
+		    screen_size_x(&w->screen), screen_size_y(&w->screen));
 	}
 
 	if (ctx->cmdclient != NULL)
diff --git a/input.c b/input.c
index f215b861..f9061aab 100644
--- a/input.c
+++ b/input.c
@@ -1,4 +1,4 @@
-/* $Id: input.c,v 1.32 2007-11-20 18:46:32 nicm Exp $ */
+/* $Id: input.c,v 1.33 2007-11-20 21:42:29 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -75,6 +75,13 @@ void	 input_handle_sequence_decstbm(struct input_ctx *);
 void	 input_handle_sequence_sgr(struct input_ctx *);
 void	 input_handle_sequence_dsr(struct input_ctx *);
 
+#define input_limit(v, lower, upper) do {	\
+	if (v < lower)				\
+		v = lower;			\
+	if (v > upper)				\
+		v = upper;			\
+} while (0)
+
 int
 input_new_argument(struct input_ctx *ictx)
 {
@@ -365,18 +372,16 @@ input_handle_character(u_char ch, struct input_ctx *ictx)
 
 	log_debug2("-- ch %zu: %hhu (%c)", ictx->off, ch, ch);
 	
-	if (s->cx > s->sx || s->cy > s->sy - 1)
-		return;
-
-	if (s->cx == s->sx) {
+	if (s->cx == screen_size_x(s)) {
 		input_store8(ictx->b, '\r');
 		input_store8(ictx->b, '\n');
 
 		s->cx = 0;
-		screen_cursor_down_scroll(s);
-	}
+		screen_display_cursor_down(s);
+	} else if (!screen_in_x(s, s->cx) || !screen_in_y(s, s->cy))
+		return;
 
-	screen_write_character(s, ch);
+	screen_display_cursor_set(s, ch);
 	input_store8(ictx->b, ch);
 
 	s->cx++;
@@ -393,7 +398,7 @@ input_handle_c0_control(u_char ch, struct input_ctx *ictx)
 	case '\0':	/* NUL */
 		break;
 	case '\n':	/* LF */
- 		screen_cursor_down_scroll(s);
+ 		screen_display_cursor_down(s);
 		break;
 	case '\r':	/* CR */
 		s->cx = 0;
@@ -407,9 +412,9 @@ input_handle_c0_control(u_char ch, struct input_ctx *ictx)
 		break;
 	case '\011': 	/* TAB */
 		s->cx = ((s->cx / 8) * 8) + 8;
-		if (s->cx > s->sx) {
+		if (s->cx > screen_last_x(s)) {
 			s->cx = 0;
-			screen_cursor_down_scroll(s);
+			screen_display_cursor_down(s);
 		}
 		input_store_two(
 		    ictx->b, CODE_CURSORMOVE, s->cy + 1, s->cx + 1);	
@@ -430,7 +435,7 @@ input_handle_c1_control(u_char ch, struct input_ctx *ictx)
 
 	switch (ch) {
 	case 'M':	/* RI */
-		screen_cursor_up_scroll(s);
+		screen_display_cursor_up(s);
 		input_store_zero(ictx->b, CODE_REVERSEINDEX);
 		break;
 	default:
@@ -521,7 +526,7 @@ input_handle_sequence(u_char ch, struct input_ctx *ictx)
 	
 	log_debug2("-- sq %zu: %hhu (%c): %u [sx=%u, sy=%u, cx=%u, cy=%u]",
 	    ictx->off, ch, ch, ARRAY_LENGTH(&ictx->args),
-	    s->sx, s->sy, s->cx, s->cy);
+	    screen_size_x(s), screen_size_y(s), s->cx, s->cy);
 	for (i = 0; i < ARRAY_LENGTH(&ictx->args); i++) {
 		iarg = &ARRAY_ITEM(&ictx->args, i);
 		if (*iarg->data != '\0')
@@ -576,10 +581,9 @@ input_handle_sequence_cud(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 0, &n, 1) != 0)
 		return;
 
-	if (n == 0 || n > s->sy - s->cy - 1) {
-		log_debug3("cud: out of range: %hu", n);
+	if (n == 0)
 		return;
-	}
+	input_limit(n, 1, screen_last_y(s) - s->cy);
 
 	s->cy += n;
 	input_store_one(ictx->b, CODE_CURSORDOWN, n);
@@ -599,10 +603,9 @@ input_handle_sequence_cuf(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 0, &n, 1) != 0)
 		return;
 
-	if (n == 0 || n > s->sx - s->cx - 1) {
-		log_debug3("cuf: out of range: %hu", n);
+	if (n == 0)
 		return;
-	}
+	input_limit(n, 1, screen_last_x(s) - s->cx);
 
 	s->cx += n;
 	input_store_one(ictx->b, CODE_CURSORRIGHT, n);
@@ -645,12 +648,11 @@ input_handle_sequence_dch(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 0, &n, 1) != 0)
 		return;
 
-	if (n == 0 || n > s->sx - s->cx - 1) {
-		log_debug3("dch: out of range: %hu", n);
+	if (n == 0)
 		return;
-	}
+	input_limit(n, 1, screen_last_x(s) - s->cx);
 
-	screen_delete_characters(s, s->cx, s->cy, n);
+	screen_display_delete_characters(s, s->cx, s->cy, n);
 	input_store_one(ictx->b, CODE_DELETECHARACTER, n);
 }
 
@@ -668,15 +670,14 @@ input_handle_sequence_dl(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 0, &n, 1) != 0)
 		return;
 
-	if (n == 0 || n > s->sy - s->cy - 1) {
-		log_debug3("dl: out of range: %hu", n);
+	if (n == 0)
 		return;
-	}
+	input_limit(n, 1, screen_last_y(s) - s->cy);
 
 	if (s->cy < s->rupper || s->cy > s->rlower)
-		screen_delete_lines(s, s->cy, n);
+		screen_display_delete_lines(s, s->cy, n);
 	else
-		screen_delete_lines_region(s, s->cy, n);
+		screen_display_delete_lines_region(s, s->cy, n);
 	input_store_one(ictx->b, CODE_DELETELINE, n);
 }
 
@@ -694,12 +695,11 @@ input_handle_sequence_ich(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 0, &n, 1) != 0)
 		return;
 
-	if (n == 0 || n > s->sx - s->cx - 1) {
-		log_debug3("ich: out of range: %hu", n);
+	if (n == 0)
 		return;
-	}
+	input_limit(n, 1, screen_last_x(s) - s->cx);
 
-	screen_insert_characters(s, s->cx, s->cy, n);
+	screen_display_insert_characters(s, s->cx, s->cy, n);
 	input_store_one(ictx->b, CODE_INSERTCHARACTER, n);
 }
 
@@ -717,14 +717,14 @@ input_handle_sequence_il(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 0, &n, 1) != 0)
 		return;
 
-	if (n == 0 || n > s->sy - s->cy - 1) {
-		log_debug3("il: out of range: %hu", n);
+	if (n == 0)
 		return;
-	}
+	input_limit(n, 1, screen_last_y(s) - s->cy);
+
 	if (s->cy < s->rupper || s->cy > s->rlower)
-		screen_insert_lines(s, s->cy, n);
+		screen_display_insert_lines(s, s->cy, n);
 	else
-		screen_insert_lines_region(s, s->cy, n);
+		screen_display_insert_lines_region(s, s->cy, n);
 	input_store_one(ictx->b, CODE_INSERTLINE, n);
 }
 
@@ -742,10 +742,9 @@ input_handle_sequence_vpa(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 0, &n, 1) != 0)
 		return;
 
-	if (n == 0 || n > s->sy) {
-		log_debug3("vpa: out of range: %hu", n);
+	if (n == 0)
 		return;
-	}
+	input_limit(n, 1, screen_size_y(s));
 
 	s->cy = n - 1;
 	input_store_two(ictx->b, CODE_CURSORMOVE, n, s->cx + 1);
@@ -765,10 +764,9 @@ input_handle_sequence_hpa(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 0, &n, 1) != 0)
 		return;
 
-	if (n == 0 || n > s->sx) {
-		log_debug3("hpa: out of range: %hu", n);
+	if (n == 0)
 		return;
-	}
+	input_limit(n, 1, screen_size_x(s));
 
 	s->cx = n - 1;
 	input_store_two(ictx->b, CODE_CURSORMOVE, s->cy + 1, n);
@@ -790,14 +788,8 @@ input_handle_sequence_cup(struct input_ctx *ictx)
 	if (input_get_argument(ictx, 1, &m, 1) != 0)
 		return;
 
-	if (n == 0)
-		n = 1;
-	if (n > s->sy)
-		n = s->sy;
-	if (m == 0)
-		m = 1;
-	if (m > s->sx)
-		m = s->sx;
+	input_limit(n, 1, screen_size_y(s));
+	input_limit(m, 1, screen_size_x(s));
 
 	s->cx = m - 1;
 	s->cy = n - 1;
@@ -824,10 +816,11 @@ input_handle_sequence_ed(struct input_ctx *ictx)
 
 	switch (n) {
 	case 0:
-		screen_fill_end_of_screen(
-		    s, 0, s->cy, SCREEN_DEFDATA, s->attr, s->colr);
+		screen_display_fill_cursor_eos(
+		    s, SCREEN_DEFDATA, s->attr, s->colr);
+
 		input_store_zero(ictx->b, CODE_CLEARLINE);
-		for (i = s->cy + 1; i < s->sy; i++) {
+		for (i = s->cy + 1; i < screen_size_y(s); i++) {
 			input_store_two(ictx->b, CODE_CURSORMOVE, i + 1, 1);
 			input_store_zero(ictx->b, CODE_CLEARLINE);
 		}
@@ -835,8 +828,10 @@ input_handle_sequence_ed(struct input_ctx *ictx)
 		    ictx->b, CODE_CURSORMOVE, s->cy + 1, s->cx + 1);
 		break;
 	case 2:
-		screen_fill_screen(s, SCREEN_DEFDATA, s->attr, s->colr);
-		for (i = 0; i < s->sy; i++) {
+		screen_display_fill_lines(
+		    s, 0, screen_size_y(s), SCREEN_DEFDATA, s->attr, s->colr);
+		
+		for (i = 0; i < screen_size_y(s); i++) {
 			input_store_two(ictx->b, CODE_CURSORMOVE, i + 1, 1);
 			input_store_zero(ictx->b, CODE_CLEARLINE);
 		}
@@ -865,17 +860,18 @@ input_handle_sequence_el(struct input_ctx *ictx)
 
 	switch (n) {
 	case 0:
-		screen_fill_end_of_line(
-		    s, s->cx, s->cy, SCREEN_DEFDATA, s->attr, s->colr);
+		screen_display_fill_cursor_eol(
+		    s, SCREEN_DEFDATA, s->attr, s->colr);
 		input_store_zero(ictx->b, CODE_CLEARENDOFLINE);
 		break;
 	case 1:
-		screen_fill_start_of_line(
-		    s, s->cx, s->cy, SCREEN_DEFDATA, s->attr, s->colr);
+		screen_display_fill_cursor_bol(
+		    s, SCREEN_DEFDATA, s->attr, s->colr);
 		input_store_zero(ictx->b, CODE_CLEARSTARTOFLINE);
 		break;
 	case 2:
-		screen_fill_line(s, s->cy, SCREEN_DEFDATA, s->attr, s->colr);
+		screen_display_fill_line(
+		    s, s->cy, SCREEN_DEFDATA, s->attr, s->colr);
 		input_store_zero(ictx->b, CODE_CLEARLINE);
 		break;
 	}
@@ -1008,17 +1004,11 @@ input_handle_sequence_decstbm(struct input_ctx *ictx)
 	/* XXX this will catch [0;0r and [;r etc too, is this right? */
 	if (n == 0 && m == 0) {
 		n = 1;
-		m = s->sy;
+		m = screen_size_y(s);
 	}
 
-	if (n == 0)
-		n = 1;
-	if (n > s->sy)
-		n = s->sy;
-	if (m == 0)
-		m = 1;
-	if (m > s->sy)
-		m = s->sy;
+	input_limit(n, 1, screen_size_y(s));
+	input_limit(m, 1, screen_size_y(s));
 
 	if (n > m) {
 		log_debug3("decstbm: out of range: %hu,%hu", n, m);
diff --git a/key-bindings.c b/key-bindings.c
index 7be5df60..0af94f8d 100644
--- a/key-bindings.c
+++ b/key-bindings.c
@@ -1,4 +1,4 @@
-/* $Id: key-bindings.c,v 1.16 2007-11-20 18:11:37 nicm Exp $ */
+/* $Id: key-bindings.c,v 1.17 2007-11-20 21:42:29 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -166,15 +166,18 @@ key_bindings_print(struct cmd_ctx *ctx, const char *fmt, ...)
 	va_list		 ap;
 	char		*msg;
 	size_t		 size;
-	u_int		 i;
+	u_int		 i, sx, sy;
+
+	sx = screen_size_x(s);
+	sy = screen_size_y(s);
 
 	buffer_ensure(c->out, sizeof hdr);
 	buffer_add(c->out, sizeof hdr);
 	size = BUFFER_USED(c->out);
 
-	if (line == 2 * s->sy || !(c->flags & CLIENT_HOLD)) {
+	if (line == 2 * sy || !(c->flags & CLIENT_HOLD)) {
 		input_store_zero(c->out, CODE_CURSOROFF);
-		for (i = 0; i < s->sy; i++) {
+		for (i = 0; i < sy; i++) {
 			input_store_two(c->out, CODE_CURSORMOVE, i + 1, 1);
 			input_store_zero(c->out, CODE_CLEARLINE);
 		}			
@@ -184,20 +187,19 @@ key_bindings_print(struct cmd_ctx *ctx, const char *fmt, ...)
 		line = 0;
 		c->flags |= CLIENT_HOLD;
 	}
-	if (line >= s->sy) {
-		input_store_two(
-		    c->out, CODE_CURSORMOVE, line - s->sy + 1, s->sx / 2);
+	if (line >= sy) {
+		input_store_two(c->out, CODE_CURSORMOVE, line - sy + 1, sx / 2);
 	}
 	line++;
 
 	va_start(ap, fmt);
 	xvasprintf(&msg, fmt, ap);
 	va_end(ap);
-	if (strlen(msg) > s->sx / 2)
-		msg[s->sx / 2] = '\0';
+	if (strlen(msg) > sx / 2)
+		msg[sx / 2] = '\0';
 
 	buffer_write(c->out, msg, strlen(msg));
-	if (line != s->sy && line != 2 * s->sy) {
+	if (line != sy && line != 2 * sy) {
 		input_store8(c->out, '\r');
 		input_store8(c->out, '\n');
 	}
diff --git a/resize.c b/resize.c
index 71392604..2e9380c3 100644
--- a/resize.c
+++ b/resize.c
@@ -1,4 +1,4 @@
-/* $Id: resize.c,v 1.4 2007-10-19 10:21:35 nicm Exp $ */
+/* $Id: resize.c,v 1.5 2007-11-20 21:42:29 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -107,11 +107,12 @@ recalculate_sizes(void)
 		if (ssx == UINT_MAX || ssy == UINT_MAX)
 			continue;
 
-		if (w->screen.sx == ssx && w->screen.sy == ssy)
+		if (screen_size_x(&w->screen) == ssx &&
+		    screen_size_y(&w->screen) == ssy)
 			continue;
 
-		log_debug("window size %u,%u (was %u,%u)", 
-		    ssx, ssy, w->screen.sx, w->screen.sy);
+		log_debug("window size %u,%u (was %u,%u)", ssx, ssy,
+		    screen_size_x(&w->screen), screen_size_y(&w->screen));
 
 		server_clear_window_cur(w);
 		window_resize(w, ssx, ssy);
diff --git a/screen-display.c b/screen-display.c
new file mode 100644
index 00000000..5f2790aa
--- /dev/null
+++ b/screen-display.c
@@ -0,0 +1,430 @@
+/* $Id: screen-display.c,v 1.1 2007-11-20 21:42:29 nicm Exp $ */
+
+/*
+ * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+
+#include <string.h>
+
+#include "tmux.h"
+
+/*
+ * Screen display modification functions. These alter the displayed portion
+ * of the screen.
+ */
+
+/* Create a region of lines. */
+void
+screen_display_make_lines(struct screen *s, u_int py, u_int ny)
+{
+	if (ny == 0 || !screen_in_y(s, py) || !screen_in_y(s, py + ny - 1))
+		fatalx("bad value");
+	screen_make_lines(s, screen_y(s, py), ny);
+}
+
+/* Free a region of lines. */
+void
+screen_display_free_lines(struct screen *s, u_int py, u_int ny)
+{
+	if (ny == 0 || !screen_in_y(s, py) || !screen_in_y(s, py + ny - 1))
+		fatalx("bad value");
+	screen_free_lines(s, screen_y(s, py), ny);
+}
+
+/* Move a set of lines. */
+void
+screen_display_move_lines(struct screen *s, u_int dy, u_int py, u_int ny)
+{
+	if (ny == 0 || !screen_in_y(s, py) || !screen_in_y(s, py + ny - 1))
+		fatalx("bad value");
+	if (!screen_in_y(s, dy) || !screen_in_y(s, dy + ny - 1) || dy == py)
+		fatalx("bad value");
+	screen_move_lines(s, screen_y(s, dy), screen_y(s, py), ny);
+}
+
+/* Fill a set of lines. */
+void
+screen_display_fill_lines(
+    struct screen *s, u_int py, u_int ny, u_char data, u_char attr, u_char colr)
+{
+	if (ny == 0 || !screen_in_y(s, py) || !screen_in_y(s, py + ny - 1))
+		fatalx("bad value");
+	screen_fill_lines(s, screen_y(s, py), ny, data, attr, colr);
+}
+
+/* Fill a set of cellss. */
+void
+screen_display_fill_cells(struct screen *s,
+    u_int px, u_int py, u_int nx, u_char data, u_char attr, u_char colr)
+{
+	if (nx == 0 || !screen_in_x(s, px) || !screen_in_y(s, py))
+		fatalx("bad value");
+	screen_fill_cells(
+	    s, screen_x(s, px), screen_y(s, py), nx, data, attr, colr);
+}
+
+/* Fill entire screen. */
+void
+screen_display_fill_screen(
+    struct screen *s, u_char data, u_char attr, u_char colr)
+{
+	screen_display_fill_lines(s, 0, screen_size_y(s), data, attr, colr);
+}
+
+/* Fill end of screen from cursor. */
+void
+screen_display_fill_cursor_eos(
+    struct screen *s, u_char data, u_char attr, u_char colr)
+{
+	screen_display_fill_cursor_eol(s, data, attr, colr);
+	if (s->cy != screen_last_y(s)) {
+		screen_display_fill_lines(
+		    s, s->cy, screen_size_y(s) - s->cy, data, attr, colr);
+	}
+}
+
+/* Fill beginning of screen from cursor. */
+void
+screen_display_fill_cursor_bos(
+    struct screen *s, u_char data, u_char attr, u_char colr)
+{
+	screen_display_fill_lines(s, 0, s->cy, data, attr, colr);
+}
+
+/* Fill a single line. */
+void
+screen_display_fill_line(
+    struct screen *s, u_int py, u_char data, u_char attr, u_char colr)
+{
+	screen_display_fill_lines(s, py, 1, data, attr, colr);
+}
+
+/* Fill cursor to beginning of line. */
+void
+screen_display_fill_cursor_bol(
+    struct screen *s, u_char data, u_char attr, u_char colr)
+{
+	screen_display_fill_cells(s, 0, s->cy, s->cx, data, attr, colr);
+}
+
+/* Fill cursor to end of line. */
+void
+screen_display_fill_cursor_eol(
+    struct screen *s, u_char data, u_char attr, u_char colr)
+{
+	screen_display_fill_cells(
+	    s, s->cx, s->cy, screen_size_x(s) - s->cx, data, attr, colr);
+}
+
+/* Set character at cursor. */
+void
+screen_display_cursor_set(struct screen *s, u_char ch)
+{
+	u_int	px, py;
+
+	px = screen_x(s, s->cx);
+	py = screen_y(s, s->cy);
+
+	s->grid_data[py][px] = ch;
+	s->grid_attr[py][px] = s->attr;
+	s->grid_colr[py][px] = s->colr;
+}
+
+/* Move cursor up and scroll if necessary. */
+void
+screen_display_cursor_up(struct screen *s)
+{
+	if (s->cy == s->rupper)
+		screen_display_scroll_region_down(s);
+	else if (s->cy > 0)
+		s->cy--;
+}
+
+/* Move cursor down and scroll if necessary. */
+void
+screen_display_cursor_down(struct screen *s)
+{
+	if (s->cy == s->rlower)
+		screen_display_scroll_region_up(s);
+	else if (s->cy < screen_last_y(s))
+		s->cy++;
+}
+
+/* Scroll region up. */
+void
+screen_display_scroll_region_up(struct screen *s)
+{
+	/* 
+	 * Scroll scrolling region up:
+	 * 	- delete rupper
+	 *	- move rupper + 1 to rlower to rupper
+	 *	- make new line at rlower
+	 *
+	 * Example: region is 12 to 24.
+	 *	rlower = 24, rupper = 12
+	 *	screen_free_lines(s, 12, 1);
+	 *	screen_move_lines(s, 12, 13, 12);
+	 *	screen_make_lines(s, 24, 1);
+	 */
+
+	screen_display_free_lines(s, s->rupper, 1);
+
+	if (s->rupper != s->rlower) {
+		screen_display_move_lines(s, 
+		    s->rupper, s->rupper + 1, s->rlower - s->rupper);
+	}
+
+	screen_display_make_lines(s, s->rlower, 1);
+	screen_display_fill_lines(
+	    s, s->rlower, 1, SCREEN_DEFDATA, SCREEN_DEFATTR, SCREEN_DEFCOLR);
+}
+
+/* Scroll region down. */
+void
+screen_display_scroll_region_down(struct screen *s)
+{
+	/* 
+	 * Scroll scrolling region down:
+	 * 	- delete rlower
+	 *	- move rupper to rlower - 1 to rupper + 1
+	 *	- make new line at rupper
+	 *
+	 * Example: region is 12 to 24.
+	 *	rlower = 24, rupper = 12
+	 *	screen_free_lines(s, 24, 1);
+	 *	screen_move_lines(s, 13, 12, 12);
+	 *	screen_make_lines(s, 12, 1);
+	 */
+
+	screen_display_free_lines(s, s->rlower, 1);
+
+	if (s->rupper != s->rlower) {
+		screen_display_move_lines(s,
+		    s->rupper + 1, s->rupper, s->rlower - s->rupper);
+	}
+
+	screen_display_make_lines(s, s->rupper, 1);
+	screen_display_fill_lines(
+	    s, s->rupper, 1, SCREEN_DEFDATA, SCREEN_DEFATTR, SCREEN_DEFCOLR);
+}
+
+/* Insert lines. */
+void
+screen_display_insert_lines(struct screen *s, u_int py, u_int ny)
+{
+	if (!screen_in_y(s, py))
+		fatalx("bad value");
+	if (ny == 0)
+		fatalx("bad value");
+
+	if (py + ny > screen_last_y(s))
+		ny = screen_last_y(s) - py;
+
+	/*
+	 * Insert range of ny lines at py:
+	 *	- Free ny lines from end of screen.
+	 *	- Move from py to end of screen - ny to py + ny.
+	 *	- Create ny lines at py.
+	 *
+	 * Example: insert 2 lines at 4.
+	 *	sy = 10, py = 4, ny = 2
+	 *	screen_free_lines(s, 8, 2);	- delete lines 8,9
+	 *	screen_move_lines(s, 6, 4, 4);	- move 4,5,6,7 to 6,7,8,9
+	 *	screen_make_lines(s, 4, 2);	- make lines 4,5
+	 */
+
+	screen_display_free_lines(s, screen_size_y(s) - ny, ny);
+
+	if (py != screen_last_y(s)) {
+		screen_display_move_lines(
+		    s, py + ny, py, screen_size_y(s) - py - ny);
+	}
+
+	screen_display_make_lines(s, py, ny);
+}
+
+/* Insert lines in region. */
+void
+screen_display_insert_lines_region(struct screen *s, u_int py, u_int ny)
+{
+	if (!screen_in_region(s, py))
+		fatalx("bad value");
+	if (ny == 0)
+		fatalx("bad value");
+
+	if (py + ny > s->rlower)
+		ny = s->rlower - py;
+
+	/*
+	 * Insert range of ny lines at py:
+	 *	- Free ny lines from end of screen.
+	 *	- Move from py to end of screen - ny to py + ny.
+	 *	- Create ny lines at py.
+	 *
+	 * Example: insert 2 lines at 4.
+	 *	ryu = 11, ryl = 16, py = 13, ny = 2
+	 *	screen_free_lines(s, 15, 2);	- delete lines 15,16
+	 *	screen_move_lines(s, 13, 15, 2);- move 13,14 to 15,16
+	 *	screen_make_lines(s, 13, 2);	- make lines 13,14
+	 */
+
+	screen_display_free_lines(s, (s->rlower + 1) - ny, ny);
+
+	if (py != s->rlower) {
+		screen_display_move_lines(
+		    s, py + ny, py, (s->rlower + 1) - py - ny);
+	}
+
+	screen_display_make_lines(s, py, ny);
+}
+
+/* Delete lines. */
+void
+screen_display_delete_lines(struct screen *s, u_int py, u_int ny)
+{
+	if (!screen_in_y(s, py))
+		fatalx("bad value");
+	if (ny == 0)
+		fatalx("bad value");
+
+	if (py + ny > screen_last_y(s))
+		ny = screen_last_y(s) - py;
+
+	/*
+	 * Delete range of ny lines at py:
+	 * 	- Free ny lines at py.
+	 *	- Move from py + ny to end of screen to py.
+	 *	- Free and recreate last ny lines.
+	 *
+	 * Example: delete lines 3,4.
+	 *	sy = 10, py = 3, ny = 2
+	 *	screen_free_lines(s, 3, 2);	- delete lines 3,4
+	 *	screen_move_lines(s, 3, 5, 5);	- move 5,6,7,8,9 to 3
+	 *	screen_make_lines(s, 8, 2);	- make lines 8,9
+	 */
+
+	screen_display_free_lines(s, py, ny);
+
+	if (py != screen_last_y(s)) {
+		screen_display_move_lines(
+		    s, py, py + ny, screen_size_y(s) - py - ny);
+	}
+
+	screen_display_make_lines(s, screen_size_y(s) - ny, ny);
+}
+
+/* Delete lines inside scroll region. */
+void
+screen_display_delete_lines_region(struct screen *s, u_int py, u_int ny)
+{
+	if (!screen_in_region(s, py))
+		fatalx("bad value");
+	if (ny == 0)
+		fatalx("bad value");
+
+	if (py + ny > s->rlower)
+		ny = s->rlower - py;
+
+	/*
+	 * Delete range of ny lines at py:
+	 * 	- Free ny lines at py.
+	 *	- Move from py + ny to end of region to py.
+	 *	- Free and recreate last ny lines.
+	 *
+	 * Example: delete lines 13,14.
+	 *	ryu = 11, ryl = 16, py = 13, ny = 2
+	 *	screen_free_lines(s, 13, 2);	- delete lines 13,14
+	 *	screen_move_lines(s, 15, 16, 2);- move 15,16 to 13
+	 *	screen_make_lines(s, 15, 16);	- make lines 15,16
+	 */
+
+	screen_display_free_lines(s, py, ny);
+
+	if (py != s->rlower) {
+		screen_display_move_lines(
+		    s, py, py + ny, (s->rlower + 1) - py - ny);
+	}
+
+	screen_display_make_lines(s, (s->rlower + 1) - ny, ny);
+}
+
+/* Insert characters. */
+void
+screen_display_insert_characters(struct screen *s, u_int px, u_int py, u_int nx)
+{
+	u_int	mx;
+
+	px = screen_x(s, px);
+	py = screen_y(s, py);
+
+	if (!screen_in_x(s, px) || !screen_in_y(s, py))
+		fatalx("bad value");
+
+	if (px + nx > screen_last_x(s))
+		nx = screen_last_x(s) - px;
+
+	/*
+	 * Inserting a range of nx at px.
+	 *
+	 * - Move sx - (px + nx) from px to px + nx.
+	 * - Clear the range at px.
+	 */
+
+	if (px + nx != screen_last_x(s)) {
+		mx = screen_last_x(s) - (px + nx);
+		memmove(&s->grid_data[py][px + nx], &s->grid_data[py][px], mx);
+		memmove(&s->grid_attr[py][px + nx], &s->grid_attr[py][px], mx);
+		memmove(&s->grid_colr[py][px + nx], &s->grid_colr[py][px], mx);
+	}
+	memset(&s->grid_data[py][px], SCREEN_DEFDATA, nx);
+	memset(&s->grid_attr[py][px], SCREEN_DEFATTR, nx);
+	memset(&s->grid_colr[py][px], SCREEN_DEFCOLR, nx);
+}
+
+/* Delete characters. */
+void
+screen_display_delete_characters(struct screen *s, u_int px, u_int py, u_int nx)
+{
+	u_int	mx;
+
+	px = screen_x(s, px);
+	py = screen_y(s, py);
+
+	if (!screen_in_x(s, px) || !screen_in_y(s, py))
+		fatalx("bad value");
+
+	if (px + nx > screen_last_x(s))
+		nx = screen_last_x(s) - px;
+
+	/*
+	 * Deleting the range from px to px + nx.
+	 *
+	 * - Move sx - (px + nx) from px + nx to px.
+	 * - Clear the range from the last x - (rx - lx)  to the last x.
+	 */
+
+	if (px + nx != screen_last_x(s)) {
+		mx = screen_last_x(s) - (px + nx);
+		memmove(&s->grid_data[py][px], &s->grid_data[py][px + nx], mx);
+		memmove(&s->grid_attr[py][px], &s->grid_attr[py][px + nx], mx);
+		memmove(&s->grid_colr[py][px], &s->grid_colr[py][px + nx], mx);
+	}
+
+	memset(&s->grid_data[py][screen_size_x(s) - nx], SCREEN_DEFDATA, nx);
+	memset(&s->grid_attr[py][screen_size_x(s) - nx], SCREEN_DEFATTR, nx);
+	memset(&s->grid_colr[py][screen_size_x(s) - nx], SCREEN_DEFCOLR, nx);
+}
diff --git a/screen.c b/screen.c
index d4bee630..a59cadae 100644
--- a/screen.c
+++ b/screen.c
@@ -1,4 +1,4 @@
-/* $Id: screen.c,v 1.24 2007-11-20 18:46:32 nicm Exp $ */
+/* $Id: screen.c,v 1.25 2007-11-20 21:42:29 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -28,21 +28,6 @@
  * XXX Much of this file sucks.
  */
 
-void	 screen_free_lines(struct screen *, u_int, u_int);
-void	 screen_make_lines(struct screen *, u_int, u_int);
-void	 screen_move_lines(struct screen *, u_int, u_int, u_int);
-void	 screen_fill_lines(
-	     struct screen *, u_int, u_int, u_char, u_char, u_char);
-
-#define screen_last_y(s) ((s)->sy - 1)
-#define screen_last_x(s) ((s)->sx - 1)
-
-#define screen_range_y(lx, rx) (((rx) - (lx)) + 1)
-#define screen_range_x(ux, lx) (((lx) - (ux)) + 1)
-
-#define screen_offset_y(py, ny) ((py) + (ny) - 1)
-#define screen_offset_x(px, nx) ((px) + (nx) - 1)
-
 /* Colour to string. */
 const char *
 screen_colourstring(u_char c)
@@ -97,15 +82,18 @@ screen_stringcolour(const char *s)
 
 /* Create a new screen. */
 void
-screen_create(struct screen *s, u_int sx, u_int sy)
+screen_create(struct screen *s, u_int dx, u_int dy)
 {
-	s->sx = sx;
-	s->sy = sy;
+	s->dx = dx;
+	s->dy = dy;
 	s->cx = 0;
 	s->cy = 0;
 
 	s->rupper = 0;
-	s->rlower = screen_last_y(s);
+	s->rlower = s->dy - 1;
+
+	s->ysize = dy;
+	s->ylimit = SHRT_MAX;
 
 	s->attr = SCREEN_DEFATTR;
 	s->colr = SCREEN_DEFCOLR;
@@ -113,11 +101,10 @@ screen_create(struct screen *s, u_int sx, u_int sy)
 	s->mode = MODE_CURSOR;
 	*s->title = '\0';
 
-	s->grid_data = xmalloc(sy * (sizeof *s->grid_data));
-	s->grid_attr = xmalloc(sy * (sizeof *s->grid_attr));
-	s->grid_colr = xmalloc(sy * (sizeof *s->grid_colr));
-	screen_make_lines(s, 0, sy);
-	screen_fill_screen(s, SCREEN_DEFDATA, 0, SCREEN_DEFCOLR);
+	s->grid_data = xmalloc(dy * (sizeof *s->grid_data));
+	s->grid_attr = xmalloc(dy * (sizeof *s->grid_attr));
+	s->grid_colr = xmalloc(dy * (sizeof *s->grid_colr));
+	screen_make_lines(s, 0, dy);
 }
 
 /* Resize screen. */
@@ -126,7 +113,7 @@ screen_resize(struct screen *s, u_int sx, u_int sy)
 {
 	u_int	i, ox, oy, ny;
 
-	if (sx == s->sx && sy == s->sy)
+	if (sx == s->dx && sy == s->dy)
 		return;
 
 	if (sx < 1)
@@ -134,16 +121,16 @@ screen_resize(struct screen *s, u_int sx, u_int sy)
 	if (sy < 1)
 		sy = 1;
 
-	ox = s->sx;
-	oy = s->sy;
+	ox = s->dx;
+	oy = s->dy;
 
 	log_debug("resizing screen (%u, %u) -> (%u, %u)", ox, oy, sx, sy);
 
-	s->sx = sx;
-	s->sy = sy;
+	s->dx = sx;
+	s->dy = sy;
 
 	s->rupper = 0;
-	s->rlower = screen_last_y(s);
+	s->rlower = s->dy - 1;
 
 	if (sy < oy) {
 		ny = oy - sy;
@@ -190,7 +177,7 @@ screen_resize(struct screen *s, u_int sx, u_int sy)
 			s->grid_data[i] = xmalloc(sx);
 			s->grid_attr[i] = xmalloc(sx);
 			s->grid_colr[i] = xmalloc(sx);
-			screen_fill_line(s, i,
+			screen_display_fill_line(s, i,
 			    SCREEN_DEFDATA, SCREEN_DEFATTR, SCREEN_DEFCOLR);
 		}
 		sy = oy;
@@ -203,7 +190,7 @@ screen_resize(struct screen *s, u_int sx, u_int sy)
 			s->grid_attr[i] = xrealloc(s->grid_attr[i], sx, 1);
 			s->grid_colr[i] = xrealloc(s->grid_colr[i], sx, 1);
 			if (sx > ox) {
-				screen_fill_end_of_line(s, ox, i,
+				screen_display_fill_cells(s, ox, i, s->dx - ox,
 				    SCREEN_DEFDATA, SCREEN_DEFATTR,
 				    SCREEN_DEFCOLR);
 			}
@@ -217,7 +204,7 @@ screen_resize(struct screen *s, u_int sx, u_int sy)
 void
 screen_destroy(struct screen *s)
 {
-	screen_free_lines(s, 0, s->sy);
+	screen_free_lines(s, 0, s->dy);
 	xfree(s->grid_data);
 	xfree(s->grid_attr);
 	xfree(s->grid_colr);
@@ -230,7 +217,7 @@ screen_draw(struct screen *s, struct buffer *b, u_int uy, u_int ly)
 	u_char		 attr, colr;
 	u_int		 i, j;
 
-	if (uy > screen_last_y(s) || ly > screen_last_y(s) || ly < uy)
+	if (uy > s->dy - 1 || ly > s->dy - 1 || ly < uy)
 		fatalx("bad range");
 
 	/* XXX. This is naive and rough right now. */
@@ -263,35 +250,28 @@ screen_draw(struct screen *s, struct buffer *b, u_int uy, u_int ly)
 		input_store_zero(b, CODE_CURSORON);
 }
 
-/* Make a range of lines. */
+/* Create a range of lines. */
 void
 screen_make_lines(struct screen *s, u_int py, u_int ny)
 {
 	u_int	i;
 
-	log_debug("making lines %u,%u", py, ny);
-
-	if (py > screen_last_y(s) || py + ny - 1 > screen_last_y(s))
-		fatalx("bad range");
-	
 	for (i = py; i < py + ny; i++) {
-		s->grid_data[i] = xmalloc(s->sx);
-		s->grid_attr[i] = xmalloc(s->sx);
-		s->grid_colr[i] = xmalloc(s->sx);
+		s->grid_data[i] = xmalloc(s->dx);
+		s->grid_attr[i] = xmalloc(s->dx);
+		s->grid_colr[i] = xmalloc(s->dx);
 	}
+	screen_fill_lines(
+	    s, py, ny, SCREEN_DEFDATA, SCREEN_DEFATTR, SCREEN_DEFCOLR);
 }
 
-/* Free a range of lines. */
+
+/* Free a range of ny lines at py. */
 void
 screen_free_lines(struct screen *s, u_int py, u_int ny)
 {
 	u_int	i;
 
-	log_debug("freeing lines %u,%u", py, ny);
-
-	if (py > screen_last_y(s) || py + ny - 1 > screen_last_y(s))
-		fatalx("bad range");