wayland/clients/terminal.c

/*
 * Copyright © 2008 Kristian Høgsberg
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF 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 <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <math.h>
#include <time.h>
#include <pty.h>
#include <ctype.h>
#include <cairo.h>
#include <glib.h>

#include <X11/keysym.h>

#include "window.h"

static int option_fullscreen;

#define MOD_SHIFT	0x01
#define MOD_ALT		0x02
#define MOD_CTRL	0x04

#define ATTRMASK_UNDERLINE	0x80
#define ATTRMASK_BACKGROUND	0x70
#define ATTRSHIFT_BACKGROUND	4
#define ATTRMASK_FOREGROUND	0x0F
#define ATTRSHIFT_FOREGROUND	0
#define ATTRMASK_INTENSITY	0x08

/* UTF-8 characters are at most 4 chars wide */
#define MAX_CHAR_WIDTH		4

/* Buffer sizes */
#define MAX_RESPONSE		11
#define MAX_ESCAPE		64

union utf8_char {
	unsigned char byte[4];
	uint32_t ch;
};

enum utf8_state {
	UTF8STATE_START,
	UTF8STATE_ACCEPT,
	UTF8STATE_REJECT,
	UTF8STATE_EXPECT3,
	UTF8STATE_EXPECT2,
	UTF8STATE_EXPECT1
};

struct utf8_state_machine {
	enum utf8_state state;
	int len;
	union utf8_char s;
};

static void
init_state_machine(struct utf8_state_machine *machine)
{
	machine->state = UTF8STATE_START;
	machine->len = 0;
	memset(machine->s.byte, 0, 4);
}

static enum utf8_state
utf8_next_char(struct utf8_state_machine *machine, char c)
{
	switch (machine->state) {
	case UTF8STATE_START:
	case UTF8STATE_ACCEPT:
	case UTF8STATE_REJECT:
		memset(machine->s.byte, 0, 4);
		machine->len = 0;
		if(c == 0xC0 || c == 0xC1) {
			/* overlong encoding, reject */
			machine->state = UTF8STATE_REJECT;
		} else if((c & 0x80) == 0) {
			/* single byte, accept */
			machine->s.byte[machine->len++] = c;
			machine->state = UTF8STATE_ACCEPT;
		} else if((c & 0xC0) == 0x80) {
			/* parser out of sync, ignore byte */
			machine->state = UTF8STATE_START;
		} else if((c & 0xE0) == 0xC0) {
			/* start of two byte sequence */
			machine->s.byte[machine->len++] = c;
			machine->state = UTF8STATE_EXPECT1;
		} else if((c & 0xF0) == 0xE0) {
			/* start of three byte sequence */
			machine->s.byte[machine->len++] = c;
			machine->state = UTF8STATE_EXPECT2;
		} else if((c & 0xF8) == 0xF0) {
			/* start of four byte sequence */
			machine->s.byte[machine->len++] = c;
			machine->state = UTF8STATE_EXPECT3;
		} else {
			/* overlong encoding, reject */
			machine->state = UTF8STATE_REJECT;
		}
		break;
	case UTF8STATE_EXPECT3:
		machine->s.byte[machine->len++] = c;
		if((c & 0xC0) == 0x80) {
			/* all good, continue */
			machine->state = UTF8STATE_EXPECT2;
		} else {
			/* missing extra byte, reject */
			machine->state = UTF8STATE_REJECT;
		}
		break;
	case UTF8STATE_EXPECT2:
		machine->s.byte[machine->len++] = c;
		if((c & 0xC0) == 0x80) {
			/* all good, continue */
			machine->state = UTF8STATE_EXPECT1;
		} else {
			/* missing extra byte, reject */
			machine->state = UTF8STATE_REJECT;
		}
		break;
	case UTF8STATE_EXPECT1:
		machine->s.byte[machine->len++] = c;
		if((c & 0xC0) == 0x80) {
			/* all good, accept */
			machine->state = UTF8STATE_ACCEPT;
		} else {
			/* missing extra byte, reject */
			machine->state = UTF8STATE_REJECT;
		}
		break;
	default:
		machine->state = UTF8STATE_REJECT;
		break;
	}

	return machine->state;
}

struct character_set {
	unsigned char match[4];
	unsigned char replace[4];
};
/* Set last character_set match to NULL char */

struct character_set CS_US[] = {
	{ { 0, }, { 0, } }
};
static struct character_set CS_UK[] = {
	{ { '#', 0, }, { 0xC2, 0xA3, 0, } },
	{ { 0, }, { 0, } }
};
static struct character_set CS_SPECIAL[] = {
	{ { '`', 0, }, { 0xE2, 0x99, 0xA6, 0} }, /* diamond */
	{ { 'a', 0, }, { 0xE2, 0x96, 0x92, 0} }, /* 50% cell */
	{ { 'b', 0, }, { 0xE2, 0x90, 0x89, 0} }, /* HT */
	{ { 'c', 0, }, { 0xE2, 0x90, 0x8C, 0} }, /* FF */
	{ { 'd', 0, }, { 0xE2, 0x90, 0x8D, 0} }, /* CR */
	{ { 'e', 0, }, { 0xE2, 0x90, 0x8A, 0} }, /* LF */
	{ { 'f', 0, }, { 0xC2, 0xB0, 0, } }, /* Degree */
	{ { 'g', 0, }, { 0xC2, 0xB1, 0, } }, /* Plus/Minus */
	{ { 'h', 0, }, { 0xE2, 0x90, 0xA4, 0} }, /* NL */
	{ { 'i', 0, }, { 0xE2, 0x90, 0x8B, 0} }, /* VT */
	{ { 'j', 0, }, { 0xE2, 0x94, 0x98, 0} }, /* CN_RB */
	{ { 'k', 0, }, { 0xE2, 0x94, 0x90, 0} }, /* CN_RT */
	{ { 'l', 0, }, { 0xE2, 0x94, 0x8C, 0} }, /* CN_LT */
	{ { 'm', 0, }, { 0xE2, 0x94, 0x94, 0} }, /* CN_RB */
	{ { 'n', 0, }, { 0xE2, 0x94, 0xBC, 0} }, /* CROSS */
	{ { 'o', 0, }, { 0xE2, 0x94, 0x80, 0} }, /* H */
	{ { 'p', 0, }, { 0xE2, 0x94, 0x80, 0} }, /* H */
	{ { 'q', 0, }, { 0xE2, 0x94, 0x80, 0} }, /* H */
	{ { 'r', 0, }, { 0xE2, 0x94, 0x80, 0} }, /* H */
	{ { 's', 0, }, { 0xE2, 0x94, 0x80, 0} }, /* H */
	{ { 't', 0, }, { 0xE2, 0x94, 0x9C, 0} }, /* TR */
	{ { 'u', 0, }, { 0xE2, 0x94, 0xA4, 0} }, /* TL */
	{ { 'v', 0, }, { 0xE2, 0x94, 0xB4, 0} }, /* TU */
	{ { 'w', 0, }, { 0xE2, 0x94, 0xAC, 0} }, /* TD */
	{ { 'x', 0, }, { 0xE2, 0x94, 0x82, 0} }, /* V */
	{ { 'y', 0, }, { 0xE2, 0x89, 0xA4, 0} }, /* LE */
	{ { 'z', 0, }, { 0xE2, 0x89, 0xA5, 0} }, /* GE */
	{ { '{', 0, }, { 0xCF, 0x80, 0, } }, /* PI */
	{ { '|', 0, }, { 0xE2, 0x89, 0xA0, 0} }, /* NEQ */
	{ { '}', 0, }, { 0xC2, 0xA3, 0, } }, /* POUND */
	{ { '~', 0, }, { 0xE2, 0x8B, 0x85, 0} }, /* DOT */
	{ { 0, }, { 0, } }
};

static void
apply_char_set(struct character_set * cs, unsigned char *c)
{
	unsigned char *match;
	int i = 0;

	while (*(cs[i].match)) {
		match = cs[i++].match;
		if (*((uint32_t*) c) == *((uint32_t*) match)) {
			memcpy(c, cs[i-1].replace, 4);
			break;
		}
	}
}

struct keyboard_map {
	int sym;
	char response[MAX_RESPONSE];
};
/* Set last key_sub sym to NULL */

static struct keyboard_map KM_NORMAL[] = {
	{ XK_Left,      "\e[D" },
	{ XK_Right,     "\e[C" },
	{ XK_Up,        "\e[A" },
	{ XK_Down,      "\e[B" },
	{ XK_Home,      "\e[H" },
	{ XK_End,       "\e[E" },
	{ 0, "" }
};
static struct keyboard_map KM_APPLICATION[] = {
	{ XK_Left,      "\eOD" },
	{ XK_Right,     "\eOC" },
	{ XK_Up,        "\eOA" },
	{ XK_Down,      "\eOB" },
	{ XK_Home,      "\eOH" },
	{ XK_End,       "\eOE" },
	{ 0, ""}
};

/* returns the number of bytes written into response,
 * which must have room for MAX_RESPONSE bytes */
static int
apply_key_map(struct keyboard_map *mode, int sym, char *response)
{
	struct keyboard_map map;
	int len = 0;
	int i = 0;

	while (mode[i].sym) {
		map = mode[i++];
		if (sym == map.sym) {
			len = strlen(map.response);
			memcpy(response, map.response, len + 1);
			break;
		}
	}

	return len;
}

struct terminal_color { double r, g, b, a; };
struct color_scheme {
	struct terminal_color palette[16];
	int border_color;
	char default_attr;
};

struct terminal {
	struct window *window;
	struct display *display;
	union utf8_char *data;
	char *tab_ruler;
	char *data_attr;   /* one byte per cell, format:
			    * 76543210
			    * ugbrigbr
			    *  BBBFFFF
			    * where u = underline bit,
			    *       B = background color bit
			    *       F = foreground color bit
			    *       i = intensity bit
			    * but it isn't enough, will need
			    * to expand this to two bytes
			    * at some stage. */
	/* These should be refactored into some flags */
	char curr_attr;
	char inverse_video;    /* SGR inverse is on */
	char origin_mode;      /* 0 for abs, 1 for rel */
	char show_cursor;

	char autowrap;
	char normal_newline;   /* 0 for <LF>, 1 for <CR><LF> */
	char inverse_mode;     /* mode ?5 (inverse video) is on */
	char irm;              /* mode 4 (insert/replace) is on */

	char deleteSendsDel;
	char altSendsEsc;

	char auto_repeat;
	char saved_attr;
	char saved_inverse_video;
	char saved_origin_mode;

	union utf8_char last_char;

	int margin_top, margin_bottom;

	struct character_set *cs, *g0, *g1;
	struct character_set *saved_cs, *saved_g0, *saved_g1;
	struct keyboard_map *key_mode;

	int pitch;             /* The width in bytes of a line */
	int width, height, start, row, column;
	int saved_row, saved_column;
	int fd, master;
	GIOChannel *channel;
	uint32_t modifiers;
	char escape[MAX_ESCAPE];
	int escape_length;
	int state;
	int qmark_flag;

	struct utf8_state_machine state_machine;

	int margin;
	int fullscreen;
	int focused;
	struct color_scheme *color_scheme;
	cairo_font_extents_t extents;
	cairo_scaled_font_t *font_normal, *font_bold;
};

/* Create default tab stops, every 8 characters */
static void
terminal_init_tabs(struct terminal *terminal)
{
	int i = 0;

	while (i < terminal->width) {
		if (i % 8 == 0)
			terminal->tab_ruler[i] = 1;
		else
			terminal->tab_ruler[i] = 0;
		i++;
	}
}

static void
terminal_init(struct terminal *terminal)
{
	terminal->curr_attr = terminal->color_scheme->default_attr;
	terminal->inverse_video = 0;
	terminal->origin_mode = 0;
	terminal->show_cursor = 1;
	terminal->autowrap = 1;
	terminal->normal_newline = 0;
	terminal->inverse_mode = 0;
	terminal->irm = 0;
	terminal->auto_repeat = 1;

	terminal->deleteSendsDel = 0;
	terminal->altSendsEsc = 1;

	terminal->saved_attr = terminal->curr_attr;
	terminal->saved_inverse_video = terminal->inverse_video;
	terminal->saved_origin_mode = terminal->origin_mode;

	terminal->margin_top = 0;
	terminal->margin_bottom = terminal->height-1;

	terminal->row = 0;
	terminal->column = 0;

	terminal->g0 = CS_US;
	terminal->g1 = CS_US;
	terminal->cs = terminal->g0;

	terminal->key_mode = KM_NORMAL;

	terminal->saved_g0 = terminal->g0;
	terminal->saved_g1 = terminal->g1;
	terminal->saved_cs = terminal->cs;

	if (terminal->tab_ruler != NULL)
		terminal_init_tabs(terminal);
}

static union utf8_char *
terminal_get_row(struct terminal *terminal, int row)
{
	int index;

	index = (row + terminal->start) % terminal->height;

	return &terminal->data[index * terminal->width];
}

static char*
terminal_get_attr_row(struct terminal *terminal, int row)
{
	int index;

	index = (row + terminal->start) % terminal->height;

	return &terminal->data_attr[index * terminal->width];
}

static char
terminal_get_attr(struct terminal *terminal, int row, int col)
{
	return terminal_get_attr_row(terminal, row)[col];
}

static void
terminal_scroll_buffer(struct terminal *terminal, int d)
{
	int i;

	d = d % (terminal->height + 1);
	terminal->start = (terminal->start + d) % terminal->height;
	if (terminal->start < 0) terminal->start = terminal->height + terminal->start;
	if(d < 0) {
		d = 0 - d;
		for(i = 0; i < d; i++) {
			memset(terminal_get_row(terminal, i), 0, terminal->pitch);
			memset(terminal_get_attr_row(terminal, i),
			    terminal->curr_attr, terminal->width);
		}
	} else {
		for(i = terminal->height - d; i < terminal->height; i++) {
			memset(terminal_get_row(terminal, i), 0, terminal->pitch);
			memset(terminal_get_attr_row(terminal, i),
			    terminal->curr_attr, terminal->width);
		}
	}
}

static void
terminal_scroll_window(struct terminal *terminal, int d)
{
	int i;
	int window_height;
	int from_row, to_row;
	char *dup_attr;

	/* scrolling range is inclusive */
	window_height = terminal->margin_bottom - terminal->margin_top + 1;
	d = d % (window_height + 1);
	if(d < 0) {
		d = 0 - d;
		to_row = terminal->margin_bottom;
		from_row = terminal->margin_bottom - d;

		for (i = 0; i < (window_height - d); i++) {
			memcpy(terminal_get_row(terminal, to_row - i),
			       terminal_get_row(terminal, from_row - i),
			       terminal->pitch);
			memcpy(terminal_get_attr_row(terminal, to_row - i),
			       terminal_get_attr_row(terminal, from_row - i),
			       terminal->width);
		}
		dup_attr = terminal_get_attr_row(terminal, terminal->margin_top);
		for (i = terminal->margin_top; i < (terminal->margin_top + d); i++) {
			memset(terminal_get_row(terminal, i), 0, terminal->pitch);
			if (i > terminal->margin_top) {
				memcpy(terminal_get_attr_row(terminal, i),
				       dup_attr, terminal->width);
			}
		}
	} else {
		to_row = terminal->margin_top;
		from_row = terminal->margin_top + d;

		for (i = 0; i < (window_height - d); i++) {
			memcpy(terminal_get_row(terminal, to_row + i),
			       terminal_get_row(terminal, from_row + i),
			       terminal->pitch);
			memcpy(terminal_get_attr_row(terminal, to_row + i),
			       terminal_get_attr_row(terminal, from_row + i),
			       terminal->width);
		}
		dup_attr = terminal_get_attr_row(terminal, terminal->margin_bottom);
		for (i = terminal->margin_bottom - d + 1; i <= terminal->margin_bottom; i++) {
			memset(terminal_get_row(terminal, i), 0, terminal->pitch);
			if (i < terminal->margin_bottom) {
				memcpy(terminal_get_attr_row(terminal, i),
				       dup_attr, terminal->width);
			}
		}
	}
}

static void
terminal_scroll(struct terminal *terminal, int d)
{
	if(terminal->margin_top == 0 && terminal->margin_bottom == terminal->height - 1)
		terminal_scroll_buffer(terminal, d);
	else
		terminal_scroll_window(terminal, d);
}

static void
terminal_shift_line(struct terminal *terminal, int d)
{
	union utf8_char *row;
	char *attr_row, attr;

	row = terminal_get_row(terminal, terminal->row);
	attr_row = terminal_get_attr_row(terminal, terminal->row);

	if ((terminal->width + d) <= terminal->column)
		d = terminal->column + 1 - terminal->width;
	if ((terminal->column + d) >= terminal->width)
		d = terminal->width - terminal->column - 1;

	if (d < 0) {
		d = 0 - d;
		memmove(&row[terminal->column],
			&row[terminal->column + d],
			(terminal->width - terminal->column - d) * MAX_CHAR_WIDTH);
		attr = attr_row[terminal->width - 1];
		memmove(&attr_row[terminal->column], &attr_row[terminal->column + d],
			terminal->width - terminal->column - d);
		memset(&row[terminal->width - d], 0, d * MAX_CHAR_WIDTH);
		memset(&attr_row[terminal->width - d], terminal->curr_attr, d);
	} else {
		memmove(&row[terminal->column + d], &row[terminal->column],
			(terminal->width - terminal->column - d) * MAX_CHAR_WIDTH);
		memmove(&attr_row[terminal->column + d], &attr_row[terminal->column],
			terminal->width - terminal->column - d);
		memset(&row[terminal->column], 0, d * MAX_CHAR_WIDTH);
		memset(&attr_row[terminal->column], terminal->curr_attr, d);
	}
}

static void
terminal_resize(struct terminal *terminal, int width, int height)
{
	size_t size;
	union utf8_char *data;
	char *data_attr, *tab_ruler;
	int pitch;
	int i, l, total_rows, start;
	struct rectangle rectangle;
	struct winsize ws;

	if (terminal->width == width && terminal->height == height)
		return;

	pitch = width * sizeof(union utf8_char);
	size = pitch * height;
	data = malloc(size);
	data_attr = malloc(width * height);
	tab_ruler = malloc(width);
	memset(data, 0, size);
	memset(tab_ruler, 0, width);
	memset(data_attr, terminal->curr_attr, width * height);
	if (terminal->data && terminal->data_attr && terminal->tab_ruler) {
		if (width > terminal->width)
			l = terminal->width;
		else
			l = width;

		if (terminal->height > height) {
			total_rows = height;
			start = terminal->height - height;
		} else {
			total_rows = terminal->height;
			start = 0;
		}

		memcpy(tab_ruler, terminal->tab_ruler, l);
		for (i = 0; i < total_rows; i++) {
			memcpy(&data[width * i],
			       terminal_get_row(terminal, i), l);
			memcpy(&data_attr[width * i],
			       terminal_get_attr_row(terminal, i), l);
		}

		free(terminal->data);
		free(terminal->data_attr);
		free(terminal->tab_ruler);
	}

	terminal->pitch = pitch;
	terminal->width = width;
	terminal->height = height;
	if(terminal->margin_bottom >= terminal->height)
		terminal->margin_bottom = terminal->height - 1;
	terminal->data = data;
	terminal->data_attr = data_attr;
	terminal->tab_ruler = tab_ruler;
	terminal_init_tabs(terminal);

	if (terminal->row >= terminal->height)
		terminal->row = terminal->height - 1;
	if (terminal->column >= terminal->width)
		terminal->column = terminal->width - 1;
	terminal->start = 0;

	if (!terminal->fullscreen) {
		rectangle.width = terminal->width *
			terminal->extents.max_x_advance + 2 * terminal->margin;
		rectangle.height = terminal->height *
			terminal->extents.height + 2 * terminal->margin;
		window_set_child_size(terminal->window, &rectangle);
	}

	/* Update the window size */
	ws.ws_row = terminal->height;
	ws.ws_col = terminal->width;
	window_get_child_rectangle(terminal->window, &rectangle);
	ws.ws_xpixel = rectangle.width;
	ws.ws_ypixel = rectangle.height;
	ioctl(terminal->master, TIOCSWINSZ, &ws);
}

struct color_scheme DEFAULT_COLORS = {
	{
		{ 0,    0,    0,    1 }, /* black */
		{ 0.66, 0,    0,    1 }, /* red */
		{ 0  ,  0.66, 0,    1 }, /* green */
		{ 0.66, 0.33, 0,    1 }, /* orange (nicer than muddy yellow) */
		{ 0  ,  0  ,  0.66, 1 }, /* blue */
		{ 0.66, 0  ,  0.66, 1 }, /* magenta */
		{ 0,    0.66, 0.66, 1 }, /* cyan */
		{ 0.66, 0.66, 0.66, 1 }, /* light grey */
		{ 0.22, 0.33, 0.33, 1 }, /* dark grey */
		{ 1,    0.33, 0.33, 1 }, /* high red */
		{ 0.33, 1,    0.33, 1 }, /* high green */
		{ 1,    1,    0.33, 1 }, /* high yellow */
		{ 0.33, 0.33, 1,    1 }, /* high blue */
		{ 1,    0.33, 1,    1 }, /* high magenta */
		{ 0.33, 1,    1,    1 }, /* high cyan */
		{ 1,    1,    1,    1 }  /* white */
	},
	0,			       /* black border */
	0x07                           /* bg:black, fg:light gray  */
};

static void
terminal_draw_contents(struct terminal *terminal)
{
	struct rectangle rectangle;
	cairo_t *cr;
	cairo_font_extents_t extents;
	int top_margin, side_margin;
	int row, col;
	char attr;
	int border, foreground, background, bold, underline, tmp;
	int text_x, text_y;
	cairo_surface_t *surface;
	double d;
	struct terminal_color color;
	int num_glyphs;
	cairo_scaled_font_t *font;
	cairo_glyph_t glyphs[256], *g;

	window_get_child_rectangle(terminal->window, &rectangle);

	surface = display_create_surface(terminal->display, &rectangle);
	cr = cairo_create(surface);

	cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
	border = terminal->color_scheme->border_color;
	color = terminal->color_scheme->palette[border];
	cairo_set_source_rgba(cr, color.r, color.g, color.b, color.a);
	cairo_paint(cr);

	cairo_set_scaled_font (cr, terminal->font_normal);
	cairo_font_extents(cr, &extents);

	side_margin = (rectangle.width - terminal->width * extents.max_x_advance) / 2;
	top_margin = (rectangle.height - terminal->height * extents.height) / 2;

	cairo_set_line_width(cr, 1.0);
	cairo_set_antialias(cr, CAIRO_ANTIALIAS_SUBPIXEL);

	/* paint the background */
	for (row = 0; row < terminal->height; row++)
		for (col = 0; col < terminal->width; col++)
	{
		/* get the attributes for this character cell */
		attr = terminal_get_attr(terminal, row, col);
		foreground = (attr & ATTRMASK_FOREGROUND) >> ATTRSHIFT_FOREGROUND;
		background = (attr & ATTRMASK_BACKGROUND) >> ATTRSHIFT_BACKGROUND;
		if (terminal->inverse_mode ||
		    (terminal->show_cursor && terminal->focused &&
		     terminal->row == row && terminal->column == col)) {
			tmp = foreground;
			foreground = background | (foreground & ATTRMASK_INTENSITY);
			background = tmp & ~ATTRMASK_INTENSITY;
		}

		if (background == border)
			continue;

		color = terminal->color_scheme->palette[background];
		cairo_set_source_rgba(cr, color.r, color.g, color.b, color.a);
		cairo_move_to(cr, side_margin + (col * extents.max_x_advance),
		      top_margin + (row * extents.height));
		cairo_rel_line_to(cr, extents.max_x_advance, 0);
		cairo_rel_line_to(cr, 0, extents.height);
		cairo_rel_line_to(cr, -extents.max_x_advance, 0);
		cairo_close_path(cr);
		cairo_fill(cr);
	}

	cairo_set_operator(cr, CAIRO_OPERATOR_OVER);

	/* paint the foreground */
	for (row = 0; row < terminal->height; row++)
		for (col = 0; col < terminal->width; col++)
	{
		attr = terminal_get_attr(terminal, row, col);
		foreground = (attr & ATTRMASK_FOREGROUND) >> ATTRSHIFT_FOREGROUND;
		background = (attr & ATTRMASK_BACKGROUND) >> ATTRSHIFT_BACKGROUND;
		bold = (attr & ATTRMASK_INTENSITY);
		underline = (attr & ATTRMASK_UNDERLINE);

		if (terminal->inverse_mode ||
		    (terminal->show_cursor && terminal->focused &&
		     terminal->row == row && terminal->column == col)) {
			tmp = foreground;
			foreground = background | (foreground & ATTRMASK_INTENSITY);
			background = tmp & ~ATTRMASK_INTENSITY;
		}

		if (bold)
			font = terminal->font_bold;
		else
			font = terminal->font_normal;
		cairo_set_scaled_font (cr, font);
		color = terminal->color_scheme->palette[foreground];
		cairo_set_source_rgba(cr, color.r, color.g, color.b, color.a);

		text_x = side_margin + col * extents.max_x_advance;
		text_y = top_margin + extents.ascent + row * extents.height;
		if (underline) {
			cairo_move_to(cr, text_x, text_y + 2);
			cairo_line_to(cr, text_x + extents.max_x_advance, text_y + 2);
			cairo_stroke(cr);
		}
		cairo_move_to(cr, text_x, text_y);

		g = glyphs;
		num_glyphs = ARRAY_LENGTH(glyphs);
		cairo_scaled_font_text_to_glyphs (font, text_x, text_y,
						  (char *) &terminal_get_row(terminal, row)[col].byte, 4,
						  &g, &num_glyphs,
						  NULL, NULL, NULL);
		cairo_show_glyphs (cr, g, num_glyphs);
	}

	if (terminal->show_cursor && !terminal->focused) {
		d = 0.5;

		cairo_set_line_width(cr, 1);
		cairo_move_to(cr, side_margin + (terminal->column * extents.max_x_advance) + d,
			      top_margin + (terminal->row * extents.height) + d);
		cairo_rel_line_to(cr, extents.max_x_advance - (2 * d), 0);
		cairo_rel_line_to(cr, 0, extents.height - (2 * d));
		cairo_rel_line_to(cr, -extents.max_x_advance + (2 * d), 0);
		cairo_close_path(cr);
		cairo_stroke(cr);
	}

	cairo_destroy(cr);

	window_copy_surface(terminal->window,
			    &rectangle,
			    surface);

	cairo_surface_destroy(surface);
}

static void
terminal_draw(struct terminal *terminal)
{
	struct rectangle rectangle;
	int32_t width, height;

	window_get_child_rectangle(terminal->window, &rectangle);

	width = (rectangle.width - 2 * terminal->margin) /
		(int32_t) terminal->extents.max_x_advance;
	height = (rectangle.height - 2 * terminal->margin) /
		(int32_t) terminal->extents.height;
	terminal_resize(terminal, width, height);

	window_draw(terminal->window);
	terminal_draw_contents(terminal);
	window_flush(terminal->window);
}

static void
redraw_handler(struct window *window, void *data)
{
	struct terminal *terminal = data;

	terminal_draw(terminal);
}

#define STATE_NORMAL 0
#define STATE_ESCAPE 1
#define STATE_ESCAPE_SPECIAL 2
#define STATE_ESCAPE_CSI  3

static void
terminal_data(struct terminal *terminal, const char *data, size_t length);

static void
handle_char(struct terminal *terminal, union utf8_char utf8);

static void
handle_sgr(struct terminal *terminal, int code);

static void
handle_term_parameter(struct terminal *terminal, int code, int sr)
{
	int i;

	if (terminal->qmark_flag) {
		switch(code) {
		case 1:  /* DECCKM */
			if (sr)
				terminal->key_mode = KM_APPLICATION;
			else
				terminal->key_mode = KM_NORMAL;
			break;
		case 2:  /* DECANM */
			/* No VT52 support yet */
			terminal->g0 = CS_US;
			terminal->g1 = CS_US;
			terminal->cs = terminal->g0;
			break;
		case 3:  /* DECCOLM */
			if (sr)
				terminal_resize(terminal, 132, 24);
			else
				terminal_resize(terminal, 80, 24);

			/* set columns, but also home cursor and clear screen */
			terminal->row = 0; terminal->column = 0;
			for (i = 0; i < terminal->height; i++) {
				memset(terminal_get_row(terminal, i),
				    0, terminal->pitch);
				memset(terminal_get_attr_row(terminal, i),
				    terminal->curr_attr, terminal->width);
			}
			break;
		case 5:  /* DECSCNM */
			terminal->inverse_mode = sr;
			break;
		case 6:  /* DECOM */
			terminal->origin_mode = sr;
			if (terminal->origin_mode)
				terminal->row = terminal->margin_top;
			else
				terminal->row = 0;
			terminal->column = 0;
			break;
		case 7:  /* DECAWM */
			terminal->autowrap = sr;
			break;
		case 8:  /* DECARM */
			terminal->auto_repeat = sr;
			break;
		case 25:
			terminal->show_cursor = sr;
			break;
		case 1037:   /* deleteSendsDel */
			terminal->deleteSendsDel = sr;
			break;
		case 1039:   /* altSendsEscape */
			terminal->altSendsEsc = sr;
			break;
		default:
			break;
		}
	} else {
		switch(code) {
		case 4:  /* IRM */
			terminal->irm = sr;
			break;
		case 20: /* LNM */
			terminal->normal_newline = sr;
			break;
		}
	}
}

static void
handle_escape(struct terminal *terminal)
{
	union utf8_char *row;
	char *p, *attr_row;
	int i, count, x, y, top, bottom;
	int args[10], set[10] = { 0, };
	char response[MAX_RESPONSE] = {0, };

	terminal->escape[terminal->escape_length++] = '\0';
	i = 0;
	p = &terminal->escape[2];
	while ((isdigit(*p) || *p == ';') && i < 10) {
		if (*p == ';') {
			if (!set[i]) {
				args[i] = 0;
				set[i] = 1;
			}
			p++;
			i++;
		} else {
			args[i] = strtol(p, &p, 10);
			set[i] = 1;
		}
	}

	switch (*p) {
	case '@':    /* ICH */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		terminal_shift_line(terminal, count);
		break;
	case 'A':    /* CUU */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		if (terminal->row - count >= terminal->margin_top)
			terminal->row -= count;
		else
			terminal->row = terminal->margin_top;
		break;
	case 'B':    /* CUD */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		if (terminal->row + count <= terminal->margin_bottom)
			terminal->row += count;
		else
			terminal->row = terminal->margin_bottom;
		break;
	case 'C':    /* CUF */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		if ((terminal->column + count) < terminal->width)
			terminal->column += count;
		else
			terminal->column = terminal->width - 1;
		break;
	case 'D':    /* CUB */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		if ((terminal->column - count) >= 0)
			terminal->column -= count;
		else
			terminal->column = 0;
		break;
	case 'E':    /* CNL */
		count = set[0] ? args[0] : 1;
		if(terminal->row + count <= terminal->margin_bottom)
			terminal->row += count;
		else
			terminal->row = terminal->margin_bottom;
		terminal->column = 0;
		break;
	case 'F':    /* CPL */
		count = set[0] ? args[0] : 1;
		if(terminal->row - count >= terminal->margin_top)
			terminal->row -= count;
		else
			terminal->row = terminal->margin_top;
		terminal->column = 0;
		break;
	case 'G':    /* CHA */
		y = set[0] ? args[0] : 1;
		y = y <= 0 ? 1 : y > terminal->width ? terminal->width : y;

		terminal->column = y - 1;
		break;
	case 'f':    /* HVP */
	case 'H':    /* CUP */
		x = (set[1] ? args[1] : 1) - 1;
		x = x < 0 ? 0 :
		    (x >= terminal->width ? terminal->width - 1 : x);

		y = (set[0] ? args[0] : 1) - 1;
		if(terminal->origin_mode) {
			y += terminal->margin_top;
			y = y < terminal->margin_top ? terminal->margin_top :
			    (y > terminal->margin_bottom ? terminal->margin_bottom : y);
		} else {
			y = y < 0 ? 0 :
			    (y >= terminal->height ? terminal->height - 1 : y);
		}

		terminal->row = y;
		terminal->column = x;
		break;
	case 'I':    /* CHT */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		while (count > 0 && terminal->column < terminal->width) {
			if (terminal->tab_ruler[terminal->column]) count--;
			terminal->column++;
		}
		terminal->column--;
		break;
	case 'J':    /* ED */
		row = terminal_get_row(terminal, terminal->row);
		attr_row = terminal_get_attr_row(terminal, terminal->row);
		if(!set[0] || args[0] == 0 || args[0] > 2) {
			memset(&row[terminal->column],
			       0, (terminal->width - terminal->column) * MAX_CHAR_WIDTH);
			memset(&attr_row[terminal->column],
			       terminal->curr_attr, terminal->width - terminal->column);
			for (i = terminal->row + 1; i < terminal->height; i++) {
				memset(terminal_get_row(terminal, i),
				    0, terminal->pitch);
				memset(terminal_get_attr_row(terminal, i),
				    terminal->curr_attr, terminal->width);
			}
		} else if(args[0] == 1) {
			memset(row, 0, (terminal->column+1) * MAX_CHAR_WIDTH);
			memset(attr_row, terminal->curr_attr, terminal->column+1);
			for (i = 0; i < terminal->row; i++) {
				memset(terminal_get_row(terminal, i),
				    0, terminal->pitch);
				memset(terminal_get_attr_row(terminal, i),
				    terminal->curr_attr, terminal->width);
			}
		} else if(args[0] == 2) {
			for (i = 0; i < terminal->height; i++) {
				memset(terminal_get_row(terminal, i),
				    0, terminal->pitch);
				memset(terminal_get_attr_row(terminal, i),
				    terminal->curr_attr, terminal->width);
			}
		}
		break;
	case 'K':    /* EL */
		row = terminal_get_row(terminal, terminal->row);
		attr_row = terminal_get_attr_row(terminal, terminal->row);
		if(!set[0] || args[0] == 0 || args[0] > 2) {
			memset(&row[terminal->column], 0,
			    (terminal->width - terminal->column) * MAX_CHAR_WIDTH);
			memset(&attr_row[terminal->column], terminal->curr_attr,
			    terminal->width - terminal->column);
		} else if(args[0] == 1) {
			memset(row, 0, (terminal->column+1) * MAX_CHAR_WIDTH);
			memset(attr_row, terminal->curr_attr, terminal->column+1);
		} else if(args[0] == 2) {
			memset(row, 0, terminal->pitch);
			memset(attr_row, terminal->curr_attr, terminal->width);
		}
		break;
	case 'L':    /* IL */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		if (terminal->row >= terminal->margin_top &&
			terminal->row < terminal->margin_bottom)
		{
			top = terminal->margin_top;
			terminal->margin_top = terminal->row;
			terminal_scroll(terminal, 0 - count);
			terminal->margin_top = top;
		} else if (terminal->row == terminal->margin_bottom) {
			memset(terminal_get_row(terminal, terminal->row),
			       0, terminal->pitch);
			memset(terminal_get_attr_row(terminal, terminal->row),
				terminal->curr_attr, terminal->width);
		}
		break;
	case 'M':    /* DL */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		if (terminal->row >= terminal->margin_top &&
			terminal->row < terminal->margin_bottom)
		{
			top = terminal->margin_top;
			terminal->margin_top = terminal->row;
			terminal_scroll(terminal, count);
			terminal->margin_top = top;
		} else if (terminal->row == terminal->margin_bottom) {
			memset(terminal_get_row(terminal, terminal->row),
			       0, terminal->pitch);
		}
		break;
	case 'P':    /* DCH */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		terminal_shift_line(terminal, 0 - count);
		break;
	case 'S':    /* SU */
		terminal_scroll(terminal, set[0] ? args[0] : 1);
		break;
	case 'T':    /* SD */
		terminal_scroll(terminal, 0 - (set[0] ? args[0] : 1));
		break;
	case 'X':    /* ECH */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		if ((terminal->column + count) > terminal->width)
			count = terminal->width - terminal->column;
		row = terminal_get_row(terminal, terminal->row);
		attr_row = terminal_get_attr_row(terminal, terminal->row);
		memset(&row[terminal->column], 0, count * MAX_CHAR_WIDTH);
		memset(&attr_row[terminal->column], terminal->curr_attr, count);
		break;
	case 'Z':    /* CBT */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		while (count > 0 && terminal->column >= 0) {
			if (terminal->tab_ruler[terminal->column]) count--;
			terminal->column--;
		}
		terminal->column++;
		break;
	case '`':    /* HPA */
		y = set[0] ? args[0] : 1;
		y = y <= 0 ? 1 : y > terminal->width ? terminal->width : y;

		terminal->column = y - 1;
		break;
	case 'b':    /* REP */
		count = set[0] ? args[0] : 1;
		if (count == 0) count = 1;
		if (terminal->last_char.byte[0])
			for (i = 0; i < count; i++)
				handle_char(terminal, terminal->last_char);
		terminal->last_char.byte[0] = 0;
		break;
	case 'c':    /* Primary DA */
		write(terminal->master, "\e[?1;2c", 7);
		sleep(1);
		break;
	case 'd':    /* VPA */
		x = set[0] ? args[0] : 1;
		x = x <= 0 ? 1 : x > terminal->height ? terminal->height : x;

		terminal->row = x - 1;
		break;
	case 'g':    /* TBC */
		if (!set[0] || args[0] == 0) {
			terminal->tab_ruler[terminal->column] = 0;
		} else if (args[0] == 3) {
			memset(terminal->tab_ruler, 0, terminal->width);
		}
		break;
	case 'h':    /* SM */
		for(i = 0; i < 10 && set[i]; i++) {
			handle_term_parameter(terminal, args[i], 1);
		}
		break;
	case 'l':    /* RM */
		for(i = 0; i < 10 && set[i]; i++) {
			handle_term_parameter(terminal, args[i], 0);
		}
		break;
	case 'm':    /* SGR */
		for(i = 0; i < 10; i++) {
			if(set[i]) {
				handle_sgr(terminal, args[i]);
			} else if(i == 0) {
				handle_sgr(terminal, 0);
				break;
			} else {
				break;
			}
		}
		break;
	case 'n':    /* DSR */
		i = set[0] ? args[0] : 0;
		if (i == 0 || i == 5) {
			write(terminal->master, "\e[0n", 4);
		} else if (i == 6) {
			snprintf(response, MAX_RESPONSE, "\e[%d;%dR",
				 terminal->origin_mode ?
				     terminal->row+terminal->margin_top : terminal->row+1,
				 terminal->column+1);
			write(terminal->master, response, strlen(response));
		}
		sleep(1);  /* is this required? why? */
		break;
	case 'r':
		if(!set[0]) {
			terminal->margin_top = 0;
			terminal->margin_bottom = terminal->height-1;
			terminal->row = 0;
			terminal->column = 0;
		} else {
			top = (set[0] ? args[0] : 1) - 1;
			top = top < 0 ? 0 :
			      (top >= terminal->height ? terminal->height - 1 : top);
			bottom = (set[1] ? args[1] : 1) - 1;
			bottom = bottom < 0 ? 0 :
				(bottom >= terminal->height ? terminal->height - 1 : bottom);
			if(bottom > top) {
				terminal->margin_top = top;
				terminal->margin_bottom = bottom;
			} else {
				terminal->margin_top = 0;
				terminal->margin_bottom = terminal->height-1;
			}
			if(terminal->origin_mode)
				terminal->row = terminal->margin_top;
			else
				terminal->row = 0;
			terminal->column = 0;
		}
		break;
	case 's':
		terminal->saved_row = terminal->row;
		terminal->saved_column = terminal->column;
		break;
	case 'u':
		terminal->row = terminal->saved_row;
		terminal->column = terminal->saved_column;
		break;
	default:
		break;
	}
}

static char
inverse_video(struct terminal *terminal, char attr) {
	int foreground, background;

	foreground = (attr & (~ATTRMASK_INTENSITY & ATTRMASK_FOREGROUND)) >> ATTRSHIFT_FOREGROUND;
	background = (attr & ATTRMASK_BACKGROUND) >> ATTRSHIFT_BACKGROUND;
	return (attr & ~(ATTRMASK_FOREGROUND & ~ATTRMASK_INTENSITY) & ~ATTRMASK_BACKGROUND) |
	    (foreground << ATTRSHIFT_BACKGROUND) | (background << ATTRSHIFT_FOREGROUND);
}

static void
handle_sgr(struct terminal *terminal, int code)
{
	int foreground, background;

	switch(code) {
	case 0:
		terminal->curr_attr = terminal->color_scheme->default_attr;
		terminal->inverse_video = 0;
		break;
	case 1:
		terminal->curr_attr |= ATTRMASK_INTENSITY;
		break;
	case 4:
		terminal->curr_attr |= ATTRMASK_UNDERLINE;
		break;
	case 2:
	case 21:
	case 22:
		terminal->curr_attr &= ~ATTRMASK_INTENSITY;
		break;
	case 24:
		terminal->curr_attr &= ~ATTRMASK_UNDERLINE;
		break;
	case 7:
	case 26:
		if(!terminal->inverse_video)
			terminal->curr_attr =
			    inverse_video(terminal, terminal->curr_attr);
		terminal->inverse_video = 1;
		break;
	case 27:
		if(terminal->inverse_video)
			terminal->curr_attr =
			    inverse_video(terminal, terminal->curr_attr);
		terminal->inverse_video = 0;
		break;
	case 39:
		terminal->curr_attr &= ~(ATTRMASK_FOREGROUND & ~ATTRMASK_INTENSITY);
		terminal->curr_attr |= terminal->color_scheme->default_attr &
			(ATTRMASK_FOREGROUND & ~ATTRMASK_INTENSITY);
		break;
	case 49:
		terminal->curr_attr &= ~ATTRMASK_BACKGROUND;
		terminal->curr_attr |= terminal->color_scheme->default_attr &
			ATTRMASK_BACKGROUND;
		break;
	default:
		if(code >= 30 && code <= 37) {
			foreground = code - 30;
			terminal->curr_attr &= ~(ATTRMASK_FOREGROUND & ~ATTRMASK_INTENSITY);
			terminal->curr_attr |=
			    (foreground << ATTRSHIFT_FOREGROUND) & ATTRMASK_FOREGROUND;
			if(terminal->inverse_video)
				terminal->curr_attr =
				    inverse_video(terminal, terminal->curr_attr);
		} else if(code >= 40 && code <= 47) {
			background = code - 40;
			terminal->curr_attr &= ~ATTRMASK_BACKGROUND;
			terminal->curr_attr |=
			    (background << ATTRSHIFT_BACKGROUND) & ATTRMASK_BACKGROUND;
			if(terminal->inverse_video)
				terminal->curr_attr =
				    inverse_video(terminal, terminal->curr_attr);
		}
		break;
	}
}

static void
handle_non_csi_escape(struct terminal *terminal, char code)
{
	switch(code) {
	case 'M':    /* RI */
		terminal->row -= 1;
		if(terminal->row < terminal->margin_top) {
			terminal->row = terminal->margin_top;
			terminal_scroll(terminal, -1);
		}
		break;
	case 'E':    /* NEL */
		terminal->column = 0;
		/* fallthrough */
	case 'D':    /* IND */
		terminal->row += 1;
		if(terminal->row > terminal->margin_bottom) {
			terminal->row = terminal->margin_bottom;
			terminal_scroll(terminal, +1);
		}
		break;
	case 'c':    /* RIS */
		terminal_init(terminal);
		break;
	case 'H':    /* HTS */
		terminal->tab_ruler[terminal->column] = 1;
		break;
	case '7':    /* DECSC */
		terminal->saved_row = terminal->row;
		terminal->saved_column = terminal->column;
		terminal->saved_attr = terminal->curr_attr;
		terminal->saved_inverse_video = terminal->inverse_video;
		terminal->saved_origin_mode = terminal->origin_mode;
		terminal->saved_cs = terminal->cs;
		terminal->saved_g0 = terminal->g0;
		terminal->saved_g1 = terminal->g1;
		break;
	case '8':    /* DECRC */
		terminal->row = terminal->saved_row;
		terminal->column = terminal->saved_column;
		terminal->curr_attr = terminal->saved_attr;
		terminal->inverse_video = terminal->saved_inverse_video;
		terminal->origin_mode = terminal->saved_origin_mode;
		terminal->cs = terminal->saved_cs;
		terminal->g0 = terminal->saved_g0;
		terminal->g1 = terminal->saved_g1;
		break;
	case '=':    /* DECPAM */
		terminal->key_mode = KM_APPLICATION;
		break;
	case '>':    /* DECPNM */
		terminal->key_mode = KM_NORMAL;
		break;
	default:
		break;
	}
}

static void
handle_special_escape(struct terminal *terminal, char special, char code)
{
	int i, numChars;

	if (special == '#') {
		switch(code) {
		case '8':
			/* fill with 'E', no cheap way to do this */
			memset(terminal->data, 0, terminal->pitch * terminal->height);
			numChars = terminal->width * terminal->height;
			for(i = 0; i < numChars; i++) {
				terminal->data[i].byte[0] = 'E';
				terminal->data[i].byte[1] = '\0';
			}
			break;
		default:
			break;
		}
	} else if (special == '(' || special == ')') {
		switch(code) {
		case '0':
			if (special == '(')
				terminal->g0 = CS_SPECIAL;
			else
				terminal->g1 = CS_SPECIAL;
			break;
		case 'A':
			if (special == '(')
				terminal->g0 = CS_UK;
			else
				terminal->g1 = CS_UK;
			break;
		case 'B':
			if (special == '(')
				terminal->g0 = CS_US;
			else
				terminal->g1 = CS_US;
			break;
		default:
			break;
		}
	}
}

/* Returns 1 if c was special, otherwise 0 */
static int
handle_special_char(struct terminal *terminal, char c)
{
	union utf8_char *row;
	char *attr_row;

	row = terminal_get_row(terminal, terminal->row);
	attr_row = terminal_get_attr_row(terminal, terminal->row);

	switch(c) {
		case '\r':
			terminal->column = 0;
			break;
		case '\n':
			if (terminal->normal_newline) {
				terminal->column = 0;
			}
			/* fallthrough */
		case '\v':
		case '\f':
			terminal->row++;
			if(terminal->row > terminal->margin_bottom) {
				terminal->row = terminal->margin_bottom;
				terminal_scroll(terminal, +1);
			}
			break;
		case '\t':
			while (terminal->column < terminal->width) {
				if (terminal->tab_ruler[terminal->column])
					break;
				if (terminal->irm) terminal_shift_line(terminal, +1);
				row[terminal->column].byte[0] = ' ';
				row[terminal->column].byte[1] = '\0';
				attr_row[terminal->column] = terminal->curr_attr;
				terminal->column++;
			}
			if (terminal->column >= terminal->width) {
				terminal->column = terminal->width - 1;
			}

			break;
		case '\b':
			if (terminal->column >= terminal->width) {
				terminal->column = terminal->width - 2;
			} else if (terminal->column > 0) {
				terminal->column--;
			} else if (terminal->autowrap) {
				terminal->column = terminal->width - 1;
				terminal->row -= 1;
				if (terminal->row < terminal->margin_top) {
					terminal_scroll(terminal, -1);
				}
			}
			break;
		case '\a':
			/* Bell */
			break;
		case '\x0E': /* SO */
			terminal->cs = terminal->g1;
			break;
		case '\x0F': /* SI */
			terminal->cs = terminal->g0;
			break;
		default:
			return 0;
	}

	return 1;
}

static void
handle_char(struct terminal *terminal, union utf8_char utf8)
{
	union utf8_char *row;
	char *attr_row;

	if (handle_special_char(terminal, utf8.byte[0])) return;

	apply_char_set(terminal->cs, utf8.byte);

	/* There are a whole lot of non-characters, control codes,
	 * and formatting codes that should probably be ignored,
	 * for example: */
	if (strncmp((char*) utf8.byte, "\xEF\xBB\xBF", 3) == 0) {
		/* BOM, ignore */
		return;
	}

	/* Some of these non-characters should be translated, e.g.: */
	if (utf8.byte[0] < 32) {
		utf8.byte[0] = utf8.byte[0] + 64;
	}

	/* handle right margin effects */
	if (terminal->column >= terminal->width) {
		if (terminal->autowrap) {
			terminal->column = 0;
			terminal->row += 1;
			if (terminal->row > terminal->margin_bottom) {
				terminal->row = terminal->margin_bottom;
				terminal_scroll(terminal, +1);
			}
		} else {
			terminal->column--;
		}
	}

	row = terminal_get_row(terminal, terminal->row);
	attr_row = terminal_get_attr_row(terminal, terminal->row);

	if (terminal->irm) terminal_shift_line(terminal, +1);
	row[terminal->column] = utf8;
	attr_row[terminal->column++] = terminal->curr_attr;

	if (utf8.ch != terminal->last_char.ch)
		terminal->last_char = utf8;
}

static void
terminal_data(struct terminal *terminal, const char *data, size_t length)
{
	int i;
	union utf8_char utf8;
	enum utf8_state parser_state;

	for (i = 0; i < length; i++) {
		parser_state =
		    utf8_next_char(&terminal->state_machine, data[i]);
		switch(parser_state) {
		case UTF8STATE_ACCEPT:
			/* memcpy(utf8_char, terminal->state_machine.s, 4); */
			utf8.ch = terminal->state_machine.s.ch;
			break;
		case UTF8STATE_REJECT:
			/* the unicode replacement character */
			utf8.byte[0] = 0xEF;
			utf8.byte[1] = 0xBF;
			utf8.byte[2] = 0xBD;
			utf8.byte[3] = 0x00;
			break;
		default:
			continue;
		}

		/* assume escape codes never use non-ASCII characters */
		if (terminal->state == STATE_ESCAPE) {
			terminal->escape[terminal->escape_length++] = utf8.byte[0];
			if (utf8.byte[0] == '[') {
				terminal->state = STATE_ESCAPE_CSI;
				continue;
			} else if (utf8.byte[0] == '#' || utf8.byte[0] == '(' ||
				utf8.byte[0] == ')')
			{
				terminal->state = STATE_ESCAPE_SPECIAL;
				continue;
			} else {
				terminal->state = STATE_NORMAL;
				handle_non_csi_escape(terminal, utf8.byte[0]);
				continue;
			}
		} else if (terminal->state == STATE_ESCAPE_SPECIAL) {
			terminal->escape[terminal->escape_length++] = utf8.byte[0];
			terminal->state = STATE_NORMAL;
			if (isdigit(utf8.byte[0]) || isalpha(utf8.byte[0])) {
				handle_special_escape(terminal, terminal->escape[1],
						      utf8.byte[0]);
				continue;
			}
		} else if (terminal->state == STATE_ESCAPE_CSI) {
			if (handle_special_char(terminal, utf8.byte[0]) != 0) {
				/* do nothing */
			} else if (utf8.byte[0] == '?') {
				terminal->qmark_flag = 1;
			} else {
				/* Don't overflow the buffer */
				if (terminal->escape_length < MAX_ESCAPE) {
					terminal->escape[terminal->escape_length++] = utf8.byte[0];
				} else {
					terminal->state = STATE_NORMAL;
					continue;
				}
			}

			if (isalpha(utf8.byte[0]) || utf8.byte[0] == '@' ||
				utf8.byte[0] == '`')
			{
				terminal->state = STATE_NORMAL;
				handle_escape(terminal);
				continue;
			} else {
				continue;
			}
		}

		/* this is valid, because ASCII characters are never used to
		 * introduce a multibyte sequence in UTF-8 */
		if (utf8.byte[0] == '\e') {
			terminal->state = STATE_ESCAPE;
			terminal->escape[0] = '\e';
			terminal->escape_length = 1;
			terminal->qmark_flag = 0;
		} else {
			handle_char(terminal, utf8);
		}
	}

	window_schedule_redraw(terminal->window);
}

static void
key_handler(struct window *window, uint32_t key, uint32_t sym,
	    uint32_t state, uint32_t modifiers, void *data)
{
	struct terminal *terminal = data;
	char ch[MAX_RESPONSE];
	int len = 0;

	switch(sym) {
	case XK_F11:
		if (!state)
			break;
		terminal->fullscreen ^= 1;
		window_set_fullscreen(window, terminal->fullscreen);
		window_schedule_redraw(terminal->window);
		break;
	case XK_BackSpace:
	case XK_Tab:
	case XK_Linefeed:
	case XK_Clear:
	case XK_Pause:
	case XK_Scroll_Lock:
	case XK_Sys_Req:
	case XK_Escape:
		ch[len++] = sym & 0x7f;
		break;
	case XK_Return:
		if (terminal->normal_newline) {
			ch[len++] = 0x0D;
			ch[len++] = 0x0A;
		} else {
			ch[len++] = 0x0D;
		}
		break;
	case XK_Shift_L:
	case XK_Shift_R:
	case XK_Control_L:
	case XK_Control_R:
	case XK_Alt_L:
	case XK_Alt_R:
		break;
	case XK_Insert:
		ch[0] = '\e';ch[1] = '[';ch[2] = '2'; ch[3] = '~';
		len += 4;
		break;
	case XK_Delete:
		if (terminal->deleteSendsDel) {
			ch[len++] = '\x7F';
		} else {
			ch[0] = '\e';ch[1] = '[';ch[2] = '3'; ch[3] = '~';
			len += 4;
		}
		break;
	case XK_Page_Up:
		ch[0] = '\e';ch[1] = '[';ch[2] = '5'; ch[3] = '~';
		len += 4;
		break;
	case XK_Page_Down:
		ch[0] = '\e';ch[1] = '[';ch[2] = '6'; ch[3] = '~';
		len += 4;
		break;
	case XK_F1:
		ch[0] = '\e';ch[1] = 'O';ch[2] = 'P';
		len += 3;
		break;
	case XK_F2:
		ch[0] = '\e';ch[1] = 'O';ch[2] = 'Q';
		len += 3;
		break;
	case XK_F3:
		ch[0] = '\e';ch[1] = 'O';ch[2] = 'R';
		len += 3;
		break;
	case XK_F4:
		ch[0] = '\e';ch[1] = 'O';ch[2] = 'S';
		len += 3;
		break;
	case XK_F5:
		ch[0] = '\e';ch[1] = '[';ch[2] = '1';ch[3] = '5';ch[4] = '~';
		len += 5;
		break;
	case XK_F6:
		ch[0] = '\e';ch[1] = '[';ch[2] = '1';ch[3] = '7';ch[4] = '~';
		len += 5;
		break;
	case XK_F7:
		ch[0] = '\e';ch[1] = '[';ch[2] = '1';ch[3] = '8';ch[4] = '~';
		len += 5;
		break;
	case XK_F8:
		ch[0] = '\e';ch[1] = '[';ch[2] = '1';ch[3] = '9';ch[4] = '~';
		len += 5;
		break;
	case XK_F9:
		ch[0] = '\e';ch[1] = '[';ch[2] = '2';ch[3] = '0';ch[4] = '~';
		len += 5;
		break;
	case XK_F10:
		ch[0] = '\e';ch[1] = '[';ch[2] = '2';ch[3] = '1';ch[4] = '~';
		len += 5;
		break;
	case XK_F12:
		ch[0] = '\e';ch[1] = '[';ch[2] = '2';ch[3] = '4';ch[4] = '~';
		len += 5;
		break;
	default:
		/* Handle special keys with alternate mappings */
		len = apply_key_map(terminal->key_mode, sym, ch);
		if (len != 0) break;

		if (modifiers & WINDOW_MODIFIER_CONTROL)
			sym = sym & 0x1f;
		else if (terminal->altSendsEsc && (modifiers & WINDOW_MODIFIER_ALT))
			ch[len++] = 0x1b;
		else if (modifiers & WINDOW_MODIFIER_ALT)
			sym = sym | 0x80;
		if (sym < 256)
			ch[len++] = sym;
		break;
	}

	if (state && len > 0)
		write(terminal->master, ch, len);
}

static void
keyboard_focus_handler(struct window *window,
		       struct input *device, void *data)
{
	struct terminal *terminal = data;

	terminal->focused = (device != NULL);
	window_schedule_redraw(terminal->window);
}

static struct terminal *
terminal_create(struct display *display, int fullscreen)
{
	struct terminal *terminal;
	cairo_surface_t *surface;
	cairo_t *cr;

	terminal = malloc(sizeof *terminal);
	if (terminal == NULL)
		return terminal;

	memset(terminal, 0, sizeof *terminal);
	terminal->fullscreen = fullscreen;

	terminal->color_scheme = &DEFAULT_COLORS;
	terminal_init(terminal);
	terminal->margin_top = 0;
	terminal->margin_bottom = 10000;  /* much too large, will be
					   * trimmed down by
					   * terminal_resize */

	init_state_machine(&terminal->state_machine);

	terminal->window = window_create(display, "Wayland Terminal", 500, 400);
	terminal->display = display;
	terminal->margin = 5;

	window_set_fullscreen(terminal->window, terminal->fullscreen);
	window_set_user_data(terminal->window, terminal);
	window_set_redraw_handler(terminal->window, redraw_handler);

	window_set_key_handler(terminal->window, key_handler);
	window_set_keyboard_focus_handler(terminal->window,
					  keyboard_focus_handler);

	surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 0, 0);
	cr = cairo_create(surface);

	cairo_set_font_size(cr, 14);
	cairo_select_font_face (cr, "mono",
				CAIRO_FONT_SLANT_NORMAL,
				CAIRO_FONT_WEIGHT_BOLD);
	terminal->font_bold = cairo_get_scaled_font (cr);
	cairo_scaled_font_reference(terminal->font_bold);

	cairo_select_font_face (cr, "mono",
				CAIRO_FONT_SLANT_NORMAL,
				CAIRO_FONT_WEIGHT_NORMAL);
	terminal->font_normal = cairo_get_scaled_font (cr);
	cairo_scaled_font_reference(terminal->font_normal);
	cairo_font_extents(cr, &terminal->extents);
	cairo_destroy(cr);
	cairo_surface_destroy(surface);

	terminal_resize(terminal, 80, 24);
	terminal_draw(terminal);

	return terminal;
}

static gboolean
io_handler(GIOChannel   *source,
	   GIOCondition  condition,
	   gpointer      data)
{
	struct terminal *terminal = data;
	gchar buffer[256];
	gsize bytes_read;
	GError *error = NULL;

	g_io_channel_read_chars(source, buffer, sizeof buffer,
				&bytes_read, &error);

	terminal_data(terminal, buffer, bytes_read);

	return TRUE;
}

static int
terminal_run(struct terminal *terminal, const char *path)
{
	int master;
	pid_t pid;

	pid = forkpty(&master, NULL, NULL, NULL);
	if (pid == 0) {
		setenv("TERM", "xterm", 1);
		setenv("COLORTERM", "xterm", 1);
		if (execl(path, path, NULL)) {
			printf("exec failed: %m\n");
			exit(EXIT_FAILURE);
		}
	} else if (pid < 0) {
		return -1;
	}

	terminal->master = master;
	terminal->channel = g_io_channel_unix_new(master);
	fcntl(master, F_SETFL, O_NONBLOCK);
	g_io_add_watch(terminal->channel, G_IO_IN,
		       io_handler, terminal);

	return 0;
}

static const GOptionEntry option_entries[] = {
	{ "fullscreen", 'f', 0, G_OPTION_ARG_NONE,
	  &option_fullscreen, "Run in fullscreen mode" },
	{ NULL }
};

int main(int argc, char *argv[])
{
	struct display *d;
	struct terminal *terminal;

	d = display_create(&argc, &argv, option_entries);
	if (d == NULL) {
		return -1;
	}

	terminal = terminal_create(d, option_fullscreen);
	if (terminal_run(terminal, "/bin/bash"))
		exit(EXIT_FAILURE);

	display_run(d);

	return 0;
}