text: /*
   * Copyright © 2008 Kristian Høgsberg
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice (including the next
   * paragraph) shall be included in all copies or substantial portions of the
   * Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   */
  
  #include "config.h"
  
  #include <signal.h>
  #include <stdbool.h>
  #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 <sys/epoll.h>
  #include <wchar.h>
  #include <locale.h>
  #include <errno.h>
  
  #include <linux/input.h>
  
  #include <wayland-client.h>
  
  #include <libweston/config-parser.h>
  #include "shared/helpers.h"
  #include "shared/xalloc.h"
  #include "window.h"
  
  static bool option_fullscreen;
  static bool option_maximize;
  static char *option_font;
  static int option_font_size;
  static char *option_term;
  static char *option_shell;
  
  static struct wl_list terminal_list;
  
  static struct terminal *
  terminal_create(struct display *display);
  static void
  terminal_destroy(struct terminal *terminal);
  static int
  terminal_run(struct terminal *terminal, const char *path);
  
  #define TERMINAL_DRAW_SINGLE_WIDE_CHARACTERS    \
      " !\"#$%&'()*+,-./"                         \
      "0123456789"                                \
      ":;<=>?@"                                   \
      "ABCDEFGHIJKLMNOPQRSTUVWXYZ"                \
      "[\\]^_`"                                   \
      "abcdefghijklmnopqrstuvwxyz"                \
      "{|}~"                                      \
      ""
  
  #define MOD_SHIFT	0x01
  #define MOD_ALT		0x02
  #define MOD_CTRL	0x04
  
  #define ATTRMASK_BOLD		0x01
  #define ATTRMASK_UNDERLINE	0x02
  #define ATTRMASK_BLINK		0x04
  #define ATTRMASK_INVERSE	0x08
  #define ATTRMASK_CONCEALED	0x10
  
  /* Buffer sizes */
  #define MAX_RESPONSE		256
  #define MAX_ESCAPE		255
  
  /* Terminal modes */
  #define MODE_SHOW_CURSOR	0x00000001
  #define MODE_INVERSE		0x00000002
  #define MODE_AUTOWRAP		0x00000004
  #define MODE_AUTOREPEAT		0x00000008
  #define MODE_LF_NEWLINE		0x00000010
  #define MODE_IRM		0x00000020
  #define MODE_DELETE_SENDS_DEL	0x00000040
  #define MODE_ALT_SENDS_ESC	0x00000080
  
  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;
  	uint32_t unicode;
  };
  
  static void
  init_state_machine(struct utf8_state_machine *machine)
  {
  	machine->state = utf8state_start;
  	machine->len = 0;
  	machine->s.ch = 0;
  	machine->unicode = 0;
  }
  
  static enum utf8_state
  utf8_next_char(struct utf8_state_machine *machine, unsigned char c)
  {
  	switch(machine->state) {
  	case utf8state_start:
  	case utf8state_accept:
  	case utf8state_reject:
  		machine->s.ch = 0;
  		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;
  			machine->unicode = c;
  		} 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;
  			machine->unicode = c & 0x1f;
  		} else if ((c & 0xF0) == 0xE0) {
  			/* start of three byte sequence */
  			machine->s.byte[machine->len++] = c;
  			machine->state = utf8state_expect2;
  			machine->unicode = c & 0x0f;
  		} else if ((c & 0xF8) == 0xF0) {
  			/* start of four byte sequence */
  			machine->s.byte[machine->len++] = c;
  			machine->state = utf8state_expect3;
  			machine->unicode = c & 0x07;
  		} else {
  			/* overlong encoding, reject */
  			machine->state = utf8state_reject;
  		}
  		break;
  	case utf8state_expect3:
  		machine->s.byte[machine->len++] = c;
  		machine->unicode = (machine->unicode << 6) | (c & 0x3f);
  		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;
  		machine->unicode = (machine->unicode << 6) | (c & 0x3f);
  		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;
  		machine->unicode = (machine->unicode << 6) | (c & 0x3f);
  		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;
  }
  
  static uint32_t
  get_unicode(union utf8_char utf8)
  {
  	struct utf8_state_machine machine;
  	int i;
  
  	init_state_machine(&machine);
  	for (i = 0; i < 4; i++) {
  		utf8_next_char(&machine, utf8.byte[i]);
  		if (machine.state == utf8state_accept ||
  		    machine.state == utf8state_reject)
  			break;
  	}
  
  	if (machine.state == utf8state_reject)
  		return 0xfffd;
  
  	return machine.unicode;
  }
  
  static bool
  is_wide(union utf8_char utf8)
  {
  	uint32_t unichar = get_unicode(utf8);
  	return wcwidth(unichar) > 1;
  }
  
  struct char_sub {
  	union utf8_char match;
  	union utf8_char replace;
  };
  /* Set last char_sub match to NULL char */
  typedef struct char_sub *character_set;
  
  struct char_sub CS_US[] = {
  	{{{0, }}, {{0, }}}
  };
  static struct char_sub CS_UK[] = {
  	{{{'#', 0, }}, {{0xC2, 0xA3, 0, }}}, /* POUND: £ */
  	{{{0, }}, {{0, }}}
  };
  static struct char_sub 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_LB: └ */
  	{{{'n', 0, }}, {{0xE2, 0x94, 0xBC, 0}}}, /* CROSS: ┼ */
  	{{{'o', 0, }}, {{0xE2, 0x8E, 0xBA, 0}}}, /* Horiz. Scan Line 1: ⎺ */
  	{{{'p', 0, }}, {{0xE2, 0x8E, 0xBB, 0}}}, /* Horiz. Scan Line 3: ⎻ */
  	{{{'q', 0, }}, {{0xE2, 0x94, 0x80, 0}}}, /* Horiz. Scan Line 5: ─ */
  	{{{'r', 0, }}, {{0xE2, 0x8E, 0xBC, 0}}}, /* Horiz. Scan Line 7: ⎼ */
  	{{{'s', 0, }}, {{0xE2, 0x8E, 0xBD, 0}}}, /* Horiz. Scan Line 9: ⎽ */
  	{{{'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: π */
  	{{{'|', 0, }}, {{0xE2, 0x89, 0xA0, 0}}}, /* NEQ: ≠ */
  	{{{'}', 0, }}, {{0xC2, 0xA3, 0, }}}, /* POUND: £ */
  	{{{'~', 0, }}, {{0xE2, 0x8B, 0x85, 0}}}, /* DOT: ⋅ */
  	{{{0, }}, {{0, }}}
  };
  
  static void
  apply_char_set(character_set cs, union utf8_char *utf8)
  {
  	int i = 0;
  
  	while (cs[i].match.byte[0]) {
  		if ((*utf8).ch == cs[i].match.ch) {
  			*utf8 = cs[i].replace;
  			break;
  		}
  		i++;
  	}
  }
  
  struct key_map {
  	int sym;
  	int num;
  	char escape;
  	char code;
  };
  /* Set last key_sub sym to NULL */
  typedef struct key_map *keyboard_mode;
  
  static struct key_map KM_NORMAL[] = {
  	{ XKB_KEY_Left,  1, '[', 'D' },
  	{ XKB_KEY_Right, 1, '[', 'C' },
  	{ XKB_KEY_Up,    1, '[', 'A' },
  	{ XKB_KEY_Down,  1, '[', 'B' },
  	{ XKB_KEY_Home,  1, '[', 'H' },
  	{ XKB_KEY_End,   1, '[', 'F' },
  	{ 0, 0, 0, 0 }
  };
  static struct key_map KM_APPLICATION[] = {
  	{ XKB_KEY_Left,          1, 'O', 'D' },
  	{ XKB_KEY_Right,         1, 'O', 'C' },
  	{ XKB_KEY_Up,            1, 'O', 'A' },
  	{ XKB_KEY_Down,          1, 'O', 'B' },
  	{ XKB_KEY_Home,          1, 'O', 'H' },
  	{ XKB_KEY_End,           1, 'O', 'F' },
  	{ XKB_KEY_KP_Enter,      1, 'O', 'M' },
  	{ XKB_KEY_KP_Multiply,   1, 'O', 'j' },
  	{ XKB_KEY_KP_Add,        1, 'O', 'k' },
  	{ XKB_KEY_KP_Separator,  1, 'O', 'l' },
  	{ XKB_KEY_KP_Subtract,   1, 'O', 'm' },
  	{ XKB_KEY_KP_Divide,     1, 'O', 'o' },
  	{ 0, 0, 0, 0 }
  };
  
  static int
  function_key_response(char escape, int num, uint32_t modifiers,
  		      char code, char *response)
  {
  	int mod_num = 0;
  	int len;
  
  	if (modifiers & MOD_SHIFT_MASK) mod_num   |= 1;
  	if (modifiers & MOD_ALT_MASK) mod_num    |= 2;
  	if (modifiers & MOD_CONTROL_MASK) mod_num |= 4;
  
  	if (mod_num != 0)
  		len = snprintf(response, MAX_RESPONSE, "\e[%d;%d%c",
  			       num, mod_num + 1, code);
  	else if (code != '~')
  		len = snprintf(response, MAX_RESPONSE, "\e%c%c",
  			       escape, code);
  	else
  		len = snprintf(response, MAX_RESPONSE, "\e%c%d%c",
  			       escape, num, code);
  
  	if (len >= MAX_RESPONSE)	return MAX_RESPONSE - 1;
  	else				return len;
  }
  
  /* returns the number of bytes written into response,
   * which must have room for MAX_RESPONSE bytes */
  static int
  apply_key_map(keyboard_mode mode, int sym, uint32_t modifiers, char *response)
  {
  	struct key_map map;
  	int len = 0;
  	int i = 0;
  
  	while (mode[i].sym) {
  		map = mode[i++];
  		if (sym == map.sym) {
  			len = function_key_response(map.escape, map.num,
  						    modifiers, map.code,
  						    response);
  			break;
  		}
  	}
  
  	return len;
  }
  
  struct terminal_color { double r, g, b, a; };
  struct attr {
  	unsigned char fg, bg;
  	char a;        /* attributes format:
  	                * 76543210
  			*    cilub */
  	char s;        /* in selection */
  };
  struct color_scheme {
  	struct terminal_color palette[16];
  	char border;
  	struct attr default_attr;
  };
  
  static void
  attr_init(struct attr *data_attr, struct attr attr, int n)
  {
  	int i;
  	for (i = 0; i < n; i++) {
  		data_attr[i] = attr;
  	}
  }
  
  enum escape_state {
  	escape_state_normal = 0,
  	escape_state_escape,
  	escape_state_dcs,
  	escape_state_csi,
  	escape_state_osc,
  	escape_state_inner_escape,
  	escape_state_ignore,
  	escape_state_special
  };
  
  #define ESC_FLAG_WHAT	0x01
  #define ESC_FLAG_GT	0x02
  #define ESC_FLAG_BANG	0x04
  #define ESC_FLAG_CASH	0x08
  #define ESC_FLAG_SQUOTE 0x10
  #define ESC_FLAG_DQUOTE	0x20
  #define ESC_FLAG_SPACE	0x40
  
  enum {
  	SELECT_NONE,
  	SELECT_CHAR,
  	SELECT_WORD,
  	SELECT_LINE
  };
  
  struct terminal {
  	struct window *window;
  	struct widget *widget;
  	struct display *display;
  	char *title;
  	union utf8_char *data;
  	struct task io_task;
  	char *tab_ruler;
  	struct attr *data_attr;
  	struct attr curr_attr;
  	uint32_t mode;
  	char origin_mode;
  	char saved_origin_mode;
  	struct attr saved_attr;
  	union utf8_char last_char;
  	int margin_top, margin_bottom;
  	character_set cs, g0, g1;
  	character_set saved_cs, saved_g0, saved_g1;
  	keyboard_mode key_mode;
  	int data_pitch, attr_pitch;  /* The width in bytes of a line */
  	int width, height, row, column, max_width;
  	uint32_t buffer_height;
  	uint32_t start, end, saved_start, log_size;
  	wl_fixed_t smooth_scroll;
  	int saved_row, saved_column;
  	int scrolling;
  	int send_cursor_position;
  	int fd, master;
  	uint32_t modifiers;
  	char escape[MAX_ESCAPE+1];
  	int escape_length;
  	enum escape_state state;
  	enum escape_state outer_state;
  	int escape_flags;
  	struct utf8_state_machine state_machine;
  	int margin;
  	struct color_scheme *color_scheme;
  	struct terminal_color color_table[256];
  	cairo_font_extents_t extents;
  	double average_width;
  	cairo_scaled_font_t *font_normal, *font_bold;
  	uint32_t hide_cursor_serial;
  	int size_in_title;
  
  	struct wl_data_source *selection;
  	uint32_t click_time;
  	int dragging, click_count;
  	int selection_start_x, selection_start_y;
  	int selection_end_x, selection_end_y;
  	int selection_start_row, selection_start_col;
  	int selection_end_row, selection_end_col;
  	struct wl_list link;
  	int pace_pipe;
  };
  
  /* 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->origin_mode = 0;
  	terminal->mode = MODE_SHOW_CURSOR |
  			 MODE_AUTOREPEAT |
  			 MODE_ALT_SENDS_ESC |
  			 MODE_AUTOWRAP;
  
  	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;
  
  	terminal->saved_attr = terminal->curr_attr;
  	terminal->saved_origin_mode = terminal->origin_mode;
  	terminal->saved_row = terminal->row;
  	terminal->saved_column = terminal->column;
  
  	if (terminal->tab_ruler != NULL) terminal_init_tabs(terminal);
  }
  
  static void
  init_color_table(struct terminal *terminal)
  {
  	int c, r;
  	struct terminal_color *color_table = terminal->color_table;
  
  	for (c = 0; c < 256; c ++) {
  		if (c < 16) {
  			color_table[c] = terminal->color_scheme->palette[c];
  		} else if (c < 232) {
  			r = c - 16;
  			color_table[c].b = ((double)(r % 6) / 6.0); r /= 6;
  			color_table[c].g = ((double)(r % 6) / 6.0); r /= 6;
  			color_table[c].r = ((double)(r % 6) / 6.0);
  			color_table[c].a = 1.0;
  		} else {
  			r = (c - 232) * 10 + 8;
  			color_table[c].r = ((double) r) / 256.0;
  			color_table[c].g = color_table[c].r;
  			color_table[c].b = color_table[c].r;
  			color_table[c].a = 1.0;
  		}
  	}
  }
  
  static union utf8_char *
  terminal_get_row(struct terminal *terminal, int row)
  {
  	int index;
  
  	index = (row + terminal->start) & (terminal->buffer_height - 1);
  
  	return (void *) terminal->data + index * terminal->data_pitch;
  }
  
  static struct attr*
  terminal_get_attr_row(struct terminal *terminal, int row)
  {
  	int index;
  
  	index = (row + terminal->start) & (terminal->buffer_height - 1);
  
  	return (void *) terminal->data_attr + index * terminal->attr_pitch;
  }
  
  union decoded_attr {
  	struct attr attr;
  	uint32_t key;
  };
  
  static void
  terminal_decode_attr(struct terminal *terminal, int row, int col,
  		     union decoded_attr *decoded)
  {
  	struct attr attr;
  	int foreground, background, tmp;
  
  	decoded->attr.s = 0;
  	if (((row == terminal->selection_start_row &&
  	      col >= terminal->selection_start_col) ||
  	     row > terminal->selection_start_row) &&
  	    ((row == terminal->selection_end_row &&
  	      col < terminal->selection_end_col) ||
  	     row < terminal->selection_end_row))
  		decoded->attr.s = 1;
  
  	/* get the attributes for this character cell */
  	attr = terminal_get_attr_row(terminal, row)[col];
  	if ((attr.a & ATTRMASK_INVERSE) ||
  	    decoded->attr.s ||
  	    ((terminal->mode & MODE_SHOW_CURSOR) &&
  	     window_has_focus(terminal->window) && terminal->row == row &&
  	     terminal->column == col)) {
  		foreground = attr.bg;
  		background = attr.fg;
  		if (attr.a & ATTRMASK_BOLD) {
  			if (foreground <= 16) foreground |= 0x08;
  			if (background <= 16) background &= 0x07;
  		}
  	} else {
  		foreground = attr.fg;
  		background = attr.bg;
  	}
  
  	if (terminal->mode & MODE_INVERSE) {
  		tmp = foreground;
  		foreground = background;
  		background = tmp;
  		if (attr.a & ATTRMASK_BOLD) {
  			if (foreground <= 16) foreground |= 0x08;
  			if (background <= 16) background &= 0x07;
  		}
  	}
  
  	decoded->attr.fg = foreground;
  	decoded->attr.bg = background;
  	decoded->attr.a = attr.a;
  }
  
  
  static void
  terminal_scroll_buffer(struct terminal *terminal, int d)
  {
  	int i;
  
  	terminal->start += d;
  	if (d < 0) {
  		d = 0 - d;
  		for (i = 0; i < d; i++) {
  			memset(terminal_get_row(terminal, i), 0, terminal->data_pitch);
  			attr_init(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->data_pitch);
  			attr_init(terminal_get_attr_row(terminal, i),
  			    terminal->curr_attr, terminal->width);
  		}
  	}
  
  	terminal->selection_start_row -= d;
  	terminal->selection_end_row -= d;
  }
  
  static void
  terminal_scroll_window(struct terminal *terminal, int d)
  {
  	int i;
  	int window_height;
  	int from_row, to_row;
  
  	// 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->data_pitch);
  			memcpy(terminal_get_attr_row(terminal, to_row - i),
  			       terminal_get_attr_row(terminal, from_row - i),
  			       terminal->attr_pitch);
  		}
  		for (i = terminal->margin_top; i < (terminal->margin_top + d); i++) {
  			memset(terminal_get_row(terminal, i), 0, terminal->data_pitch);
  			attr_init(terminal_get_attr_row(terminal, i),
  				terminal->curr_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->data_pitch);
  			memcpy(terminal_get_attr_row(terminal, to_row + i),
  			       terminal_get_attr_row(terminal, from_row + i),
  			       terminal->attr_pitch);
  		}
  		for (i = terminal->margin_bottom - d + 1; i <= terminal->margin_bottom; i++) {
  			memset(terminal_get_row(terminal, i), 0, terminal->data_pitch);
  			attr_init(terminal_get_attr_row(terminal, i),
  				terminal->curr_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;
  	struct attr *attr_row;
  
  	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) * sizeof(union utf8_char));
  		memmove(&attr_row[terminal->column], &attr_row[terminal->column + d],
  		        (terminal->width - terminal->column - d) * sizeof(struct attr));
  		memset(&row[terminal->width - d], 0, d * sizeof(union utf8_char));
  		attr_init(&attr_row[terminal->width - d], terminal->curr_attr, d);
  	} else {
  		memmove(&row[terminal->column + d], &row[terminal->column],
  			(terminal->width - terminal->column - d) * sizeof(union utf8_char));
  		memmove(&attr_row[terminal->column + d], &attr_row[terminal->column],
  			(terminal->width - terminal->column - d) * sizeof(struct attr));
  		memset(&row[terminal->column], 0, d * sizeof(union utf8_char));
  		attr_init(&attr_row[terminal->column], terminal->curr_attr, d);
  	}
  }
  
  static void
  terminal_resize_cells(struct terminal *terminal,
  		      int width, int height)
  {
  	union utf8_char *data;
  	struct attr *data_attr;
  	char *tab_ruler;
  	int data_pitch, attr_pitch;
  	int i, l, total_rows;
  	uint32_t d, uheight = height;
  	struct rectangle allocation;
  	struct winsize ws;
  
  	if (uheight > terminal->buffer_height)
  		height = terminal->buffer_height;
  
  	if (terminal->width == width && terminal->height == height)
  		return;
  
  	if (terminal->data && width <= terminal->max_width) {
  		d = 0;
  		if (height < terminal->height && height <= terminal->row)
  			d = terminal->height - height;
  		else if (height > terminal->height &&
  			 terminal->height - 1 == terminal->row) {
  			d = terminal->height - height;
  			if (terminal->log_size < uheight)
  				d = -terminal->start;
  		}
  
  		terminal->start += d;
  		terminal->row -= d;
  	} else {
  		terminal->max_width = width;
  		data_pitch = width * sizeof(union utf8_char);
  		data = xzalloc(data_pitch * terminal->buffer_height);
  		attr_pitch = width * sizeof(struct attr);
  		data_attr = xmalloc(attr_pitch * terminal->buffer_height);
  		tab_ruler = xzalloc(width);
  		attr_init(data_attr, terminal->curr_attr,
  			  width * terminal->buffer_height);
  
  		if (terminal->data && terminal->data_attr) {
  			if (width > terminal->width)
  				l = terminal->width;
  			else
  				l = width;
  
  			if (terminal->height > height) {
  				total_rows = height;
  				i = 1 + terminal->row - height;
  				if (i > 0) {
  					terminal->start += i;
  					terminal->row = terminal->row - i;
  				}
  			} else {
  				total_rows = terminal->height;
  			}
  
  			for (i = 0; i < total_rows; i++) {
  				memcpy(&data[width * i],
  				       terminal_get_row(terminal, i),
  				       l * sizeof(union utf8_char));
  				memcpy(&data_attr[width * i],
  				       terminal_get_attr_row(terminal, i),
  				       l * sizeof(struct attr));
  			}
  
  			free(terminal->data);
  			free(terminal->data_attr);
  			free(terminal->tab_ruler);
  		}
  
  		terminal->data_pitch = data_pitch;
  		terminal->attr_pitch = attr_pitch;
  		terminal->data = data;
  		terminal->data_attr = data_attr;
  		terminal->tab_ruler = tab_ruler;
  		terminal->start = 0;
  	}
  
  	terminal->margin_bottom =
  		height - (terminal->height - terminal->margin_bottom);
  	terminal->width = width;
  	terminal->height = height;
  	terminal_init_tabs(terminal);
  
  	/* Update the window size */
  	ws.ws_row = terminal->height;
  	ws.ws_col = terminal->width;
  	widget_get_allocation(terminal->widget, &allocation);
  	ws.ws_xpixel = allocation.width;
  	ws.ws_ypixel = allocation.height;
  	ioctl(terminal->master, TIOCSWINSZ, &ws);
  }
  
  static void
  update_title(struct terminal *terminal)
  {
  	if (window_is_resizing(terminal->window)) {
  		char *p;
  		if (asprintf(&p, "%s — [%dx%d]", terminal->title, terminal->width, terminal->height) > 0) {
  			window_set_title(terminal->window, p);
  			free(p);
  		}
  	} else {
  		window_set_title(terminal->window, terminal->title);
  	}
  }
  
  static void
  resize_handler(struct widget *widget,
  	       int32_t width, int32_t height, void *data)
  {
  	struct terminal *terminal = data;
  	int32_t columns, rows, m;
  
  	if (terminal->pace_pipe >= 0) {
  		close(terminal->pace_pipe);
  		terminal->pace_pipe = -1;
  	}
  	m = 2 * terminal->margin;
  	columns = (width - m) / (int32_t) terminal->average_width;
  	rows = (height - m) / (int32_t) terminal->extents.height;
  
  	if (!window_is_fullscreen(terminal->window) &&
  	    !window_is_maximized(terminal->window)) {
  		width = columns * terminal->average_width + m;
  		height = rows * terminal->extents.height + m;
  		widget_set_size(terminal->widget, width, height);
  	}
  
  	terminal_resize_cells(terminal, columns, rows);
  	update_title(terminal);
  }
  
  static void
  state_changed_handler(struct window *window, void *data)
  {
  	struct terminal *terminal = data;
  	update_title(terminal);
  }
  
  static void
  terminal_resize(struct terminal *terminal, int columns, int rows)
  {
  	int32_t width, height, m;
  
  	if (window_is_fullscreen(terminal->window) ||
  	    window_is_maximized(terminal->window))
  		return;
  
  	m = 2 * terminal->margin;
  	width = columns * terminal->average_width + m;
  	height = rows * terminal->extents.height + m;
  
  	window_frame_set_child_size(terminal->widget, width, height);
  }
  
  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 */
  	{7, 0, 0, }                    /* bg:black (0), fg:light gray (7)  */
  };
  
  static void
  terminal_set_color(struct terminal *terminal, cairo_t *cr, int index)
  {
  	cairo_set_source_rgba(cr,
  			      terminal->color_table[index].r,
  			      terminal->color_table[index].g,
  			      terminal->color_table[index].b,
  			      terminal->color_table[index].a);
  }
  
  static void
  terminal_send_selection(struct terminal *terminal, int fd)
  {
  	int row, col;
  	union utf8_char *p_row;
  	union decoded_attr attr;
  	FILE *fp;
  	int len;
  
  	fp = fdopen(fd, "w");
  	if (fp == NULL){
  		close(fd);
  		return;
  	}
  	for (row = terminal->selection_start_row; row < terminal->height; row++) {
  		p_row = terminal_get_row(terminal, row);
  		for (col = 0; col < terminal->width; col++) {
  			if (p_row[col].ch == 0x200B) /* space glyph */
  				continue;
  			/* get the attributes for this character cell */
  			terminal_decode_attr(terminal, row, col, &attr);
  			if (!attr.attr.s)
  				continue;
  			len = strnlen((char *) p_row[col].byte, 4);
  			if (len > 0)
  				fwrite(p_row[col].byte, 1, len, fp);
  			if (len == 0 || col == terminal->width - 1) {
  				fwrite("\n", 1, 1, fp);
  				break;
  			}
  		}
  	}
  	fclose(fp);
  }
  
  struct glyph_run {
  	struct terminal *terminal;
  	cairo_t *cr;
  	unsigned int count;
  	union decoded_attr attr;
  	cairo_glyph_t glyphs[256], *g;
  };
  
  static void
  glyph_run_init(struct glyph_run *run, struct terminal *terminal, cairo_t *cr)
  {
  	run->terminal = terminal;
  	run->cr = cr;
  	run->g = run->glyphs;
  	run->count = 0;
  	run->attr.key = 0;
  }
  
  static void
  glyph_run_flush(struct glyph_run *run, union decoded_attr attr)
  {
  	cairo_scaled_font_t *font;
  
  	if (run->count > ARRAY_LENGTH(run->glyphs) - 10 ||
  	    (attr.key != run->attr.key)) {
  		if (run->attr.attr.a & (ATTRMASK_BOLD | ATTRMASK_BLINK))
  			font = run->terminal->font_bold;
  		else
  			font = run->terminal->font_normal;
  		cairo_set_scaled_font(run->cr, font);
  		terminal_set_color(run->terminal, run->cr,
  				   run->attr.attr.fg);
  
  		if (!(run->attr.attr.a & ATTRMASK_CONCEALED))
  			cairo_show_glyphs (run->cr, run->glyphs, run->count);
  		run->g = run->glyphs;
  		run->count = 0;
  	}
  	run->attr = attr;
  }
  
  static void
  glyph_run_add(struct glyph_run *run, int x, int y, union utf8_char *c)
  {
  	int num_glyphs;
  	cairo_scaled_font_t *font;
  
  	num_glyphs = ARRAY_LENGTH(run->glyphs) - run->count;
  
  	if (run->attr.attr.a & (ATTRMASK_BOLD | ATTRMASK_BLINK))
  		font = run->terminal->font_bold;
  	else
  		font = run->terminal->font_normal;
  
  	cairo_move_to(run->cr, x, y);
  	cairo_scaled_font_text_to_glyphs (font, x, y,
  					  (char *) c->byte, 4,
  					  &run->g, &num_glyphs,
  					  NULL, NULL, NULL);
  	run->g += num_glyphs;
  	run->count += num_glyphs;
  }
  
  
  static void
  redraw_handler(struct widget *widget, void *data)
  {
  	struct terminal *terminal = data;
  	struct rectangle allocation;
  	cairo_t *cr;
  	int top_margin, side_margin;
  	int row, col, cursor_x, cursor_y;
  	union utf8_char *p_row;
  	union decoded_attr attr;
  	int text_x, text_y;
  	cairo_surface_t *surface;
  	double d;
  	struct glyph_run run;
  	cairo_font_extents_t extents;
  	double average_width;
  	double unichar_width;
  
  	surface = window_get_surface(terminal->window);
  	widget_get_allocation(terminal->widget, &allocation);
  	cr = widget_cairo_create(terminal->widget);
  	cairo_rectangle(cr, allocation.x, allocation.y,
  			allocation.width, allocation.height);
  	cairo_clip(cr);
  	cairo_push_group(cr);
  
  	cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
  	terminal_set_color(terminal, cr, terminal->color_scheme->border);
  	cairo_paint(cr);
  
  	cairo_set_scaled_font(cr, terminal->font_normal);
  
  	extents = terminal->extents;
  	average_width = terminal->average_width;
  	side_margin = (allocation.width - terminal->width * average_width) / 2;
  	top_margin = (allocation.height - terminal->height * extents.height) / 2;
  
  	cairo_set_line_width(cr, 1.0);
  	cairo_translate(cr, allocation.x + side_margin,
  			allocation.y + top_margin);
  	/* paint the background */
  	for (row = 0; row < terminal->height; row++) {
  		p_row = terminal_get_row(terminal, row);
  		for (col = 0; col < terminal->width; col++) {
  			/* get the attributes for this character cell */
  			terminal_decode_attr(terminal, row, col, &attr);
  
  			if (attr.attr.bg == terminal->color_scheme->border)
  				continue;
  
  			if (is_wide(p_row[col]))
  				unichar_width = 2 * average_width;
  			else
  				unichar_width = average_width;
  
  			terminal_set_color(terminal, cr, attr.attr.bg);
  			cairo_move_to(cr, col * average_width,
  				      row * extents.height);
  			cairo_rel_line_to(cr, unichar_width, 0);
  			cairo_rel_line_to(cr, 0, extents.height);
  			cairo_rel_line_to(cr, -unichar_width, 0);
  			cairo_close_path(cr);
  			cairo_fill(cr);
  		}
  	}
  
  	cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
  
  	/* paint the foreground */
  	glyph_run_init(&run, terminal, cr);
  	for (row = 0; row < terminal->height; row++) {
  		p_row = terminal_get_row(terminal, row);
  		for (col = 0; col < terminal->width; col++) {
  			/* get the attributes for this character cell */
  			terminal_decode_attr(terminal, row, col, &attr);
  
  			glyph_run_flush(&run, attr);
  
  			text_x = col * average_width;
  			text_y = extents.ascent + row * extents.height;
  			if (attr.attr.a & ATTRMASK_UNDERLINE) {
  				terminal_set_color(terminal, cr, attr.attr.fg);
  				cairo_move_to(cr, text_x, (double)text_y + 1.5);
  				cairo_line_to(cr, text_x + average_width, (double) text_y + 1.5);
  				cairo_stroke(cr);
  			}
  
                          /* skip space glyph (RLE) we use as a placeholder of
                             the right half of a double-width character,
                             because RLE is not available in every font. */
  			if (p_row[col].ch == 0x200B)
  				continue;
  
  			glyph_run_add(&run, text_x, text_y, &p_row[col]);
  		}
  	}
  
  	attr.key = ~0;
  	glyph_run_flush(&run, attr);
  
  	if ((terminal->mode & MODE_SHOW_CURSOR) &&
  	    !window_has_focus(terminal->window)) {
  		d = 0.5;
  
  		cairo_set_line_width(cr, 1);
  		cairo_move_to(cr, terminal->column * average_width + d,
  			      terminal->row * extents.height + d);
  		cairo_rel_line_to(cr, average_width - 2 * d, 0);
  		cairo_rel_line_to(cr, 0, extents.height - 2 * d);
  		cairo_rel_line_to(cr, -average_width + 2 * d, 0);
  		cairo_close_path(cr);
  
  		cairo_stroke(cr);
  	}
  
  	cairo_pop_group_to_source(cr);
  	cairo_paint(cr);
  	cairo_destroy(cr);
  	cairo_surface_destroy(surface);
  
  	if (terminal->send_cursor_position) {
  		cursor_x = side_margin + allocation.x +
  				terminal->column * average_width;
  		cursor_y = top_margin + allocation.y +
  				terminal->row * extents.height;
  		window_set_text_cursor_position(terminal->window,
  						cursor_x, cursor_y);
  		terminal->send_cursor_position = 0;
  	}
  }
  
  static void
  terminal_write(struct terminal *terminal, const char *data, size_t length)
  {
  	if (write(terminal->master, data, length) < 0)
  		abort();
  	terminal->send_cursor_position = 1;
  }
  
  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->escape_flags & ESC_FLAG_WHAT) {
  		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->data_pitch);
  				attr_init(terminal_get_attr_row(terminal, i),
  				    terminal->curr_attr, terminal->width);
  			}
  			break;
  		case 5:  /* DECSCNM */
  			if (sr)	terminal->mode |=  MODE_INVERSE;
  			else	terminal->mode &= ~MODE_INVERSE;
  			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 */
  			if (sr)	terminal->mode |=  MODE_AUTOWRAP;
  			else	terminal->mode &= ~MODE_AUTOWRAP;
  			break;
  		case 8:  /* DECARM */
  			if (sr)	terminal->mode |=  MODE_AUTOREPEAT;
  			else	terminal->mode &= ~MODE_AUTOREPEAT;
  			break;
  		case 12:  /* Very visible cursor (CVVIS) */
  			/* FIXME: What do we do here. */
  			break;
  		case 25:
  			if (sr)	terminal->mode |=  MODE_SHOW_CURSOR;
  			else	terminal->mode &= ~MODE_SHOW_CURSOR;
  			break;
  		case 1034:   /* smm/rmm, meta mode on/off */
  			/* ignore */
  			break;
  		case 1037:   /* deleteSendsDel */
  			if (sr)	terminal->mode |=  MODE_DELETE_SENDS_DEL;
  			else	terminal->mode &= ~MODE_DELETE_SENDS_DEL;
  			break;
  		case 1039:   /* altSendsEscape */
  			if (sr)	terminal->mode |=  MODE_ALT_SENDS_ESC;
  			else	terminal->mode &= ~MODE_ALT_SENDS_ESC;
  			break;
  		case 1049:   /* rmcup/smcup, alternate screen */
  			/* Ignore.  Should be possible to implement,
  			 * but it's kind of annoying. */
  			break;
  		default:
  			fprintf(stderr, "Unknown parameter: ?%d\n", code);
  			break;
  		}
  	} else {
  		switch(code) {
  		case 4:  /* IRM */
  			if (sr)	terminal->mode |=  MODE_IRM;
  			else	terminal->mode &= ~MODE_IRM;
  			break;
  		case 20: /* LNM */
  			if (sr)	terminal->mode |=  MODE_LF_NEWLINE;
  			else	terminal->mode &= ~MODE_LF_NEWLINE;
  			break;
  		default:
  			fprintf(stderr, "Unknown parameter: %d\n", code);
  			break;
  		}
  	}
  }
  
  static void
  handle_dcs(struct terminal *terminal)
  {
  }
  
  static void
  handle_osc(struct terminal *terminal)
  {
  	char *p;
  	int code;
  
  	terminal->escape[terminal->escape_length++] = '\0';
  	p = &terminal->escape[2];
  	code = strtol(p, &p, 10);
  	if (*p == ';') p++;
  
  	switch (code) {
  	case 0: /* Icon name and window title */
  	case 1: /* Icon label */
  	case 2: /* Window title*/
  		free(terminal->title);
  		terminal->title = strdup(p);
  		window_set_title(terminal->window, p);
  		break;
  	case 7: /* shell cwd as uri */
  		break;
  	case 777: /* Desktop notifications */
  		break;
  	default:
  		fprintf(stderr, "Unknown OSC escape code %d, text %s\n",
  			code, p);
  		break;
  	}
  }
  
  static void
  handle_escape(struct terminal *terminal)
  {
  	union utf8_char *row;
  	struct attr *attr_row;
  	char *p;
  	int i, count, x, y, top, bottom;
  	int args[10], set[10] = { 0, };
  	char response[MAX_RESPONSE] = {0, };
  	struct rectangle allocation;
  
  	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 - Insert <count> blank characters */
  		count = set[0] ? args[0] : 1;
  		if (count == 0) count = 1;
  		terminal_shift_line(terminal, count);
  		break;
  	case 'A':    /* CUU - Move cursor up <count> rows */
  		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 - Move cursor down <count> rows */
  		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 - Move cursor right by <count> columns */
  		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 - Move cursor left <count> columns */
  		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 - Move cursor down <count> rows, to column 1 */
  		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 - Move cursour up <count> rows, to column 1 */
  		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 - Move cursor to column <y> in current row */
  		y = set[0] ? args[0] : 1;
  		y = y <= 0 ? 1 : y > terminal->width ? terminal->width : y;
  
  		terminal->column = y - 1;
  		break;
  	case 'f':    /* HVP - Move cursor to <x, y> */
  	case 'H':    /* CUP - Move cursor to <x, y> (origin at 1,1) */
  		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 - Erase display */
  		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) * sizeof(union utf8_char));
  			attr_init(&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->data_pitch);
  				attr_init(terminal_get_attr_row(terminal, i),
  				    terminal->curr_attr, terminal->width);
  			}
  		} else if (args[0] == 1) {
  			memset(row, 0, (terminal->column+1) * sizeof(union utf8_char));
  			attr_init(attr_row, terminal->curr_attr, terminal->column+1);
  			for (i = 0; i < terminal->row; i++) {
  				memset(terminal_get_row(terminal, i),
  				    0, terminal->data_pitch);
  				attr_init(terminal_get_attr_row(terminal, i),
  				    terminal->curr_attr, terminal->width);
  			}
  		} else if (args[0] == 2) {
  			/* Clear screen by scrolling contents out */
  			terminal_scroll_buffer(terminal,
  					       terminal->end - terminal->start);
  		}
  		break;
  	case 'K':    /* EL - Erase line */
  		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) * sizeof(union utf8_char));
  			attr_init(&attr_row[terminal->column], terminal->curr_attr,
  			    terminal->width - terminal->column);
  		} else if (args[0] == 1) {
  			memset(row, 0, (terminal->column+1) * sizeof(union utf8_char));
  			attr_init(attr_row, terminal->curr_attr, terminal->column+1);
  		} else if (args[0] == 2) {
  			memset(row, 0, terminal->data_pitch);
  			attr_init(attr_row, terminal->curr_attr, terminal->width);
  		}
  		break;
  	case 'L':    /* IL - Insert <count> blank lines */
  		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->data_pitch);
  			attr_init(terminal_get_attr_row(terminal, terminal->row),
  				terminal->curr_attr, terminal->width);
  		}
  		break;
  	case 'M':    /* DL - Delete <count> lines */
  		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->data_pitch);
  		}
  		break;
  	case 'P':    /* DCH - Delete <count> characters on current line */
  		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 - Erase <count> characters on current line */
  		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 * sizeof(union utf8_char));
  		attr_init(&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 - Move cursor to <y> column in current row */
  		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 - Answer "I am a VT102" */
  		terminal_write(terminal, "\e[?6c", 5);
  		break;
  	case 'd':    /* VPA - Move cursor to <x> row, current column */
  		x = set[0] ? args[0] : 1;
  		x = x <= 0 ? 1 : x > terminal->height ? terminal->height : x;
  
  		terminal->row = x - 1;
  		break;
  	case 'g':    /* TBC - Clear tab stop(s) */
  		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 - Set mode */
  		for (i = 0; i < 10 && set[i]; i++) {
  			handle_term_parameter(terminal, args[i], 1);
  		}
  		break;
  	case 'l':    /* RM - Reset mode */
  		for (i = 0; i < 10 && set[i]; i++) {
  			handle_term_parameter(terminal, args[i], 0);
  		}
  		break;
  	case 'm':    /* SGR - Set attributes */
  		for (i = 0; i < 10; i++) {
  			if (i <= 7 && set[i] && set[i + 1] &&
  				set[i + 2] && args[i + 1] == 5)
  			{
  				if (args[i] == 38) {
  					handle_sgr(terminal, args[i + 2] + 256);
  					break;
  				} else if (args[i] == 48) {
  					handle_sgr(terminal, args[i + 2] + 512);
  					break;
  				}
  			}
  			if (set[i]) {
  				handle_sgr(terminal, args[i]);
  			} else if (i == 0) {
  				handle_sgr(terminal, 0);
  				break;
  			} else {
  				break;
  			}
  		}
  		break;
  	case 'n':    /* DSR - Status report */
  		i = set[0] ? args[0] : 0;
  		if (i == 0 || i == 5) {
  			terminal_write(terminal, "\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);
  			terminal_write(terminal, response, strlen(response));
  		}
   		break;
  	case 'r':    /* DECSTBM - Set scrolling region */
  		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':    /* Save cursor location */
  		terminal->saved_row = terminal->row;
  		terminal->saved_column = terminal->column;
  		break;
  	case 't':    /* windowOps */
  		if (!set[0]) break;
  		switch (args[0]) {
  		case 4:  /* resize px */
  			if (set[1] && set[2]) {
  				widget_schedule_resize(terminal->widget,
  						       args[2], args[1]);
  			}
  			break;
  		case 8:  /* resize ch */
  			if (set[1] && set[2]) {
  				terminal_resize(terminal, args[2], args[1]);
  			}
  			break;
  		case 13: /* report position */
  			widget_get_allocation(terminal->widget, &allocation);
  			snprintf(response, MAX_RESPONSE, "\e[3;%d;%dt",
  				 allocation.x, allocation.y);
  			terminal_write(terminal, response, strlen(response));
  			break;
  		case 14: /* report px */
  			widget_get_allocation(terminal->widget, &allocation);
  			snprintf(response, MAX_RESPONSE, "\e[4;%d;%dt",
  				 allocation.height, allocation.width);
  			terminal_write(terminal, response, strlen(response));
  			break;
  		case 18: /* report ch */
  			snprintf(response, MAX_RESPONSE, "\e[9;%d;%dt",
  				 terminal->height, terminal->width);
  			terminal_write(terminal, response, strlen(response));
  			break;
  		case 21: /* report title */
  			snprintf(response, MAX_RESPONSE, "\e]l%s\e\\",
  				 window_get_title(terminal->window));
  			terminal_write(terminal, response, strlen(response));
  			break;
  		default:
  			if (args[0] >= 24)
  				terminal_resize(terminal, terminal->width, args[0]);
  			else
  				fprintf(stderr, "Unimplemented windowOp %d\n", args[0]);
  			break;
  		}
  		break;
  	case 'u':    /* Restore cursor location */
  		terminal->row = terminal->saved_row;
  		terminal->column = terminal->saved_column;
  		break;
  	default:
  		fprintf(stderr, "Unknown CSI escape: %c\n", *p);
  		break;
  	}
  }
  
  static void
  handle_non_csi_escape(struct terminal *terminal, char code)
  {
  	switch(code) {
  	case 'M':    /* RI - Reverse linefeed */
  		terminal->row -= 1;
  		if (terminal->row < terminal->margin_top) {
  			terminal->row = terminal->margin_top;
  			terminal_scroll(terminal, -1);
  		}
  		break;
  	case 'E':    /* NEL - Newline */
  		terminal->column = 0;
  		// fallthrough
  	case 'D':    /* IND - Linefeed */
  		terminal->row += 1;
  		if (terminal->row > terminal->margin_bottom) {
  			terminal->row = terminal->margin_bottom;
  			terminal_scroll(terminal, +1);
  		}
  		break;
  	case 'c':    /* RIS - Reset*/
  		terminal_init(terminal);
  		break;
  	case 'H':    /* HTS - Set tab stop at current column */
  		terminal->tab_ruler[terminal->column] = 1;
  		break;
  	case '7':    /* DECSC - Save current state */
  		terminal->saved_row = terminal->row;
  		terminal->saved_column = terminal->column;
  		terminal->saved_attr = terminal->curr_attr;
  		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 - Restore state most recently saved by ESC 7 */
  		terminal->row = terminal->saved_row;
  		terminal->column = terminal->saved_column;
  		terminal->curr_attr = terminal->saved_attr;
  		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 - Set application keypad mode */
  		terminal->key_mode = KM_APPLICATION;
  		break;
  	case '>':    /* DECPNM - Set numeric keypad mode */
  		terminal->key_mode = KM_NORMAL;
  		break;
  	default:
  		fprintf(stderr, "Unknown escape code: %c\n", code);
  		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->data_pitch * terminal->height);
  			numChars = terminal->width * terminal->height;
  			for (i = 0; i < numChars; i++) {
  				terminal->data[i].byte[0] = 'E';
  			}
  			break;
  		default:
  			fprintf(stderr, "Unknown HASH escape #%c\n", code);
  			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:
  			fprintf(stderr, "Unknown character set %c\n", code);
  			break;
  		}
  	} else {
  		fprintf(stderr, "Unknown special escape %c%c\n", special, code);
  	}
  }
  
  static void
  handle_sgr(struct terminal *terminal, int code)
  {
  	switch(code) {
  	case 0:
  		terminal->curr_attr = terminal->color_scheme->default_attr;
  		break;
  	case 1:
  		terminal->curr_attr.a |= ATTRMASK_BOLD;
  		if (terminal->curr_attr.fg < 8)
  			terminal->curr_attr.fg += 8;
  		break;
  	case 4:
  		terminal->curr_attr.a |= ATTRMASK_UNDERLINE;
  		break;
  	case 5:
  		terminal->curr_attr.a |= ATTRMASK_BLINK;
  		break;
  	case 8:
  		terminal->curr_attr.a |= ATTRMASK_CONCEALED;
  		break;
  	case 2:
  	case 21:
  	case 22:
  		terminal->curr_attr.a &= ~ATTRMASK_BOLD;
  		if (terminal->curr_attr.fg < 16 && terminal->curr_attr.fg >= 8)
  			terminal->curr_attr.fg -= 8;
  		break;
  	case 24:
  		terminal->curr_attr.a &= ~ATTRMASK_UNDERLINE;
  		break;
  	case 25:
  		terminal->curr_attr.a &= ~ATTRMASK_BLINK;
  		break;
  	case 7:
  	case 26:
  		terminal->curr_attr.a |= ATTRMASK_INVERSE;
  		break;
  	case 27:
  		terminal->curr_attr.a &= ~ATTRMASK_INVERSE;
  		break;
  	case 28:
  		terminal->curr_attr.a &= ~ATTRMASK_CONCEALED;
  		break;
  	case 39:
  		terminal->curr_attr.fg = terminal->color_scheme->default_attr.fg;
  		break;
  	case 49:
  		terminal->curr_attr.bg = terminal->color_scheme->default_attr.bg;
  		break;
  	default:
  		if (code >= 30 && code <= 37) {
  			terminal->curr_attr.fg = code - 30;
  			if (terminal->curr_attr.a & ATTRMASK_BOLD)
  				terminal->curr_attr.fg += 8;
  		} else if (code >= 40 && code <= 47) {
  			terminal->curr_attr.bg = code - 40;
  		} else if (code >= 90 && code <= 97) {
  			terminal->curr_attr.fg = code - 90 + 8;
  		} else if (code >= 100 && code <= 107) {
  			terminal->curr_attr.bg = code - 100 + 8;
  		} else if (code >= 256 && code < 512) {
  			terminal->curr_attr.fg = code - 256;
  		} else if (code >= 512 && code < 768) {
  			terminal->curr_attr.bg = code - 512;
  		} else {
  			fprintf(stderr, "Unknown SGR code: %d\n", code);
  		}
  		break;
  	}
  }
  
  /* Returns 1 if c was special, otherwise 0 */
  static int
  handle_special_char(struct terminal *terminal, char c)
  {
  	union utf8_char *row;
  	struct attr *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->mode & MODE_LF_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->mode & MODE_IRM)
  				terminal_shift_line(terminal, +1);
  
  			if (row[terminal->column].byte[0] == '\0') {
  				row[terminal->column].byte[0] = ' ';
  				row[terminal->column].byte[1] = '\0';
  				attr_row[terminal->column] = terminal->curr_attr;
  			}
  
  			terminal->column++;
  			if (terminal->tab_ruler[terminal->column]) break;
  		}
  		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->mode & MODE_AUTOWRAP) {
  			terminal->column = terminal->width - 1;
  			terminal->row -= 1;
  			if (terminal->row < terminal->margin_top) {
  				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;
  	case '\0':
  		break;
  	default:
  		return 0;
  	}
  
  	return 1;
  }
  
  static void
  handle_char(struct terminal *terminal, union utf8_char utf8)
  {
  	union utf8_char *row;
  	struct attr *attr_row;
  
  	if (handle_special_char(terminal, utf8.byte[0])) return;
  
  	apply_char_set(terminal->cs, &utf8);
  
  	/* 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->mode & MODE_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->mode & MODE_IRM)
  		terminal_shift_line(terminal, +1);
  	row[terminal->column] = utf8;
  	attr_row[terminal->column++] = terminal->curr_attr;
  
  	if (terminal->row + terminal->start + 1 > terminal->end)
  		terminal->end = terminal->row + terminal->start + 1;
  	if (terminal->end == terminal->buffer_height)
  		terminal->log_size = terminal->buffer_height;
  	else if (terminal->log_size < terminal->buffer_height)
  		terminal->log_size = terminal->end;
  
  	/* cursor jump for wide character. */
  	if (is_wide(utf8))
  		row[terminal->column++].ch = 0x200B; /* space glyph */
  
  	if (utf8.ch != terminal->last_char.ch)
  		terminal->last_char = utf8;
  }
  
  static void
  escape_append_utf8(struct terminal *terminal, union utf8_char utf8)
  {
  	int len, i;
  
  	if ((utf8.byte[0] & 0x80) == 0x00)       len = 1;
  	else if ((utf8.byte[0] & 0xE0) == 0xC0)  len = 2;
  	else if ((utf8.byte[0] & 0xF0) == 0xE0)  len = 3;
  	else if ((utf8.byte[0] & 0xF8) == 0xF0)  len = 4;
  	else                                     len = 1;  /* Invalid, cannot happen */
  
  	if (terminal->escape_length + len <= MAX_ESCAPE) {
  		for (i = 0; i < len; i++)
  			terminal->escape[terminal->escape_length + i] = utf8.byte[i];
  		terminal->escape_length += len;
  	} else if (terminal->escape_length < MAX_ESCAPE) {
  		terminal->escape[terminal->escape_length++] = 0;
  	}
  }
  
  static void
  terminal_data(struct terminal *terminal, const char *data, size_t length)
  {
  	unsigned 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:
  			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 */
  		switch (terminal->state) {
  		case escape_state_escape:
  			escape_append_utf8(terminal, utf8);
  			switch (utf8.byte[0]) {
  			case 'P':  /* DCS */
  				terminal->state = escape_state_dcs;
  				break;
  			case '[':  /* CSI */
  				terminal->state = escape_state_csi;
  				break;
  			case ']':  /* OSC */
  				terminal->state = escape_state_osc;
  				break;
  			case '#':
  			case '(':
  			case ')':  /* special */
  				terminal->state = escape_state_special;
  				break;
  			case '^':  /* PM (not implemented) */
  			case '_':  /* APC (not implemented) */
  				terminal->state = escape_state_ignore;
  				break;
  			default:
  				terminal->state = escape_state_normal;
  				handle_non_csi_escape(terminal, utf8.byte[0]);
  				break;
  			}
  			continue;
  		case escape_state_csi:
  			if (handle_special_char(terminal, utf8.byte[0]) != 0) {
  				/* do nothing */
  			} else if (utf8.byte[0] == '?') {
  				terminal->escape_flags |= ESC_FLAG_WHAT;
  			} else if (utf8.byte[0] == '>') {
  				terminal->escape_flags |= ESC_FLAG_GT;
  			} else if (utf8.byte[0] == '!') {
  				terminal->escape_flags |= ESC_FLAG_BANG;
  			} else if (utf8.byte[0] == '$') {
  				terminal->escape_flags |= ESC_FLAG_CASH;
  			} else if (utf8.byte[0] == '\'') {
  				terminal->escape_flags |= ESC_FLAG_SQUOTE;
  			} else if (utf8.byte[0] == '"') {
  				terminal->escape_flags |= ESC_FLAG_DQUOTE;
  			} else if (utf8.byte[0] == ' ') {
  				terminal->escape_flags |= ESC_FLAG_SPACE;
  			} else {
  				escape_append_utf8(terminal, utf8);
  				if (terminal->escape_length >= MAX_ESCAPE)
  					terminal->state = escape_state_normal;
  			}
  
  			if (isalpha(utf8.byte[0]) || utf8.byte[0] == '@' ||
  				utf8.byte[0] == '`')
  			{
  				terminal->state = escape_state_normal;
  				handle_escape(terminal);
  			} else {
  			}
  			continue;
  		case escape_state_inner_escape:
  			if (utf8.byte[0] == '\\') {
  				terminal->state = escape_state_normal;
  				if (terminal->outer_state == escape_state_dcs) {
  					handle_dcs(terminal);
  				} else if (terminal->outer_state == escape_state_osc) {
  					handle_osc(terminal);
  				}
  			} else if (utf8.byte[0] == '\e') {
  				terminal->state = terminal->outer_state;
  				escape_append_utf8(terminal, utf8);
  				if (terminal->escape_length >= MAX_ESCAPE)
  					terminal->state = escape_state_normal;
  			} else {
  				terminal->state = terminal->outer_state;
  				if (terminal->escape_length < MAX_ESCAPE)
  					terminal->escape[terminal->escape_length++] = '\e';
  				escape_append_utf8(terminal, utf8);
  				if (terminal->escape_length >= MAX_ESCAPE)
  					terminal->state = escape_state_normal;
  			}
  			continue;
  		case escape_state_dcs:
  		case escape_state_osc:
  		case escape_state_ignore:
  			if (utf8.byte[0] == '\e') {
  				terminal->outer_state = terminal->state;
  				terminal->state = escape_state_inner_escape;
  			} else if (utf8.byte[0] == '\a' && terminal->state == escape_state_osc) {
  				terminal->state = escape_state_normal;
  				handle_osc(terminal);
  			} else {
  				escape_append_utf8(terminal, utf8);
  				if (terminal->escape_length >= MAX_ESCAPE)
  					terminal->state = escape_state_normal;
  			}
  			continue;
  		case escape_state_special:
  			escape_append_utf8(terminal, utf8);
  			terminal->state = escape_state_normal;
  			if (isdigit(utf8.byte[0]) || isalpha(utf8.byte[0])) {
  				handle_special_escape(terminal, terminal->escape[1],
  				                      utf8.byte[0]);
  			}
  			continue;
  		default:
  			break;
  		}
  
  		/* this is valid, because ASCII characters are never used to
  		 * introduce a multibyte sequence in UTF-8 */
  		if (utf8.byte[0] == '\e') {
  			terminal->state = escape_state_escape;
  			terminal->outer_state = escape_state_normal;
  			terminal->escape[0] = '\e';
  			terminal->escape_length = 1;
  			terminal->escape_flags = 0;
  		} else {
  			handle_char(terminal, utf8);
  		} /* if */
  	} /* for */
  
  	window_schedule_redraw(terminal->window);
  }
  
  static void
  data_source_target(void *data,
  		   struct wl_data_source *source, const char *mime_type)
  {
  	fprintf(stderr, "data_source_target, %s\n", mime_type);
  }
  
  static void
  data_source_send(void *data,
  		 struct wl_data_source *source,
  		 const char *mime_type, int32_t fd)
  {
  	struct terminal *terminal = data;
  
  	terminal_send_selection(terminal, fd);
  }
  
  static void
  data_source_cancelled(void *data, struct wl_data_source *source)
  {
  	wl_data_source_destroy(source);
  }
  
  static void
  data_source_dnd_drop_performed(void *data, struct wl_data_source *source)
  {
  }
  
  static void
  data_source_dnd_finished(void *data, struct wl_data_source *source)
  {
  }
  
  static void
  data_source_action(void *data,
  		   struct wl_data_source *source, uint32_t dnd_action)
  {
  }
  
  static const struct wl_data_source_listener data_source_listener = {
  	data_source_target,
  	data_source_send,
  	data_source_cancelled,
  	data_source_dnd_drop_performed,
  	data_source_dnd_finished,
  	data_source_action
  };
  
  static const char text_mime_type[] = "text/plain;charset=utf-8";
  
  static void
  data_handler(struct window *window,
  	     struct input *input,
  	     float x, float y, const char **types, void *data)
  {
  	int i, has_text = 0;
  
  	if (!types)
  		return;
  	for (i = 0; types[i]; i++)
  		if (strcmp(types[i], text_mime_type) == 0)
  			has_text = 1;
  
  	if (!has_text) {
  		input_accept(input, NULL);
  	} else {
  		input_accept(input, text_mime_type);
  	}
  }
  
  static void
  drop_handler(struct window *window, struct input *input,
  	     int32_t x, int32_t y, void *data)
  {
  	struct terminal *terminal = data;
  
  	input_receive_drag_data_to_fd(input, text_mime_type, terminal->master);
  }
  
  static void
  fullscreen_handler(struct window *window, void *data)
  {
  	struct terminal *terminal = data;
  
  	window_set_fullscreen(window, !window_is_fullscreen(terminal->window));
  }
  
  static void
  close_handler(void *data)
  {
  	struct terminal *terminal = data;
  
  	terminal_destroy(terminal);
  }
  
  static void
  terminal_copy(struct terminal *terminal, struct input *input)
  {
  	terminal->selection =
  		display_create_data_source(terminal->display);
  	if (!terminal->selection)
  		return;
  
  	wl_data_source_offer(terminal->selection,
  			     "text/plain;charset=utf-8");
  	wl_data_source_add_listener(terminal->selection,
  				    &data_source_listener, terminal);
  	input_set_selection(input, terminal->selection,
  			    display_get_serial(terminal->display));
  }
  
  static void
  terminal_paste(struct terminal *terminal, struct input *input)
  {
  	input_receive_selection_data_to_fd(input,
  					   "text/plain;charset=utf-8",
  					   terminal->master);
  
  }
  
  static void
  terminal_new_instance(struct terminal *terminal)
  {
  	struct terminal *new_terminal;
  
  	new_terminal = terminal_create(terminal->display);
  	if (terminal_run(new_terminal, option_shell))
  		terminal_destroy(new_terminal);
  }
  
  static int
  handle_bound_key(struct terminal *terminal,
  		 struct input *input, uint32_t sym, uint32_t time)
  {
  	switch (sym) {
  	case XKB_KEY_X:
  		/* Cut selection; terminal doesn't do cut, fall
  		 * through to copy. */
  	case XKB_KEY_C:
  		terminal_copy(terminal, input);
  		return 1;
  	case XKB_KEY_V:
  		terminal_paste(terminal, input);
  		return 1;
  	case XKB_KEY_N:
  		terminal_new_instance(terminal);
  		return 1;
  
  	case XKB_KEY_Up:
  		if (!terminal->scrolling)
  			terminal->saved_start = terminal->start;
  		if (terminal->start == terminal->end - terminal->log_size)
  			return 1;
  
  		terminal->scrolling = 1;
  		terminal->start--;
  		terminal->row++;
  		terminal->selection_start_row++;
  		terminal->selection_end_row++;
  		widget_schedule_redraw(terminal->widget);
  		return 1;
  
  	case XKB_KEY_Down:
  		if (!terminal->scrolling)
  			terminal->saved_start = terminal->start;
  
  		if (terminal->start == terminal->saved_start)
  			return 1;
  
  		terminal->scrolling = 1;
  		terminal->start++;
  		terminal->row--;
  		terminal->selection_start_row--;
  		terminal->selection_end_row--;
  		widget_schedule_redraw(terminal->widget);
  		return 1;
  
  	default:
  		return 0;
  	}
  }
  
  static void
  key_handler(struct window *window, struct input *input, uint32_t time,
  	    uint32_t key, uint32_t sym, enum wl_keyboard_key_state state,
  	    void *data)
  {
  	struct terminal *terminal = data;
  	char ch[MAX_RESPONSE];
  	uint32_t modifiers, serial;
  	int ret, len = 0, d;
  	bool convert_utf8 = true;
  
  	modifiers = input_get_modifiers(input);
  	if ((modifiers & MOD_CONTROL_MASK) &&
  	    (modifiers & MOD_SHIFT_MASK) &&
  	    state == WL_KEYBOARD_KEY_STATE_PRESSED &&
  	    handle_bound_key(terminal, input, sym, time))
  		return;
  
  	/* Map keypad symbols to 'normal' equivalents before processing */
  	switch (sym) {
  	case XKB_KEY_KP_Space:
  		sym = XKB_KEY_space;
  		break;
  	case XKB_KEY_KP_Tab:
  		sym = XKB_KEY_Tab;
  		break;
  	case XKB_KEY_KP_Enter:
  		sym = XKB_KEY_Return;
  		break;
  	case XKB_KEY_KP_Left:
  		sym = XKB_KEY_Left;
  		break;
  	case XKB_KEY_KP_Up:
  		sym = XKB_KEY_Up;
  		break;
  	case XKB_KEY_KP_Right:
  		sym = XKB_KEY_Right;
  		break;
  	case XKB_KEY_KP_Down:
  		sym = XKB_KEY_Down;
  		break;
  	case XKB_KEY_KP_Equal:
  		sym = XKB_KEY_equal;
  		break;
  	case XKB_KEY_KP_Multiply:
  		sym = XKB_KEY_asterisk;
  		break;
  	case XKB_KEY_KP_Add:
  		sym = XKB_KEY_plus;
  		break;
  	case XKB_KEY_KP_Separator:
  		/* Note this is actually locale-dependent and should mostly be
  		 * a comma.  But leave it as period until we one day start
  		 * doing the right thing. */
  		sym = XKB_KEY_period;
  		break;
  	case XKB_KEY_KP_Subtract:
  		sym = XKB_KEY_minus;
  		break;
  	case XKB_KEY_KP_Decimal:
  		sym = XKB_KEY_period;
  		break;
  	case XKB_KEY_KP_Divide:
  		sym = XKB_KEY_slash;
  		break;
  	case XKB_KEY_KP_0:
  	case XKB_KEY_KP_1:
  	case XKB_KEY_KP_2:
  	case XKB_KEY_KP_3:
  	case XKB_KEY_KP_4:
  	case XKB_KEY_KP_5:
  	case XKB_KEY_KP_6:
  	case XKB_KEY_KP_7:
  	case XKB_KEY_KP_8:
  	case XKB_KEY_KP_9:
  		sym = (sym - XKB_KEY_KP_0) + XKB_KEY_0;
  		break;
  	default:
  		break;
  	}
  
  	switch (sym) {
  	case XKB_KEY_BackSpace:
  		if (modifiers & MOD_ALT_MASK)
  			ch[len++] = 0x1b;
  		ch[len++] = 0x7f;
  		break;
  	case XKB_KEY_Tab:
  	case XKB_KEY_Linefeed:
  	case XKB_KEY_Clear:
  	case XKB_KEY_Pause:
  	case XKB_KEY_Scroll_Lock:
  	case XKB_KEY_Sys_Req:
  	case XKB_KEY_Escape:
  		ch[len++] = sym & 0x7f;
  		break;
  
  	case XKB_KEY_Return:
  		if (terminal->mode & MODE_LF_NEWLINE) {
  			ch[len++] = 0x0D;
  			ch[len++] = 0x0A;
  		} else {
  			ch[len++] = 0x0D;
  		}
  		break;
  
  	case XKB_KEY_Shift_L:
  	case XKB_KEY_Shift_R:
  	case XKB_KEY_Control_L:
  	case XKB_KEY_Control_R:
  	case XKB_KEY_Alt_L:
  	case XKB_KEY_Alt_R:
  	case XKB_KEY_Meta_L:
  	case XKB_KEY_Meta_R:
  	case XKB_KEY_Super_L:
  	case XKB_KEY_Super_R:
  	case XKB_KEY_Hyper_L:
  	case XKB_KEY_Hyper_R:
  		break;
  
  	case XKB_KEY_Insert:
  		len = function_key_response('[', 2, modifiers, '~', ch);
  		break;
  	case XKB_KEY_Delete:
  		if (terminal->mode & MODE_DELETE_SENDS_DEL) {
  			ch[len++] = '\x04';
  		} else {
  			len = function_key_response('[', 3, modifiers, '~', ch);
  		}
  		break;
  	case XKB_KEY_Page_Up:
  		len = function_key_response('[', 5, modifiers, '~', ch);
  		break;
  	case XKB_KEY_Page_Down:
  		len = function_key_response('[', 6, modifiers, '~', ch);
  		break;
  	case XKB_KEY_F1:
  		len = function_key_response('O', 1, modifiers, 'P', ch);
  		break;
  	case XKB_KEY_F2:
  		len = function_key_response('O', 1, modifiers, 'Q', ch);
  		break;
  	case XKB_KEY_F3:
  		len = function_key_response('O', 1, modifiers, 'R', ch);
  		break;
  	case XKB_KEY_F4:
  		len = function_key_response('O', 1, modifiers, 'S', ch);
  		break;
  	case XKB_KEY_F5:
  		len = function_key_response('[', 15, modifiers, '~', ch);
  		break;
  	case XKB_KEY_F6:
  		len = function_key_response('[', 17, modifiers, '~', ch);
  		break;
  	case XKB_KEY_F7:
  		len = function_key_response('[', 18, modifiers, '~', ch);
  		break;
  	case XKB_KEY_F8:
  		len = function_key_response('[', 19, modifiers, '~', ch);
  		break;
  	case XKB_KEY_F9:
  		len = function_key_response('[', 20, modifiers, '~', ch);
  		break;
  	case XKB_KEY_F10:
  		len = function_key_response('[', 21, modifiers, '~', ch);
  		break;
  	case XKB_KEY_F12:
  		len = function_key_response('[', 24, modifiers, '~', ch);
  		break;
  	default:
  		/* Handle special keys with alternate mappings */
  		len = apply_key_map(terminal->key_mode, sym, modifiers, ch);
  		if (len != 0) break;
  
  		if (modifiers & MOD_CONTROL_MASK) {
  			if (sym >= '3' && sym <= '7')
  				sym = (sym & 0x1f) + 8;
  
  			if (!((sym >= '!' && sym <= '/') ||
  				(sym >= '8' && sym <= '?') ||
  				(sym >= '0' && sym <= '2'))) sym = sym & 0x1f;
  			else if (sym == '2') sym = 0x00;
  			else if (sym == '/') sym = 0x1F;
  			else if (sym == '8' || sym == '?') sym = 0x7F;
  		}
  		if (modifiers & MOD_ALT_MASK) {
  			if (terminal->mode & MODE_ALT_SENDS_ESC) {
  				ch[len++] = 0x1b;
  			} else {
  				sym = sym | 0x80;
  				convert_utf8 = false;
  			}
  		}
  
  		if ((sym < 128) ||
  		    (!convert_utf8 && sym < 256)) {
  			ch[len++] = sym;
  		} else {
  			ret = xkb_keysym_to_utf8(sym, ch + len,
  						 MAX_RESPONSE - len);
  			if (ret < 0)
  				fprintf(stderr,
  					"Warning: buffer too small to encode "
  					"UTF8 character\n");
  			else
  				len += ret;
  		}
  
  		break;
  	}
  
  	if (state == WL_KEYBOARD_KEY_STATE_PRESSED && len > 0) {
  		if (terminal->scrolling) {
  			d = terminal->saved_start - terminal->start;
  			terminal->row -= d;
  			terminal->selection_start_row -= d;
  			terminal->selection_end_row -= d;
  			terminal->start = terminal->saved_start;
  			terminal->scrolling = 0;
  			widget_schedule_redraw(terminal->widget);
  		}
  
  		terminal_write(terminal, ch, len);
  
  		/* Hide cursor, except if this was coming from a
  		 * repeating key press. */
  		serial = display_get_serial(terminal->display);
  		if (terminal->hide_cursor_serial != serial) {
  			input_set_pointer_image(input, CURSOR_BLANK);
  			terminal->hide_cursor_serial = serial;
  		}
  	}
  }
  
  static void
  keyboard_focus_handler(struct window *window,
  		       struct input *device, void *data)
  {
  	struct terminal *terminal = data;
  
  	window_schedule_redraw(terminal->window);
  }
  
  static int wordsep(int ch)
  {
  	const char extra[] = "-,./?%&#:_=+@~";
  
  	if (ch > 127 || ch < 0)
  		return 1;
  
  	return ch == 0 || !(isalpha(ch) || isdigit(ch) || strchr(extra, ch));
  }
  
  static int
  recompute_selection(struct terminal *terminal)
  {
  	struct rectangle allocation;
  	int col, x, width, height;
  	int start_row, end_row;
  	int word_start, eol;
  	int side_margin, top_margin;
  	int start_x, end_x;
  	int cw, ch;
  	union utf8_char *data = NULL;
  
  	cw = terminal->average_width;
  	ch = terminal->extents.height;
  	widget_get_allocation(terminal->widget, &allocation);
  	width = terminal->width * cw;
  	height = terminal->height * ch;
  	side_margin = allocation.x + (allocation.width - width) / 2;
  	top_margin = allocation.y + (allocation.height - height) / 2;
  
  	start_row = (terminal->selection_start_y - top_margin + ch) / ch - 1;
  	end_row = (terminal->selection_end_y - top_margin + ch) / ch - 1;
  
  	if (start_row < end_row ||
  	    (start_row == end_row &&
  	     terminal->selection_start_x < terminal->selection_end_x)) {
  		terminal->selection_start_row = start_row;
  		terminal->selection_end_row = end_row;
  		start_x = terminal->selection_start_x;
  		end_x = terminal->selection_end_x;
  	} else {
  		terminal->selection_start_row = end_row;
  		terminal->selection_end_row = start_row;
  		start_x = terminal->selection_end_x;
  		end_x = terminal->selection_start_x;
  	}
  
  	eol = 0;
  	if (terminal->selection_start_row < 0) {
  		terminal->selection_start_row = 0;
  		terminal->selection_start_col = 0;
  	} else {
  		x = side_margin + cw / 2;
  		data = terminal_get_row(terminal,
  					terminal->selection_start_row);
  		word_start = 0;
  		for (col = 0; col < terminal->width; col++, x += cw) {
  			if (col == 0 || wordsep(data[col - 1].ch))
  				word_start = col;
  			if (data[col].ch != 0)
  				eol = col + 1;
  			if (start_x < x)
  				break;
  		}
  
  		switch (terminal->dragging) {
  		case SELECT_LINE:
  			terminal->selection_start_col = 0;
  			break;
  		case SELECT_WORD:
  			terminal->selection_start_col = word_start;
  			break;
  		case SELECT_CHAR:
  			terminal->selection_start_col = col;
  			break;
  		}
  	}
  
  	if (terminal->selection_end_row >= terminal->height) {
  		terminal->selection_end_row = terminal->height;
  		terminal->selection_end_col = 0;
  	} else {
  		x = side_margin + cw / 2;
  		data = terminal_get_row(terminal, terminal->selection_end_row);
  		for (col = 0; col < terminal->width; col++, x += cw) {
  			if (terminal->dragging == SELECT_CHAR && end_x < x)
  				break;
  			if (terminal->dragging == SELECT_WORD &&
  			    end_x < x && wordsep(data[col].ch))
  				break;
  		}
  		terminal->selection_end_col = col;
  	}
  
  	if (terminal->selection_end_col != terminal->selection_start_col ||
  	    terminal->selection_start_row != terminal->selection_end_row) {
  		col = terminal->selection_end_col;
  		if (col > 0 && data[col - 1].ch == 0)
  			terminal->selection_end_col = terminal->width;
  		data = terminal_get_row(terminal, terminal->selection_start_row);
  		if (data[terminal->selection_start_col].ch == 0)
  			terminal->selection_start_col = eol;
  	}
  
  	return 1;
  }
  
  static void
  terminal_minimize(struct terminal *terminal)
  {
  	window_set_minimized(terminal->window);
  }
  
  static void
  menu_func(void *data, struct input *input, int index)
  {
  	struct window *window = data;
  	struct terminal *terminal = window_get_user_data(window);
  
  	fprintf(stderr, "picked entry %d\n", index);
  
  	switch (index) {
  	case 0:
  		terminal_new_instance(terminal);
  		break;
  	case 1:
  		terminal_copy(terminal, input);
  		break;
  	case 2:
  		terminal_paste(terminal, input);
  		break;
  	case 3:
  		terminal_minimize(terminal);
  		break;
  	}
  }
  
  static void
  show_menu(struct terminal *terminal, struct input *input, uint32_t time)
  {
  	int32_t x, y;
  	static const char *entries[] = {
  		"Open Terminal", "Copy", "Paste", "Minimize"
  	};
  
  	input_get_position(input, &x, &y);
  	window_show_menu(terminal->display, input, time, terminal->window,
  			 x - 10, y - 10, menu_func,
  			 entries, ARRAY_LENGTH(entries));
  }
  
  static void
  click_handler(struct widget *widget, struct terminal *terminal,
  		struct input *input, int32_t x, int32_t y,
  		uint32_t time)
  {
  	if (time - terminal->click_time < 500)
  		terminal->click_count++;
  	else
  		terminal->click_count = 1;
  
  	terminal->click_time = time;
  	terminal->dragging = (terminal->click_count - 1) % 3 + SELECT_CHAR;
  
  	terminal->selection_end_x = terminal->selection_start_x = x;
  	terminal->selection_end_y = terminal->selection_start_y = y;
  	if (recompute_selection(terminal))
  			widget_schedule_redraw(widget);
  }
  
  static void
  button_handler(struct widget *widget,
  	       struct input *input, uint32_t time,
  	       uint32_t button,
  	       enum wl_pointer_button_state state, void *data)
  {
  	struct terminal *terminal = data;
  	int32_t x, y;
  
  	switch (button) {
  	case BTN_LEFT:
  		if (state == WL_POINTER_BUTTON_STATE_PRESSED) {
  			input_get_position(input, &x, &y);
  			click_handler(widget, terminal, input, x, y, time);
  		} else {
  			terminal->dragging = SELECT_NONE;
  		}
  		break;
  
  	case BTN_RIGHT:
  		if (state == WL_POINTER_BUTTON_STATE_PRESSED)
  			show_menu(terminal, input, time);
  		break;
  	}
  }
  
  static int
  enter_handler(struct widget *widget,
  	      struct input *input, float x, float y, void *data)
  {
  	return CURSOR_IBEAM;
  }
  
  static int
  motion_handler(struct widget *widget,
  	       struct input *input, uint32_t time,
  	       float x, float y, void *data)
  {
  	struct terminal *terminal = data;
  
  	if (terminal->dragging) {
  		input_get_position(input,
  				   &terminal->selection_end_x,
  				   &terminal->selection_end_y);
  
  		if (recompute_selection(terminal))
  			widget_schedule_redraw(widget);
  	}
  
  	return CURSOR_IBEAM;
  }
  
  /* This magnitude is chosen rather arbitrarily. Really, the scrolling
   * should happen on a (fractional) pixel basis, not a line basis. */
  #define AXIS_UNITS_PER_LINE 256
  
  static void
  axis_handler(struct widget *widget,
  	     struct input *input, uint32_t time,
  	     uint32_t axis,
  	     wl_fixed_t value,
  	     void *data)
  {
  	struct terminal *terminal = data;
  	int lines;
  
  	if (axis != WL_POINTER_AXIS_VERTICAL_SCROLL)
  		return;
  
  	terminal->smooth_scroll += value;
  	lines = terminal->smooth_scroll / AXIS_UNITS_PER_LINE;
  	terminal->smooth_scroll -= lines * AXIS_UNITS_PER_LINE;
  
  	if (lines > 0) {
  		if (terminal->scrolling) {
  			if ((uint32_t)lines > terminal->saved_start - terminal->start)
  				lines = terminal->saved_start - terminal->start;
  		} else {
  			lines = 0;
  		}
  	} else if (lines < 0) {
  		uint32_t neg_lines = -lines;
  
  		if (neg_lines > terminal->log_size + terminal->start - terminal->end)
  			lines = terminal->end - terminal->log_size - terminal->start;
  	}
  
  	if (lines) {
  		if (!terminal->scrolling)
  			terminal->saved_start = terminal->start;
  		terminal->scrolling = 1;
  
  		terminal->start += lines;
  		terminal->row -= lines;
  		terminal->selection_start_row -= lines;
  		terminal->selection_end_row -= lines;
  
  		widget_schedule_redraw(widget);
  	}
  }
  
  static void
  output_handler(struct window *window, struct output *output, int enter,
  	       void *data)
  {
  	if (enter)
  		window_set_buffer_transform(window, output_get_transform(output));
  	window_set_buffer_scale(window, window_get_output_scale(window));
  	window_schedule_redraw(window);
  }
  
  static void
  touch_down_handler(struct widget *widget, struct input *input,
  		uint32_t serial, uint32_t time, int32_t id,
  		float x, float y, void *data)
  {
  	struct terminal *terminal = data;
  
  	if (id == 0)
  		click_handler(widget, terminal, input, x, y, time);
  }
  
  static void
  touch_up_handler(struct widget *widget, struct input *input,
  		uint32_t serial, uint32_t time, int32_t id, void *data)
  {
  	struct terminal *terminal = data;
  
  	if (id == 0)
  		terminal->dragging = SELECT_NONE;
  }
  
  static void
  touch_motion_handler(struct widget *widget, struct input *input,
  		uint32_t time, int32_t id, float x, float y, void *data)
  {
  	struct terminal *terminal = data;
  
  	if (terminal->dragging &&
  		id == 0) {
  		terminal->selection_end_x = (int)x;
  		terminal->selection_end_y = (int)y;
  
  		if (recompute_selection(terminal))
  			widget_schedule_redraw(widget);
  	}
  }
  
  #ifndef howmany
  #define howmany(x, y) (((x) + ((y) - 1)) / (y))
  #endif
  
  static struct terminal *
  terminal_create(struct display *display)
  {
  	struct terminal *terminal;
  	cairo_surface_t *surface;
  	cairo_t *cr;
  	cairo_text_extents_t text_extents;
  
  	terminal = xzalloc(sizeof *terminal);
  	terminal->color_scheme = &DEFAULT_COLORS;
  	terminal_init(terminal);
  	terminal->margin_top = 0;
  	terminal->margin_bottom = -1;
  	terminal->window = window_create(display);
  	terminal->widget = window_frame_create(terminal->window, terminal);
  	terminal->title = xstrdup("Wayland Terminal");
  	window_set_title(terminal->window, terminal->title);
  	widget_set_transparent(terminal->widget, 0);
  
  	init_state_machine(&terminal->state_machine);
  	init_color_table(terminal);
  
  	terminal->display = display;
  	terminal->margin = 5;
  	terminal->buffer_height = 1024;
  	terminal->end = 1;
  
  	window_set_user_data(terminal->window, terminal);
  	window_set_key_handler(terminal->window, key_handler);
  	window_set_keyboard_focus_handler(terminal->window,
  					  keyboard_focus_handler);
  	window_set_fullscreen_handler(terminal->window, fullscreen_handler);
  	window_set_output_handler(terminal->window, output_handler);
  	window_set_close_handler(terminal->window, close_handler);
  	window_set_state_changed_handler(terminal->window, state_changed_handler);
  
  	window_set_data_handler(terminal->window, data_handler);
  	window_set_drop_handler(terminal->window, drop_handler);
  
  	widget_set_redraw_handler(terminal->widget, redraw_handler);
  	widget_set_resize_handler(terminal->widget, resize_handler);
  	widget_set_button_handler(terminal->widget, button_handler);
  	widget_set_enter_handler(terminal->widget, enter_handler);
  	widget_set_motion_handler(terminal->widget, motion_handler);
  	widget_set_axis_handler(terminal->widget, axis_handler);
  	widget_set_touch_up_handler(terminal->widget, touch_up_handler);
  	widget_set_touch_down_handler(terminal->widget, touch_down_handler);
  	widget_set_touch_motion_handler(terminal->widget, touch_motion_handler);
  
  	surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 0, 0);
  	cr = cairo_create(surface);
  	cairo_set_font_size(cr, option_font_size);
  	cairo_select_font_face (cr, option_font,
  				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, option_font,
  				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);
  
  	/* Compute the average ascii glyph width */
  	cairo_text_extents(cr, TERMINAL_DRAW_SINGLE_WIDE_CHARACTERS,
  			   &text_extents);
  	terminal->average_width = howmany
  		(text_extents.width,
  		 strlen(TERMINAL_DRAW_SINGLE_WIDE_CHARACTERS));
  	terminal->average_width = ceil(terminal->average_width);
  
  	cairo_destroy(cr);
  	cairo_surface_destroy(surface);
  
  	terminal_resize(terminal, 20, 5); /* Set minimum size first */
  	terminal_resize(terminal, 80, 25);
  
  	wl_list_insert(terminal_list.prev, &terminal->link);
  
  	return terminal;
  }
  
  static void
  terminal_destroy(struct terminal *terminal)
  {
  	display_unwatch_fd(terminal->display, terminal->master);
  	window_destroy(terminal->window);
  	close(terminal->master);
  	wl_list_remove(&terminal->link);
  
  	if (wl_list_empty(&terminal_list))
  		display_exit(terminal->display);
  
  	free(terminal->title);
  	free(terminal);
  }
  
  static void
  io_handler(struct task *task, uint32_t events)
  {
  	struct terminal *terminal =
  		container_of(task, struct terminal, io_task);
  	char buffer[256];
  	int len;
  
  	if (events & EPOLLHUP) {
  		terminal_destroy(terminal);
  		return;
  	}
  
  	len = read(terminal->master, buffer, sizeof buffer);
  	if (len < 0)
  		terminal_destroy(terminal);
  	else
  		terminal_data(terminal, buffer, len);
  }
  
  static int
  terminal_run(struct terminal *terminal, const char *path)
  {
  	int master;
  	pid_t pid;
  	int pipes[2];
  
  	/* Awkwardness: There's a sticky race condition here.  If
  	 * anything prints after the forkpty() but before the window has
  	 * a size then we'll segfault.  So we make a pipe and wait on
  	 * it before actually exec()ing the terminal.  The resize
  	 * handler closes it in the parent process and the child continues
  	 * on to launch a shell.
  	 *
  	 * The reason we don't just do terminal_run() after the window
  	 * has a size is that we'd prefer to perform the fork() before
  	 * the process opens a wayland connection.
  	 */
  	if (pipe(pipes) == -1) {
  		fprintf(stderr, "Can't create pipe for pacing.\n");
  		exit(EXIT_FAILURE);
  	}
  
  	pid = forkpty(&master, NULL, NULL, NULL);
  	if (pid == 0) {
  		int ret;
  
  		close(pipes[1]);
  		do {
  			char tmp;
  			ret = read(pipes[0], &tmp, 1);
  		} while (ret == -1 && errno == EINTR);
  		close(pipes[0]);
  		setenv("TERM", option_term, 1);
  		setenv("COLORTERM", option_term, 1);
  		if (execl(path, path, NULL)) {
  			printf("exec failed: %s\n", strerror(errno));
  			exit(EXIT_FAILURE);
  		}
  	} else if (pid < 0) {
  		fprintf(stderr, "failed to fork and create pty (%s).\n",
  			strerror(errno));
  		return -1;
  	}
  
  	close(pipes[0]);
  	terminal->master = master;
  	terminal->pace_pipe = pipes[1];
  	fcntl(master, F_SETFL, O_NONBLOCK);
  	terminal->io_task.run = io_handler;
  	display_watch_fd(terminal->display, terminal->master,
  			 EPOLLIN | EPOLLHUP, &terminal->io_task);
  
  	if (option_fullscreen)
  		window_set_fullscreen(terminal->window, 1);
  	else if (option_maximize)
  		window_set_maximized(terminal->window, 1);
  	else
  		terminal_resize(terminal, 80, 24);
  
  	return 0;
  }
  
  static const struct weston_option terminal_options[] = {
  	{ WESTON_OPTION_BOOLEAN, "fullscreen", 'f', &option_fullscreen },
  	{ WESTON_OPTION_BOOLEAN, "maximized", 'm', &option_maximize },
  	{ WESTON_OPTION_STRING, "font", 0, &option_font },
  	{ WESTON_OPTION_INTEGER, "font-size", 0, &option_font_size },
  	{ WESTON_OPTION_STRING, "shell", 0, &option_shell },
  };
  
  int main(int argc, char *argv[])
  {
  	struct display *d;
  	struct terminal *terminal;
  	const char *config_file;
  	struct sigaction sigpipe;
  	struct weston_config *config;
  	struct weston_config_section *s;
  
  	/* as wcwidth is locale-dependent,
  	   wcwidth needs setlocale call to function properly. */
  	setlocale(LC_ALL, "");
  
  	option_shell = getenv("SHELL");
  	if (!option_shell)
  		option_shell = "/bin/bash";
  
  	config_file = weston_config_get_name_from_env();
  	config = weston_config_parse(config_file);
  	s = weston_config_get_section(config, "terminal", NULL, NULL);
  	weston_config_section_get_string(s, "font", &option_font, "mono");
  	weston_config_section_get_int(s, "font-size", &option_font_size, 14);
  	weston_config_section_get_string(s, "term", &option_term, "xterm");
  	weston_config_destroy(config);
  
  	if (parse_options(terminal_options,
  			  ARRAY_LENGTH(terminal_options), &argc, argv) > 1) {
  		printf("Usage: %s [OPTIONS]\n"
  		       "  --fullscreen or -f\n"
  		       "  --maximized or -m\n"
  		       "  --font=NAME\n"
  		       "  --font-size=SIZE\n"
  		       "  --shell=NAME\n", argv[0]);
  		return 1;
  	}
  
  	/* Disable SIGPIPE so that paste operations do not crash the program
  	 * when the file descriptor provided to receive data is a pipe or
  	 * socket whose reading end has been closed */
  	sigpipe.sa_handler = SIG_IGN;
  	sigemptyset(&sigpipe.sa_mask);
  	sigpipe.sa_flags = 0;
  	sigaction(SIGPIPE, &sigpipe, NULL);
  
  	d = display_create(&argc, argv);
  	if (d == NULL) {
  		fprintf(stderr, "failed to create display: %s\n",
  			strerror(errno));
  		return -1;
  	}
  
  	wl_list_init(&terminal_list);
  	terminal = terminal_create(d);
  	if (terminal_run(terminal, option_shell))
  		exit(EXIT_FAILURE);
  
  	display_run(d);
  
  	return 0;
  }
  