hypernal/ttyjs/term-exterminate.js

/**
 * States
 */

var normal = 0
  , escaped = 1
  , csi = 2
  , osc = 3
  , charset = 4
  , dcs = 5
  , ignore = 6;

/**
 * Terminal
 */
 
var EventEmitter = require('events').EventEmitter;

module.exports = Terminal;
function Terminal(cols, rows, handler) {
  if (!(this instanceof Terminal)) return new Terminal(cols, rows, handler);
  EventEmitter.call(this);

  var options;
  if (typeof cols === 'object') {
    options = cols;
    cols = options.cols;
    rows = options.rows;
    handler = options.handler;
  }
  this._options = options || {};

  this.cols = cols || Terminal.geometry[0];
  this.rows = rows || Terminal.geometry[1];

  if (handler) {
    this.on('data', handler);
  }

  this.ybase = 0;
  this.ydisp = 0;
  this.x = 0;
  this.y = 0;
  this.cursorState = 0;
  this.cursorHidden = false;
  this.convertEol = false;
  this.state = 0;
  this.queue = '';
  this.scrollTop = 0;
  this.scrollBottom = this.rows - 1;

  // modes
  this.applicationKeypad = false;
  this.originMode = false;
  this.insertMode = false;
  this.wraparoundMode = false;
  this.normal = null;

  // charset
  this.charset = null;
  this.gcharset = null;
  this.glevel = 0;
  this.charsets = [null];

  // mouse properties
  this.decLocator;
  this.x10Mouse;
  this.vt200Mouse;
  this.vt300Mouse;
  this.normalMouse;
  this.mouseEvents;
  this.sendFocus;
  this.utfMouse;
  this.sgrMouse;
  this.urxvtMouse;

  // misc
  this.element;
  this.children;
  this.refreshStart;
  this.refreshEnd;
  this.savedX;
  this.savedY;
  this.savedCols;

  // stream
  this.readable = true;
  this.writable = true;

  this.defAttr = (257 << 9) | 256;
  this.curAttr = this.defAttr;

  this.params = [];
  this.currentParam = 0;
  this.prefix = '';
  this.postfix = '';

  this.lines = [];
  var i = this.rows;
  while (i--) {
    this.lines.push(this.blankLine());
  }

  this.tabs;
  this.setupStops();
}

inherits(Terminal, EventEmitter);

/**
 * Colors
 */

// Colors 0-15
Terminal.colors = [
  // dark:
  '#2e3436',
  '#cc0000',
  '#4e9a06',
  '#c4a000',
  '#3465a4',
  '#75507b',
  '#06989a',
  '#d3d7cf',
  // bright:
  '#555753',
  '#ef2929',
  '#8ae234',
  '#fce94f',
  '#729fcf',
  '#ad7fa8',
  '#34e2e2',
  '#eeeeec'
];

// Colors 16-255
// Much thanks to TooTallNate for writing this.
Terminal.colors = (function() {
  var colors = Terminal.colors
    , r = [0x00, 0x5f, 0x87, 0xaf, 0xd7, 0xff]
    , i;

  // 16-231
  i = 0;
  for (; i < 216; i++) {
    out(r[(i / 36) % 6 | 0], r[(i / 6) % 6 | 0], r[i % 6]);
  }

  // 232-255 (grey)
  i = 0;
  for (; i < 24; i++) {
    r = 8 + i * 10;
    out(r, r, r);
  }

  function out(r, g, b) {
    colors.push('#' + hex(r) + hex(g) + hex(b));
  }

  function hex(c) {
    c = c.toString(16);
    return c.length < 2 ? '0' + c : c;
  }

  return colors;
})();

// Default BG/FG
Terminal.defaultColors = {
  bg: '#000000',
  fg: '#f0f0f0'
};

Terminal.colors[256] = Terminal.defaultColors.bg;
Terminal.colors[257] = Terminal.defaultColors.fg;

/**
 * Options
 */

Terminal.termName = 'xterm';
Terminal.geometry = [80, 24];
Terminal.cursorBlink = true;
Terminal.visualBell = false;
Terminal.popOnBell = false;
Terminal.scrollback = 1000;
Terminal.screenKeys = false;
Terminal.programFeatures = false;
Terminal.debug = false;

/**
 * Focused Terminal
 */

Terminal.focus = null;

Terminal.prototype.focus = function() {
  if (Terminal.focus === this) return;
  if (Terminal.focus) {
    Terminal.focus.cursorState = 0;
    Terminal.focus.refresh(Terminal.focus.y, Terminal.focus.y);
    if (Terminal.focus.sendFocus) Terminal.focus.send('\x1b[O');
  }
  Terminal.focus = this;
  if (this.sendFocus) this.send('\x1b[I');
  this.showCursor();
};

/**
 * Global Events for key handling
 */

Terminal.bindKeys = function() {
  if (Terminal.focus) return;

  // We could put an "if (Terminal.focus)" check
  // here, but it shouldn't be necessary.
  on(document, 'keydown', function(ev) {
    return Terminal.focus.keyDown(ev);
  }, true);

  on(document, 'keypress', function(ev) {
    return Terminal.focus.keyPress(ev);
  }, true);
};

/**
 * Open Terminal
 */

Terminal.prototype.open = function() {
  var self = this
    , i = 0
    , div;

  this.element = document.createElement('div');
  this.element.className = 'terminal';
  this.children = [];

  for (; i < this.rows; i++) {
    div = document.createElement('div');
    this.element.appendChild(div);
    this.children.push(div);
  }

  //document.body.appendChild(this.element);

  this.refresh(0, this.rows - 1);

  //Terminal.bindKeys();
  this.focus();

  this.startBlink();

  on(this.element, 'mousedown', function() {
    self.focus();
  });

  // This probably shouldn't work,
  // ... but it does. Firefox's paste
  // event seems to only work for textareas?
  on(this.element, 'mousedown', function(ev) {
    var button = ev.button != null
      ? +ev.button
      : ev.which != null
        ? ev.which - 1
        : null;

    // Does IE9 do this?
    if (~navigator.userAgent.indexOf('MSIE')) {
      button = button === 1 ? 0 : button === 4 ? 1 : button;
    }

    if (button !== 2) return;

    self.element.contentEditable = 'true';
    setTimeout(function() {
      self.element.contentEditable = 'inherit'; // 'false';
    }, 1);
  }, true);

  on(this.element, 'paste', function(ev) {
    if (ev.clipboardData) {
      self.send(ev.clipboardData.getData('text/plain'));
    } else if (window.clipboardData) {
      self.send(window.clipboardData.getData('Text'));
    }
    // Not necessary. Do it anyway for good measure.
    self.element.contentEditable = 'inherit';
    return cancel(ev);
  });

  this.bindMouse();

  // XXX - hack, move this somewhere else.
  if (Terminal.brokenBold == null) {
    Terminal.brokenBold = isBoldBroken();
  }

  // sync default bg/fg colors
  this.element.style.backgroundColor = Terminal.defaultColors.bg;
  this.element.style.color = Terminal.defaultColors.fg;

  //this.emit('open');
};

// XTerm mouse events
// http://invisible-island.net/xterm/ctlseqs/ctlseqs.html#Mouse%20Tracking
// To better understand these
// the xterm code is very helpful:
// Relevant files:
//   button.c, charproc.c, misc.c
// Relevant functions in xterm/button.c:
//   BtnCode, EmitButtonCode, EditorButton, SendMousePosition
Terminal.prototype.bindMouse = function() {
  var el = this.element
    , self = this
    , pressed = 32;

  var wheelEvent = 'onmousewheel' in window
    ? 'mousewheel'
    : 'DOMMouseScroll';

  // mouseup, mousedown, mousewheel
  // left click: ^[[M 3<^[[M#3<
  // mousewheel up: ^[[M`3>
  function sendButton(ev) {
    var button
      , pos;

    // get the xterm-style button
    button = getButton(ev);

    // get mouse coordinates
    pos = getCoords(ev);
    if (!pos) return;

    sendEvent(button, pos);

    switch (ev.type) {
      case 'mousedown':
        pressed = button;
        break;
      case 'mouseup':
        // keep it at the left
        // button, just in case.
        pressed = 32;
        break;
      case wheelEvent:
        // nothing. don't
        // interfere with
        // `pressed`.
        break;
    }
  }

  // motion example of a left click:
  // ^[[M 3<^[[M@4<^[[M@5<^[[M@6<^[[M@7<^[[M#7<
  function sendMove(ev) {
    var button = pressed
      , pos;

    pos = getCoords(ev);
    if (!pos) return;

    // buttons marked as motions
    // are incremented by 32
    button += 32;

    sendEvent(button, pos);
  }

  // encode button and
  // position to characters
  function encode(data, ch) {
    if (!self.utfMouse) {
      if (ch === 255) return data.push(0);
      if (ch > 127) ch = 127;
      data.push(ch);
    } else {
      if (ch === 2047) return data.push(0);
      if (ch < 127) {
        data.push(ch);
      } else {
        if (ch > 2047) ch = 2047;
        data.push(0xC0 | (ch >> 6));
        data.push(0x80 | (ch & 0x3F));
      }
    }
  }

  // send a mouse event:
  // regular/utf8: ^[[M Cb Cx Cy
  // urxvt: ^[[ Cb ; Cx ; Cy M
  // sgr: ^[[ Cb ; Cx ; Cy M/m
  // vt300: ^[[ 24(1/3/5)~ [ Cx , Cy ] \r
  // locator: CSI P e ; P b ; P r ; P c ; P p & w
  function sendEvent(button, pos) {
    // self.emit('mouse', {
    //   x: pos.x - 32,
    //   y: pos.x - 32,
    //   button: button
    // });

    if (self.vt300Mouse) {
      // NOTE: Unstable.
      // http://www.vt100.net/docs/vt3xx-gp/chapter15.html
      button &= 3;
      pos.x -= 32;
      pos.y -= 32;
      var data = '\x1b[24';
      if (button === 0) data += '1';
      else if (button === 1) data += '3';
      else if (button === 2) data += '5';
      else if (button === 3) return;
      else data += '0';
      data += '~[' + pos.x + ',' + pos.y + ']\r';
      self.send(data);
      return;
    }

    if (self.decLocator) {
      // NOTE: Unstable.
      button &= 3;
      pos.x -= 32;
      pos.y -= 32;
      if (button === 0) button = 2;
      else if (button === 1) button = 4;
      else if (button === 2) button = 6;
      else if (button === 3) button = 3;
      self.send('\x1b['
        + button
        + ';'
        + (button === 3 ? 4 : 0)
        + ';'
        + pos.y
        + ';'
        + pos.x
        + ';'
        + (pos.page || 0)
        + '&w');
      return;
    }

    if (self.urxvtMouse) {
      pos.x -= 32;
      pos.y -= 32;
      pos.x++;
      pos.y++;
      self.send('\x1b[' + button + ';' + pos.x + ';' + pos.y + 'M');
      return;
    }

    if (self.sgrMouse) {
      pos.x -= 32;
      pos.y -= 32;
      self.send('\x1b[<'
        + ((button & 3) === 3 ? button & ~3 : button)
        + ';'
        + pos.x
        + ';'
        + pos.y
        + ((button & 3) === 3 ? 'm' : 'M'));
      return;
    }

    var data = [];

    encode(data, button);
    encode(data, pos.x);
    encode(data, pos.y);

    self.send('\x1b[M' + String.fromCharCode.apply(String, data));
  }

  function getButton(ev) {
    var button
      , shift
      , meta
      , ctrl
      , mod;

    // two low bits:
    // 0 = left
    // 1 = middle
    // 2 = right
    // 3 = release
    // wheel up/down:
    // 1, and 2 - with 64 added
    switch (ev.type) {
      case 'mousedown':
        button = ev.button != null
          ? +ev.button
          : ev.which != null
            ? ev.which - 1
            : null;

        if (~navigator.userAgent.indexOf('MSIE')) {
          button = button === 1 ? 0 : button === 4 ? 1 : button;
        }
        break;
      case 'mouseup':
        button = 3;
        break;
      case 'DOMMouseScroll':
        button = ev.detail < 0
          ? 64
          : 65;
        break;
      case 'mousewheel':
        button = ev.wheelDeltaY > 0
          ? 64
          : 65;
        break;
    }

    // next three bits are the modifiers:
    // 4 = shift, 8 = meta, 16 = control
    shift = ev.shiftKey ? 4 : 0;
    meta = ev.metaKey ? 8 : 0;
    ctrl = ev.ctrlKey ? 16 : 0;
    mod = shift | meta | ctrl;

    // no mods
    if (self.vt200Mouse) {
      // ctrl only
      mod &= ctrl;
    } else if (!self.normalMouse) {
      mod = 0;
    }

    // increment to SP
    button = (32 + (mod << 2)) + button;

    return button;
  }

  // mouse coordinates measured in cols/rows
  function getCoords(ev) {
    var x, y, w, h, el;

    // ignore browsers without pageX for now
    if (ev.pageX == null) return;

    x = ev.pageX;
    y = ev.pageY;
    el = self.element;

    // should probably check offsetParent
    // but this is more portable
    while (el !== document.documentElement) {
      x -= el.offsetLeft;
      y -= el.offsetTop;
      el = el.parentNode;
    }

    // convert to cols/rows
    w = self.element.clientWidth;
    h = self.element.clientHeight;
    x = ((x / w) * self.cols) | 0;
    y = ((y / h) * self.rows) | 0;

    // be sure to avoid sending
    // bad positions to the program
    if (x < 0) x = 0;
    if (x > self.cols) x = self.cols;
    if (y < 0) y = 0;
    if (y > self.rows) y = self.rows;

    // xterm sends raw bytes and
    // starts at 32 (SP) for each.
    x += 32;
    y += 32;

    return {
      x: x,
      y: y,
      down: ev.type === 'mousedown',
      up: ev.type === 'mouseup',
      wheel: ev.type === wheelEvent,
      move: ev.type === 'mousemove'
    };
  }

  on(el, 'mousedown', function(ev) {
    if (!self.mouseEvents) return;

    // send the button
    sendButton(ev);

    // ensure focus
    self.focus();

    // fix for odd bug
    if (self.vt200Mouse) {
      sendButton({ __proto__: ev, type: 'mouseup' });
      return cancel(ev);
    }

    // bind events
    if (self.normalMouse) on(document, 'mousemove', sendMove);

    // x10 compatibility mode can't send button releases
    if (!self.x10Mouse) {
      on(document, 'mouseup', function up(ev) {
        sendButton(ev);
        if (self.normalMouse) off(document, 'mousemove', sendMove);
        off(document, 'mouseup', up);
        return cancel(ev);
      });
    }

    return cancel(ev);
  });

  on(el, wheelEvent, function(ev) {
    if (!self.mouseEvents) return;
    if (self.x10Mouse
        || self.vt300Mouse
        || self.decLocator) return;
    sendButton(ev);
    return cancel(ev);
  });

  // allow mousewheel scrolling in
  // the shell for example
  on(el, wheelEvent, function(ev) {
    if (self.mouseEvents) return;
    if (self.applicationKeypad) return;
    if (ev.type === 'DOMMouseScroll') {
      self.scrollDisp(ev.detail < 0 ? -5 : 5);
    } else {
      self.scrollDisp(ev.wheelDeltaY > 0 ? -5 : 5);
    }
    return cancel(ev);
  });
};

/**
 * Destroy Terminal
 */

Terminal.prototype.destroy = function() {
  this.readable = false;
  this.writable = false;
  this._events = {};
  this.handler = function() {};
  this.write = function() {};
  //this.emit('close');
};

/**
 * Rendering Engine
 */

// In the screen buffer, each character
// is stored as a an array with a character
// and a 32-bit integer.
// First value: a utf-16 character.
// Second value:
// Next 9 bits: background color (0-511).
// Next 9 bits: foreground color (0-511).
// Next 14 bits: a mask for misc. flags:
//   1=bold, 2=underline, 4=inverse

Terminal.prototype.refresh = function(start, end) {
  var x
    , y
    , i
    , line
    , out
    , ch
    , width
    , data
    , attr
    , fgColor
    , bgColor
    , flags
    , row
    , parent;

  if (end - start >= this.rows / 2) {
    parent = this.element.parentNode;
    if (parent) parent.removeChild(this.element);
  }

  width = this.cols;
  y = start;

  // if (end > this.lines.length) {
  //   end = this.lines.length;
  // }

  for (; y <= end; y++) {
    row = y + this.ydisp;

    line = this.lines[row];
    out = '';

    if (y === this.y
        && this.cursorState
        && this.ydisp === this.ybase
        && !this.cursorHidden) {
      x = this.x;
    } else {
      x = -1;
    }

    attr = this.defAttr;
    i = 0;

    for (; i < width; i++) {
      data = line[i][0];
      ch = line[i][1];

      if (i === x) data = -1;

      if (data !== attr) {
        if (attr !== this.defAttr) {
          out += '</span>';
        }
        if (data !== this.defAttr) {
          if (data === -1) {
            out += '<span class="reverse-video">';
          } else {
            out += '<span style="';

            bgColor = data & 0x1ff;
            fgColor = (data >> 9) & 0x1ff;
            flags = data >> 18;

            if (flags & 1) {
              if (!Terminal.brokenBold) {
                out += 'font-weight:bold;';
              }
              // see: XTerm*boldColors
              if (fgColor < 8) fgColor += 8;
            }

            if (flags & 2) {
              out += 'text-decoration:underline;';
            }

            if (bgColor !== 256) {
              out += 'background-color:'
                + Terminal.colors[bgColor]
                + ';';
            }

            if (fgColor !== 257) {
              out += 'color:'
                + Terminal.colors[fgColor]
                + ';';
            }

            out += '">';
          }
        }
      }

      switch (ch) {
        case '&':
          out += '&amp;';
          break;
        case '<':
          out += '&lt;';
          break;
        case '>':
          out += '&gt;';
          break;
        default:
          if (ch <= ' ') {
            out += '&nbsp;';
          } else {
            out += ch;
          }
          break;
      }

      attr = data;
    }

    if (attr !== this.defAttr) {
      out += '</span>';
    }

    this.children[y].innerHTML = out;
  }

  if (parent) parent.appendChild(this.element);
};

Terminal.prototype.cursorBlink = function() {
  if (Terminal.focus !== this) return;
  this.cursorState ^= 1;
  this.refresh(this.y, this.y);
};

Terminal.prototype.showCursor = function() {
  if (!this.cursorState) {
    this.cursorState = 1;
    this.refresh(this.y, this.y);
  } else {
    // Temporarily disabled:
    // this.refreshBlink();
  }
};

Terminal.prototype.startBlink = function() {
  if (!Terminal.cursorBlink) return;
  var self = this;
  this._blinker = function() {
    self.cursorBlink();
  };
  this._blink = setInterval(this._blinker, 500);
};

Terminal.prototype.refreshBlink = function() {
  if (!Terminal.cursorBlink) return;
  clearInterval(this._blink);
  this._blink = setInterval(this._blinker, 500);
};

Terminal.prototype.scroll = function() {
  var row;

  if (++this.ybase === Terminal.scrollback) {
    this.ybase = this.ybase / 2 | 0;
    this.lines = this.lines.slice(-(this.ybase + this.rows) + 1);
  }

  this.ydisp = this.ybase;

  // last line
  row = this.ybase + this.rows - 1;

  // subtract the bottom scroll region
  row -= this.rows - 1 - this.scrollBottom;

  if (row === this.lines.length) {
    // potential optimization:
    // pushing is faster than splicing
    // when they amount to the same
    // behavior.
    this.lines.push(this.blankLine());
  } else {
    // add our new line
    this.lines.splice(row, 0, this.blankLine());
  }

  if (this.scrollTop !== 0) {
    if (this.ybase !== 0) {
      this.ybase--;
      this.ydisp = this.ybase;
    }
    this.lines.splice(this.ybase + this.scrollTop, 1);
  }

  // this.maxRange();
  this.updateRange(this.scrollTop);
  this.updateRange(this.scrollBottom);
};

Terminal.prototype.scrollDisp = function(disp) {
  this.ydisp += disp;

  if (this.ydisp > this.ybase) {
    this.ydisp = this.ybase;
  } else if (this.ydisp < 0) {
    this.ydisp = 0;
  }

  this.refresh(0, this.rows - 1);
};

Terminal.prototype.write = function(data) {
  var l = data.length
    , i = 0
    , cs
    , ch;

  this.refreshStart = this.y;
  this.refreshEnd = this.y;

  if (this.ybase !== this.ydisp) {
    this.ydisp = this.ybase;
    this.maxRange();
  }

  // this.log(JSON.stringify(data.replace(/\x1b/g, '^[')));

  for (; i < l; i++) {
    ch = data[i];
    switch (this.state) {
      case normal:
        switch (ch) {
          // '\0'
          // case '\0':
          //   break;

          // '\a'
          case '\x07':
            this.bell();
            break;

          // '\n', '\v', '\f'
          case '\n':
          case '\x0b':
          case '\x0c':
            if (this.convertEol) {
              this.x = 0;
            }
            this.y++;
            if (this.y > this.scrollBottom) {
              this.y--;
              this.scroll();
            }
            break;

          // '\r'
          case '\r':
            this.x = 0;
            break;

          // '\b'
          case '\x08':
            if (this.x > 0) {
              this.x--;
            }
            break;

          // '\t'
          case '\t':
            this.x = this.nextStop();
            break;

          // shift out
          case '\x0e':
            this.setgLevel(1);
            break;

          // shift in
          case '\x0f':
            this.setgLevel(0);
            break;

          // '\e'
          case '\x1b':
            this.state = escaped;
            break;

          default:
            // ' '
            if (ch >= ' ') {
              if (this.charset && this.charset[ch]) {
                ch = this.charset[ch];
              }
              if (this.x >= this.cols) {
                this.x = 0;
                this.y++;
                if (this.y > this.scrollBottom) {
                  this.y--;
                  this.scroll();
                }
              }
              this.lines[this.y + this.ybase][this.x] = [this.curAttr, ch];
              this.x++;
              this.updateRange(this.y);
            }
            break;
        }
        break;
      case escaped:
        switch (ch) {
          // ESC [ Control Sequence Introducer ( CSI is 0x9b).
          case '[':
            this.params = [];
            this.currentParam = 0;
            this.state = csi;
            break;

          // ESC ] Operating System Command ( OSC is 0x9d).
          case ']':
            this.params = [];
            this.currentParam = 0;
            this.state = osc;
            break;

          // ESC P Device Control String ( DCS is 0x90).
          case 'P':
            this.params = [];
            this.currentParam = 0;
            this.state = dcs;
            break;

          // ESC _ Application Program Command ( APC is 0x9f).
          case '_':
            this.stateType = 'apc';
            this.state = ignore;
            break;

          // ESC ^ Privacy Message ( PM is 0x9e).
          case '^':
            this.stateType = 'pm';
            this.state = ignore;
            break;

          // ESC c Full Reset (RIS).
          case 'c':
            this.reset();
            break;

          // ESC E Next Line ( NEL is 0x85).
          // ESC D Index ( IND is 0x84).
          case 'E':
            this.x = 0;
            ;
          case 'D':
            this.index();
            break;

          // ESC M Reverse Index ( RI is 0x8d).
          case 'M':
            this.reverseIndex();
            break;

          // ESC % Select default/utf-8 character set.
          // @ = default, G = utf-8
          case '%':
            //this.charset = null;
            this.setgLevel(0);
            this.setgCharset(0, Terminal.charsets.US);
            this.state = normal;
            i++;
            break;

          // ESC (,),*,+,-,. Designate G0-G2 Character Set.
          case '(': // <-- this seems to get all the attention
          case ')':
          case '*':
          case '+':
          case '-':
          case '.':
            switch (ch) {
              case '(':
                this.gcharset = 0;
                break;
              case ')':
                this.gcharset = 1;
                break;
              case '*':
                this.gcharset = 2;
                break;
              case '+':
                this.gcharset = 3;
                break;
              case '-':
                this.gcharset = 1;
                break;
              case '.':
                this.gcharset = 2;
                break;
            }
            this.state = charset;
            break;

          // Designate G3 Character Set (VT300).
          // A = ISO Latin-1 Supplemental.
          // Not implemented.
          case '/':
            this.gcharset = 3;
            this.state = charset;
            i--;
            break;

          // ESC N
          // Single Shift Select of G2 Character Set
          // ( SS2 is 0x8e). This affects next character only.
          case 'N':
            break;
          // ESC O
          // Single Shift Select of G3 Character Set
          // ( SS3 is 0x8f). This affects next character only.
          case 'O':
            break;
          // ESC n
          // Invoke the G2 Character Set as GL (LS2).
          case 'n':
            this.setgLevel(2);
            break;
          // ESC o
          // Invoke the G3 Character Set as GL (LS3).
          case 'o':
            this.setgLevel(3);
            break;
          // ESC |
          // Invoke the G3 Character Set as GR (LS3R).
          case '|':
            this.setgLevel(3);
            break;
          // ESC }
          // Invoke the G2 Character Set as GR (LS2R).
          case '}':
            this.setgLevel(2);
            break;
          // ESC ~
          // Invoke the G1 Character Set as GR (LS1R).
          case '~':
            this.setgLevel(1);
            break;

          // ESC 7 Save Cursor (DECSC).
          case '7':
            this.saveCursor();
            this.state = normal;
            break;

          // ESC 8 Restore Cursor (DECRC).
          case '8':
            this.restoreCursor();
            this.state = normal;
            break;

          // ESC # 3 DEC line height/width
          case '#':
            this.state = normal;
            i++;
            break;

          // ESC H Tab Set (HTS is 0x88).
          case 'H':
            this.tabSet();
            break;

          // ESC = Application Keypad (DECPAM).
          case '=':
            this.log('Serial port requested application keypad.');
            this.applicationKeypad = true;
            this.state = normal;
            break;

          // ESC > Normal Keypad (DECPNM).
          case '>':
            this.log('Switching back to normal keypad.');
            this.applicationKeypad = false;
            this.state = normal;
            break;

          default:
            this.state = normal;
            this.error('Unknown ESC control: %s.', ch);
            break;
        }
        break;

      case charset:
        switch (ch) {
          case '0': // DEC Special Character and Line Drawing Set.
            cs = Terminal.charsets.SCLD;
            break;
          case 'A': // UK
            cs = Terminal.charsets.UK;
            break;
          case 'B': // United States (USASCII).
            cs = Terminal.charsets.US;
            break;
          case '4': // Dutch
            cs = Terminal.charsets.Dutch;
            break;
          case 'C': // Finnish
          case '5':
            cs = Terminal.charsets.Finnish;
            break;
          case 'R': // French
            cs = Terminal.charsets.French;
            break;
          case 'Q': // FrenchCanadian
            cs = Terminal.charsets.FrenchCanadian;
            break;
          case 'K': // German
            cs = Terminal.charsets.German;
            break;
          case 'Y': // Italian
            cs = Terminal.charsets.Italian;
            break;
          case 'E': // NorwegianDanish
          case '6':
            cs = Terminal.charsets.NorwegianDanish;
            break;
          case 'Z': // Spanish
            cs = Terminal.charsets.Spanish;
            break;
          case 'H': // Swedish
          case '7':
            cs = Terminal.charsets.Swedish;
            break;
          case '=': // Swiss
            cs = Terminal.charsets.Swiss;
            break;
          case '/': // ISOLatin (actually /A)
            cs = Terminal.charsets.ISOLatin;
            i++;
            break;
          default: // Default
            cs = Terminal.charsets.US;
            break;
        }
        this.setgCharset(this.gcharset, cs);
        this.gcharset = null;
        this.state = normal;
        break;

      case osc:
        // OSC Ps ; Pt ST
        // OSC Ps ; Pt BEL
        //   Set Text Parameters.
        if (ch === '\x1b' || ch === '\x07') {
          if (ch === '\x1b') i++;

          this.params.push(this.currentParam);

          switch (this.params[0]) {
            case 0:
            case 1:
            case 2:
              if (this.params[1]) {
                this.title = this.params[1];
                this.handleTitle(this.title);
              }
              break;
            case 3:
              // set X property
              break;
            case 4:
            case 5:
              // change dynamic colors
              break;
            case 10:
            case 11:
            case 12:
            case 13:
            case 14:
            case 15:
            case 16:
            case 17:
            case 18:
            case 19:
              // change dynamic ui colors
              break;
            case 46:
              // change log file
              break;
            case 50:
              // dynamic font
              break;
            case 51:
              // emacs shell
              break;
            case 52:
              // manipulate selection data
              break;
            case 104:
            case 105:
            case 110:
            case 111:
            case 112:
            case 113:
            case 114:
            case 115:
            case 116:
            case 117:
            case 118:
              // reset colors
              break;
          }

          this.params = [];
          this.currentParam = 0;
          this.state = normal;
        } else {
          if (!this.params.length) {
            if (ch >= '0' && ch <= '9') {
              this.currentParam =
                this.currentParam * 10 + ch.charCodeAt(0) - 48;
            } else if (ch === ';') {
              this.params.push(this.currentParam);
              this.currentParam = '';
            }
          } else {
            this.currentParam += ch;
          }
        }
        break;

      case csi:
        // '?', '>', '!'
        if (ch === '?' || ch === '>' || ch === '!') {
          this.prefix = ch;
          break;
        }

        // 0 - 9
        if (ch >= '0' && ch <= '9') {
          this.currentParam = this.currentParam * 10 + ch.charCodeAt(0) - 48;
          break;
        }

        // '$', '"', ' ', '\''
        if (ch === '$' || ch === '"' || ch === ' ' || ch === '\'') {
          this.postfix = ch;
          break;
        }

        this.params.push(this.currentParam);
        this.currentParam = 0;

        // ';'
        if (ch === ';') break;

        this.state = normal;

        switch (ch) {
          // CSI Ps A
          // Cursor Up Ps Times (default = 1) (CUU).
          case 'A':
            this.cursorUp(this.params);
            break;

          // CSI Ps B
          // Cursor Down Ps Times (default = 1) (CUD).
          case 'B':
            this.cursorDown(this.params);
            break;

          // CSI Ps C
          // Cursor Forward Ps Times (default = 1) (CUF).
          case 'C':
            this.cursorForward(this.params);
            break;

          // CSI Ps D
          // Cursor Backward Ps Times (default = 1) (CUB).
          case 'D':
            this.cursorBackward(this.params);
            break;

          // CSI Ps ; Ps H
          // Cursor Position [row;column] (default = [1,1]) (CUP).
          case 'H':
            this.cursorPos(this.params);
            break;

          // CSI Ps J  Erase in Display (ED).
          case 'J':
            this.eraseInDisplay(this.params);
            break;

          // CSI Ps K  Erase in Line (EL).
          case 'K':
            this.eraseInLine(this.params);
            break;

          // CSI Pm m  Character Attributes (SGR).
          case 'm':
            this.charAttributes(this.params);
            break;

          // CSI Ps n  Device Status Report (DSR).
          case 'n':
            this.deviceStatus(this.params);
            break;

          /**
           * Additions
           */

          // CSI Ps @
          // Insert Ps (Blank) Character(s) (default = 1) (ICH).
          case '@':
            this.insertChars(this.params);
            break;

          // CSI Ps E
          // Cursor Next Line Ps Times (default = 1) (CNL).
          case 'E':
            this.cursorNextLine(this.params);
            break;

          // CSI Ps F
          // Cursor Preceding Line Ps Times (default = 1) (CNL).
          case 'F':
            this.cursorPrecedingLine(this.params);
            break;

          // CSI Ps G
          // Cursor Character Absolute  [column] (default = [row,1]) (CHA).
          case 'G':
            this.cursorCharAbsolute(this.params);
            break;

          // CSI Ps L
          // Insert Ps Line(s) (default = 1) (IL).
          case 'L':
            this.insertLines(this.params);
            break;

          // CSI Ps M
          // Delete Ps Line(s) (default = 1) (DL).
          case 'M':
            this.deleteLines(this.params);
            break;

          // CSI Ps P
          // Delete Ps Character(s) (default = 1) (DCH).
          case 'P':
            this.deleteChars(this.params);
            break;

          // CSI Ps X
          // Erase Ps Character(s) (default = 1) (ECH).
          case 'X':
            this.eraseChars(this.params);
            break;

          // CSI Pm `  Character Position Absolute
          //   [column] (default = [row,1]) (HPA).
          case '`':
            this.charPosAbsolute(this.params);
            break;

          // 141 61 a * HPR -
          // Horizontal Position Relative
          case 'a':
            this.HPositionRelative(this.params);
            break;

          // CSI P s c
          // Send Device Attributes (Primary DA).
          // CSI > P s c
          // Send Device Attributes (Secondary DA)
          case 'c':
            this.sendDeviceAttributes(this.params);
            break;

          // CSI Pm d
          // Line Position Absolute  [row] (default = [1,column]) (VPA).
          case 'd':
            this.linePosAbsolute(this.params);
            break;

          // 145 65 e * VPR - Vertical Position Relative
          case 'e':
            this.VPositionRelative(this.params);
            break;

          // CSI Ps ; Ps f
          //   Horizontal and Vertical Position [row;column] (default =
          //   [1,1]) (HVP).
          case 'f':
            this.HVPosition(this.params);
            break;

          // CSI Pm h  Set Mode (SM).
          // CSI ? Pm h - mouse escape codes, cursor escape codes
          case 'h':
            this.setMode(this.params);
            break;

          // CSI Pm l  Reset Mode (RM).
          // CSI ? Pm l
          case 'l':
            this.resetMode(this.params);
            break;

          // CSI Ps ; Ps r
          //   Set Scrolling Region [top;bottom] (default = full size of win-
          //   dow) (DECSTBM).
          // CSI ? Pm r
          case 'r':
            this.setScrollRegion(this.params);
            break;

          // CSI s
          //   Save cursor (ANSI.SYS).
          case 's':
            this.saveCursor(this.params);
            break;

          // CSI u
          //   Restore cursor (ANSI.SYS).
          case 'u':
            this.restoreCursor(this.params);
            break;

          /**
           * Lesser Used
           */

          // CSI Ps I
          // Cursor Forward Tabulation Ps tab stops (default = 1) (CHT).
          case 'I':
            this.cursorForwardTab(this.params);
            break;

          // CSI Ps S  Scroll up Ps lines (default = 1) (SU).
          case 'S':
            this.scrollUp(this.params);
            break;

          // CSI Ps T  Scroll down Ps lines (default = 1) (SD).
          // CSI Ps ; Ps ; Ps ; Ps ; Ps T
          // CSI > Ps; Ps T
          case 'T':
            // if (this.prefix === '>') {
            //   this.resetTitleModes(this.params);
            //   break;
            // }
            // if (this.params.length > 2) {
            //   this.initMouseTracking(this.params);
            //   break;
            // }
            if (this.params.length < 2 && !this.prefix) {
              this.scrollDown(this.params);
            }
            break;

          // CSI Ps Z
          // Cursor Backward Tabulation Ps tab stops (default = 1) (CBT).
          case 'Z':
            this.cursorBackwardTab(this.params);
            break;

          // CSI Ps b  Repeat the preceding graphic character Ps times (REP).
          case 'b':
            this.repeatPrecedingCharacter(this.params);
            break;

          // CSI Ps g  Tab Clear (TBC).
          case 'g':
            this.tabClear(this.params);
            break;

          // CSI Pm i  Media Copy (MC).
          // CSI ? Pm i
          // case 'i':
          //   this.mediaCopy(this.params);
          //   break;

          // CSI Pm m  Character Attributes (SGR).
          // CSI > Ps; Ps m
          // case 'm': // duplicate
          //   if (this.prefix === '>') {
          //     this.setResources(this.params);
          //   } else {
          //     this.charAttributes(this.params);
          //   }
          //   break;

          // CSI Ps n  Device Status Report (DSR).
          // CSI > Ps n
          // case 'n': // duplicate
          //   if (this.prefix === '>') {
          //     this.disableModifiers(this.params);
          //   } else {
          //     this.deviceStatus(this.params);
          //   }
          //   break;

          // CSI > Ps p  Set pointer mode.
          // CSI ! p   Soft terminal reset (DECSTR).
          // CSI Ps$ p
          //   Request ANSI mode (DECRQM).
          // CSI ? Ps$ p
          //   Request DEC private mode (DECRQM).
          // CSI Ps ; Ps " p
          case 'p':
            switch (this.prefix) {
              // case '>':
              //   this.setPointerMode(this.params);
              //   break;
              case '!':
                this.softReset(this.params);
                break;
              // case '?':
              //   if (this.postfix === '$') {
              //     this.requestPrivateMode(this.params);
              //   }
              //   break;
              // default:
              //   if (this.postfix === '"') {
              //     this.setConformanceLevel(this.params);
              //   } else if (this.postfix === '$') {
              //     this.requestAnsiMode(this.params);
              //   }
              //   break;
            }
            break;

          // CSI Ps q  Load LEDs (DECLL).
          // CSI Ps SP q
          // CSI Ps " q
          // case 'q':
          //   if (this.postfix === ' ') {
          //     this.setCursorStyle(this.params);
          //     break;
          //   }
          //   if (this.postfix === '"') {
          //     this.setCharProtectionAttr(this.params);
          //     break;
          //   }
          //   this.loadLEDs(this.params);
          //   break;

          // CSI Ps ; Ps r
          //   Set Scrolling Region [top;bottom] (default = full size of win-
          //   dow) (DECSTBM).
          // CSI ? Pm r
          // CSI Pt; Pl; Pb; Pr; Ps$ r
          // case 'r': // duplicate
          //   if (this.prefix === '?') {
          //     this.restorePrivateValues(this.params);
          //   } else if (this.postfix === '$') {
          //     this.setAttrInRectangle(this.params);
          //   } else {
          //     this.setScrollRegion(this.params);
          //   }
          //   break;

          // CSI s     Save cursor (ANSI.SYS).
          // CSI ? Pm s
          // case 's': // duplicate
          //   if (this.prefix === '?') {
          //     this.savePrivateValues(this.params);
          //   } else {
          //     this.saveCursor(this.params);
          //   }
          //   break;

          // CSI Ps ; Ps ; Ps t
          // CSI Pt; Pl; Pb; Pr; Ps$ t
          // CSI > Ps; Ps t
          // CSI Ps SP t
          // case 't':
          //   if (this.postfix === '$') {
          //     this.reverseAttrInRectangle(this.params);
          //   } else if (this.postfix === ' ') {
          //     this.setWarningBellVolume(this.params);
          //   } else {
          //     if (this.prefix === '>') {
          //       this.setTitleModeFeature(this.params);
          //     } else {
          //       this.manipulateWindow(this.params);
          //     }
          //   }
          //   break;

          // CSI u     Restore cursor (ANSI.SYS).
          // CSI Ps SP u
          // case 'u': // duplicate
          //   if (this.postfix === ' ') {
          //     this.setMarginBellVolume(this.params);
          //   } else {
          //     this.restoreCursor(this.params);
          //   }
          //   break;

          // CSI Pt; Pl; Pb; Pr; Pp; Pt; Pl; Pp$ v
          // case 'v':
          //   if (this.postfix === '$') {
          //     this.copyRectagle(this.params);
          //   }
          //   break;

          // CSI Pt ; Pl ; Pb ; Pr ' w
          // case 'w':
          //   if (this.postfix === '\'') {
          //     this.enableFilterRectangle(this.params);
          //   }
          //   break;

          // CSI Ps x  Request Terminal Parameters (DECREQTPARM).
          // CSI Ps x  Select Attribute Change Extent (DECSACE).
          // CSI Pc; Pt; Pl; Pb; Pr$ x
          // case 'x':
          //   if (this.postfix === '$') {
          //     this.fillRectangle(this.params);
          //   } else {
          //     this.requestParameters(this.params);
          //     //this.__(this.params);
          //   }
          //   break;

          // CSI Ps ; Pu ' z
          // CSI Pt; Pl; Pb; Pr$ z
          // case 'z':
          //   if (this.postfix === '\'') {
          //     this.enableLocatorReporting(this.params);
          //   } else if (this.postfix === '$') {
          //     this.eraseRectangle(this.params);
          //   }
          //   break;

          // CSI Pm ' {
          // CSI Pt; Pl; Pb; Pr$ {
          // case '{':
          //   if (this.postfix === '\'') {
          //     this.setLocatorEvents(this.params);
          //   } else if (this.postfix === '$') {
          //     this.selectiveEraseRectangle(this.params);
          //   }
          //   break;

          // CSI Ps ' |
          // case '|':
          //   if (this.postfix === '\'') {
          //     this.requestLocatorPosition(this.params);
          //   }
          //   break;

          // CSI P m SP }
          // Insert P s Column(s) (default = 1) (DECIC), VT420 and up.
          // case '}':
          //   if (this.postfix === ' ') {
          //     this.insertColumns(this.params);
          //   }
          //   break;

          // CSI P m SP ~
          // Delete P s Column(s) (default = 1) (DECDC), VT420 and up
          // case '~':
          //   if (this.postfix === ' ') {
          //     this.deleteColumns(this.params);
          //   }
          //   break;

          default:
            this.error('Unknown CSI code: %s.', ch);
            break;
        }

        this.prefix = '';
        this.postfix = '';
        break;

      case dcs:
        if (ch === '\x1b' || ch === '\x07') {
          if (ch === '\x1b') i++;

          switch (this.prefix) {
            // User-Defined Keys (DECUDK).
            case '':
              break;

            // Request Status String (DECRQSS).
            // test: echo -e '\eP$q"p\e\\'
            case '$q':
              var pt = this.currentParam
                , valid = false;

              switch (pt) {
                // DECSCA
                case '"q':
                  pt = '0"q';
                  break;

                // DECSCL
                case '"p':
                  pt = '61"p';
                  break;

                // DECSTBM
                case 'r':
                  pt = ''
                    + (this.scrollTop + 1)
                    + ';'
                    + (this.scrollBottom + 1)
                    + 'r';
                  break;

                // SGR
                case 'm':
                  pt = '0m';
                  break;

                default:
                  this.error('Unknown DCS Pt: %s.', pt);
                  pt = '';
                  break;
              }

              this.send('\x1bP' + +valid + '$r' + pt + '\x1b\\');
              break;

            // Set Termcap/Terminfo Data (xterm, experimental).
            case '+p':
              break;

            // Request Termcap/Terminfo String (xterm, experimental)
            // Regular xterm does not even respond to this sequence.
            // This can cause a small glitch in vim.
            // test: echo -ne '\eP+q6b64\e\\'
            case '+q':
              var pt = this.currentParam
                , valid = false;

              this.send('\x1bP' + +valid + '+r' + pt + '\x1b\\');
              break;

            default:
              this.error('Unknown DCS prefix: %s.', this.prefix);
              break;
          }

          this.currentParam = 0;
          this.prefix = '';
          this.state = normal;
        } else if (!this.currentParam) {
          if (!this.prefix && ch !== '$' && ch !== '+') {
            this.currentParam = ch;
          } else if (this.prefix.length === 2) {
            this.currentParam = ch;
          } else {
            this.prefix += ch;
          }
        } else {
          this.currentParam += ch;
        }
        break;

      case ignore:
        // For PM and APC.
        if (ch === '\x1b' || ch === '\x07') {
          if (ch === '\x1b') i++;
          this.emit(this.stateType, this.stateData || '');
          this.stateData = '';
          this.state = normal;
        } else {
          if (!this.stateData) this.stateData = '';
          this.stateData += ch;
        }
        break;
    }
  }

  this.updateRange(this.y);
  this.refresh(this.refreshStart, this.refreshEnd);
};

Terminal.prototype.writeln = function(data) {
  this.write(data + '\r\n');
};

Terminal.prototype.keyDown = function(ev) {
  var key;

  switch (ev.keyCode) {
    // backspace
    case 8:
      if (ev.shiftKey) {
        key = '\x08'; // ^H
        break;
      }
      key = '\x7f'; // ^?
      break;
    // tab
    case 9:
      if (ev.shiftKey) {
        key = '\x1b[Z';
        break;
      }
      key = '\t';
      break;
    // return/enter
    case 13:
      key = '\r';
      break;
    // escape
    case 27:
      key = '\x1b';
      break;
    // left-arrow
    case 37:
      if (this.applicationKeypad) {
        key = '\x1bOD'; // SS3 as ^[O for 7-bit
        //key = '\x8fD'; // SS3 as 0x8f for 8-bit
        break;
      }
      key = '\x1b[D';
      break;
    // right-arrow
    case 39:
      if (this.applicationKeypad) {
        key = '\x1bOC';
        break;
      }
      key = '\x1b[C';
      break;
    // up-arrow
    case 38:
      if (this.applicationKeypad) {
        key = '\x1bOA';
        break;
      }
      if (ev.ctrlKey) {
        this.scrollDisp(-1);
        return cancel(ev);
      } else {
        key = '\x1b[A';
      }
      break;
    // down-arrow
    case 40:
      if (this.applicationKeypad) {
        key = '\x1bOB';
        break;
      }
      if (ev.ctrlKey) {
        this.scrollDisp(1);
        return cancel(ev);
      } else {
        key = '\x1b[B';
      }
      break;
    // delete
    case 46:
      key = '\x1b[3~';
      break;
    // insert
    case 45:
      key = '\x1b[2~';
      break;
    // home
    case 36:
      if (this.applicationKeypad) {
        key = '\x1bOH';
        break;
      }
      key = '\x1bOH';
      break;
    // end
    case 35:
      if (this.applicationKeypad) {
        key = '\x1bOF';
        break;
      }
      key = '\x1bOF';
      break;
    // page up
    case 33:
      if (ev.shiftKey) {
        this.scrollDisp(-(this.rows - 1));
        return cancel(ev);
      } else {
        key = '\x1b[5~';
      }
      break;
    // page down
    case 34:
      if (ev.shiftKey) {
        this.scrollDisp(this.rows - 1);
        return cancel(ev);
      } else {
        key = '\x1b[6~';
      }
      break;
    // F1
    case 112:
      key = '\x1bOP';
      break;
    // F2
    case 113:
      key = '\x1bOQ';
      break;
    // F3
    case 114:
      key = '\x1bOR';
      break;
    // F4
    case 115:
      key = '\x1bOS';
      break;
    // F5
    case 116:
      key = '\x1b[15~';
      break;
    // F6
    case 117:
      key = '\x1b[17~';
      break;
    // F7
    case 118:
      key = '\x1b[18~';
      break;
    // F8
    case 119:
      key = '\x1b[19~';
      break;
    // F9
    case 120:
      key = '\x1b[20~';
      break;
    // F10
    case 121:
      key = '\x1b[21~';
      break;
    // F11
    case 122:
      key = '\x1b[23~';
      break;
    // F12
    case 123:
      key = '\x1b[24~';
      break;
    default:
      // a-z and space
      if (ev.ctrlKey) {
        if (ev.keyCode >= 65 && ev.keyCode <= 90) {
          key = String.fromCharCode(ev.keyCode - 64);
        } else if (ev.keyCode === 32) {
          // NUL
          key = String.fromCharCode(0);
        } else if (ev.keyCode >= 51 && ev.keyCode <= 55) {
          // escape, file sep, group sep, record sep, unit sep
          key = String.fromCharCode(ev.keyCode - 51 + 27);
        } else if (ev.keyCode === 56) {
          // delete
          key = String.fromCharCode(127);
        } else if (ev.keyCode === 219) {
          // ^[ - escape
          key = String.fromCharCode(27);
        } else if (ev.keyCode === 221) {
          // ^] - group sep
          key = String.fromCharCode(29);
        }
      } else if ((!isMac && ev.altKey) || (isMac && ev.metaKey)) {
        if (ev.keyCode >= 65 && ev.keyCode <= 90) {
          key = '\x1b' + String.fromCharCode(ev.keyCode + 32);
        } else if (ev.keyCode === 192) {
          key = '\x1b`';
        } else if (ev.keyCode >= 48 && ev.keyCode <= 57) {
          key = '\x1b' + (ev.keyCode - 48);
        }
      }
      break;
  }

  this.emit('keydown', ev);

  if (key) {
    this.emit('key', key, ev);

    this.showCursor();
    this.handler(key);

    return cancel(ev);
  }

  return true;
};

Terminal.prototype.setgLevel = function(g) {
  this.glevel = g;
  this.charset = this.charsets[g];
};

Terminal.prototype.setgCharset = function(g, charset) {
  this.charsets[g] = charset;
  if (this.glevel === g) {
    this.charset = charset;
  }
};

Terminal.prototype.keyPress = function(ev) {
  var key;

  cancel(ev);

  if (ev.charCode) {
    key = ev.charCode;
  } else if (ev.which == null) {
    key = ev.keyCode;
  } else if (ev.which !== 0 && ev.charCode !== 0) {
    key = ev.which;
  } else {
    return false;
  }

  if (!key || ev.ctrlKey || ev.altKey || ev.metaKey) return false;

  key = String.fromCharCode(key);

  this.emit('keypress', key, ev);
  this.emit('key', key, ev);

  this.showCursor();
  this.handler(key);

  return false;
};

Terminal.prototype.send = function(data) {
  var self = this;

  if (!this.queue) {
    setTimeout(function() {
      self.handler(self.queue);
      self.queue = '';
    }, 1);
  }

  this.queue += data;
};

Terminal.prototype.bell = function() {
  if (!Terminal.visualBell) return;
  var self = this;
  this.element.style.borderColor = 'white';
  setTimeout(function() {
    self.element.style.borderColor = '';
  }, 10);
  if (Terminal.popOnBell) this.focus();
};

Terminal.prototype.log = function() {
  if (!Terminal.debug) return;
  if (!window.console || !window.console.log) return;
  var args = Array.prototype.slice.call(arguments);
  window.console.log.apply(window.console, args);
};

Terminal.prototype.error = function() {
  if (!Terminal.debug) return;
  if (!window.console || !window.console.error) return;
  var args = Array.prototype.slice.call(arguments);
  window.console.error.apply(window.console, args);
};

Terminal.prototype.resize = function(x, y) {
  var line
    , el
    , i
    , j
    , ch;

  if (x < 1) x = 1;
  if (y < 1) y = 1;

  // resize cols
  j = this.cols;
  if (j < x) {
    ch = [this.defAttr, ' '];
    i = this.lines.length;
    while (i--) {
      while (this.lines[i].length < x) {
        this.lines[i].push(ch);
      }
    }
  } else if (j > x) {
    i = this.lines.length;
    while (i--) {
      while (this.lines[i].length > x) {
        this.lines[i].pop();
      }
    }
  }
  this.setupStops(j);
  this.cols = x;

  // resize rows
  j = this.rows;
  if (j < y) {
    el = this.element;
    while (j++ < y) {
      if (this.lines.length < y + this.ybase) {
        this.lines.push(this.blankLine());
      }
      if (this.children.length < y) {
        line = document.createElement('div');
        el.appendChild(line);
        this.children.push(line);
      }
    }
  } else if (j > y) {
    while (j-- > y) {
      if (this.lines.length > y + this.ybase) {
        this.lines.pop();
      }
      if (this.children.length > y) {
        el = this.children.pop();
        if (!el) continue;
        el.parentNode.removeChild(el);
      }
    }
  }
  this.rows = y;

  // make sure the cursor stays on screen
  if (this.y >= y) this.y = y - 1;
  if (this.x >= x) this.x = x - 1;

  this.scrollTop = 0;
  this.scrollBottom = y - 1;

  this.refresh(0, this.rows - 1);

  // it's a real nightmare trying
  // to resize the original
  // screen buffer. just set it
  // to null for now.
  this.normal = null;
};

Terminal.prototype.updateRange = function(y) {
  if (y < this.refreshStart) this.refreshStart = y;
  if (y > this.refreshEnd) this.refreshEnd = y;
  // if (y > this.refreshEnd) {
  //   this.refreshEnd = y;
  //   if (y > this.rows - 1) {
  //     this.refreshEnd = this.rows - 1;
  //   }
  // }
};

Terminal.prototype.maxRange = function() {
  this.refreshStart = 0;
  this.refreshEnd = this.rows - 1;
};

Terminal.prototype.setupStops = function(i) {
  if (i != null) {
    if (!this.tabs[i]) {
      i = this.prevStop(i);
    }
  } else {
    this.tabs = {};
    i = 0;
  }

  for (; i < this.cols; i += 8) {
    this.tabs[i] = true;
  }
};

Terminal.prototype.prevStop = function(x) {
  if (x == null) x = this.x;
  while (!this.tabs[--x] && x > 0);
  return x >= this.cols
    ? this.cols - 1
    : x < 0 ? 0 : x;
};

Terminal.prototype.nextStop = function(x) {
  if (x == null) x = this.x;
  while (!this.tabs[++x] && x < this.cols);
  return x >= this.cols
    ? this.cols - 1
    : x < 0 ? 0 : x;
};

Terminal.prototype.eraseRight = function(x, y) {
  var line = this.lines[this.ybase + y]
    , ch = [this.curAttr, ' ']; // xterm

  for (; x < this.cols; x++) {
    line[x] = ch;
  }

  this.updateRange(y);
};

Terminal.prototype.eraseLeft = function(x, y) {
  var line = this.lines[this.ybase + y]
    , ch = [this.curAttr, ' ']; // xterm

  x++;
  while (x--) line[x] = ch;

  this.updateRange(y);
};

Terminal.prototype.eraseLine = function(y) {
  this.eraseRight(0, y);
};

Terminal.prototype.blankLine = function(cur) {
  var attr = cur
    ? this.curAttr
    : this.defAttr;

  var ch = [attr, ' ']
    , line = []
    , i = 0;

  for (; i < this.cols; i++) {
    line[i] = ch;
  }

  return line;
};

Terminal.prototype.ch = function(cur) {
  return cur
    ? [this.curAttr, ' ']
    : [this.defAttr, ' '];
};

Terminal.prototype.is = function(term) {
  var name = this.termName || Terminal.termName;
  return (name + '').indexOf(term) === 0;
};

Terminal.prototype.handler = function(data) {
  this.emit('data', data);
};

Terminal.prototype.handleTitle = function(title) {
  this.emit('title', title);
};

/**
 * ESC
 */

// ESC D Index (IND is 0x84).
Terminal.prototype.index = function() {
  this.y++;
  if (this.y > this.scrollBottom) {
    this.y--;
    this.scroll();
  }
  this.state = normal;
};

// ESC M Reverse Index (RI is 0x8d).
Terminal.prototype.reverseIndex = function() {
  var j;
  this.y--;
  if (this.y < this.scrollTop) {
    this.y++;
    // possibly move the code below to term.reverseScroll();
    // test: echo -ne '\e[1;1H\e[44m\eM\e[0m'
    // blankLine(true) is xterm/linux behavior
    this.lines.splice(this.y + this.ybase, 0, this.blankLine(true));
    j = this.rows - 1 - this.scrollBottom;
    this.lines.splice(this.rows - 1 + this.ybase - j + 1, 1);
    // this.maxRange();
    this.updateRange(this.scrollTop);
    this.updateRange(this.scrollBottom);
  }
  this.state = normal;
};

// ESC c Full Reset (RIS).
Terminal.prototype.reset = function() {
  Terminal.call(this, this.cols, this.rows);
  this.refresh(0, this.rows - 1);
};

// ESC H Tab Set (HTS is 0x88).
Terminal.prototype.tabSet = function() {
  this.tabs[this.x] = true;
  this.state = normal;
};

/**
 * CSI
 */

// CSI Ps A
// Cursor Up Ps Times (default = 1) (CUU).
Terminal.prototype.cursorUp = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.y -= param;
  if (this.y < 0) this.y = 0;
};

// CSI Ps B
// Cursor Down Ps Times (default = 1) (CUD).
Terminal.prototype.cursorDown = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.y += param;
  if (this.y >= this.rows) {
    this.y = this.rows - 1;
  }
};

// CSI Ps C
// Cursor Forward Ps Times (default = 1) (CUF).
Terminal.prototype.cursorForward = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.x += param;
  if (this.x >= this.cols) {
    this.x = this.cols - 1;
  }
};

// CSI Ps D
// Cursor Backward Ps Times (default = 1) (CUB).
Terminal.prototype.cursorBackward = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.x -= param;
  if (this.x < 0) this.x = 0;
};

// CSI Ps ; Ps H
// Cursor Position [row;column] (default = [1,1]) (CUP).
Terminal.prototype.cursorPos = function(params) {
  var row, col;

  row = params[0] - 1;

  if (params.length >= 2) {
    col = params[1] - 1;
  } else {
    col = 0;
  }

  if (row < 0) {
    row = 0;
  } else if (row >= this.rows) {
    row = this.rows - 1;
  }

  if (col < 0) {
    col = 0;
  } else if (col >= this.cols) {
    col = this.cols - 1;
  }

  this.x = col;
  this.y = row;
};

// CSI Ps J  Erase in Display (ED).
//     Ps = 0  -> Erase Below (default).
//     Ps = 1  -> Erase Above.
//     Ps = 2  -> Erase All.
//     Ps = 3  -> Erase Saved Lines (xterm).
// CSI ? Ps J
//   Erase in Display (DECSED).
//     Ps = 0  -> Selective Erase Below (default).
//     Ps = 1  -> Selective Erase Above.
//     Ps = 2  -> Selective Erase All.
Terminal.prototype.eraseInDisplay = function(params) {
  var j;
  switch (params[0]) {
    case 0:
      this.eraseRight(this.x, this.y);
      j = this.y + 1;
      for (; j < this.rows; j++) {
        this.eraseLine(j);
      }
      break;
    case 1:
      this.eraseLeft(this.x, this.y);
      j = this.y;
      while (j--) {
        this.eraseLine(j);
      }
      break;
    case 2:
      j = this.rows;
      while (j--) this.eraseLine(j);
      break;
    case 3:
      ; // no saved lines
      break;
  }
  this.emit('erase', {
    0: 'below',
    1: 'above',
    2: 'all',
    3: 'saved'
  }[params]);
};

// CSI Ps K  Erase in Line (EL).
//     Ps = 0  -> Erase to Right (default).
//     Ps = 1  -> Erase to Left.
//     Ps = 2  -> Erase All.
// CSI ? Ps K
//   Erase in Line (DECSEL).
//     Ps = 0  -> Selective Erase to Right (default).
//     Ps = 1  -> Selective Erase to Left.
//     Ps = 2  -> Selective Erase All.
Terminal.prototype.eraseInLine = function(params) {
  switch (params[0]) {
    case 0:
      this.eraseRight(this.x, this.y);
      break;
    case 1:
      this.eraseLeft(this.x, this.y);
      break;
    case 2:
      this.eraseLine(this.y);
      break;
  }
};

// CSI Pm m  Character Attributes (SGR).
//     Ps = 0  -> Normal (default).
//     Ps = 1  -> Bold.
//     Ps = 4  -> Underlined.
//     Ps = 5  -> Blink (appears as Bold).
//     Ps = 7  -> Inverse.
//     Ps = 8  -> Invisible, i.e., hidden (VT300).
//     Ps = 2 2  -> Normal (neither bold nor faint).
//     Ps = 2 4  -> Not underlined.
//     Ps = 2 5  -> Steady (not blinking).
//     Ps = 2 7  -> Positive (not inverse).
//     Ps = 2 8  -> Visible, i.e., not hidden (VT300).
//     Ps = 3 0  -> Set foreground color to Black.
//     Ps = 3 1  -> Set foreground color to Red.
//     Ps = 3 2  -> Set foreground color to Green.
//     Ps = 3 3  -> Set foreground color to Yellow.
//     Ps = 3 4  -> Set foreground color to Blue.
//     Ps = 3 5  -> Set foreground color to Magenta.
//     Ps = 3 6  -> Set foreground color to Cyan.
//     Ps = 3 7  -> Set foreground color to White.
//     Ps = 3 9  -> Set foreground color to default (original).
//     Ps = 4 0  -> Set background color to Black.
//     Ps = 4 1  -> Set background color to Red.
//     Ps = 4 2  -> Set background color to Green.
//     Ps = 4 3  -> Set background color to Yellow.
//     Ps = 4 4  -> Set background color to Blue.
//     Ps = 4 5  -> Set background color to Magenta.
//     Ps = 4 6  -> Set background color to Cyan.
//     Ps = 4 7  -> Set background color to White.
//     Ps = 4 9  -> Set background color to default (original).

//   If 16-color support is compiled, the following apply.  Assume
//   that xterm's resources are set so that the ISO color codes are
//   the first 8 of a set of 16.  Then the aixterm colors are the
//   bright versions of the ISO colors:
//     Ps = 9 0  -> Set foreground color to Black.
//     Ps = 9 1  -> Set foreground color to Red.
//     Ps = 9 2  -> Set foreground color to Green.
//     Ps = 9 3  -> Set foreground color to Yellow.
//     Ps = 9 4  -> Set foreground color to Blue.
//     Ps = 9 5  -> Set foreground color to Magenta.
//     Ps = 9 6  -> Set foreground color to Cyan.
//     Ps = 9 7  -> Set foreground color to White.
//     Ps = 1 0 0  -> Set background color to Black.
//     Ps = 1 0 1  -> Set background color to Red.
//     Ps = 1 0 2  -> Set background color to Green.
//     Ps = 1 0 3  -> Set background color to Yellow.
//     Ps = 1 0 4  -> Set background color to Blue.
//     Ps = 1 0 5  -> Set background color to Magenta.
//     Ps = 1 0 6  -> Set background color to Cyan.
//     Ps = 1 0 7  -> Set background color to White.

//   If xterm is compiled with the 16-color support disabled, it
//   supports the following, from rxvt:
//     Ps = 1 0 0  -> Set foreground and background color to
//     default.

//   If 88- or 256-color support is compiled, the following apply.
//     Ps = 3 8  ; 5  ; Ps -> Set foreground color to the second
//     Ps.
//     Ps = 4 8  ; 5  ; Ps -> Set background color to the second
//     Ps.
Terminal.prototype.charAttributes = function(params) {
  var l = params.length
    , i = 0
    , bg
    , fg
    , p;

  for (; i < l; i++) {
    p = params[i];
    if (p >= 30 && p <= 37) {
      // fg color 8
      this.curAttr = (this.curAttr & ~(0x1ff << 9)) | ((p - 30) << 9);
    } else if (p >= 40 && p <= 47) {
      // bg color 8
      this.curAttr = (this.curAttr & ~0x1ff) | (p - 40);
    } else if (p >= 90 && p <= 97) {
      // fg color 16
      p += 8;
      this.curAttr = (this.curAttr & ~(0x1ff << 9)) | ((p - 90) << 9);
    } else if (p >= 100 && p <= 107) {
      // bg color 16
      p += 8;
      this.curAttr = (this.curAttr & ~0x1ff) | (p - 100);
    } else if (p === 0) {
      // default
      this.curAttr = this.defAttr;
    } else if (p === 1) {
      // bold text
      this.curAttr = this.curAttr | (1 << 18);
    } else if (p === 4) {
      // underlined text
      this.curAttr = this.curAttr | (2 << 18);
    } else if (p === 7 || p === 27) {
      // inverse and positive
      // test with: echo -e '\e[31m\e[42mhello\e[7mworld\e[27mhi\e[m'
      if (p === 7) {
        if ((this.curAttr >> 18) & 4) continue;
        this.curAttr = this.curAttr | (4 << 18);
      } else if (p === 27) {
        if (~(this.curAttr >> 18) & 4) continue;
        this.curAttr = this.curAttr & ~(4 << 18);
      }

      bg = this.curAttr & 0x1ff;
      fg = (this.curAttr >> 9) & 0x1ff;

      this.curAttr = (this.curAttr & ~0x3ffff) | ((bg << 9) | fg);
    } else if (p === 22) {
      // not bold
      this.curAttr = this.curAttr & ~(1 << 18);
    } else if (p === 24) {
      // not underlined
      this.curAttr = this.curAttr & ~(2 << 18);
    } else if (p === 39) {
      // reset fg
      this.curAttr = this.curAttr & ~(0x1ff << 9);
      this.curAttr = this.curAttr | (((this.defAttr >> 9) & 0x1ff) << 9);
    } else if (p === 49) {
      // reset bg
      this.curAttr = this.curAttr & ~0x1ff;
      this.curAttr = this.curAttr | (this.defAttr & 0x1ff);
    } else if (p === 38) {
      // fg color 256
      if (params[i+1] !== 5) continue;
      i += 2;
      p = params[i] & 0xff;
      // convert 88 colors to 256
      // if (this.is('rxvt-unicode') && p < 88) p = p * 2.9090 | 0;
      this.curAttr = (this.curAttr & ~(0x1ff << 9)) | (p << 9);
    } else if (p === 48) {
      // bg color 256
      if (params[i+1] !== 5) continue;
      i += 2;
      p = params[i] & 0xff;
      // convert 88 colors to 256
      // if (this.is('rxvt-unicode') && p < 88) p = p * 2.9090 | 0;
      this.curAttr = (this.curAttr & ~0x1ff) | p;
    }
  }
};

// CSI Ps n  Device Status Report (DSR).
//     Ps = 5  -> Status Report.  Result (``OK'') is
//   CSI 0 n
//     Ps = 6  -> Report Cursor Position (CPR) [row;column].
//   Result is
//   CSI r ; c R
// CSI ? Ps n
//   Device Status Report (DSR, DEC-specific).
//     Ps = 6  -> Report Cursor Position (CPR) [row;column] as CSI
//     ? r ; c R (assumes page is zero).
//     Ps = 1 5  -> Report Printer status as CSI ? 1 0  n  (ready).
//     or CSI ? 1 1  n  (not ready).
//     Ps = 2 5  -> Report UDK status as CSI ? 2 0  n  (unlocked)
//     or CSI ? 2 1  n  (locked).
//     Ps = 2 6  -> Report Keyboard status as
//   CSI ? 2 7  ;  1  ;  0  ;  0  n  (North American).
//   The last two parameters apply to VT400 & up, and denote key-
//   board ready and LK01 respectively.
//     Ps = 5 3  -> Report Locator status as
//   CSI ? 5 3  n  Locator available, if compiled-in, or
//   CSI ? 5 0  n  No Locator, if not.
Terminal.prototype.deviceStatus = function(params) {
  if (!this.prefix) {
    switch (params[0]) {
      case 5:
        // status report
        this.send('\x1b[0n');
        break;
      case 6:
        // cursor position
        this.send('\x1b['
          + (this.y + 1)
          + ';'
          + (this.x + 1)
          + 'R');
        break;
    }
  } else if (this.prefix === '?') {
    // modern xterm doesnt seem to
    // respond to any of these except ?6, 6, and 5
    switch (params[0]) {
      case 6:
        // cursor position
        this.send('\x1b[?'
          + (this.y + 1)
          + ';'
          + (this.x + 1)
          + 'R');
        break;
      case 15:
        // no printer
        // this.send('\x1b[?11n');
        break;
      case 25:
        // dont support user defined keys
        // this.send('\x1b[?21n');
        break;
      case 26:
        // north american keyboard
        // this.send('\x1b[?27;1;0;0n');
        break;
      case 53:
        // no dec locator/mouse
        // this.send('\x1b[?50n');
        break;
    }
  }
};

/**
 * Additions
 */

// CSI Ps @
// Insert Ps (Blank) Character(s) (default = 1) (ICH).
Terminal.prototype.insertChars = function(params) {
  var param, row, j, ch;

  param = params[0];
  if (param < 1) param = 1;

  row = this.y + this.ybase;
  j = this.x;
  ch = [this.curAttr, ' ']; // xterm

  while (param-- && j < this.cols) {
    this.lines[row].splice(j++, 0, ch);
    this.lines[row].pop();
  }
};

// CSI Ps E
// Cursor Next Line Ps Times (default = 1) (CNL).
// same as CSI Ps B ?
Terminal.prototype.cursorNextLine = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.y += param;
  if (this.y >= this.rows) {
    this.y = this.rows - 1;
  }
  this.x = 0;
};

// CSI Ps F
// Cursor Preceding Line Ps Times (default = 1) (CNL).
// reuse CSI Ps A ?
Terminal.prototype.cursorPrecedingLine = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.y -= param;
  if (this.y < 0) this.y = 0;
  this.x = 0;
};

// CSI Ps G
// Cursor Character Absolute  [column] (default = [row,1]) (CHA).
Terminal.prototype.cursorCharAbsolute = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.x = param - 1;
};

// CSI Ps L
// Insert Ps Line(s) (default = 1) (IL).
Terminal.prototype.insertLines = function(params) {
  var param, row, j;

  param = params[0];
  if (param < 1) param = 1;
  row = this.y + this.ybase;

  j = this.rows - 1 - this.scrollBottom;
  j = this.rows - 1 + this.ybase - j + 1;

  while (param--) {
    // test: echo -e '\e[44m\e[1L\e[0m'
    // blankLine(true) - xterm/linux behavior
    this.lines.splice(row, 0, this.blankLine(true));
    this.lines.splice(j, 1);
  }

  // this.maxRange();
  this.updateRange(this.y);
  this.updateRange(this.scrollBottom);
};

// CSI Ps M
// Delete Ps Line(s) (default = 1) (DL).
Terminal.prototype.deleteLines = function(params) {
  var param, row, j;

  param = params[0];
  if (param < 1) param = 1;
  row = this.y + this.ybase;

  j = this.rows - 1 - this.scrollBottom;
  j = this.rows - 1 + this.ybase - j;

  while (param--) {
    // test: echo -e '\e[44m\e[1M\e[0m'
    // blankLine(true) - xterm/linux behavior
    this.lines.splice(j + 1, 0, this.blankLine(true));
    this.lines.splice(row, 1);
  }

  // this.maxRange();
  this.updateRange(this.y);
  this.updateRange(this.scrollBottom);
};

// CSI Ps P
// Delete Ps Character(s) (default = 1) (DCH).
Terminal.prototype.deleteChars = function(params) {
  var param, row, ch;

  param = params[0];
  if (param < 1) param = 1;

  row = this.y + this.ybase;
  ch = [this.curAttr, ' ']; // xterm

  while (param--) {
    this.lines[row].splice(this.x, 1);
    this.lines[row].push(ch);
  }
};

// CSI Ps X
// Erase Ps Character(s) (default = 1) (ECH).
Terminal.prototype.eraseChars = function(params) {
  var param, row, j, ch;

  param = params[0];
  if (param < 1) param = 1;

  row = this.y + this.ybase;
  j = this.x;
  ch = [this.curAttr, ' ']; // xterm

  while (param-- && j < this.cols) {
    this.lines[row][j++] = ch;
  }
};

// CSI Pm `  Character Position Absolute
//   [column] (default = [row,1]) (HPA).
Terminal.prototype.charPosAbsolute = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.x = param - 1;
  if (this.x >= this.cols) {
    this.x = this.cols - 1;
  }
};

// 141 61 a * HPR -
// Horizontal Position Relative
// reuse CSI Ps C ?
Terminal.prototype.HPositionRelative = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.x += param;
  if (this.x >= this.cols) {
    this.x = this.cols - 1;
  }
};

// CSI Ps c  Send Device Attributes (Primary DA).
//     Ps = 0  or omitted -> request attributes from terminal.  The
//     response depends on the decTerminalID resource setting.
//     -> CSI ? 1 ; 2 c  (``VT100 with Advanced Video Option'')
//     -> CSI ? 1 ; 0 c  (``VT101 with No Options'')
//     -> CSI ? 6 c  (``VT102'')
//     -> CSI ? 6 0 ; 1 ; 2 ; 6 ; 8 ; 9 ; 1 5 ; c  (``VT220'')
//   The VT100-style response parameters do not mean anything by
//   themselves.  VT220 parameters do, telling the host what fea-
//   tures the terminal supports:
//     Ps = 1  -> 132-columns.
//     Ps = 2  -> Printer.
//     Ps = 6  -> Selective erase.
//     Ps = 8  -> User-defined keys.
//     Ps = 9  -> National replacement character sets.
//     Ps = 1 5  -> Technical characters.
//     Ps = 2 2  -> ANSI color, e.g., VT525.
//     Ps = 2 9  -> ANSI text locator (i.e., DEC Locator mode).
// CSI > Ps c
//   Send Device Attributes (Secondary DA).
//     Ps = 0  or omitted -> request the terminal's identification
//     code.  The response depends on the decTerminalID resource set-
//     ting.  It should apply only to VT220 and up, but xterm extends
//     this to VT100.
//     -> CSI  > Pp ; Pv ; Pc c
//   where Pp denotes the terminal type
//     Pp = 0  -> ``VT100''.
//     Pp = 1  -> ``VT220''.
//   and Pv is the firmware version (for xterm, this was originally
//   the XFree86 patch number, starting with 95).  In a DEC termi-
//   nal, Pc indicates the ROM cartridge registration number and is
//   always zero.
// More information:
//   xterm/charproc.c - line 2012, for more information.
//   vim responds with ^[[?0c or ^[[?1c after the terminal's response (?)
Terminal.prototype.sendDeviceAttributes = function(params) {
  if (params[0] > 0) return;

  if (!this.prefix) {
    if (this.is('xterm')
        || this.is('rxvt-unicode')
        || this.is('screen')) {
      this.send('\x1b[?1;2c');
    } else if (this.is('linux')) {
      this.send('\x1b[?6c');
    }
  } else if (this.prefix === '>') {
    // xterm and urxvt
    // seem to spit this
    // out around ~370 times (?).
    if (this.is('xterm')) {
      this.send('\x1b[>0;276;0c');
    } else if (this.is('rxvt-unicode')) {
      this.send('\x1b[>85;95;0c');
    } else if (this.is('linux')) {
      // not supported by linux console.
      // linux console echoes parameters.
      this.send(params[0] + 'c');
    } else if (this.is('screen')) {
      this.send('\x1b[>83;40003;0c');
    }
  }
};

// CSI Pm d
// Line Position Absolute  [row] (default = [1,column]) (VPA).
Terminal.prototype.linePosAbsolute = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.y = param - 1;
  if (this.y >= this.rows) {
    this.y = this.rows - 1;
  }
};

// 145 65 e * VPR - Vertical Position Relative
// reuse CSI Ps B ?
Terminal.prototype.VPositionRelative = function(params) {
  var param = params[0];
  if (param < 1) param = 1;
  this.y += param;
  if (this.y >= this.rows) {
    this.y = this.rows - 1;
  }
};

// CSI Ps ; Ps f
//   Horizontal and Vertical Position [row;column] (default =
//   [1,1]) (HVP).
Terminal.prototype.HVPosition = function(params) {
  if (params[0] < 1) params[0] = 1;
  if (params[1] < 1) params[1] = 1;

  this.y = params[0] - 1;
  if (this.y >= this.rows) {
    this.y = this.rows - 1;
  }

  this.x = params[1] - 1;
  if (this.x >= this.cols) {
    this.x = this.cols - 1;
  }
};

// CSI Pm h  Set Mode (SM).
//     Ps = 2  -> Keyboard Action Mode (AM).
//     Ps = 4  -> Insert Mode (IRM).
//     Ps = 1 2  -> Send/receive (SRM).
//     Ps = 2 0  -> Automatic Newline (LNM).
// CSI ? Pm h
//   DEC Private Mode Set (DECSET).
//     Ps = 1  -> Application Cursor Keys (DECCKM).
//     Ps = 2  -> Designate USASCII for character sets G0-G3
//     (DECANM), and set VT100 mode.
//     Ps = 3  -> 132 Column Mode (DECCOLM).
//     Ps = 4  -> Smooth (Slow) Scroll (DECSCLM).
//     Ps = 5  -> Reverse Video (DECSCNM).
//     Ps = 6  -> Origin Mode (DECOM).
//     Ps = 7  -> Wraparound Mode (DECAWM).
//     Ps = 8  -> Auto-repeat Keys (DECARM).
//     Ps = 9  -> Send Mouse X & Y on button press.  See the sec-
//     tion Mouse Tracking.
//     Ps = 1 0  -> Show toolbar (rxvt).
//     Ps = 1 2  -> Start Blinking Cursor (att610).
//     Ps = 1 8  -> Print form feed (DECPFF).
//     Ps = 1 9  -> Set print extent to full screen (DECPEX).
//     Ps = 2 5  -> Show Cursor (DECTCEM).
//     Ps = 3 0  -> Show scrollbar (rxvt).
//     Ps = 3 5  -> Enable font-shifting functions (rxvt).
//     Ps = 3 8  -> Enter Tektronix Mode (DECTEK).
//     Ps = 4 0  -> Allow 80 -> 132 Mode.
//     Ps = 4 1  -> more(1) fix (see curses resource).
//     Ps = 4 2  -> Enable Nation Replacement Character sets (DECN-
//     RCM).
//     Ps = 4 4  -> Turn On Margin Bell.
//     Ps = 4 5  -> Reverse-wraparound Mode.
//     Ps = 4 6  -> Start Logging.  This is normally disabled by a
//     compile-time option.
//     Ps = 4 7  -> Use Alternate Screen Buffer.  (This may be dis-
//     abled by the titeInhibit resource).
//     Ps = 6 6  -> Application keypad (DECNKM).
//     Ps = 6 7  -> Backarrow key sends backspace (DECBKM).
//     Ps = 1 0 0 0  -> Send Mouse X & Y on button press and
//     release.  See the section Mouse Tracking.
//     Ps = 1 0 0 1  -> Use Hilite Mouse Tracking.
//     Ps = 1 0 0 2  -> Use Cell Motion Mouse Tracking.
//     Ps = 1 0 0 3  -> Use All Motion Mouse Tracking.
//     Ps = 1 0 0 4  -> Send FocusIn/FocusOut events.
//     Ps = 1 0 0 5  -> Enable Extended Mouse Mode.
//     Ps = 1 0 1 0  -> Scroll to bottom on tty output (rxvt).
//     Ps = 1 0 1 1  -> Scroll to bottom on key press (rxvt).
//     Ps = 1 0 3 4  -> Interpret "meta" key, sets eighth bit.
//     (enables the eightBitInput resource).
//     Ps = 1 0 3 5  -> Enable special modifiers for Alt and Num-
//     Lock keys.  (This enables the numLock resource).
//     Ps = 1 0 3 6  -> Send ESC   when Meta modifies a key.  (This
//     enables the metaSendsEscape resource).
//     Ps = 1 0 3 7  -> Send DEL from the editing-keypad Delete
//     key.
//     Ps = 1 0 3 9  -> Send ESC  when Alt modifies a key.  (This
//     enables the altSendsEscape resource).
//     Ps = 1 0 4 0  -> Keep selection even if not highlighted.
//     (This enables the keepSelection resource).
//     Ps = 1 0 4 1  -> Use the CLIPBOARD selection.  (This enables
//     the selectToClipboard resource).
//     Ps = 1 0 4 2  -> Enable Urgency window manager hint when
//     Control-G is received.  (This enables the bellIsUrgent
//     resource).
//     Ps = 1 0 4 3  -> Enable raising of the window when Control-G
//     is received.  (enables the popOnBell resource).
//     Ps = 1 0 4 7  -> Use Alternate Screen Buffer.  (This may be
//     disabled by the titeInhibit resource).
//     Ps = 1 0 4 8  -> Save cursor as in DECSC.  (This may be dis-
//     abled by the titeInhibit resource).
//     Ps = 1 0 4 9  -> Save cursor as in DECSC and use Alternate
//     Screen Buffer, clearing it first.  (This may be disabled by
//     the titeInhibit resource).  This combines the effects of the 1
//     0 4 7  and 1 0 4 8  modes.  Use this with terminfo-based
//     applications rather than the 4 7  mode.
//     Ps = 1 0 5 0  -> Set terminfo/termcap function-key mode.
//     Ps = 1 0 5 1  -> Set Sun function-key mode.
//     Ps = 1 0 5 2  -> Set HP function-key mode.
//     Ps = 1 0 5 3  -> Set SCO function-key mode.
//     Ps = 1 0 6 0  -> Set legacy keyboard emulation (X11R6).
//     Ps = 1 0 6 1  -> Set VT220 keyboard emulation.
//     Ps = 2 0 0 4  -> Set bracketed paste mode.
// Modes:
//   http://vt100.net/docs/vt220-rm/chapter4.html
Terminal.prototype.setMode = function(params) {
  if (typeof params === 'object') {
    var l = params.length
      , i = 0;

    for (; i < l; i++) {
      this.setMode(params[i]);
    }

    return;
  }

  if (!this.prefix) {
    switch (params) {
      case 4:
        this.insertMode = true;
        break;
      case 20:
        //this.convertEol = true;
        break;
    }
  } else if (this.prefix === '?') {
    switch (params) {
      case 1:
        this.applicationKeypad = true;
        break;
      case 2:
        this.setgCharset(0, Terminal.charsets.US);
        this.setgCharset(1, Terminal.charsets.US);
        this.setgCharset(2, Terminal.charsets.US);
        this.setgCharset(3, Terminal.charsets.US);
        // set VT100 mode here
        break;
      case 3: // 132 col mode
        this.savedCols = this.cols;
        this.resize(132, this.rows);
        break;
      case 6:
        this.originMode = true;
        break;
      case 7:
        this.wraparoundMode = true;
        break;
      case 12:
        // this.cursorBlink = true;
        break;
      case 9: // X10 Mouse
        // no release, no motion, no wheel, no modifiers.
      case 1000: // vt200 mouse
        // no motion.
        // no modifiers, except control on the wheel.
      case 1002: // button event mouse
      case 1003: // any event mouse
        // any event - sends motion events,
        // even if there is no button held down.
        this.x10Mouse = params === 9;
        this.vt200Mouse = params === 1000;
        this.normalMouse = params > 1000;
        this.mouseEvents = true;
        this.element.style.cursor = 'default';
        this.log('Binding to mouse events.');
        break;
      case 1004: // send focusin/focusout events
        // focusin: ^[[I
        // focusout: ^[[O
        this.sendFocus = true;
        break;
      case 1005: // utf8 ext mode mouse
        this.utfMouse = true;
        // for wide terminals
        // simply encodes large values as utf8 characters
        break;
      case 1006: // sgr ext mode mouse
        this.sgrMouse = true;
        // for wide terminals
        // does not add 32 to fields
        // press: ^[[<b;x;yM
        // release: ^[[<b;x;ym
        break;
      case 1015: // urxvt ext mode mouse
        this.urxvtMouse = true;
        // for wide terminals
        // numbers for fields
        // press: ^[[b;x;yM
        // motion: ^[[b;x;yT
        break;
      case 25: // show cursor
        this.cursorHidden = false;
        break;
      case 1049: // alt screen buffer cursor
        //this.saveCursor();
        ; // FALL-THROUGH
      case 47: // alt screen buffer
      case 1047: // alt screen buffer
        if (!this.normal) {
          var normal = {
            lines: this.lines,
            ybase: this.ybase,
            ydisp: this.ydisp,
            x: this.x,
            y: this.y,
            scrollTop: this.scrollTop,
            scrollBottom: this.scrollBottom,
            tabs: this.tabs
            // XXX save charset(s) here?
            // charset: this.charset,
            // glevel: this.glevel,
            // charsets: this.charsets
          };
          this.reset();
          this.normal = normal;
          this.showCursor();
        }
        break;
    }
  }
};

// CSI Pm l  Reset Mode (RM).
//     Ps = 2  -> Keyboard Action Mode (AM).
//     Ps = 4  -> Replace Mode (IRM).
//     Ps = 1 2  -> Send/receive (SRM).
//     Ps = 2 0  -> Normal Linefeed (LNM).
// CSI ? Pm l
//   DEC Private Mode Reset (DECRST).
//     Ps = 1  -> Normal Cursor Keys (DECCKM).
//     Ps = 2  -> Designate VT52 mode (DECANM).
//     Ps = 3  -> 80 Column Mode (DECCOLM).
//     Ps = 4  -> Jump (Fast) Scroll (DECSCLM).
//     Ps = 5  -> Normal Video (DECSCNM).
//     Ps = 6  -> Normal Cursor Mode (DECOM).
//     Ps = 7  -> No Wraparound Mode (DECAWM).
//     Ps = 8  -> No Auto-repeat Keys (DECARM).
//     Ps = 9  -> Don't send Mouse X & Y on button press.
//     Ps = 1 0  -> Hide toolbar (rxvt).
//     Ps = 1 2  -> Stop Blinking Cursor (att610).
//     Ps = 1 8  -> Don't print form feed (DECPFF).
//     Ps = 1 9  -> Limit print to scrolling region (DECPEX).
//     Ps = 2 5  -> Hide Cursor (DECTCEM).
//     Ps = 3 0  -> Don't show scrollbar (rxvt).
//     Ps = 3 5  -> Disable font-shifting functions (rxvt).
//     Ps = 4 0  -> Disallow 80 -> 132 Mode.
//     Ps = 4 1  -> No more(1) fix (see curses resource).
//     Ps = 4 2  -> Disable Nation Replacement Character sets (DEC-
//     NRCM).
//     Ps = 4 4  -> Turn Off Margin Bell.
//     Ps = 4 5  -> No Reverse-wraparound Mode.
//     Ps = 4 6  -> Stop Logging.  (This is normally disabled by a
//     compile-time option).
//     Ps = 4 7  -> Use Normal Screen Buffer.
//     Ps = 6 6  -> Numeric keypad (DECNKM).
//     Ps = 6 7  -> Backarrow key sends delete (DECBKM).
//     Ps = 1 0 0 0  -> Don't send Mouse X & Y on button press and
//     release.  See the section Mouse Tracking.
//     Ps = 1 0 0 1  -> Don't use Hilite Mouse Tracking.
//     Ps = 1 0 0 2  -> Don't use Cell Motion Mouse Tracking.
//     Ps = 1 0 0 3  -> Don't use All Motion Mouse Tracking.
//     Ps = 1 0 0 4  -> Don't send FocusIn/FocusOut events.
//     Ps = 1 0 0 5  -> Disable Extended Mouse Mode.
//     Ps = 1 0 1 0  -> Don't scroll to bottom on tty output
//     (rxvt).
//     Ps = 1 0 1 1  -> Don't scroll to bottom on key press (rxvt).
//     Ps = 1 0 3 4  -> Don't interpret "meta" key.  (This disables
//     the eightBitInput resource).
//     Ps = 1 0 3 5  -> Disable special modifiers for Alt and Num-
//     Lock keys.  (This disables the numLock resource).
//     Ps = 1 0 3 6  -> Don't send ESC  when Meta modifies a key.
//     (This disables the metaSendsEscape resource).
//     Ps = 1 0 3 7  -> Send VT220 Remove from the editing-keypad
//     Delete key.
//     Ps = 1 0 3 9  -> Don't send ESC  when Alt modifies a key.
//     (This disables the altSendsEscape resource).
//     Ps = 1 0 4 0  -> Do not keep selection when not highlighted.
//     (This disables the keepSelection resource).
//     Ps = 1 0 4 1  -> Use the PRIMARY selection.  (This disables
//     the selectToClipboard resource).
//     Ps = 1 0 4 2  -> Disable Urgency window manager hint when
//     Control-G is received.  (This disables the bellIsUrgent
//     resource).
//     Ps = 1 0 4 3  -> Disable raising of the window when Control-
//     G is received.  (This disables the popOnBell resource).
//     Ps = 1 0 4 7  -> Use Normal Screen Buffer, clearing screen
//     first if in the Alternate Screen.  (This may be disabled by
//     the titeInhibit resource).
//     Ps = 1 0 4 8  -> Restore cursor as in DECRC.  (This may be
//     disabled by the titeInhibit resource).
//     Ps = 1 0 4 9  -> Use Normal Screen Buffer and restore cursor
//     as in DECRC.  (This may be disabled by the titeInhibit
//     resource).  This combines the effects of the 1 0 4 7  and 1 0
//     4 8  modes.  Use this with terminfo-based applications rather
//     than the 4 7  mode.
//     Ps = 1 0 5 0  -> Reset terminfo/termcap function-key mode.
//     Ps = 1 0 5 1  -> Reset Sun function-key mode.
//     Ps = 1 0 5 2  -> Reset HP function-key mode.
//     Ps = 1 0 5 3  -> Reset SCO function-key mode.
//     Ps = 1 0 6 0  -> Reset legacy keyboard emulation (X11R6).
//     Ps = 1 0 6 1  -> Reset keyboard emulation to Sun/PC style.
//     Ps = 2 0 0 4  -> Reset bracketed paste mode.
Terminal.prototype.resetMode = function(params) {
  if (typeof params === 'object') {
    var l = params.length
      , i = 0;

    for (; i < l; i++) {
      this.resetMode(params[i]);
    }

    return;
  }

  if (!this.prefix) {
    switch (params) {
      case 4:
        this.insertMode = false;
        break;
      case 20:
        //this.convertEol = false;
        break;
    }
  } else if (this.prefix === '?') {
    switch (params) {
      case 1:
        this.applicationKeypad = false;
        break;
      case 3:
        if (this.cols === 132 && this.savedCols) {
          this.resize(this.savedCols, this.rows);
        }
        delete this.savedCols;
        break;
      case 6:
        this.originMode = false;
        break;
      case 7:
        this.wraparoundMode = false;
        break;
      case 12:
        // this.cursorBlink = false;
        break;
      case 9: // X10 Mouse
      case 1000: // vt200 mouse
      case 1002: // button event mouse
      case 1003: // any event mouse
        this.x10Mouse = false;
        this.vt200Mouse = false;
        this.normalMouse = false;
        this.mouseEvents = false;
        this.element.style.cursor = '';
        break;
      case 1004: // send focusin/focusout events
        this.sendFocus = false;
        break;
      case 1005: // utf8 ext mode mouse
        this.utfMouse = false;
        break;
      case 1006: // sgr ext mode mouse
        this.sgrMouse = false;
        break;
      case 1015: // urxvt ext mode mouse
        this.urxvtMouse = false;
        break;
      case 25: // hide cursor
        this.cursorHidden = true;
        break;
      case 1049: // alt screen buffer cursor
        ; // FALL-THROUGH
      case 47: // normal screen buffer
      case 1047: // normal screen buffer - clearing it first
        if (this.normal) {
          this.lines = this.normal.lines;
          this.ybase = this.normal.ybase;
          this.ydisp = this.normal.ydisp;
          this.x = this.normal.x;
          this.y = this.normal.y;
          this.scrollTop = this.normal.scrollTop;
          this.scrollBottom = this.normal.scrollBottom;
          this.tabs = this.normal.tabs;
          this.normal = null;
          // if (params === 1049) {
          //   this.x = this.savedX;
          //   this.y = this.savedY;
          // }
          this.refresh(0, this.rows - 1);
          this.showCursor();
        }
        break;
    }
  }
};

// CSI Ps ; Ps r
//   Set Scrolling Region [top;bottom] (default = full size of win-
//   dow) (DECSTBM).
// CSI ? Pm r
Terminal.prototype.setScrollRegion = function(params) {
  if (this.prefix) return;
  this.scrollTop = (params[0] || 1) - 1;
  this.scrollBottom = (params[1] || this.rows) - 1;
  this.x = 0;
  this.y = 0;
};

// CSI s
//   Save cursor (ANSI.SYS).
Terminal.prototype.saveCursor = function(params) {
  this.savedX = this.x;
  this.savedY = this.y;
};

// CSI u
//   Restore cursor (ANSI.SYS).
Terminal.prototype.restoreCursor = function(params) {
  this.x = this.savedX || 0;
  this.y = this.savedY || 0;
};

/**
 * Lesser Used
 */

// CSI Ps I
//   Cursor Forward Tabulation Ps tab stops (default = 1) (CHT).
Terminal.prototype.cursorForwardTab = function(params) {
  var param = params[0] || 1;
  while (param--) {
    this.x = this.nextStop();
  }
};

// CSI Ps S  Scroll up Ps lines (default = 1) (SU).
Terminal.prototype.scrollUp = function(params) {
  var param = params[0] || 1;
  while (param--) {
    this.lines.splice(this.ybase + this.scrollTop, 1);
    this.lines.splice(this.ybase + this.scrollBottom, 0, this.blankLine());
  }
  // this.maxRange();
  this.updateRange(this.scrollTop);
  this.updateRange(this.scrollBottom);
};

// CSI Ps T  Scroll down Ps lines (default = 1) (SD).
Terminal.prototype.scrollDown = function(params) {
  var param = params[0] || 1;
  while (param--) {
    this.lines.splice(this.ybase + this.scrollBottom, 1);
    this.lines.splice(this.ybase + this.scrollTop, 0, this.blankLine());
  }
  // this.maxRange();
  this.updateRange(this.scrollTop);
  this.updateRange(this.scrollBottom);
};

// CSI Ps ; Ps ; Ps ; Ps ; Ps T
//   Initiate highlight mouse tracking.  Parameters are
//   [func;startx;starty;firstrow;lastrow].  See the section Mouse
//   Tracking.
Terminal.prototype.initMouseTracking = function(params) {
  // Relevant: DECSET 1001
};

// CSI > Ps; Ps T
//   Reset one or more features of the title modes to the default
//   value.  Normally, "reset" disables the feature.  It is possi-
//   ble to disable the ability to reset features by compiling a
//   different default for the title modes into xterm.
//     Ps = 0  -> Do not set window/icon labels using hexadecimal.
//     Ps = 1  -> Do not query window/icon labels using hexadeci-
//     mal.
//     Ps = 2  -> Do not set window/icon labels using UTF-8.
//     Ps = 3  -> Do not query window/icon labels using UTF-8.
//   (See discussion of "Title Modes").
Terminal.prototype.resetTitleModes = function(params) {
  ;
};

// CSI Ps Z  Cursor Backward Tabulation Ps tab stops (default = 1) (CBT).
Terminal.prototype.cursorBackwardTab = function(params) {
  var param = params[0] || 1;
  while (param--) {
    this.x = this.prevStop();
  }
};

// CSI Ps b  Repeat the preceding graphic character Ps times (REP).
Terminal.prototype.repeatPrecedingCharacter = function(params) {
  var param = params[0] || 1
    , line = this.lines[this.ybase + this.y]
    , ch = line[this.x - 1] || [this.defAttr, ' '];

  while (param--) line[this.x++] = ch;
};

// CSI Ps g  Tab Clear (TBC).
//     Ps = 0  -> Clear Current Column (default).
//     Ps = 3  -> Clear All.
// Potentially:
//   Ps = 2  -> Clear Stops on Line.
//   http://vt100.net/annarbor/aaa-ug/section6.html
Terminal.prototype.tabClear = function(params) {
  var param = params[0];
  if (param <= 0) {
    delete this.tabs[this.x];
  } else if (param === 3) {
    this.tabs = {};
  }
};

// CSI Pm i  Media Copy (MC).
//     Ps = 0  -> Print screen (default).
//     Ps = 4  -> Turn off printer controller mode.
//     Ps = 5  -> Turn on printer controller mode.
// CSI ? Pm i
//   Media Copy (MC, DEC-specific).
//     Ps = 1  -> Print line containing cursor.
//     Ps = 4  -> Turn off autoprint mode.
//     Ps = 5  -> Turn on autoprint mode.
//     Ps = 1  0  -> Print composed display, ignores DECPEX.
//     Ps = 1  1  -> Print all pages.
Terminal.prototype.mediaCopy = function(params) {
  ;
};

// CSI > Ps; Ps m
//   Set or reset resource-values used by xterm to decide whether
//   to construct escape sequences holding information about the
//   modifiers pressed with a given key.  The first parameter iden-
//   tifies the resource to set/reset.  The second parameter is the
//   value to assign to the resource.  If the second parameter is
//   omitted, the resource is reset to its initial value.
//     Ps = 1  -> modifyCursorKeys.
//     Ps = 2  -> modifyFunctionKeys.
//     Ps = 4  -> modifyOtherKeys.
//   If no parameters are given, all resources are reset to their
//   initial values.
Terminal.prototype.setResources = function(params) {
  ;
};

// CSI > Ps n
//   Disable modifiers which may be enabled via the CSI > Ps; Ps m
//   sequence.  This corresponds to a resource value of "-1", which
//   cannot be set with the other sequence.  The parameter identi-
//   fies the resource to be disabled:
//     Ps = 1  -> modifyCursorKeys.
//     Ps = 2  -> modifyFunctionKeys.
//     Ps = 4  -> modifyOtherKeys.
//   If the parameter is omitted, modifyFunctionKeys is disabled.
//   When modifyFunctionKeys is disabled, xterm uses the modifier
//   keys to make an extended sequence of functions rather than
//   adding a parameter to each function key to denote the modi-
//   fiers.
Terminal.prototype.disableModifiers = function(params) {
  ;
};

// CSI > Ps p
//   Set resource value pointerMode.  This is used by xterm to
//   decide whether to hide the pointer cursor as the user types.
//   Valid values for the parameter:
//     Ps = 0  -> never hide the pointer.
//     Ps = 1  -> hide if the mouse tracking mode is not enabled.
//     Ps = 2  -> always hide the pointer.  If no parameter is
//     given, xterm uses the default, which is 1 .
Terminal.prototype.setPointerMode = function(params) {
  ;
};

// CSI ! p   Soft terminal reset (DECSTR).
// http://vt100.net/docs/vt220-rm/table4-10.html
Terminal.prototype.softReset = function(params) {
  this.cursorHidden = false;
  this.insertMode = false;
  this.originMode = false;
  this.wraparoundMode = false; // autowrap
  this.applicationKeypad = false; // ?
  this.scrollTop = 0;
  this.scrollBottom = this.rows - 1;
  this.curAttr = this.defAttr;
  this.x = this.y = 0; // ?
  this.charset = null;
  this.glevel = 0; // ??
  this.charsets = [null]; // ??
};

// CSI Ps$ p
//   Request ANSI mode (DECRQM).  For VT300 and up, reply is
//     CSI Ps; Pm$ y
//   where Ps is the mode number as in RM, and Pm is the mode
//   value:
//     0 - not recognized
//     1 - set
//     2 - reset
//     3 - permanently set
//     4 - permanently reset
Terminal.prototype.requestAnsiMode = function(params) {
  ;
};

// CSI ? Ps$ p
//   Request DEC private mode (DECRQM).  For VT300 and up, reply is
//     CSI ? Ps; Pm$ p
//   where Ps is the mode number as in DECSET, Pm is the mode value
//   as in the ANSI DECRQM.
Terminal.prototype.requestPrivateMode = function(params) {
  ;
};

// CSI Ps ; Ps " p
//   Set conformance level (DECSCL).  Valid values for the first
//   parameter:
//     Ps = 6 1  -> VT100.
//     Ps = 6 2  -> VT200.
//     Ps = 6 3  -> VT300.
//   Valid values for the second parameter:
//     Ps = 0  -> 8-bit controls.
//     Ps = 1  -> 7-bit controls (always set for VT100).
//     Ps = 2  -> 8-bit controls.
Terminal.prototype.setConformanceLevel = function(params) {
  ;
};

// CSI Ps q  Load LEDs (DECLL).
//     Ps = 0  -> Clear all LEDS (default).
//     Ps = 1  -> Light Num Lock.
//     Ps = 2  -> Light Caps Lock.
//     Ps = 3  -> Light Scroll Lock.
//     Ps = 2  1  -> Extinguish Num Lock.
//     Ps = 2  2  -> Extinguish Caps Lock.
//     Ps = 2  3  -> Extinguish Scroll Lock.
Terminal.prototype.loadLEDs = function(params) {
  ;
};

// CSI Ps SP q
//   Set cursor style (DECSCUSR, VT520).
//     Ps = 0  -> blinking block.
//     Ps = 1  -> blinking block (default).
//     Ps = 2  -> steady block.
//     Ps = 3  -> blinking underline.
//     Ps = 4  -> steady underline.
Terminal.prototype.setCursorStyle = function(params) {
  ;
};

// CSI Ps " q
//   Select character protection attribute (DECSCA).  Valid values
//   for the parameter:
//     Ps = 0  -> DECSED and DECSEL can erase (default).
//     Ps = 1  -> DECSED and DECSEL cannot erase.
//     Ps = 2  -> DECSED and DECSEL can erase.
Terminal.prototype.setCharProtectionAttr = function(params) {
  ;
};

// CSI ? Pm r
//   Restore DEC Private Mode Values.  The value of Ps previously
//   saved is restored.  Ps values are the same as for DECSET.
Terminal.prototype.restorePrivateValues = function(params) {
  ;
};

// CSI Pt; Pl; Pb; Pr; Ps$ r
//   Change Attributes in Rectangular Area (DECCARA), VT400 and up.
//     Pt; Pl; Pb; Pr denotes the rectangle.
//     Ps denotes the SGR attributes to change: 0, 1, 4, 5, 7.
// NOTE: xterm doesn't enable this code by default.
Terminal.prototype.setAttrInRectangle = function(params) {
  var t = params[0]
    , l = params[1]
    , b = params[2]
    , r = params[3]
    , attr = params[4];

  var line
    , i;

  for (; t < b + 1; t++) {
    line = this.lines[this.ybase + t];
    for (i = l; i < r; i++) {
      line[i] = [attr, line[i][1]];
    }
  }

  // this.maxRange();
  this.updateRange(params[0]);
  this.updateRange(params[2]);
};

// CSI ? Pm s
//   Save DEC Private Mode Values.  Ps values are the same as for
//   DECSET.
Terminal.prototype.savePrivateValues = function(params) {
  ;
};

// CSI Ps ; Ps ; Ps t
//   Window manipulation (from dtterm, as well as extensions).
//   These controls may be disabled using the allowWindowOps
//   resource.  Valid values for the first (and any additional
//   parameters) are:
//     Ps = 1  -> De-iconify window.
//     Ps = 2  -> Iconify window.
//     Ps = 3  ;  x ;  y -> Move window to [x, y].
//     Ps = 4  ;  height ;  width -> Resize the xterm window to
//     height and width in pixels.
//     Ps = 5  -> Raise the xterm window to the front of the stack-
//     ing order.
//     Ps = 6  -> Lower the xterm window to the bottom of the
//     stacking order.
//     Ps = 7  -> Refresh the xterm window.
//     Ps = 8  ;  height ;  width -> Resize the text area to
//     [height;width] in characters.
//     Ps = 9  ;  0  -> Restore maximized window.
//     Ps = 9  ;  1  -> Maximize window (i.e., resize to screen
//     size).
//     Ps = 1 0  ;  0  -> Undo full-screen mode.
//     Ps = 1 0  ;  1  -> Change to full-screen.
//     Ps = 1 1  -> Report xterm window state.  If the xterm window
//     is open (non-iconified), it returns CSI 1 t .  If the xterm
//     window is iconified, it returns CSI 2 t .
//     Ps = 1 3  -> Report xterm window position.  Result is CSI 3
//     ; x ; y t
//     Ps = 1 4  -> Report xterm window in pixels.  Result is CSI
//     4  ;  height ;  width t
//     Ps = 1 8  -> Report the size of the text area in characters.
//     Result is CSI  8  ;  height ;  width t
//     Ps = 1 9  -> Report the size of the screen in characters.
//     Result is CSI  9  ;  height ;  width t
//     Ps = 2 0  -> Report xterm window's icon label.  Result is
//     OSC  L  label ST
//     Ps = 2 1  -> Report xterm window's title.  Result is OSC  l
//     label ST
//     Ps = 2 2  ;  0  -> Save xterm icon and window title on
//     stack.
//     Ps = 2 2  ;  1  -> Save xterm icon title on stack.
//     Ps = 2 2  ;  2  -> Save xterm window title on stack.
//     Ps = 2 3  ;  0  -> Restore xterm icon and window title from
//     stack.
//     Ps = 2 3  ;  1  -> Restore xterm icon title from stack.
//     Ps = 2 3  ;  2  -> Restore xterm window title from stack.
//     Ps >= 2 4  -> Resize to Ps lines (DECSLPP).
Terminal.prototype.manipulateWindow = function(params) {
  ;
};

// CSI Pt; Pl; Pb; Pr; Ps$ t
//   Reverse Attributes in Rectangular Area (DECRARA), VT400 and
//   up.
//     Pt; Pl; Pb; Pr denotes the rectangle.
//     Ps denotes the attributes to reverse, i.e.,  1, 4, 5, 7.
// NOTE: xterm doesn't enable this code by default.
Terminal.prototype.reverseAttrInRectangle = function(params) {
  ;
};

// CSI > Ps; Ps t
//   Set one or more features of the title modes.  Each parameter
//   enables a single feature.
//     Ps = 0  -> Set window/icon labels using hexadecimal.
//     Ps = 1  -> Query window/icon labels using hexadecimal.
//     Ps = 2  -> Set window/icon labels using UTF-8.
//     Ps = 3  -> Query window/icon labels using UTF-8.  (See dis-
//     cussion of "Title Modes")
Terminal.prototype.setTitleModeFeature = function(params) {
  ;
};

// CSI Ps SP t
//   Set warning-bell volume (DECSWBV, VT520).
//     Ps = 0  or 1  -> off.
//     Ps = 2 , 3  or 4  -> low.
//     Ps = 5 , 6 , 7 , or 8  -> high.
Terminal.prototype.setWarningBellVolume = function(params) {
  ;
};

// CSI Ps SP u
//   Set margin-bell volume (DECSMBV, VT520).
//     Ps = 1  -> off.
//     Ps = 2 , 3  or 4  -> low.
//     Ps = 0 , 5 , 6 , 7 , or 8  -> high.
Terminal.prototype.setMarginBellVolume = function(params) {
  ;
};

// CSI Pt; Pl; Pb; Pr; Pp; Pt; Pl; Pp$ v
//   Copy Rectangular Area (DECCRA, VT400 and up).
//     Pt; Pl; Pb; Pr denotes the rectangle.
//     Pp denotes the source page.
//     Pt; Pl denotes the target location.
//     Pp denotes the target page.
// NOTE: xterm doesn't enable this code by default.
Terminal.prototype.copyRectangle = function(params) {
  ;
};

// CSI Pt ; Pl ; Pb ; Pr ' w
//   Enable Filter Rectangle (DECEFR), VT420 and up.
//   Parameters are [top;left;bottom;right].
//   Defines the coordinates of a filter rectangle and activates
//   it.  Anytime the locator is detected outside of the filter
//   rectangle, an outside rectangle event is generated and the
//   rectangle is disabled.  Filter rectangles are always treated
//   as "one-shot" events.  Any parameters that are omitted default
//   to the current locator position.  If all parameters are omit-
//   ted, any locator motion will be reported.  DECELR always can-
//   cels any prevous rectangle definition.
Terminal.prototype.enableFilterRectangle = function(params) {
  ;
};

// CSI Ps x  Request Terminal Parameters (DECREQTPARM).
//   if Ps is a "0" (default) or "1", and xterm is emulating VT100,
//   the control sequence elicits a response of the same form whose
//   parameters describe the terminal:
//     Ps -> the given Ps incremented by 2.
//     Pn = 1  <- no parity.
//     Pn = 1  <- eight bits.
//     Pn = 1  <- 2  8  transmit 38.4k baud.
//     Pn = 1  <- 2  8  receive 38.4k baud.
//     Pn = 1  <- clock multiplier.
//     Pn = 0  <- STP flags.
Terminal.prototype.requestParameters = function(params) {
  ;
};

// CSI Ps x  Select Attribute Change Extent (DECSACE).
//     Ps = 0  -> from start to end position, wrapped.
//     Ps = 1  -> from start to end position, wrapped.
//     Ps = 2  -> rectangle (exact).
Terminal.prototype.selectChangeExtent = function(params) {
  ;
};

// CSI Pc; Pt; Pl; Pb; Pr$ x
//   Fill Rectangular Area (DECFRA), VT420 and up.
//     Pc is the character to use.
//     Pt; Pl; Pb; Pr denotes the rectangle.
// NOTE: xterm doesn't enable this code by default.
Terminal.prototype.fillRectangle = function(params) {
  var ch = params[0]
    , t = params[1]
    , l = params[2]
    , b = params[3]
    , r = params[4];

  var line
    , i;

  for (; t < b + 1; t++) {
    line = this.lines[this.ybase + t];
    for (i = l; i < r; i++) {
      line[i] = [line[i][0], String.fromCharCode(ch)];
    }
  }

  // this.maxRange();
  this.updateRange(params[1]);
  this.updateRange(params[3]);
};

// CSI Ps ; Pu ' z
//   Enable Locator Reporting (DECELR).
//   Valid values for the first parameter:
//     Ps = 0  -> Locator disabled (default).
//     Ps = 1  -> Locator enabled.
//     Ps = 2  -> Locator enabled for one report, then disabled.
//   The second parameter specifies the coordinate unit for locator
//   reports.
//   Valid values for the second parameter:
//     Pu = 0  <- or omitted -> default to character cells.
//     Pu = 1  <- device physical pixels.
//     Pu = 2  <- character cells.
Terminal.prototype.enableLocatorReporting = function(params) {
  var val = params[0] > 0;
  //this.mouseEvents = val;
  //this.decLocator = val;
};

// CSI Pt; Pl; Pb; Pr$ z
//   Erase Rectangular Area (DECERA), VT400 and up.
//     Pt; Pl; Pb; Pr denotes the rectangle.
// NOTE: xterm doesn't enable this code by default.
Terminal.prototype.eraseRectangle = function(params) {
  var t = params[0]
    , l = params[1]
    , b = params[2]
    , r = params[3];

  var line
    , i
    , ch;

  ch = [this.curAttr, ' ']; // xterm?

  for (; t < b + 1; t++) {
    line = this.lines[this.ybase + t];
    for (i = l; i < r; i++) {
      line[i] = ch;
    }
  }

  // this.maxRange();
  this.updateRange(params[0]);
  this.updateRange(params[2]);
};

// CSI Pm ' {
//   Select Locator Events (DECSLE).
//   Valid values for the first (and any additional parameters)
//   are:
//     Ps = 0  -> only respond to explicit host requests (DECRQLP).
//                (This is default).  It also cancels any filter
//   rectangle.
//     Ps = 1  -> report button down transitions.
//     Ps = 2  -> do not report button down transitions.
//     Ps = 3  -> report button up transitions.
//     Ps = 4  -> do not report button up transitions.
Terminal.prototype.setLocatorEvents = function(params) {
  ;
};

// CSI Pt; Pl; Pb; Pr$ {
//   Selective Erase Rectangular Area (DECSERA), VT400 and up.
//     Pt; Pl; Pb; Pr denotes the rectangle.
Terminal.prototype.selectiveEraseRectangle = function(params) {
  ;
};

// CSI Ps ' |
//   Request Locator Position (DECRQLP).
//   Valid values for the parameter are:
//     Ps = 0 , 1 or omitted -> transmit a single DECLRP locator
//     report.

//   If Locator Reporting has been enabled by a DECELR, xterm will
//   respond with a DECLRP Locator Report.  This report is also
//   generated on button up and down events if they have been
//   enabled with a DECSLE, or when the locator is detected outside
//   of a filter rectangle, if filter rectangles have been enabled
//   with a DECEFR.

//     -> CSI Pe ; Pb ; Pr ; Pc ; Pp &  w

//   Parameters are [event;button;row;column;page].
//   Valid values for the event:
//     Pe = 0  -> locator unavailable - no other parameters sent.
//     Pe = 1  -> request - xterm received a DECRQLP.
//     Pe = 2  -> left button down.
//     Pe = 3  -> left button up.
//     Pe = 4  -> middle button down.
//     Pe = 5  -> middle button up.
//     Pe = 6  -> right button down.
//     Pe = 7  -> right button up.
//     Pe = 8  -> M4 button down.
//     Pe = 9  -> M4 button up.
//     Pe = 1 0  -> locator outside filter rectangle.
//   ``button'' parameter is a bitmask indicating which buttons are
//     pressed:
//     Pb = 0  <- no buttons down.
//     Pb & 1  <- right button down.
//     Pb & 2  <- middle button down.
//     Pb & 4  <- left button down.
//     Pb & 8  <- M4 button down.
//   ``row'' and ``column'' parameters are the coordinates of the
//     locator position in the xterm window, encoded as ASCII deci-
//     mal.
//   The ``page'' parameter is not used by xterm, and will be omit-
//   ted.
Terminal.prototype.requestLocatorPosition = function(params) {
  ;
};

// CSI P m SP }
// Insert P s Column(s) (default = 1) (DECIC), VT420 and up.
// NOTE: xterm doesn't enable this code by default.
Terminal.prototype.insertColumns = function() {
  var param = params[0]
    , l = this.ybase + this.rows
    , ch = [this.curAttr, ' '] // xterm?
    , i;

  while (param--) {
    for (i = this.ybase; i < l; i++) {
      this.lines[i].splice(this.x + 1, 0, ch);
      this.lines[i].pop();
    }
  }

  this.maxRange();
};

// CSI P m SP ~
// Delete P s Column(s) (default = 1) (DECDC), VT420 and up
// NOTE: xterm doesn't enable this code by default.
Terminal.prototype.deleteColumns = function() {
  var param = params[0]
    , l = this.ybase + this.rows
    , ch = [this.curAttr, ' '] // xterm?
    , i;

  while (param--) {
    for (i = this.ybase; i < l; i++) {
      this.lines[i].splice(this.x, 1);
      this.lines[i].push(ch);
    }
  }

  this.maxRange();
};

/**
 * Character Sets
 */

Terminal.charsets = {};

// DEC Special Character and Line Drawing Set.
// http://vt100.net/docs/vt102-ug/table5-13.html
// A lot of curses apps use this if they see TERM=xterm.
// testing: echo -e '\e(0a\e(B'
// The xterm output sometimes seems to conflict with the
// reference above. xterm seems in line with the reference
// when running vttest however.
// The table below now uses xterm's output from vttest.
Terminal.charsets.SCLD = { // (0
  '`': '\u25c6', // '◆'
  'a': '\u2592', // '▒'
  'b': '\u0009', // '\t'
  'c': '\u000c', // '\f'
  'd': '\u000d', // '\r'
  'e': '\u000a', // '\n'
  'f': '\u00b0', // '°'
  'g': '\u00b1', // '±'
  'h': '\u2424', // '\u2424' (NL)
  'i': '\u000b', // '\v'
  'j': '\u2518', // '┘'
  'k': '\u2510', // '┐'
  'l': '\u250c', // '┌'
  'm': '\u2514', // '└'
  'n': '\u253c', // '┼'
  'o': '\u23ba', // '⎺'
  'p': '\u23bb', // '⎻'
  'q': '\u2500', // '─'
  'r': '\u23bc', // '⎼'
  's': '\u23bd', // '⎽'
  't': '\u251c', // '├'
  'u': '\u2524', // '┤'
  'v': '\u2534', // '┴'
  'w': '\u252c', // '┬'
  'x': '\u2502', // '│'
  'y': '\u2264', // '≤'
  'z': '\u2265', // '≥'
  '{': '\u03c0', // 'π'
  '|': '\u2260', // '≠'
  '}': '\u00a3', // '£'
  '~': '\u00b7'  // '·'
};

Terminal.charsets.UK = null; // (A
Terminal.charsets.US = null; // (B (USASCII)
Terminal.charsets.Dutch = null; // (4
Terminal.charsets.Finnish = null; // (C or (5
Terminal.charsets.French = null; // (R
Terminal.charsets.FrenchCanadian = null; // (Q
Terminal.charsets.German = null; // (K
Terminal.charsets.Italian = null; // (Y
Terminal.charsets.NorwegianDanish = null; // (E or (6
Terminal.charsets.Spanish = null; // (Z
Terminal.charsets.Swedish = null; // (H or (7
Terminal.charsets.Swiss = null; // (=
Terminal.charsets.ISOLatin = null; // /A

/**
 * Helpers
 */

function on(el, type, handler, capture) {
  el.addEventListener(type, handler, capture || false);
}

function off(el, type, handler, capture) {
  el.removeEventListener(type, handler, capture || false);
}

function cancel(ev) {
  if (ev.preventDefault) ev.preventDefault();
  ev.returnValue = false;
  if (ev.stopPropagation) ev.stopPropagation();
  ev.cancelBubble = true;
  return false;
}

function inherits(child, parent) {
  function f() {
    this.constructor = child;
  }
  f.prototype = parent.prototype;
  child.prototype = new f;
}

var isMac = ~navigator.userAgent.indexOf('Mac');

// if bold is broken, we can't
// use it in the terminal.
function isBoldBroken() {
  var el = document.createElement('span');
  el.innerHTML = 'hello world';
  document.body.appendChild(el);
  var w1 = el.scrollWidth;
  el.style.fontWeight = 'bold';
  var w2 = el.scrollWidth;
  document.body.removeChild(el);
  return w1 !== w2;
}

var String = this.String;
var setTimeout = this.setTimeout;
var setInterval = this.setInterval;

/**
 * Expose
 */

Terminal.EventEmitter = EventEmitter;
Terminal.isMac = isMac;
Terminal.on = on;
Terminal.off = off;
Terminal.cancel = cancel;

if (typeof module !== 'undefined') {
  module.exports = Terminal;
} else {
  this.Terminal = Terminal;
}