neo-neo-bblessed/lib/keys.ts

A fork of neo-blessed (which is a fork of blessed) with bug fixes and maintenance.

/**
 * keys.js - emit key presses
 * Copyright (c) 2010-2015, Joyent, Inc. and other contributors (MIT License)
 * https://github.com/chjj/blessed
 */

// Originally taken from the node.js tree:
//
// Copyright Joyent, Inc. and other Node contributors. All rights reserved.
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:

// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.

// eslint-disable-next-line @typescript-eslint/no-unused-vars
import { EventEmitter } from 'events';
import { StringDecoder } from 'string_decoder';

// NOTE: node <=v0.8.x has no EventEmitter.listenerCount
interface KeypressEvent {
  name?: string;
  ctrl?: boolean;
  meta?: boolean;
  shift?: boolean;
  sequence?: string;
  [key: string]: any;
}

interface KeypressStream {
  _keypressDecoder?: any;
  encoding?: string;
  listeners(event: string): Function[];
  listenerCount?(event: string): number;
  on(event: string, listener: Function): this;
  once(event: string, listener: Function): this;
  removeListener(event: string, listener: Function): this;
  removeAllListeners(event?: string): this;
  emit(event: string, ...args: any[]): boolean;
}

function listenerCount(stream: KeypressStream, event: string): number {
  return stream.listenerCount
    ? stream.listenerCount(event)
    : stream.listeners(event).length;
}

/**
 * accepts a readable Stream instance and makes it emit "keypress" events
 */

function emitKeypressEvents(stream: KeypressStream): void {
  if (stream._keypressDecoder) return;
  // StringDecoder imported at top of file
  stream._keypressDecoder = new StringDecoder('utf8');

  function onData(b: Buffer): void {
    if (listenerCount(stream, 'keypress') > 0) {
      var r = stream._keypressDecoder.write(b);
      if (r) emitKeys(stream, r);
    } else {
      // Nobody's watching anyway
      stream.removeListener('data', onData);
      stream.on('newListener', onNewListener);
    }
  }

  function onNewListener(event: string): void {
    if (event === 'keypress') {
      stream.on('data', onData);
      stream.removeListener('newListener', onNewListener);
    }
  }

  if (listenerCount(stream, 'keypress') > 0) {
    stream.on('data', onData);
  } else {
    stream.on('newListener', onNewListener);
  }
}
exports.emitKeypressEvents = emitKeypressEvents;

/*
  Some patterns seen in terminal key escape codes, derived from combos seen
  at http://www.midnight-commander.org/browser/lib/tty/key.c

  ESC letter
  ESC [ letter
  ESC [ modifier letter
  ESC [ 1 ; modifier letter
  ESC [ num char
  ESC [ num ; modifier char
  ESC O letter
  ESC O modifier letter
  ESC O 1 ; modifier letter
  ESC N letter
  ESC [ [ num ; modifier char
  ESC [ [ 1 ; modifier letter
  ESC ESC [ num char
  ESC ESC O letter

  - char is usually ~ but $ and ^ also happen with rxvt
  - modifier is 1 +
                (shift     * 1) +
                (left_alt  * 2) +
                (ctrl      * 4) +
                (right_alt * 8)
  - two leading ESCs apparently mean the same as one leading ESC
*/

// Regexes used for ansi escape code splitting
var metaKeyCodeReAnywhere = /(?:\x1b)([a-zA-Z0-9])/;
var metaKeyCodeRe = new RegExp('^' + metaKeyCodeReAnywhere.source + '$');
var functionKeyCodeReAnywhere = new RegExp(
  '(?:\x1b+)(O|N|\\[|\\[\\[)(?:' +
    [
      '(\\d+)(?:;(\\d+))?([~^$])',
      '(?:M([@ #!a`])(.)(.))', // mouse
      '(?:1;)?(\\d+)?([a-zA-Z])',
    ].join('|') +
    ')'
);
var functionKeyCodeRe = new RegExp('^' + functionKeyCodeReAnywhere.source);
var escapeCodeReAnywhere = new RegExp(
  [
    functionKeyCodeReAnywhere.source,
    metaKeyCodeReAnywhere.source,
    /\x1b./.source,
  ].join('|')
);

function emitKeys(stream: KeypressStream, s: string | Buffer): void {
  if (Buffer.isBuffer(s)) {
    if (s[0] > 127 && s[1] === undefined) {
      const buf = Buffer.from(s);
      buf[0] -= 128;
      s = '\x1b' + buf.toString((stream.encoding as BufferEncoding) || 'utf-8');
    } else {
      s = s.toString((stream.encoding as BufferEncoding) || 'utf-8');
    }
  }

  if (isMouse(s)) return;

  var buffer: string[] = [];
  var match: RegExpExecArray | null;
  while ((match = escapeCodeReAnywhere.exec(s))) {
    buffer = buffer.concat(s.slice(0, match.index).split(''));
    buffer.push(match[0]);
    s = s.slice(match.index + match[0].length);
  }
  buffer = buffer.concat(s.split(''));

  buffer.forEach(function (s: string): void {
    var ch: string,
      key: KeypressEvent = {
        sequence: s,
        name: undefined,
        ctrl: false,
        meta: false,
        shift: false,
      },
      parts;

    if (s === '\r') {
      // carriage return
      key.name = 'return';
    } else if (s === '\n') {
      // enter, should have been called linefeed
      key.name = 'enter';
      // linefeed
      // key.name = 'linefeed';
    } else if (s === '\t') {
      // tab
      key.name = 'tab';
    } else if (
      s === '\b' ||
      s === '\x7f' ||
      s === '\x1b\x7f' ||
      s === '\x1b\b'
    ) {
      // backspace or ctrl+h
      key.name = 'backspace';
      key.meta = s.charAt(0) === '\x1b';
    } else if (s === '\x1b' || s === '\x1b\x1b') {
      // escape key
      key.name = 'escape';
      key.meta = s.length === 2;
    } else if (s === ' ' || s === '\x1b ') {
      key.name = 'space';
      key.meta = s.length === 2;
    } else if (s.length === 1 && s <= '\x1a') {
      // ctrl+letter
      key.name = String.fromCharCode(s.charCodeAt(0) + 'a'.charCodeAt(0) - 1);
      key.ctrl = true;
    } else if (s.length === 1 && s >= 'a' && s <= 'z') {
      // lowercase letter
      key.name = s;
    } else if (s.length === 1 && s >= 'A' && s <= 'Z') {
      // shift+letter
      key.name = s.toLowerCase();
      key.shift = true;
    } else if ((parts = metaKeyCodeRe.exec(s))) {
      // meta+character key
      key.name = parts[1].toLowerCase();
      key.meta = true;
      key.shift = /^[A-Z]$/.test(parts[1]);
    } else if ((parts = functionKeyCodeRe.exec(s))) {
      // ansi escape sequence

      // reassemble the key code leaving out leading \x1b's,
      // the modifier key bitflag and any meaningless "1;" sequence
      var code =
          (parts[1] || '') +
          (parts[2] || '') +
          (parts[4] || '') +
          (parts[9] || ''),
        modifier = (parts[3] || parts[8] || 1) - 1;

      // Parse the key modifier
      key.ctrl = !!(modifier & 4);
      key.meta = !!(modifier & 10);
      key.shift = !!(modifier & 1);
      key.code = code;

      // Parse the key itself
      switch (code) {
        /* xterm/gnome ESC O letter */
        case 'OP':
          key.name = 'f1';
          break;
        case 'OQ':
          key.name = 'f2';
          break;
        case 'OR':
          key.name = 'f3';
          break;
        case 'OS':
          key.name = 'f4';
          break;

        /* xterm/rxvt ESC [ number ~ */
        case '[11~':
          key.name = 'f1';
          break;
        case '[12~':
          key.name = 'f2';
          break;
        case '[13~':
          key.name = 'f3';
          break;
        case '[14~':
          key.name = 'f4';
          break;

        /* from Cygwin and used in libuv */
        case '[[A':
          key.name = 'f1';
          break;
        case '[[B':
          key.name = 'f2';
          break;
        case '[[C':
          key.name = 'f3';
          break;
        case '[[D':
          key.name = 'f4';
          break;
        case '[[E':
          key.name = 'f5';
          break;

        /* common */
        case '[15~':
          key.name = 'f5';
          break;
        case '[17~':
          key.name = 'f6';
          break;
        case '[18~':
          key.name = 'f7';
          break;
        case '[19~':
          key.name = 'f8';
          break;
        case '[20~':
          key.name = 'f9';
          break;
        case '[21~':
          key.name = 'f10';
          break;
        case '[23~':
          key.name = 'f11';
          break;
        case '[24~':
          key.name = 'f12';
          break;

        /* xterm ESC [ letter */
        case '[A':
          key.name = 'up';
          break;
        case '[B':
          key.name = 'down';
          break;
        case '[C':
          key.name = 'right';
          break;
        case '[D':
          key.name = 'left';
          break;
        case '[E':
          key.name = 'clear';
          break;
        case '[F':
          key.name = 'end';
          break;
        case '[H':
          key.name = 'home';
          break;

        /* xterm/gnome ESC O letter */
        case 'OA':
          key.name = 'up';
          break;
        case 'OB':
          key.name = 'down';
          break;
        case 'OC':
          key.name = 'right';
          break;
        case 'OD':
          key.name = 'left';
          break;
        case 'OE':
          key.name = 'clear';
          break;
        case 'OF':
          key.name = 'end';
          break;
        case 'OH':
          key.name = 'home';
          break;

        /* xterm/rxvt ESC [ number ~ */
        case '[1~':
          key.name = 'home';
          break;
        case '[2~':
          key.name = 'insert';
          break;
        case '[3~':
          key.name = 'delete';
          break;
        case '[4~':
          key.name = 'end';
          break;
        case '[5~':
          key.name = 'pageup';
          break;
        case '[6~':
          key.name = 'pagedown';
          break;

        /* putty */
        case '[[5~':
          key.name = 'pageup';
          break;
        case '[[6~':
          key.name = 'pagedown';
          break;

        /* rxvt */
        case '[7~':
          key.name = 'home';
          break;
        case '[8~':
          key.name = 'end';
          break;

        /* rxvt keys with modifiers */
        case '[a':
          key.name = 'up';
          key.shift = true;
          break;
        case '[b':
          key.name = 'down';
          key.shift = true;
          break;
        case '[c':
          key.name = 'right';
          key.shift = true;
          break;
        case '[d':
          key.name = 'left';
          key.shift = true;
          break;
        case '[e':
          key.name = 'clear';
          key.shift = true;
          break;

        case '[2$':
          key.name = 'insert';
          key.shift = true;
          break;
        case '[3$':
          key.name = 'delete';
          key.shift = true;
          break;
        case '[5$':
          key.name = 'pageup';
          key.shift = true;
          break;
        case '[6$':
          key.name = 'pagedown';
          key.shift = true;
          break;
        case '[7$':
          key.name = 'home';
          key.shift = true;
          break;
        case '[8$':
          key.name = 'end';
          key.shift = true;
          break;

        case 'Oa':
          key.name = 'up';
          key.ctrl = true;
          break;
        case 'Ob':
          key.name = 'down';
          key.ctrl = true;
          break;
        case 'Oc':
          key.name = 'right';
          key.ctrl = true;
          break;
        case 'Od':
          key.name = 'left';
          key.ctrl = true;
          break;
        case 'Oe':
          key.name = 'clear';
          key.ctrl = true;
          break;

        case '[2^':
          key.name = 'insert';
          key.ctrl = true;
          break;
        case '[3^':
          key.name = 'delete';
          key.ctrl = true;
          break;
        case '[5^':
          key.name = 'pageup';
          key.ctrl = true;
          break;
        case '[6^':
          key.name = 'pagedown';
          key.ctrl = true;
          break;
        case '[7^':
          key.name = 'home';
          key.ctrl = true;
          break;
        case '[8^':
          key.name = 'end';
          key.ctrl = true;
          break;

        /* misc. */
        case '[Z':
          key.name = 'tab';
          key.shift = true;
          break;
        default:
          key.name = 'undefined';
          break;
      }
    }

    // Don't emit a key if no name was found
    if (key.name === undefined) {
      key = undefined;
    }

    if (s.length === 1) {
      ch = s;
    }

    if (key || ch) {
      stream.emit('keypress', ch, key);
      // if (key && key.name === 'return') {
      //   var nkey = {};
      //   Object.keys(key).forEach(function(k) {
      //     nkey[k] = key[k];
      //   });
      //   nkey.name = 'enter';
      //   stream.emit('keypress', ch, nkey);
      // }
    }
  });
}

function isMouse(s: string): boolean {
  return (
    /\x1b\[M/.test(s) ||
    /\x1b\[M([\x00\u0020-\uffff]{3})/.test(s) ||
    /\x1b\[(\d+;\d+;\d+)M/.test(s) ||
    /\x1b\[<(\d+;\d+;\d+)([mM])/.test(s) ||
    /\x1b\[<(\d+;\d+;\d+;\d+)&w/.test(s) ||
    /\x1b\[24([0135])~\[(\d+),(\d+)\]\r/.test(s) ||
    /\x1b\[(O|I)/.test(s)
  );
}