enigma-bbs/core/word_wrap.js

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/* jslint node: true */
'use strict';
const renderStringLength = require('./string_util.js').renderStringLength;
// deps
const assert = require('assert');
const _ = require('lodash');
exports.wordWrapText = wordWrapText;
const SPACE_CHARS = [
' ', '\f', '\n', '\r', '\v',
'\u00a0', '\u1680', '\u180e', '\u2000', '\u2001', '\u2002', '\u2003', '\u2004',
'\u2005', '\u2006', '\u2007', '\u2008', '\u2009', '\u200a', '\u2028', '\u2029',
'\u202f', '\u205f', '\u3000',
];
const REGEXP_WORD_WRAP = new RegExp(`\t|[${SPACE_CHARS.join('')}]`, 'g');
function wordWrapText(text, options) {
assert(_.isObject(options));
assert(_.isNumber(options.width));
options.tabHandling = options.tabHandling || 'expand';
options.tabWidth = options.tabWidth || 4;
options.tabChar = options.tabChar || ' ';
//const REGEXP_GOBBLE = new RegExp(`.{0,${options.width}}`, 'g');
//
// For a given word, match 0->options.width chars -- alwasy include a full trailing ESC
// sequence if present!
//
// :TODO: Need to create ansi.getMatchRegex or something - this is used all over
const REGEXP_GOBBLE = new RegExp(`.{0,${options.width}}\\x1b\\[[\\?=;0-9]*[ABCDEFGHJKLMSTfhlmnprsu]|.{0,${options.width}}`, 'g');
let m;
let word;
let c;
let renderLen;
let i = 0;
let wordStart = 0;
let result = { wrapped : [ '' ], renderLen : [ 0 ] };
function expandTab(column) {
const remainWidth = options.tabWidth - (column % options.tabWidth);
return new Array(remainWidth).join(options.tabChar);
}
function appendWord() {
word.match(REGEXP_GOBBLE).forEach( w => {
renderLen = renderStringLength(w);
if(result.renderLen[i] + renderLen > options.width) {
if(0 === i) {
result.firstWrapRange = { start : wordStart, end : wordStart + w.length };
}
result.wrapped[++i] = w;
result.renderLen[i] = renderLen;
} else {
result.wrapped[i] += w;
result.renderLen[i] = (result.renderLen[i] || 0) + renderLen;
}
});
}
//
// Some of the way we word wrap is modeled after Sublime Test 3:
//
// * Sublime Text 3 for example considers spaces after a word
// part of said word. For example, "word " would be wraped
// in it's entirity.
//
// * Tabs in Sublime Text 3 are also treated as a word, so, e.g.
// "\t" may resolve to " " and must fit within the space.
//
// * If a word is ultimately too long to fit, break it up until it does.
//
while(null !== (m = REGEXP_WORD_WRAP.exec(text))) {
word = text.substring(wordStart, REGEXP_WORD_WRAP.lastIndex - 1);
c = m[0].charAt(0);
if(SPACE_CHARS.indexOf(c) > -1) {
word += m[0];
} else if('\t' === c) {
if('expand' === options.tabHandling) {
// Good info here: http://c-for-dummies.com/blog/?p=424
word += expandTab(result.wrapped[i].length + word.length) + options.tabChar;
} else {
word += m[0];
}
}
appendWord();
wordStart = REGEXP_WORD_WRAP.lastIndex + m[0].length - 1;
}
word = text.substring(wordStart);
appendWord();
return result;
}