blob: df3e6cc44e856177b57dbe1543ed028de940b627 [file] [log] [blame]
"use strict"
var wcwidth = require('./width')
/**
* repeat string `str` up to total length of `len`
*
* @param String str string to repeat
* @param Number len total length of output string
*/
function repeatString(str, len) {
return Array.apply(null, {length: len + 1}).join(str).slice(0, len)
}
/**
* Pad `str` up to total length `max` with `chr`.
* If `str` is longer than `max`, padRight will return `str` unaltered.
*
* @param String str string to pad
* @param Number max total length of output string
* @param String chr optional. Character to pad with. default: ' '
* @return String padded str
*/
function padRight(str, max, chr) {
str = str != null ? str : ''
str = String(str)
var length = max - wcwidth(str)
if (length <= 0) return str
return str + repeatString(chr || ' ', length)
}
/**
* Pad `str` up to total length `max` with `chr`.
* If `str` is longer than `max`, padCenter will return `str` unaltered.
*
* @param String str string to pad
* @param Number max total length of output string
* @param String chr optional. Character to pad with. default: ' '
* @return String padded str
*/
function padCenter(str, max, chr) {
str = str != null ? str : ''
str = String(str)
var length = max - wcwidth(str)
if (length <= 0) return str
var lengthLeft = Math.floor(length/2)
var lengthRight = length - lengthLeft
return repeatString(chr || ' ', lengthLeft) + str + repeatString(chr || ' ', lengthRight)
}
/**
* Pad `str` up to total length `max` with `chr`, on the left.
* If `str` is longer than `max`, padRight will return `str` unaltered.
*
* @param String str string to pad
* @param Number max total length of output string
* @param String chr optional. Character to pad with. default: ' '
* @return String padded str
*/
function padLeft(str, max, chr) {
str = str != null ? str : ''
str = String(str)
var length = max - wcwidth(str)
if (length <= 0) return str
return repeatString(chr || ' ', length) + str
}
/**
* Split a String `str` into lines of maxiumum length `max`.
* Splits on word boundaries. Preserves existing new lines.
*
* @param String str string to split
* @param Number max length of each line
* @return Array Array containing lines.
*/
function splitIntoLines(str, max) {
function _splitIntoLines(str, max) {
return str.trim().split(' ').reduce(function(lines, word) {
var line = lines[lines.length - 1]
if (line && wcwidth(line.join(' ')) + wcwidth(word) < max) {
lines[lines.length - 1].push(word) // add to line
}
else lines.push([word]) // new line
return lines
}, []).map(function(l) {
return l.join(' ')
})
}
return str.split('\n').map(function(str) {
return _splitIntoLines(str, max)
}).reduce(function(lines, line) {
return lines.concat(line)
}, [])
}
/**
* Add spaces and `truncationChar` between words of
* `str` which are longer than `max`.
*
* @param String str string to split
* @param Number max length of each line
* @param Number truncationChar character to append to split words
* @return String
*/
function splitLongWords(str, max, truncationChar) {
str = str.trim()
var result = []
var words = str.split(' ')
var remainder = ''
var truncationWidth = wcwidth(truncationChar)
while (remainder || words.length) {
if (remainder) {
var word = remainder
remainder = ''
} else {
var word = words.shift()
}
if (wcwidth(word) > max) {
// slice is based on length no wcwidth
var i = 0
var wwidth = 0
var limit = max - truncationWidth
while (i < word.length) {
var w = wcwidth(word.charAt(i))
if (w + wwidth > limit) {
break
}
wwidth += w
++i
}
remainder = word.slice(i) // get remainder
// save remainder for next loop
word = word.slice(0, i) // grab truncated word
word += truncationChar // add trailing … or whatever
}
result.push(word)
}
return result.join(' ')
}
/**
* Truncate `str` into total width `max`
* If `str` is shorter than `max`, will return `str` unaltered.
*
* @param String str string to truncated
* @param Number max total wcwidth of output string
* @return String truncated str
*/
function truncateString(str, max) {
str = str != null ? str : ''
str = String(str)
if(max == Infinity) return str
var i = 0
var wwidth = 0
while (i < str.length) {
var w = wcwidth(str.charAt(i))
if(w + wwidth > max)
break
wwidth += w
++i
}
return str.slice(0, i)
}
/**
* Exports
*/
module.exports.padRight = padRight
module.exports.padCenter = padCenter
module.exports.padLeft = padLeft
module.exports.splitIntoLines = splitIntoLines
module.exports.splitLongWords = splitLongWords
module.exports.truncateString = truncateString