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355 lines
8.0 KiB
JavaScript

'use strict'
const stringWidth = require('string-width')
const stripAnsi = require('strip-ansi')
const wrap = require('wrap-ansi')
const align = {
right: alignRight,
center: alignCenter
}
const top = 0
const right = 1
const bottom = 2
const left = 3
class UI {
constructor (opts) {
this.width = opts.width
this.wrap = opts.wrap
this.rows = []
}
span (...args) {
const cols = this.div(...args)
cols.span = true
}
resetOutput () {
this.rows = []
}
div (...args) {
if (args.length === 0) {
this.div('')
}
if (this.wrap && this._shouldApplyLayoutDSL(...args)) {
return this._applyLayoutDSL(args[0])
}
const cols = args.map(arg => {
if (typeof arg === 'string') {
return this._colFromString(arg)
}
return arg
})
this.rows.push(cols)
return cols
}
_shouldApplyLayoutDSL (...args) {
return args.length === 1 && typeof args[0] === 'string' &&
/[\t\n]/.test(args[0])
}
_applyLayoutDSL (str) {
const rows = str.split('\n').map(row => row.split('\t'))
let leftColumnWidth = 0
// simple heuristic for layout, make sure the
// second column lines up along the left-hand.
// don't allow the first column to take up more
// than 50% of the screen.
rows.forEach(columns => {
if (columns.length > 1 && stringWidth(columns[0]) > leftColumnWidth) {
leftColumnWidth = Math.min(
Math.floor(this.width * 0.5),
stringWidth(columns[0])
)
}
})
// generate a table:
// replacing ' ' with padding calculations.
// using the algorithmically generated width.
rows.forEach(columns => {
this.div(...columns.map((r, i) => {
return {
text: r.trim(),
padding: this._measurePadding(r),
width: (i === 0 && columns.length > 1) ? leftColumnWidth : undefined
}
}))
})
return this.rows[this.rows.length - 1]
}
_colFromString (text) {
return {
text,
padding: this._measurePadding(text)
}
}
_measurePadding (str) {
// measure padding without ansi escape codes
const noAnsi = stripAnsi(str)
return [0, noAnsi.match(/\s*$/)[0].length, 0, noAnsi.match(/^\s*/)[0].length]
}
toString () {
const lines = []
this.rows.forEach(row => {
this.rowToString(row, lines)
})
// don't display any lines with the
// hidden flag set.
return lines
.filter(line => !line.hidden)
.map(line => line.text)
.join('\n')
}
rowToString (row, lines) {
this._rasterize(row).forEach((rrow, r) => {
let str = ''
rrow.forEach((col, c) => {
const { width } = row[c] // the width with padding.
const wrapWidth = this._negatePadding(row[c]) // the width without padding.
let ts = col // temporary string used during alignment/padding.
if (wrapWidth > stringWidth(col)) {
ts += ' '.repeat(wrapWidth - stringWidth(col))
}
// align the string within its column.
if (row[c].align && row[c].align !== 'left' && this.wrap) {
ts = align[row[c].align](ts, wrapWidth)
if (stringWidth(ts) < wrapWidth) {
ts += ' '.repeat(width - stringWidth(ts) - 1)
}
}
// apply border and padding to string.
const padding = row[c].padding || [0, 0, 0, 0]
if (padding[left]) {
str += ' '.repeat(padding[left])
}
str += addBorder(row[c], ts, '| ')
str += ts
str += addBorder(row[c], ts, ' |')
if (padding[right]) {
str += ' '.repeat(padding[right])
}
// if prior row is span, try to render the
// current row on the prior line.
if (r === 0 && lines.length > 0) {
str = this._renderInline(str, lines[lines.length - 1])
}
})
// remove trailing whitespace.
lines.push({
text: str.replace(/ +$/, ''),
span: row.span
})
})
return lines
}
// if the full 'source' can render in
// the target line, do so.
_renderInline (source, previousLine) {
const leadingWhitespace = source.match(/^ */)[0].length
const target = previousLine.text
const targetTextWidth = stringWidth(target.trimRight())
if (!previousLine.span) {
return source
}
// if we're not applying wrapping logic,
// just always append to the span.
if (!this.wrap) {
previousLine.hidden = true
return target + source
}
if (leadingWhitespace < targetTextWidth) {
return source
}
previousLine.hidden = true
return target.trimRight() + ' '.repeat(leadingWhitespace - targetTextWidth) + source.trimLeft()
}
_rasterize (row) {
const rrows = []
const widths = this._columnWidths(row)
let wrapped
// word wrap all columns, and create
// a data-structure that is easy to rasterize.
row.forEach((col, c) => {
// leave room for left and right padding.
col.width = widths[c]
if (this.wrap) {
wrapped = wrap(col.text, this._negatePadding(col), { hard: true }).split('\n')
} else {
wrapped = col.text.split('\n')
}
if (col.border) {
wrapped.unshift('.' + '-'.repeat(this._negatePadding(col) + 2) + '.')
wrapped.push("'" + '-'.repeat(this._negatePadding(col) + 2) + "'")
}
// add top and bottom padding.
if (col.padding) {
wrapped.unshift(...new Array(col.padding[top] || 0).fill(''))
wrapped.push(...new Array(col.padding[bottom] || 0).fill(''))
}
wrapped.forEach((str, r) => {
if (!rrows[r]) {
rrows.push([])
}
const rrow = rrows[r]
for (let i = 0; i < c; i++) {
if (rrow[i] === undefined) {
rrow.push('')
}
}
rrow.push(str)
})
})
return rrows
}
_negatePadding (col) {
let wrapWidth = col.width
if (col.padding) {
wrapWidth -= (col.padding[left] || 0) + (col.padding[right] || 0)
}
if (col.border) {
wrapWidth -= 4
}
return wrapWidth
}
_columnWidths (row) {
if (!this.wrap) {
return row.map(col => {
return col.width || stringWidth(col.text)
})
}
let unset = row.length
let remainingWidth = this.width
// column widths can be set in config.
const widths = row.map(col => {
if (col.width) {
unset--
remainingWidth -= col.width
return col.width
}
return undefined
})
// any unset widths should be calculated.
const unsetWidth = unset ? Math.floor(remainingWidth / unset) : 0
return widths.map((w, i) => {
if (w === undefined) {
return Math.max(unsetWidth, _minWidth(row[i]))
}
return w
})
}
}
function addBorder (col, ts, style) {
if (col.border) {
if (/[.']-+[.']/.test(ts)) {
return ''
}
if (ts.trim().length !== 0) {
return style
}
return ' '
}
return ''
}
// calculates the minimum width of
// a column, based on padding preferences.
function _minWidth (col) {
const padding = col.padding || []
const minWidth = 1 + (padding[left] || 0) + (padding[right] || 0)
if (col.border) {
return minWidth + 4
}
return minWidth
}
function getWindowWidth () {
/* istanbul ignore next: depends on terminal */
if (typeof process === 'object' && process.stdout && process.stdout.columns) {
return process.stdout.columns
}
}
function alignRight (str, width) {
str = str.trim()
const strWidth = stringWidth(str)
if (strWidth < width) {
return ' '.repeat(width - strWidth) + str
}
return str
}
function alignCenter (str, width) {
str = str.trim()
const strWidth = stringWidth(str)
/* istanbul ignore next */
if (strWidth >= width) {
return str
}
return ' '.repeat((width - strWidth) >> 1) + str
}
module.exports = function (opts = {}) {
return new UI({
width: opts.width || getWindowWidth() || /* istanbul ignore next */ 80,
wrap: opts.wrap !== false
})
}