114 lines
3.2 KiB
JavaScript
114 lines
3.2 KiB
JavaScript
|
'use strict'
|
||
|
|
|
||
|
|
/*!
|
||
|
|
* Canvas
|
||
|
|
* Copyright (c) 2010 LearnBoost <tj@learnboost.com>
|
||
|
|
* MIT Licensed
|
||
|
|
*/
|
||
|
|
|
||
|
|
const bindings = require('./bindings')
|
||
|
|
const Canvas = module.exports = bindings.Canvas
|
||
|
|
const Context2d = require('./context2d')
|
||
|
|
const PNGStream = require('./pngstream')
|
||
|
|
const PDFStream = require('./pdfstream')
|
||
|
|
const JPEGStream = require('./jpegstream')
|
||
|
|
const FORMATS = ['image/png', 'image/jpeg']
|
||
|
|
const util = require('util')
|
||
|
|
|
||
|
|
// TODO || is for Node.js pre-v6.6.0
|
||
|
|
Canvas.prototype[util.inspect.custom || 'inspect'] = function () {
|
||
|
|
return `[Canvas ${this.width}x${this.height}]`
|
||
|
|
}
|
||
|
|
|
||
|
|
Canvas.prototype.getContext = function (contextType, contextAttributes) {
|
||
|
|
if (contextType == '2d') {
|
||
|
|
const ctx = this._context2d || (this._context2d = new Context2d(this, contextAttributes))
|
||
|
|
this.context = ctx
|
||
|
|
ctx.canvas = this
|
||
|
|
return ctx
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
Canvas.prototype.pngStream =
|
||
|
|
Canvas.prototype.createPNGStream = function (options) {
|
||
|
|
return new PNGStream(this, options)
|
||
|
|
}
|
||
|
|
|
||
|
|
Canvas.prototype.pdfStream =
|
||
|
|
Canvas.prototype.createPDFStream = function (options) {
|
||
|
|
return new PDFStream(this, options)
|
||
|
|
}
|
||
|
|
|
||
|
|
Canvas.prototype.jpegStream =
|
||
|
|
Canvas.prototype.createJPEGStream = function (options) {
|
||
|
|
return new JPEGStream(this, options)
|
||
|
|
}
|
||
|
|
|
||
|
|
Canvas.prototype.toDataURL = function (a1, a2, a3) {
|
||
|
|
// valid arg patterns (args -> [type, opts, fn]):
|
||
|
|
// [] -> ['image/png', null, null]
|
||
|
|
// [qual] -> ['image/png', null, null]
|
||
|
|
// [undefined] -> ['image/png', null, null]
|
||
|
|
// ['image/png'] -> ['image/png', null, null]
|
||
|
|
// ['image/png', qual] -> ['image/png', null, null]
|
||
|
|
// [fn] -> ['image/png', null, fn]
|
||
|
|
// [type, fn] -> [type, null, fn]
|
||
|
|
// [undefined, fn] -> ['image/png', null, fn]
|
||
|
|
// ['image/png', qual, fn] -> ['image/png', null, fn]
|
||
|
|
// ['image/jpeg', fn] -> ['image/jpeg', null, fn]
|
||
|
|
// ['image/jpeg', opts, fn] -> ['image/jpeg', opts, fn]
|
||
|
|
// ['image/jpeg', qual, fn] -> ['image/jpeg', {quality: qual}, fn]
|
||
|
|
// ['image/jpeg', undefined, fn] -> ['image/jpeg', null, fn]
|
||
|
|
// ['image/jpeg'] -> ['image/jpeg', null, fn]
|
||
|
|
// ['image/jpeg', opts] -> ['image/jpeg', opts, fn]
|
||
|
|
// ['image/jpeg', qual] -> ['image/jpeg', {quality: qual}, fn]
|
||
|
|
|
||
|
|
let type = 'image/png'
|
||
|
|
let opts = {}
|
||
|
|
let fn
|
||
|
|
|
||
|
|
if (typeof a1 === 'function') {
|
||
|
|
fn = a1
|
||
|
|
} else {
|
||
|
|
if (typeof a1 === 'string' && FORMATS.includes(a1.toLowerCase())) {
|
||
|
|
type = a1.toLowerCase()
|
||
|
|
}
|
||
|
|
|
||
|
|
if (typeof a2 === 'function') {
|
||
|
|
fn = a2
|
||
|
|
} else {
|
||
|
|
if (typeof a2 === 'object') {
|
||
|
|
opts = a2
|
||
|
|
} else if (typeof a2 === 'number') {
|
||
|
|
opts = { quality: Math.max(0, Math.min(1, a2)) }
|
||
|
|
}
|
||
|
|
|
||
|
|
if (typeof a3 === 'function') {
|
||
|
|
fn = a3
|
||
|
|
} else if (undefined !== a3) {
|
||
|
|
throw new TypeError(`${typeof a3} is not a function`)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (this.width === 0 || this.height === 0) {
|
||
|
|
// Per spec, if the bitmap has no pixels, return this string:
|
||
|
|
const str = 'data:,'
|
||
|
|
if (fn) {
|
||
|
|
setTimeout(() => fn(null, str))
|
||
|
|
return
|
||
|
|
} else {
|
||
|
|
return str
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (fn) {
|
||
|
|
this.toBuffer((err, buf) => {
|
||
|
|
if (err) return fn(err)
|
||
|
|
fn(null, `data:${type};base64,${buf.toString('base64')}`)
|
||
|
|
}, type, opts)
|
||
|
|
} else {
|
||
|
|
return `data:${type};base64,${this.toBuffer(type, opts).toString('base64')}`
|
||
|
|
}
|
||
|
|
}
|