64 lines
1.5 KiB
JavaScript
64 lines
1.5 KiB
JavaScript
|
const Utils = require('./utils')
|
||
|
|
|
||
|
|
function clearCanvas (ctx, canvas, size) {
|
||
|
|
ctx.clearRect(0, 0, canvas.width, canvas.height)
|
||
|
|
|
||
|
|
if (!canvas.style) canvas.style = {}
|
||
|
|
canvas.height = size
|
||
|
|
canvas.width = size
|
||
|
|
canvas.style.height = size + 'px'
|
||
|
|
canvas.style.width = size + 'px'
|
||
|
|
}
|
||
|
|
|
||
|
|
function getCanvasElement () {
|
||
|
|
try {
|
||
|
|
return document.createElement('canvas')
|
||
|
|
} catch (e) {
|
||
|
|
throw new Error('You need to specify a canvas element')
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
exports.render = function render (qrData, canvas, options) {
|
||
|
|
let opts = options
|
||
|
|
let canvasEl = canvas
|
||
|
|
|
||
|
|
if (typeof opts === 'undefined' && (!canvas || !canvas.getContext)) {
|
||
|
|
opts = canvas
|
||
|
|
canvas = undefined
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!canvas) {
|
||
|
|
canvasEl = getCanvasElement()
|
||
|
|
}
|
||
|
|
|
||
|
|
opts = Utils.getOptions(opts)
|
||
|
|
const size = Utils.getImageWidth(qrData.modules.size, opts)
|
||
|
|
|
||
|
|
const ctx = canvasEl.getContext('2d')
|
||
|
|
const image = ctx.createImageData(size, size)
|
||
|
|
Utils.qrToImageData(image.data, qrData, opts)
|
||
|
|
|
||
|
|
clearCanvas(ctx, canvasEl, size)
|
||
|
|
ctx.putImageData(image, 0, 0)
|
||
|
|
|
||
|
|
return canvasEl
|
||
|
|
}
|
||
|
|
|
||
|
|
exports.renderToDataURL = function renderToDataURL (qrData, canvas, options) {
|
||
|
|
let opts = options
|
||
|
|
|
||
|
|
if (typeof opts === 'undefined' && (!canvas || !canvas.getContext)) {
|
||
|
|
opts = canvas
|
||
|
|
canvas = undefined
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!opts) opts = {}
|
||
|
|
|
||
|
|
const canvasEl = exports.render(qrData, canvas, opts)
|
||
|
|
|
||
|
|
const type = opts.type || 'image/png'
|
||
|
|
const rendererOpts = opts.rendererOpts || {}
|
||
|
|
|
||
|
|
return canvasEl.toDataURL(type, rendererOpts.quality)
|
||
|
|
}
|