Cable-Desktop/components/blueimp-canvas-to-blob/js/canvas-to-blob.js
2015-03-03 18:44:18 -08:00

95 lines
3.7 KiB
JavaScript

/*
* JavaScript Canvas to Blob 2.0.5
* https://github.com/blueimp/JavaScript-Canvas-to-Blob
*
* Copyright 2012, Sebastian Tschan
* https://blueimp.net
*
* Licensed under the MIT license:
* http://www.opensource.org/licenses/MIT
*
* Based on stackoverflow user Stoive's code snippet:
* http://stackoverflow.com/q/4998908
*/
/*jslint nomen: true, regexp: true */
/*global window, atob, Blob, ArrayBuffer, Uint8Array, define */
(function (window) {
'use strict';
var CanvasPrototype = window.HTMLCanvasElement &&
window.HTMLCanvasElement.prototype,
hasBlobConstructor = window.Blob && (function () {
try {
return Boolean(new Blob());
} catch (e) {
return false;
}
}()),
hasArrayBufferViewSupport = hasBlobConstructor && window.Uint8Array &&
(function () {
try {
return new Blob([new Uint8Array(100)]).size === 100;
} catch (e) {
return false;
}
}()),
BlobBuilder = window.BlobBuilder || window.WebKitBlobBuilder ||
window.MozBlobBuilder || window.MSBlobBuilder,
dataURLtoBlob = (hasBlobConstructor || BlobBuilder) && window.atob &&
window.ArrayBuffer && window.Uint8Array && function (dataURI) {
var byteString,
arrayBuffer,
intArray,
i,
mimeString,
bb;
if (dataURI.split(',')[0].indexOf('base64') >= 0) {
// Convert base64 to raw binary data held in a string:
byteString = atob(dataURI.split(',')[1]);
} else {
// Convert base64/URLEncoded data component to raw binary data:
byteString = decodeURIComponent(dataURI.split(',')[1]);
}
// Write the bytes of the string to an ArrayBuffer:
arrayBuffer = new ArrayBuffer(byteString.length);
intArray = new Uint8Array(arrayBuffer);
for (i = 0; i < byteString.length; i += 1) {
intArray[i] = byteString.charCodeAt(i);
}
// Separate out the mime component:
mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
// Write the ArrayBuffer (or ArrayBufferView) to a blob:
if (hasBlobConstructor) {
return new Blob(
[hasArrayBufferViewSupport ? intArray : arrayBuffer],
{type: mimeString}
);
}
bb = new BlobBuilder();
bb.append(arrayBuffer);
return bb.getBlob(mimeString);
};
if (window.HTMLCanvasElement && !CanvasPrototype.toBlob) {
if (CanvasPrototype.mozGetAsFile) {
CanvasPrototype.toBlob = function (callback, type, quality) {
if (quality && CanvasPrototype.toDataURL && dataURLtoBlob) {
callback(dataURLtoBlob(this.toDataURL(type, quality)));
} else {
callback(this.mozGetAsFile('blob', type));
}
};
} else if (CanvasPrototype.toDataURL && dataURLtoBlob) {
CanvasPrototype.toBlob = function (callback, type, quality) {
callback(dataURLtoBlob(this.toDataURL(type, quality)));
};
}
}
if (typeof define === 'function' && define.amd) {
define(function () {
return dataURLtoBlob;
});
} else {
window.dataURLtoBlob = dataURLtoBlob;
}
}(this));