update: use local resources

Author: jerikchan

examples/public/scripts/JavaScript-Canvas-to-Blob/js/canvas-to-blob.js

@@ -0,0 +1,126 @@
+/*
+ * JavaScript Canvas to Blob
+ * https://github.com/blueimp/JavaScript-Canvas-to-Blob
+ *
+ * Copyright 2012, Sebastian Tschan
+ * https://blueimp.net
+ *
+ * Licensed under the MIT license:
+ * https://opensource.org/licenses/MIT
+ *
+ * Based on stackoverflow user Stoive's code snippet:
+ * http://stackoverflow.com/q/4998908
+ */
+
+/* global define, Uint8Array, ArrayBuffer, module */
+
+;(function (window) {
+  'use strict'
+
+  var CanvasPrototype =
+    window.HTMLCanvasElement && window.HTMLCanvasElement.prototype
+  var hasBlobConstructor =
+    window.Blob &&
+    (function () {
+      try {
+        return Boolean(new Blob())
+      } catch (e) {
+        return false
+      }
+    })()
+  var hasArrayBufferViewSupport =
+    hasBlobConstructor &&
+    window.Uint8Array &&
+    (function () {
+      try {
+        return new Blob([new Uint8Array(100)]).size === 100
+      } catch (e) {
+        return false
+      }
+    })()
+  var BlobBuilder =
+    window.BlobBuilder ||
+    window.WebKitBlobBuilder ||
+    window.MozBlobBuilder ||
+    window.MSBlobBuilder
+  var dataURIPattern = /^data:((.*?)(;charset=.*?)?)(;base64)?,/
+  var dataURLtoBlob =
+    (hasBlobConstructor || BlobBuilder) &&
+    window.atob &&
+    window.ArrayBuffer &&
+    window.Uint8Array &&
+    function (dataURI) {
+      var matches,
+        mediaType,
+        isBase64,
+        dataString,
+        byteString,
+        arrayBuffer,
+        intArray,
+        i,
+        bb
+      // Parse the dataURI components as per RFC 2397
+      matches = dataURI.match(dataURIPattern)
+      if (!matches) {
+        throw new Error('invalid data URI')
+      }
+      // Default to text/plain;charset=US-ASCII
+      mediaType = matches[2]
+        ? matches[1]
+        : 'text/plain' + (matches[3] || ';charset=US-ASCII')
+      isBase64 = !!matches[4]
+      dataString = dataURI.slice(matches[0].length)
+      if (isBase64) {
+        // Convert base64 to raw binary data held in a string:
+        byteString = atob(dataString)
+      } else {
+        // Convert base64/URLEncoded data component to raw binary:
+        byteString = decodeURIComponent(dataString)
+      }
+      // 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)
+      }
+      // Write the ArrayBuffer (or ArrayBufferView) to a blob:
+      if (hasBlobConstructor) {
+        return new Blob([hasArrayBufferViewSupport ? intArray : arrayBuffer], {
+          type: mediaType
+        })
+      }
+      bb = new BlobBuilder()
+      bb.append(arrayBuffer)
+      return bb.getBlob(mediaType)
+    }
+  if (window.HTMLCanvasElement && !CanvasPrototype.toBlob) {
+    if (CanvasPrototype.mozGetAsFile) {
+      CanvasPrototype.toBlob = function (callback, type, quality) {
+        var self = this
+        setTimeout(function () {
+          if (quality && CanvasPrototype.toDataURL && dataURLtoBlob) {
+            callback(dataURLtoBlob(self.toDataURL(type, quality)))
+          } else {
+            callback(self.mozGetAsFile('blob', type))
+          }
+        })
+      }
+    } else if (CanvasPrototype.toDataURL && dataURLtoBlob) {
+      CanvasPrototype.toBlob = function (callback, type, quality) {
+        var self = this
+        setTimeout(function () {
+          callback(dataURLtoBlob(self.toDataURL(type, quality)))
+        })
+      }
+    }
+  }
+  if (typeof define === 'function' && define.amd) {
+    define(function () {
+      return dataURLtoBlob
+    })
+  } else if (typeof module === 'object' && module.exports) {
+    module.exports = dataURLtoBlob
+  } else {
+    window.dataURLtoBlob = dataURLtoBlob
+  }
+})(window)