diff --git a/webclient/components/utilities/utilities-service.js b/webclient/components/utilities/utilities-service.js
index fc0ee580dc..f9e52eacf8 100644
--- a/webclient/components/utilities/utilities-service.js
+++ b/webclient/components/utilities/utilities-service.js
@@ -22,7 +22,7 @@
angular.module('mUtilities', [])
.service('mUtilities', ['$q', function ($q) {
/*
- * Gets the size of an image
+ * Get the size of an image
* @param {File} imageFile the file containing the image
* @returns {promise} A promise that will be resolved by an object with 2 members:
* width & height
@@ -50,4 +50,89 @@ angular.module('mUtilities', [])
return deferred.promise;
};
+
+ /*
+ * Resize the image to fit in a square of the side maxSize.
+ * The aspect ratio is kept. The returned image data uses JPEG compression.
+ * Source: http://hacks.mozilla.org/2011/01/how-to-develop-a-html5-image-uploader/
+ * @param {File} imageFile the file containing the image
+ * @param {Integer} maxSize the max side size
+ * @returns {promise} A promise that will be resolved by a Blob object containing
+ * the resized image data
+ */
+ this.resizeImage = function(imageFile, maxSize) {
+ var self = this;
+ var deferred = $q.defer();
+
+ var canvas = document.createElement("canvas");
+
+ var img = document.createElement("img");
+ var reader = new FileReader();
+ reader.onload = function(e) {
+
+ img.src = e.target.result;
+
+ var ctx = canvas.getContext("2d");
+ ctx.drawImage(img, 0, 0);
+
+ var MAX_WIDTH = maxSize;
+ var MAX_HEIGHT = maxSize;
+ var width = img.width;
+ var height = img.height;
+
+ if (width > height) {
+ if (width > MAX_WIDTH) {
+ height *= MAX_WIDTH / width;
+ width = MAX_WIDTH;
+ }
+ } else {
+ if (height > MAX_HEIGHT) {
+ width *= MAX_HEIGHT / height;
+ height = MAX_HEIGHT;
+ }
+ }
+ canvas.width = width;
+ canvas.height = height;
+ var ctx = canvas.getContext("2d");
+ ctx.drawImage(img, 0, 0, width, height);
+
+ var dataUrl = canvas.toDataURL("image/jpeg", 0.7);
+ deferred.resolve(self.dataURItoBlob(dataUrl));
+ };
+ reader.onerror = function(e) {
+ deferred.reject(e);
+ };
+ reader.readAsDataURL(imageFile);
+
+ return deferred.promise;
+ };
+
+ /*
+ * Convert a dataURI string to a blob
+ * Source: http://stackoverflow.com/a/17682951
+ * @param {String} dataURI the dataURI can be a base64 encoded string or an URL encoded string.
+ * @returns {Blob} the blob
+ */
+ this.dataURItoBlob = function(dataURI) {
+ // convert base64 to raw binary data held in a string
+ // doesn't handle URLEncoded DataURIs
+ var byteString;
+ if (dataURI.split(',')[0].indexOf('base64') >= 0)
+ byteString = atob(dataURI.split(',')[1]);
+ else
+ byteString = unescape(dataURI.split(',')[1]);
+ // separate out the mime component
+ var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
+
+ // write the bytes of the string to an ArrayBuffer
+ var ab = new ArrayBuffer(byteString.length);
+ var ia = new Uint8Array(ab);
+ for (var i = 0; i < byteString.length; i++) {
+ ia[i] = byteString.charCodeAt(i);
+ }
+
+ // write the ArrayBuffer to a blob, and you're done
+ return new Blob([ab],{type: mimeString});
+ };
+
}]);
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