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author | Erik Johnston <erik@matrix.org> | 2014-08-22 15:50:23 +0100 |
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committer | Erik Johnston <erik@matrix.org> | 2014-08-22 15:50:23 +0100 |
commit | e1297c922d7f88eed088b365bd6cf15951443506 (patch) | |
tree | 57fb71ff724a4046d3a8e3ea4ce3de4735b9dd69 /webclient/components/utilities/utilities-service.js | |
parent | Added initial swagger REST API spec. (diff) | |
parent | Merge branch 'develop' of github.com:matrix-org/synapse into release-v0.0.1 (diff) | |
download | synapse-e1297c922d7f88eed088b365bd6cf15951443506.tar.xz |
Merge branch 'release-v0.0.1' of github.com:matrix-org/synapse
Diffstat (limited to 'webclient/components/utilities/utilities-service.js')
-rw-r--r-- | webclient/components/utilities/utilities-service.js | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/webclient/components/utilities/utilities-service.js b/webclient/components/utilities/utilities-service.js new file mode 100644 index 0000000000..3df2f04458 --- /dev/null +++ b/webclient/components/utilities/utilities-service.js @@ -0,0 +1,151 @@ +/* + Copyright 2014 matrix.org + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. + */ + +'use strict'; + +/* + * This service contains multipurpose helper functions. + */ +angular.module('mUtilities', []) +.service('mUtilities', ['$q', function ($q) { + /* + * Get the size of an image + * @param {File|Blob} imageFile the file containing the image + * @returns {promise} A promise that will be resolved by an object with 2 members: + * width & height + */ + this.getImageSize = function(imageFile) { + var deferred = $q.defer(); + + // Load the file into an html element + var img = document.createElement("img"); + + var reader = new FileReader(); + reader.onload = function(e) { + img.src = e.target.result; + + // Once ready, returns its size + img.onload = function() { + deferred.resolve({ + width: img.width, + height: img.height + }); + }; + img.onerror = function(e) { + deferred.reject(e); + }; + }; + reader.onerror = function(e) { + deferred.reject(e); + }; + reader.readAsDataURL(imageFile); + + 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; + + // Once ready, returns its size + img.onload = function() { + 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); + + // Extract image data in the same format as the original one. + // The 0.7 compression value will work with formats that supports it like JPEG. + var dataUrl = canvas.toDataURL(imageFile.type, 0.7); + deferred.resolve(self.dataURItoBlob(dataUrl)); + }; + img.onerror = function(e) { + deferred.reject(e); + }; + }; + 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}); + }; + +}]); \ No newline at end of file |