silverstripe-framework/thirdparty/javascript-loadimage/load-image.js

115 lines
3.7 KiB
JavaScript
Raw Normal View History

/*
* JavaScript Load Image 1.1.3
* https://github.com/blueimp/JavaScript-Load-Image
*
* Copyright 2011, Sebastian Tschan
* https://blueimp.net
*
* Licensed under the MIT license:
* http://www.opensource.org/licenses/MIT
*/
/*jslint nomen: true */
/*global window, document, URL, webkitURL, Blob, FileReader, define */
(function ($) {
'use strict';
// Loads an image for a given File object.
// Invokes the callback with an img or optional canvas
// element (if supported by the browser) as parameter:
var loadImage = function (file, callback, options) {
var img = document.createElement('img'),
url,
isFile;
if (window.Blob && file instanceof Blob) {
url = loadImage.createObjectURL(file);
isFile = true;
} else {
url = file;
}
img.onerror = callback;
img.onload = function () {
if (isFile) {
loadImage.revokeObjectURL(url);
}
callback(loadImage.scale(img, options));
};
if (url) {
img.src = url;
return img;
} else {
return loadImage.readFile(file, function (url) {
img.src = url;
});
}
},
urlAPI = (window.createObjectURL && window) ||
(window.URL && URL) || (window.webkitURL && webkitURL);
// Scales the given image (img HTML element)
// using the given options.
// Returns a canvas object if the canvas option is true
// and the browser supports canvas, else the scaled image:
loadImage.scale = function (img, options) {
options = options || {};
var canvas = document.createElement('canvas'),
scale = Math.max(
(options.minWidth || img.width) / img.width,
(options.minHeight || img.height) / img.height
);
if (scale > 1) {
img.width = parseInt(img.width * scale, 10);
img.height = parseInt(img.height * scale, 10);
}
scale = Math.min(
(options.maxWidth || img.width) / img.width,
(options.maxHeight || img.height) / img.height
);
if (scale < 1) {
img.width = parseInt(img.width * scale, 10);
img.height = parseInt(img.height * scale, 10);
}
if (!options.canvas || !canvas.getContext) {
return img;
}
canvas.width = img.width;
canvas.height = img.height;
canvas.getContext('2d')
.drawImage(img, 0, 0, img.width, img.height);
return canvas;
};
loadImage.createObjectURL = function (file) {
return urlAPI ? urlAPI.createObjectURL(file) : false;
};
loadImage.revokeObjectURL = function (url) {
return urlAPI ? urlAPI.revokeObjectURL(url) : false;
};
// Loads a given File object via FileReader interface,
// invokes the callback with a data url:
loadImage.readFile = function (file, callback) {
if (window.FileReader && FileReader.prototype.readAsDataURL) {
var fileReader = new FileReader();
fileReader.onload = function (e) {
callback(e.target.result);
};
fileReader.readAsDataURL(file);
return fileReader;
}
return false;
};
if (typeof define !== 'undefined' && define.amd) {
// Register as an AMD module:
define('loadImage', function () {
return loadImage;
});
} else {
// Bind to the global (window) object:
$.loadImage = loadImage;
}
}(this));