JavaScript-Load-Image/load-image.js at master · IndacoSystems/JavaScript-Load-Image · GitHub

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* JavaScript Load Image 1.7

* https://github.com/blueimp/JavaScript-Load-Image

* https://blueimp.net

* Licensed under the MIT license:

* http://www.opensource.org/licenses/MIT

/*jslint nomen: true */

/*global define, window, document, URL, webkitURL, Blob, File, FileReader */

(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,

oUrl;

img.onerror = callback;

img.onload = function () {

if (oUrl && !(options && options.noRevoke)) {

loadImage.revokeObjectURL(oUrl);

}

if (callback) {

callback(loadImage.scale(img, options));

}

};

if (loadImage.isInstanceOf('Blob', file) ||

// Files are also Blob instances, but some browsers

// (Firefox 3.6) support the File API but not Blobs:

loadImage.isInstanceOf('File', file)) {

url = oUrl = loadImage.createObjectURL(file);

// Store the file type for resize processing:

img._type = file.type;

} else if (typeof file === 'string') {

url = file;

if (options && options.crossOrigin) {

img.crossOrigin = options.crossOrigin;

}

} else {

return false;

}

if (url) {

img.src = url;

return img;

}

return loadImage.readFile(file, function (e) {

var target = e.target;

if (target && target.result) {

img.src = target.result;

} else {

if (callback) {

callback(e);

}

});

// The check for URL.revokeObjectURL fixes an issue with Opera 12,

// which provides URL.createObjectURL but doesn't properly implement it:

urlAPI = (window.createObjectURL && window) ||

(window.URL && URL.revokeObjectURL && URL) ||

(window.webkitURL && webkitURL);

loadImage.isInstanceOf = function (type, obj) {

// Cross-frame instanceof check

return Object.prototype.toString.call(obj) === '[object ' + type + ']';

};

// Transform image orientation based on the given EXIF orientation data:

loadImage.transformCoordinates = function (canvas, orientation) {

var ctx = canvas.getContext('2d'),

width = canvas.width,

height = canvas.height;

if (orientation > 4) {

canvas.width = height;

canvas.height = width;

}

switch (orientation) {

case 2:

// horizontal flip

ctx.translate(width, 0);

ctx.scale(-1, 1);

break;

case 3:

// 180 rotate left

ctx.translate(width, height);

ctx.rotate(Math.PI);

break;

case 4:

// vertical flip

ctx.translate(0, height);

ctx.scale(1, -1);

break;

case 5:

// vertical flip + 90 rotate right

ctx.rotate(0.5 * Math.PI);

ctx.scale(1, -1);

break;

case 6:

// 90 rotate right

ctx.rotate(0.5 * Math.PI);

ctx.translate(0, -height);

break;

case 7:

// horizontal flip + 90 rotate right

ctx.rotate(0.5 * Math.PI);

ctx.translate(width, -height);

ctx.scale(-1, 1);

break;

case 8:

// 90 rotate left

ctx.rotate(-0.5 * Math.PI);

ctx.translate(-width, 0);

break;

}

};

// Canvas render method, allows to override the

// rendering e.g. to work around issues on iOS:

loadImage.renderImageToCanvas = function (

canvas,

img,

sourceX,

sourceY,

sourceWidth,

sourceHeight,

destX,

destY,

destWidth,

destHeight

) {

canvas.getContext('2d').drawImage(

img,

sourceX,

sourceY,

sourceWidth,

sourceHeight,

destX,

destY,

destWidth,

destHeight

);

return canvas;

};

// Scales the given image (img or canvas HTML element)

// using the given options.

// Returns a canvas object if the browser supports canvas

// and the canvas or crop option is true or a canvas object

// is passed as image, else the scaled image:

loadImage.scale = function (img, options) {

options = options || {};

var canvas = document.createElement('canvas'),

useCanvas = img.getContext ||

((options.canvas || options.crop || options.orientation) &&

canvas.getContext),

width = img.width,

height = img.height,

sourceWidth = width,

sourceHeight = height,

sourceX = 0,

sourceY = 0,

destX = 0,

destY = 0,

maxWidth,

maxHeight,

minWidth,

minHeight,

destWidth,

destHeight,

scale;

if (useCanvas && options.orientation > 4) {

maxWidth = options.maxHeight;

maxHeight = options.maxWidth;

minWidth = options.minHeight;

minHeight = options.minWidth;

} else {

maxWidth = options.maxWidth;

maxHeight = options.maxHeight;

minWidth = options.minWidth;

minHeight = options.minHeight;

}

if (useCanvas && maxWidth && maxHeight && options.crop) {

destWidth = maxWidth;

destHeight = maxHeight;

if (width / height < maxWidth / maxHeight) {

sourceHeight = maxHeight * width / maxWidth;

sourceY = (height - sourceHeight) / 2;

} else {

sourceWidth = maxWidth * height / maxHeight;

sourceX = (width - sourceWidth) / 2;

}

} else {

destWidth = width;

destHeight = height;

scale = Math.max(

(minWidth || destWidth) / destWidth,

(minHeight || destHeight) / destHeight

);

if (scale > 1) {

destWidth = Math.ceil(destWidth * scale);

destHeight = Math.ceil(destHeight * scale);

}

scale = Math.min(

(maxWidth || destWidth) / destWidth,

(maxHeight || destHeight) / destHeight

);

if (scale < 1) {

destWidth = Math.ceil(destWidth * scale);

destHeight = Math.ceil(destHeight * scale);

}

if (useCanvas) {

canvas.width = destWidth;

canvas.height = destHeight;

loadImage.transformCoordinates(

canvas,

options.orientation

);

return loadImage.renderImageToCanvas(

canvas,

img,

sourceX,

sourceY,

sourceWidth,

sourceHeight,

destX,

destY,

destWidth,

destHeight

);

}

img.width = destWidth;

img.height = destHeight;

return img;

};

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 the event object (load or error).

// The result can be read via event.target.result:

loadImage.readFile = function (file, callback, method) {

if (window.FileReader) {

var fileReader = new FileReader();

fileReader.onload = fileReader.onerror = callback;

method = method || 'readAsDataURL';

if (fileReader[method]) {

fileReader[method](file);

return fileReader;

}

return false;

};

if (typeof define === 'function' && define.amd) {

define(function () {

return loadImage;

});

} else {

$.loadImage = loadImage;

}

}(this));

JavaScript-Load-Image/load-image.js at master · IndacoSystems/JavaScript-Load-Image · GitHub

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