pdf.js/web/compatibility.js
Mitar 628de8a1f4 Fix for bind compatibility implementation (polyfill).
Previously, reconstruction of arguments was incorrect if arguments contained
arrays. Arrays were added to arguments as their elements and not as a whole
array. It is enough to simply pass whole array to concat and it will be (only
one level deep) added to arguments.

In addition, we call slice on arguments for maximum compatibility (it is used
in Underscore.js library, with which I was comparing implementations while
debugging).
2014-02-15 03:48:18 -08:00

492 lines
15 KiB
JavaScript

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/* Copyright 2012 Mozilla Foundation
*
* 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.
*/
/* globals VBArray, PDFJS */
'use strict';
// Initializing PDFJS global object here, it case if we need to change/disable
// some PDF.js features, e.g. range requests
if (typeof PDFJS === 'undefined') {
(typeof window !== 'undefined' ? window : this).PDFJS = {};
}
// Checking if the typed arrays are supported
(function checkTypedArrayCompatibility() {
if (typeof Uint8Array !== 'undefined') {
// some mobile versions do not support subarray (e.g. safari 5 / iOS)
if (typeof Uint8Array.prototype.subarray === 'undefined') {
Uint8Array.prototype.subarray = function subarray(start, end) {
return new Uint8Array(this.slice(start, end));
};
Float32Array.prototype.subarray = function subarray(start, end) {
return new Float32Array(this.slice(start, end));
};
}
// some mobile version might not support Float64Array
if (typeof Float64Array === 'undefined')
window.Float64Array = Float32Array;
return;
}
function subarray(start, end) {
return new TypedArray(this.slice(start, end));
}
function setArrayOffset(array, offset) {
if (arguments.length < 2)
offset = 0;
for (var i = 0, n = array.length; i < n; ++i, ++offset)
this[offset] = array[i] & 0xFF;
}
function TypedArray(arg1) {
var result;
if (typeof arg1 === 'number') {
result = [];
for (var i = 0; i < arg1; ++i)
result[i] = 0;
} else if ('slice' in arg1) {
result = arg1.slice(0);
} else {
result = [];
for (var i = 0, n = arg1.length; i < n; ++i) {
result[i] = arg1[i];
}
}
result.subarray = subarray;
result.buffer = result;
result.byteLength = result.length;
result.set = setArrayOffset;
if (typeof arg1 === 'object' && arg1.buffer)
result.buffer = arg1.buffer;
return result;
}
window.Uint8Array = TypedArray;
// we don't need support for set, byteLength for 32-bit array
// so we can use the TypedArray as well
window.Uint32Array = TypedArray;
window.Int32Array = TypedArray;
window.Uint16Array = TypedArray;
window.Float32Array = TypedArray;
window.Float64Array = TypedArray;
})();
// URL = URL || webkitURL
(function normalizeURLObject() {
if (!window.URL) {
window.URL = window.webkitURL;
}
})();
// Object.create() ?
(function checkObjectCreateCompatibility() {
if (typeof Object.create !== 'undefined')
return;
Object.create = function objectCreate(proto) {
function Constructor() {}
Constructor.prototype = proto;
return new Constructor();
};
})();
// Object.defineProperty() ?
(function checkObjectDefinePropertyCompatibility() {
if (typeof Object.defineProperty !== 'undefined') {
var definePropertyPossible = true;
try {
// some browsers (e.g. safari) cannot use defineProperty() on DOM objects
// and thus the native version is not sufficient
Object.defineProperty(new Image(), 'id', { value: 'test' });
// ... another test for android gb browser for non-DOM objects
var Test = function Test() {};
Test.prototype = { get id() { } };
Object.defineProperty(new Test(), 'id',
{ value: '', configurable: true, enumerable: true, writable: false });
} catch (e) {
definePropertyPossible = false;
}
if (definePropertyPossible) return;
}
Object.defineProperty = function objectDefineProperty(obj, name, def) {
delete obj[name];
if ('get' in def)
obj.__defineGetter__(name, def['get']);
if ('set' in def)
obj.__defineSetter__(name, def['set']);
if ('value' in def) {
obj.__defineSetter__(name, function objectDefinePropertySetter(value) {
this.__defineGetter__(name, function objectDefinePropertyGetter() {
return value;
});
return value;
});
obj[name] = def.value;
}
};
})();
// Object.keys() ?
(function checkObjectKeysCompatibility() {
if (typeof Object.keys !== 'undefined')
return;
Object.keys = function objectKeys(obj) {
var result = [];
for (var i in obj) {
if (obj.hasOwnProperty(i))
result.push(i);
}
return result;
};
})();
// No readAsArrayBuffer ?
(function checkFileReaderReadAsArrayBuffer() {
if (typeof FileReader === 'undefined')
return; // FileReader is not implemented
var frPrototype = FileReader.prototype;
// Older versions of Firefox might not have readAsArrayBuffer
if ('readAsArrayBuffer' in frPrototype)
return; // readAsArrayBuffer is implemented
Object.defineProperty(frPrototype, 'readAsArrayBuffer', {
value: function fileReaderReadAsArrayBuffer(blob) {
var fileReader = new FileReader();
var originalReader = this;
fileReader.onload = function fileReaderOnload(evt) {
var data = evt.target.result;
var buffer = new ArrayBuffer(data.length);
var uint8Array = new Uint8Array(buffer);
for (var i = 0, ii = data.length; i < ii; i++)
uint8Array[i] = data.charCodeAt(i);
Object.defineProperty(originalReader, 'result', {
value: buffer,
enumerable: true,
writable: false,
configurable: true
});
var event = document.createEvent('HTMLEvents');
event.initEvent('load', false, false);
originalReader.dispatchEvent(event);
};
fileReader.readAsBinaryString(blob);
}
});
})();
// No XMLHttpRequest.response ?
(function checkXMLHttpRequestResponseCompatibility() {
var xhrPrototype = XMLHttpRequest.prototype;
if (!('overrideMimeType' in xhrPrototype)) {
// IE10 might have response, but not overrideMimeType
Object.defineProperty(xhrPrototype, 'overrideMimeType', {
value: function xmlHttpRequestOverrideMimeType(mimeType) {}
});
}
if ('response' in xhrPrototype ||
'mozResponseArrayBuffer' in xhrPrototype ||
'mozResponse' in xhrPrototype ||
'responseArrayBuffer' in xhrPrototype)
return;
// IE9 ?
if (typeof VBArray !== 'undefined') {
Object.defineProperty(xhrPrototype, 'response', {
get: function xmlHttpRequestResponseGet() {
return new Uint8Array(new VBArray(this.responseBody).toArray());
}
});
return;
}
// other browsers
function responseTypeSetter() {
// will be only called to set "arraybuffer"
this.overrideMimeType('text/plain; charset=x-user-defined');
}
if (typeof xhrPrototype.overrideMimeType === 'function') {
Object.defineProperty(xhrPrototype, 'responseType',
{ set: responseTypeSetter });
}
function responseGetter() {
var text = this.responseText;
var i, n = text.length;
var result = new Uint8Array(n);
for (i = 0; i < n; ++i)
result[i] = text.charCodeAt(i) & 0xFF;
return result;
}
Object.defineProperty(xhrPrototype, 'response', { get: responseGetter });
})();
// window.btoa (base64 encode function) ?
(function checkWindowBtoaCompatibility() {
if ('btoa' in window)
return;
var digits =
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
window.btoa = function windowBtoa(chars) {
var buffer = '';
var i, n;
for (i = 0, n = chars.length; i < n; i += 3) {
var b1 = chars.charCodeAt(i) & 0xFF;
var b2 = chars.charCodeAt(i + 1) & 0xFF;
var b3 = chars.charCodeAt(i + 2) & 0xFF;
var d1 = b1 >> 2, d2 = ((b1 & 3) << 4) | (b2 >> 4);
var d3 = i + 1 < n ? ((b2 & 0xF) << 2) | (b3 >> 6) : 64;
var d4 = i + 2 < n ? (b3 & 0x3F) : 64;
buffer += (digits.charAt(d1) + digits.charAt(d2) +
digits.charAt(d3) + digits.charAt(d4));
}
return buffer;
};
})();
// window.atob (base64 encode function) ?
(function checkWindowAtobCompatibility() {
if ('atob' in window)
return;
// https://github.com/davidchambers/Base64.js
var digits =
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
window.atob = function (input) {
input = input.replace(/=+$/, '');
if (input.length % 4 == 1) throw new Error('bad atob input');
for (
// initialize result and counters
var bc = 0, bs, buffer, idx = 0, output = '';
// get next character
buffer = input.charAt(idx++);
// character found in table?
// initialize bit storage and add its ascii value
~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
// and if not first of each 4 characters,
// convert the first 8 bits to one ascii character
bc++ % 4) ? output += String.fromCharCode(255 & bs >> (-2 * bc & 6)) : 0
) {
// try to find character in table (0-63, not found => -1)
buffer = digits.indexOf(buffer);
}
return output;
};
})();
// Function.prototype.bind ?
(function checkFunctionPrototypeBindCompatibility() {
if (typeof Function.prototype.bind !== 'undefined')
return;
Function.prototype.bind = function functionPrototypeBind(obj) {
var fn = this, headArgs = Array.prototype.slice.call(arguments, 1);
var bound = function functionPrototypeBindBound() {
var args = headArgs.concat(Array.prototype.slice.call(arguments));
return fn.apply(obj, args);
};
return bound;
};
})();
// HTMLElement dataset property
(function checkDatasetProperty() {
var div = document.createElement('div');
if ('dataset' in div)
return; // dataset property exists
Object.defineProperty(HTMLElement.prototype, 'dataset', {
get: function() {
if (this._dataset)
return this._dataset;
var dataset = {};
for (var j = 0, jj = this.attributes.length; j < jj; j++) {
var attribute = this.attributes[j];
if (attribute.name.substring(0, 5) != 'data-')
continue;
var key = attribute.name.substring(5).replace(/\-([a-z])/g,
function(all, ch) { return ch.toUpperCase(); });
dataset[key] = attribute.value;
}
Object.defineProperty(this, '_dataset', {
value: dataset,
writable: false,
enumerable: false
});
return dataset;
},
enumerable: true
});
})();
// HTMLElement classList property
(function checkClassListProperty() {
var div = document.createElement('div');
if ('classList' in div)
return; // classList property exists
function changeList(element, itemName, add, remove) {
var s = element.className || '';
var list = s.split(/\s+/g);
if (list[0] === '') list.shift();
var index = list.indexOf(itemName);
if (index < 0 && add)
list.push(itemName);
if (index >= 0 && remove)
list.splice(index, 1);
element.className = list.join(' ');
return (index >= 0);
}
var classListPrototype = {
add: function(name) {
changeList(this.element, name, true, false);
},
contains: function(name) {
return changeList(this.element, name, false, false);
},
remove: function(name) {
changeList(this.element, name, false, true);
},
toggle: function(name) {
changeList(this.element, name, true, true);
}
};
Object.defineProperty(HTMLElement.prototype, 'classList', {
get: function() {
if (this._classList)
return this._classList;
var classList = Object.create(classListPrototype, {
element: {
value: this,
writable: false,
enumerable: true
}
});
Object.defineProperty(this, '_classList', {
value: classList,
writable: false,
enumerable: false
});
return classList;
},
enumerable: true
});
})();
// Check console compatibility
(function checkConsoleCompatibility() {
if (!('console' in window)) {
window.console = {
log: function() {},
error: function() {},
warn: function() {}
};
} else if (!('bind' in console.log)) {
// native functions in IE9 might not have bind
console.log = (function(fn) {
return function(msg) { return fn(msg); };
})(console.log);
console.error = (function(fn) {
return function(msg) { return fn(msg); };
})(console.error);
console.warn = (function(fn) {
return function(msg) { return fn(msg); };
})(console.warn);
}
})();
// Check onclick compatibility in Opera
(function checkOnClickCompatibility() {
// workaround for reported Opera bug DSK-354448:
// onclick fires on disabled buttons with opaque content
function ignoreIfTargetDisabled(event) {
if (isDisabled(event.target)) {
event.stopPropagation();
}
}
function isDisabled(node) {
return node.disabled || (node.parentNode && isDisabled(node.parentNode));
}
if (navigator.userAgent.indexOf('Opera') != -1) {
// use browser detection since we cannot feature-check this bug
document.addEventListener('click', ignoreIfTargetDisabled, true);
}
})();
// Checks if possible to use URL.createObjectURL()
(function checkOnBlobSupport() {
// sometimes IE loosing the data created with createObjectURL(), see #3977
if (navigator.userAgent.indexOf('Trident') >= 0) {
PDFJS.disableCreateObjectURL = true;
}
})();
// Checks if navigator.language is supported
(function checkNavigatorLanguage() {
if ('language' in navigator)
return;
Object.defineProperty(navigator, 'language', {
get: function navigatorLanguage() {
var language = navigator.userLanguage || 'en-US';
return language.substring(0, 2).toLowerCase() +
language.substring(2).toUpperCase();
},
enumerable: true
});
})();
(function checkRangeRequests() {
// Safari has issues with cached range requests see:
// https://github.com/mozilla/pdf.js/issues/3260
// Last tested with version 6.0.4.
var isSafari = Object.prototype.toString.call(
window.HTMLElement).indexOf('Constructor') > 0;
// Older versions of Android (pre 3.0) has issues with range requests, see:
// https://github.com/mozilla/pdf.js/issues/3381.
// Make sure that we only match webkit-based Android browsers,
// since Firefox/Fennec works as expected.
var regex = /Android\s[0-2][^\d]/;
var isOldAndroid = regex.test(navigator.userAgent);
if (isSafari || isOldAndroid) {
PDFJS.disableRange = true;
}
})();
// Check if the browser supports manipulation of the history.
(function checkHistoryManipulation() {
if (!window.history.pushState) {
PDFJS.disableHistory = true;
}
})();