pdf.js/web/compatibility.js
2011-10-17 20:39:29 +02:00

193 lines
5.7 KiB
JavaScript

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
'use strict';
// Checking if the typed arrays are supported
(function checkTypedArrayCompatibility() {
if (typeof Uint8Array !== 'undefined')
return;
function subarray(start, end) {
return 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
result = arg1.slice(0);
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;
})();
// Object.create() ?
(function checkObjectCreateCompatibility() {
if (typeof Object.create !== 'undefined')
return;
Object.create = function objectCreate(proto) {
var constructor = function objectCreateConstructor() {};
constructor.prototype = proto;
return new constructor();
};
})();
// Object.defineProperty() ?
(function checkObjectDefinePropertyCompatibility() {
if (typeof Object.defineProperty !== 'undefined')
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;
}
};
})();
// No XMLHttpRequest.response ?
(function checkXMLHttpRequestResponseCompatibility() {
var xhrPrototype = XMLHttpRequest.prototype;
if ('response' in xhrPrototype ||
'mozResponseArrayBuffer' in xhrPrototype ||
'mozResponse' in xhrPrototype ||
'responseArrayBuffer' in xhrPrototype)
return;
// IE ?
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;
};
})();
// 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 = Array.prototype.concat.apply(headArgs, arguments);
return fn.apply(obj, args);
};
return bound;
};
})();
// IE9 text/html data URI
(function checkDocumentDocumentModeCompatibility() {
if (!('documentMode' in document) || document.documentMode !== 9)
return;
// overriding the src property
var originalSrcDescriptor = Object.getOwnPropertyDescriptor(
HTMLIFrameElement.prototype, 'src');
Object.defineProperty(HTMLIFrameElement.prototype, 'src', {
get: function htmlIFrameElementPrototypeSrcGet() { return this.$src; },
set: function htmlIFrameElementPrototypeSrcSet(src) {
this.$src = src;
if (src.substr(0, 14) != 'data:text/html') {
originalSrcDescriptor.set.call(this, src);
return;
}
// for text/html, using blank document and then
// document's open, write, and close operations
originalSrcDescriptor.set.call(this, 'about:blank');
setTimeout((function htmlIFrameElementPrototypeSrcOpenWriteClose() {
var doc = this.contentDocument;
doc.open('text/html');
doc.write(src.substr(src.indexOf(',') + 1));
doc.close();
}).bind(this), 0);
},
enumerable: true
});
})();