Fixes CanvasPixelArray set polyfill for chrome < 21 (#4974)

This commit is contained in:
Fabian Lange 2014-06-24 12:12:17 +02:00
parent 10db93be29
commit 9fd6cc7f1e

View File

@ -481,9 +481,9 @@ if (typeof PDFJS === 'undefined') {
}
})();
// TODO CanvasPixelArray is deprecated; use Uint8ClampedArray
// once it's supported.
// Support: IE<11, Chrome<21
(function checkSetPresenceInImageData() {
// IE < 11 will use window.CanvasPixelArray which lacks set function.
if (window.CanvasPixelArray) {
if (typeof window.CanvasPixelArray.prototype.set !== 'function') {
window.CanvasPixelArray.prototype.set = function(arr) {
@ -492,6 +492,25 @@ if (typeof PDFJS === 'undefined') {
}
};
}
} else {
// Chrome < 21 uses an inaccessible CanvasPixelArray prototype.
// Because we cannot feature detect it, we rely on user agent.
if (navigator.userAgent.indexOf('Chrom') >= 0) {
var versionMatch = navigator.userAgent.match(/Chrom(e|ium)\/([0-9]+)\./);
if (versionMatch && parseInt(versionMatch[2]) < 21) {
var contextPrototype = window.CanvasRenderingContext2D.prototype;
contextPrototype._createImageData = contextPrototype.createImageData;
contextPrototype.createImageData = function(w, h) {
var imageData = this._createImageData(w, h);
imageData.data.set = function(arr) {
for (var i = 0, ii = this.length; i < ii; i++) {
this[i] = arr[i];
}
};
return imageData;
};
}
}
}
})();