gecko-dev/dom/browser-element/mochitest/browserElement_GetScreenshotDppx.js

109 lines
2.9 KiB
JavaScript

/* Any copyright is dedicated to the public domain.
http://creativecommons.org/publicdomain/zero/1.0/ */
// Test the getScreenshot property for mozbrowser
"use strict";
SimpleTest.waitForExplicitFinish();
browserElementTestHelpers.setEnabledPref(true);
browserElementTestHelpers.addPermission();
function runTest() {
var dppxPref = 'layout.css.devPixelsPerPx';
var cssPixelWidth = 600;
var cssPixelHeight = 400;
var iframe1 = document.createElement('iframe');
iframe1.setAttribute('width', cssPixelWidth);
iframe1.setAttribute('height', cssPixelHeight);
SpecialPowers.wrap(iframe1).mozbrowser = true;
iframe1.src = 'data:text/html,<html><body>hello</body></html>';
document.body.appendChild(iframe1);
var images = [];
function screenshotTaken(image) {
images.push(image);
if (images.length === 1) {
ok(true, 'Got initial non blank screenshot');
if (image.width !== cssPixelWidth || image.height !== cssPixelHeight) {
ok(false, 'The pixel width of the image received is not correct');
SimpleTest.finish();
return;
}
ok(true, 'The pixel width of the image received is correct');
SpecialPowers.pushPrefEnv(
{'set': [['layout.css.devPixelsPerPx', 2]]}, takeScreenshot);
}
else if (images.length === 2) {
ok(true, 'Got updated screenshot after source page changed');
if (image.width !== cssPixelWidth * 2 ||
image.height !== cssPixelHeight * 2) {
ok(false, 'The pixel width of the 2dppx image received is not correct');
SimpleTest.finish();
return;
}
ok(true, 'The pixel width of the 2dppx image received is correct');
SimpleTest.finish();
}
}
function takeScreenshot() {
function gotImage(e) {
// |this| is the Image.
URL.revokeObjectURL(this.src);
if (e.type === 'error' || !this.width || !this.height) {
tryAgain();
return;
}
screenshotTaken(this);
}
function tryAgain() {
if (--attempts === 0) {
ok(false, 'Timed out waiting for correct screenshot');
SimpleTest.finish();
} else {
setTimeout(function() {
iframe1.getScreenshot(cssPixelWidth, cssPixelHeight).onsuccess =
getScreenshotImageData;
}, 200);
}
}
function getScreenshotImageData(e) {
var blob = e.target.result;
if (blob.size === 0) {
tryAgain();
return;
}
var img = new Image();
img.src = URL.createObjectURL(blob);
img.onload = img.onerror = gotImage;
}
var attempts = 10;
iframe1.getScreenshot(cssPixelWidth, cssPixelHeight).onsuccess =
getScreenshotImageData;
}
function iframeLoadedHandler() {
SpecialPowers.pushPrefEnv(
{'set': [['layout.css.devPixelsPerPx', 1]]}, takeScreenshot);
}
iframe1.addEventListener('mozbrowserloadend', iframeLoadedHandler);
}
addEventListener('testready', runTest);