Source code
Revision control
Copy as Markdown
Other Tools
Test Info:
- This WPT test may be referenced by the following Test IDs:
- /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfercontrol.to.offscreen.w.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/html/canvas/resources/canvas-tests.js"></script>
<script id="myWorker" type="text/worker">
function testSize(offscreenCanvas)
{
if (offscreenCanvas.width == 100 && offscreenCanvas.height == 50)
return true;
return false;
}
self.onmessage = function(e) {
switch (e.data.msg) {
case 'test1':
self.postMessage(testSize(e.data.data));
break;
case 'test2':
self.postMessage("");
break;
case 'test3':
self.postMessage("");
break;
}
};
</script>
<script>
function makeWorker(script)
{
var blob = new Blob([script]);
return new Worker(URL.createObjectURL(blob));
}
async_test(function(t) {
var placeholder = document.createElement('canvas');
placeholder.width = 100;
placeholder.height = 50;
var offscreenCanvas = placeholder.transferControlToOffscreen();
var worker = makeWorker(document.getElementById("myWorker").textContent);
worker.addEventListener('message', t.step_func_done(function(msg) {
assert_true(msg.data);
}));
worker.postMessage({msg: 'test1', data: offscreenCanvas}, [offscreenCanvas]);
}, "Test that an OffscreenCanvas generated by transferControlToOffscreen gets correct width and height when it is transferred to a worker");
async_test(function(t) {
var placeholder = document.createElement('canvas');
placeholder.width = 100;
placeholder.height = 50;
var offscreenCanvas = placeholder.transferControlToOffscreen();
var worker = makeWorker(document.getElementById("myWorker").textContent);
worker.addEventListener('message', t.step_func_done(function(msg) {
assert_throws_dom("InvalidStateError", function() { placeholder.getContext('2d'); });
}));
worker.postMessage({msg: 'test2', data: offscreenCanvas}, [offscreenCanvas]);
}, "Test that calling getContext on a placeholder canvas that is transferred its control to an OffscreenCanvas throws an exception, when the OffscreenCanvas is transferred to a worker");
async_test(function(t) {
var placeholder = document.createElement('canvas');
placeholder.width = 100;
placeholder.height = 50;
var offscreenCanvas = placeholder.transferControlToOffscreen();
var worker = makeWorker(document.getElementById("myWorker").textContent);
worker.addEventListener('message', t.step_func_done(function(msg) {
assert_throws_dom("InvalidStateError", function() { placeholder.transferControlToOffscreen(); });
}));
worker.postMessage({msg: 'test3', data: offscreenCanvas}, [offscreenCanvas]);
}, "Test that calling transferControlToOffscreen twice throws an exception, when its associated OffscreenCanvas is transferred to a worker");
</script>