Add a test for fullscreen for the A/B/A case
See the discussion at [1] for more context. This test requests
fullscreen on A, then B, then A, where A and B are sibling divs. All
three requests should succeed, and at the end, A should be topmost (and
the fullscreen element) with both A and B in the top layer.
[1] https://github.com/whatwg/fullscreen/pull/223
Change-Id: I3f35dda5b9eb1bc24201616bb5bb4949d20fd170
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4501251
Commit-Queue: Mason Freed <masonf@chromium.org>
Reviewed-by: Joey Arhar <jarhar@chromium.org>
Auto-Submit: Mason Freed <masonf@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1141456}
diff --git a/fullscreen/api/fullscreen-reordering.html b/fullscreen/api/fullscreen-reordering.html
new file mode 100644
index 0000000..1a286c3
--- /dev/null
+++ b/fullscreen/api/fullscreen-reordering.html
@@ -0,0 +1,62 @@
+<!DOCTYPE html>
+<title>Re-requesting fullscreen doesn't fail but doesn't change order</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<script src="../../html/semantics/popovers/resources/popover-utils.js"></script>
+
+<div class="elements">
+ <div id="A">Element A</div>
+ <div id="B">Element B</div>
+</div>
+
+<style>
+ .elements>div {
+ width:200px;
+ height:200px;
+ }
+ #A { background: blue; }
+ #B { background: green; }
+</style>
+
+<script>
+promise_test(async (t) => {
+ t.add_cleanup(async () => {
+ while (document.fullscreenElement)
+ await document.exitFullscreen();
+ });
+ document.onfullscreenerror = () => assert_unreached('fullscreenerror should not happen');
+ const A = document.getElementById('A');
+ const B = document.getElementById('B');
+ assert_true(!isTopLayer(A) && !isTopLayer(B));
+ await blessTopLayer(document.body);
+ await A.requestFullscreen();
+ assert_equals(document.fullscreenElement,A,'first A request');
+ assert_true(isTopLayer(A),'A top layer');
+ await blessTopLayer(A);
+ try {
+ await B.requestFullscreen();
+ } catch (error) {
+ assert_unreached('The second call to requestFullscreen rejected - it should be possible to put siblings into fullscreen together');
+ }
+ assert_equals(document.fullscreenElement,B,'B request');
+ assert_true(isTopLayer(B),'B top layer');
+ assert_true(isTopLayer(A),'A still top layer');
+ await blessTopLayer(B);
+ await A.requestFullscreen();
+ assert_true(isTopLayer(A),'A is still top layer');
+ assert_true(isTopLayer(B),'B is still top layer');
+ assert_equals(document.fullscreenElement,A,'A is moved back to the top of the top layer stack');
+ assert_equals(document.elementFromPoint(10,10),A,'A should be topmost');
+
+ await document.exitFullscreen();
+ assert_equals(document.fullscreenElement,B,'B goes back to being the fullscreen element');
+ assert_true(isTopLayer(B),'B is still top layer');
+ assert_false(isTopLayer(A),'A is no longer top layer');
+ await document.exitFullscreen();
+ assert_equals(document.fullscreenElement,null,'Both closed');
+ assert_false(isTopLayer(A),'A is no longer top layer');
+ assert_false(isTopLayer(B),'B is no longer top layer');
+}, 'Requesting fullscreen on A, then B, then A');
+</script>
diff --git a/html/semantics/popovers/resources/popover-utils.js b/html/semantics/popovers/resources/popover-utils.js
index 39de6aa..aa69b7d 100644
--- a/html/semantics/popovers/resources/popover-utils.js
+++ b/html/semantics/popovers/resources/popover-utils.js
@@ -47,6 +47,22 @@
function isElementVisible(el) {
return !!(el.offsetWidth || el.offsetHeight || el.getClientRects().length);
}
+function isTopLayer(el) {
+ // A bit of a hack. Just test a few properties of the ::backdrop pseudo
+ // element that change when in the top layer.
+ const properties = ['right','background'];
+ const testEl = document.createElement('div');
+ document.body.appendChild(testEl);
+ const computedStyle = getComputedStyle(testEl, '::backdrop');
+ const nonTopLayerValues = properties.map(p => computedStyle[p]);
+ testEl.remove();
+ for(let i=0;i<properties.length;++i) {
+ if (getComputedStyle(el,'::backdrop')[properties[i]] !== nonTopLayerValues[i]) {
+ return true;
+ }
+ }
+ return false;
+}
async function finishAnimations(popover) {
popover.getAnimations({subtree: true}).forEach(animation => animation.finish());
await waitForRender();
