Fix bug in IntersectionObserver for SVG elements with viewbox

Allowing intersection observer to work with SVG elements created a bug as the function MapToVisualRectInAncestorSpace doesn't map from viewbox coordinates to the SVG elements coordinates. This patch adds code to fix this problem Bug: 1502965 Change-Id: I86123ed256f537a8840a3d3e74edacf27a2367bb Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5041547 Auto-Submit: Yotam Hacohen <yotha@chromium.org> Commit-Queue: Yotam Hacohen <yotha@chromium.org> Reviewed-by: Stefan Zager <szager@chromium.org> Commit-Queue: Stefan Zager <szager@chromium.org> Cr-Commit-Position: refs/heads/main@{#1226418}
web-platform-tests · Nov 18, 2023 · 351988b · 351988b
1 parent 0cde829
commit 351988b
Showing 1 changed file with 49 additions and 0 deletions.
diff --git a/intersection-observer/svg-viewbox.html b/intersection-observer/svg-viewbox.html
@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<title>IntersectionObserver observing an SVG &lt;rect> element with changing 'transform'</title>
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/intersection-observer-test-utils.js"></script>
+<svg id="container" width="10" height="10" viewBox="0 0 128 128" style="background: lightblue; position: absolute; top: 0; left: 0;">
+    <rect id="target" x="0" y="0" width="128" height="128" fill="green"></rect>
+</svg>
+<script>
+const viewportWidth = document.documentElement.clientWidth;
+const viewportHeight = document.documentElement.clientHeight;
+setup(() => {
+  window.entries = [];
+  window.target = document.getElementById("target");
+  window.targetRect = target.getBoundingClientRect();
+});
+runTestCycle(function() {
+  assert_true(!!target, "target exists");
+  const observer = new IntersectionObserver(function(changes) {
+    entries = entries.concat(changes);
+  }, {root: container, threshold: [0, 0.5, 1]});
+  observer.observe(target);
+  entries = entries.concat(observer.takeRecords());
+  assert_equals(entries.length, 0, "No initial notifications");
+  runTestCycle(step0, "First rAF.");
+});
+function step0() {
+  target.setAttribute('y', '-64');
+  runTestCycle(step1, "change target's y property to -64)");
+  // The numbers in brackets are target client rect; intersection rect;
+  // and root bounds.
+  checkLastEntry(entries, 0, [
+    0, targetRect.width, 0, targetRect.height,
+    0, targetRect.width, 0, targetRect.height,
+    0, 10, 0, 10,
+    true,
+  ]);
+}
+function step1() {
+  target.style.transform = "translate(0, 50px)";
+  checkLastEntry(entries, 1, [
+    0, targetRect.width, -5, -5 + targetRect.height,
+    0, targetRect.width, 0, -5 + targetRect.height,
+    0, 10, 0, 10,
+    true,
+  ]);
+}
+</script>