| <!DOCTYPE html> |
| <!-- |
| | This test checks that calling "unobserve" on a target that has not been |
| | "observed" by a particular observer does not cause a crash. |
| | Any observed targets should become green, and any elements that have not |
| | been observed should stay yellow. |
| | https://www.w3.org/TR/intersection-observer/ |
| --> |
| <html> |
| <head> |
| <style> |
| div { |
| background-color: yellow; |
| width: 50px; |
| height: 100px; |
| margin: 25px; |
| display: inline-block; |
| } |
| </style> |
| </head> |
| <body> |
| <div id="firsttarget"></div> |
| <div id="secondtarget"></div> |
| <div id="thirdtarget"></div> |
| <div id="fourthtarget"></div> |
| <div id="fifthtarget"></div> |
| |
| <script> |
| if (window.testRunner) { |
| window.testRunner.waitUntilDone(); |
| } |
| |
| window.addEventListener("load", function() { |
| |
| function handleIntersect(entries, observer) { |
| entries.forEach(function(entry) { |
| if (entry.isIntersecting) { |
| entry.target.style.backgroundColor = "green"; |
| } |
| }); |
| } |
| |
| function createObserversAndUnobserveTargets() { |
| var firstTargetElement = document.querySelector('#firsttarget'); |
| var secondTargetElement = document.querySelector('#secondtarget'); |
| var thirdTargetElement = document.querySelector('#thirdtarget'); |
| var fourthTargetElement = document.querySelector('#fourthtarget'); |
| var fifthTargetElement = document.querySelector('#fifthtarget'); |
| |
| var options = { |
| root: null, |
| rootMargin: "0px", |
| threshold: 0.0 |
| }; |
| |
| // Create an observer and observe elements. The elements should become |
| // green. |
| var observerA = new IntersectionObserver(handleIntersect, options); |
| observerA.observe(firstTargetElement); |
| observerA.observe(secondTargetElement); |
| observerA.observe(thirdTargetElement); |
| |
| // Unobserve elements that have never been observed. Nothing should |
| // change, and nothing should crash. |
| observerA.unobserve(fourthTargetElement); |
| observerA.unobserve(fifthTargetElement); |
| |
| // Create a different observer and attempt to observe an element that |
| // has been observed by another observer. |
| // Again, nothing should change or crash. |
| var observerB = new IntersectionObserver(handleIntersect, options); |
| observerB.unobserve(thirdTargetElement); |
| } |
| |
| createObserversAndUnobserveTargets(); |
| |
| if (window.testRunner) { |
| window.testRunner.DoNonMeasuredLayout(); |
| window.setTimeout(function() { window.testRunner.notifyDone(); }, 0); |
| } |
| }); |
| </script> |
| |
| </body> |
| </html> |