| OLD | NEW |
|---|
| 1 <!DOCTYPE html> | 1 <!DOCTYPE html> |
| 2 <script src="helper-functions.js"></script> | 2 <script src="helper-functions.js"></script> |
| 3 <div style="height: 200px; width: 100px;"></div> | 3 <div style="height: 200px; width: 100px;"></div> |
| 4 <div id="target" style="background-color: green; width:100px; height:100px"></di
v> | 4 <div id="target" style="background-color: green; width:100px; height:100px"></di
v> |
| 5 <div style="height: 200px; width: 100px;"></div> | 5 <div style="height: 200px; width: 100px;"></div> |
| 6 <script> | 6 <script> |
| 7 var port; | 7 var port; |
| 8 var entries = []; | 8 var entries = []; |
| 9 var target = document.getElementById('target'); | 9 var target = document.getElementById('target'); |
| 10 var scroller = document.scrollingElement; | 10 var scroller = document.scrollingElement; |
| 11 var nextStep; | 11 var nextStep; |
| 12 | 12 |
| 13 // Note that we never use RAF in this code, because this frame might get render-
throttled. | 13 // Note that we never use RAF in this code, because this frame might get render-
throttled. |
| 14 // Instead of RAF-ing, we just post an empty message to the parent window, which
will | 14 // Instead of RAF-ing, we just post an empty message to the parent window, which
will |
| 15 // RAF when it is received, and then send us a message to cause the next step to
run. | 15 // RAF when it is received, and then send us a message to cause the next step to
run. |
| 16 | 16 |
| 17 function observer_callback(changes) { | |
| 18 for (var i in changes) | |
| 19 entries.push(changes[i]); | |
| 20 } | |
| 21 | |
| 22 // Use a rootMargin here, and verify it does NOT get applied for the cross-origi
n case. | 17 // Use a rootMargin here, and verify it does NOT get applied for the cross-origi
n case. |
| 23 var observer = new IntersectionObserver(observer_callback, {rootMargin: "7px"}); | 18 var observer = new IntersectionObserver( |
| 19 changes => { entries = entries.concat(changes) }, |
| 20 { rootMargin: "7px" } |
| 21 ); |
| 24 observer.observe(target); | 22 observer.observe(target); |
| 25 | 23 |
| 26 function step0() { | 24 function step0() { |
| 27 setTimeout(function() { | 25 entries = entries.concat(observer.takeRecords()); |
| 28 nextStep = step1; | 26 nextStep = step1; |
| 29 port.postMessage({actual: entries.map(entryToJson), expected: []}, "*"); | 27 port.postMessage({actual: entries.map(entryToJson), expected: []}, "*"); |
| 30 entries = []; | 28 entries = []; |
| 31 port.postMessage({scrollTo: 200}, "*"); | 29 port.postMessage({scrollTo: 200}, "*"); |
| 32 }); | |
| 33 } | 30 } |
| 34 | 31 |
| 35 function step1() { | 32 function step1() { |
| 36 setTimeout(function() { | 33 entries = entries.concat(observer.takeRecords()); |
| 37 port.postMessage({actual: entries.map(entryToJson), expected: []}, "*"); | 34 port.postMessage({actual: entries.map(entryToJson), expected: []}, "*"); |
| 38 entries = []; | 35 entries = []; |
| 39 scroller.scrollTop = 250; | 36 scroller.scrollTop = 250; |
| 40 nextStep = step2; | 37 nextStep = step2; |
| 41 port.postMessage({}, "*"); | 38 port.postMessage({}, "*"); |
| 42 }); | |
| 43 } | 39 } |
| 44 | 40 |
| 45 function step2() { | 41 function step2() { |
| 46 setTimeout(function() { | 42 entries = entries.concat(observer.takeRecords()); |
| 47 var expected = [{ | 43 var expected = [{ |
| 48 boundingClientRect: coordinatesToClientRectJson(-42, 108, 58, 8), | 44 boundingClientRect: coordinatesToClientRectJson(-42, 108, 58, 8), |
| 49 intersectionRect: coordinatesToClientRectJson(0, 108, 58, 8), | 45 intersectionRect: coordinatesToClientRectJson(0, 108, 58, 8), |
| 50 rootBounds: "null", | 46 rootBounds: "null", |
| 51 target: target.id | 47 target: target.id |
| 52 }]; | 48 }]; |
| 53 port.postMessage({actual: entries.map(entryToJson), expected: expected}, "*"
); | 49 port.postMessage({actual: entries.map(entryToJson), expected: expected}, "*"); |
| 54 entries = []; | 50 entries = []; |
| 55 nextStep = step3; | 51 nextStep = step3; |
| 56 port.postMessage({scrollTo: 100}, "*"); | 52 port.postMessage({scrollTo: 100}, "*"); |
| 57 }); | |
| 58 } | 53 } |
| 59 | 54 |
| 60 function step3() { | 55 function step3() { |
| 61 setTimeout(function() { | 56 entries = entries.concat(observer.takeRecords()); |
| 62 var expected = [{ | 57 var expected = [{ |
| 63 boundingClientRect: coordinatesToClientRectJson(-42, 108, 58, 8), | 58 boundingClientRect: coordinatesToClientRectJson(-42, 108, 58, 8), |
| 64 intersectionRect: coordinatesToClientRectJson(0, 0, 0, 0), | 59 intersectionRect: coordinatesToClientRectJson(0, 0, 0, 0), |
| 65 rootBounds: "null", | 60 rootBounds: "null", |
| 66 target: target.id | 61 target: target.id |
| 67 }]; | 62 }]; |
| 68 port.postMessage({actual: entries.map(entryToJson), expected: expected}, "*"
); | 63 port.postMessage({actual: entries.map(entryToJson), expected: expected}, "*"); |
| 69 port.postMessage({DONE: 1}, "*"); | 64 port.postMessage({DONE: 1}, "*"); |
| 70 }); | |
| 71 } | 65 } |
| 72 | 66 |
| 73 function handleMessage(event) | 67 function handleMessage(event) |
| 74 { | 68 { |
| 75 port = event.source; | 69 port = event.source; |
| 76 nextStep(); | 70 nextStep(); |
| 77 } | 71 } |
| 78 | 72 |
| 79 nextStep = step0; | 73 nextStep = step0; |
| 80 window.addEventListener("message", handleMessage); | 74 window.addEventListener("message", handleMessage); |
| 81 </script> | 75 </script> |
| OLD | NEW |
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Chromium Code Reviews
Issue 1806133002:
IntersectionObserver: use an idle callback to send notifications. (Closed)
Base URL: https://chromium.googlesource.com/chromium/src@master