Index: tools/perf/page_sets/perf_week/css-animations-staggered-triggering-by-inserting-style-element.html |
diff --git a/tools/perf/page_sets/perf_week/css-animations-staggered-triggering-by-inserting-style-element.html b/tools/perf/page_sets/perf_week/css-animations-staggered-triggering-by-inserting-style-element.html |
new file mode 100644 |
index 0000000000000000000000000000000000000000..d77234979659a940a090f89a101a3da557281d78 |
--- /dev/null |
+++ b/tools/perf/page_sets/perf_week/css-animations-staggered-triggering-by-inserting-style-element.html |
@@ -0,0 +1,86 @@ |
+<!doctype html> |
+<meta name="viewport" content="width=device-width, user-scalable=no"> |
+<container id="container"></container> |
+<script> |
+var N = 1000; |
+var duration = 1000; |
+var targets = []; |
+var styles = []; |
+ |
+for (var i = 0; i < N; i++) { |
+ var target = document.createElement('target'); |
+ container.appendChild(target); |
+ targets.push(target); |
+} |
+ |
+function addNewAnimationStyle(step) { |
+ // Clean up overwritten styles. |
+ var i = 0; |
+ for (; i < styles.length && styles[i].lastStep < step; i++) { |
+ styles[i].style.remove(); |
+ } |
+ styles.splice(0, i); |
+ |
+ var style = document.createElement('style'); |
+ var animationName = 'anim' + step; |
+ style.textContent = '@-webkit-keyframes ' + animationName + ' { 0% { opacity: 0; } 100% { opacity: 1; } }'; |
+ container.appendChild(style); |
+ styles.push({ |
+ style: style, |
+ lastStep: step + N, |
+ }); |
+ |
+ return animationName; |
+} |
+ |
+function startAnimations(startingTargets, startStep, endStep) { |
+ var newAnimationName = addNewAnimationStyle(startStep, endStep); |
+ startingTargets.forEach(function(startInfo) { |
+ startInfo.target.style.animationName = newAnimationName; |
+ startInfo.target.style.animationDelay = -startInfo.fastForward + 'ms'; |
+ }); |
+} |
+ |
+requestAnimationFrame(function(time) { |
+ window.measurementReady = true; |
+ var startTime = time - duration; |
+ var previousStep = 0; |
+ |
+ function staggeredStart(time) { |
+ var elapsed = time - startTime; |
+ var targetStep = Math.floor(N * elapsed / duration); |
+ var restartingTargets = []; |
+ for (var step = Math.max(targetStep - N, previousStep); step < targetStep; step++) { |
+ var stepStartTime = step / N * duration; |
+ restartingTargets.push({ |
+ target: targets[step % N], |
+ fastForward: elapsed - stepStartTime, |
+ }); |
+ } |
+ startAnimations(restartingTargets, targetStep); |
+ previousStep = targetStep; |
+ requestAnimationFrame(staggeredStart); |
+ } |
+ staggeredStart(time); |
+}); |
+</script> |
+ |
+<style> |
+body { |
+ margin: 0; |
+ overflow: hidden; |
+} |
+container { |
+ display: flex; |
+ flex-flow: row wrap; |
+ width: 550px; |
+ height: 800px; |
+ background: lightgoldenrodyellow; |
+} |
+target { |
+ display: inline-block; |
+ width: 9px; height: 9px; |
+ background: magenta; |
+ -webkit-animation: 1000ms linear; |
+} |
+</style> |