Simplify scroll tracking and greatly increase frequency of viewability events #1163
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| this.scrollTop_ = newScrollTop; | ||
| this.scrollMeasureTime_ = timer.now(); | ||
| timer.delay(() => this.scrollDeferred_(), 500); | ||
| this.vsync_.measure(() => { |
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Is vsync for throttling of for sync? Normally, when scroll event arrives, the value is already calculated by the browser and no sync needed. That, of course, mightn't always work with some of the bindings we have.
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Good point. Moved out of vsync.
Actually, if you only measure and do not mutate, it is always fine to do that in an event handler. In the worst case it trigger recalc but it would make the next vsync cheaper since we start with the measure phase.
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PTAL |
| /** | ||
| * This method is called about every 3 frames (assuming 60hz) and it | ||
| * is called in a vsync measure task. | ||
| * @private |
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LGTM with one comment to fix jsdoc with |
emit viewport change events on scroll. - The scroll event now always fires in vsync and always measures scrollTop. - The viewport change event now happens at the latest 3 frames after scrolling ended. - Increased speed at which we send change event. Needed due to resolution at slow speed, but I also feel the value is better. Changes ad intersection to fire "on scroll". Fixes ampproject#873 Fixes a bug where only the first viewability provider in an ad would get an initial viewability change record. Fixes ampproject#1126
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Simplify scroll tracking and greatly increase frequency of viewability events
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scrollTop.
scrolling ended.
Changes ad intersection to fire "on scroll". Fixes #873
Fixes a bug where only the first viewability provider in an ad would get an initial viewability change record. Fixes #1126