Add a fallback for the time tracking in the web #927
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Every browser's `performance.now()` implementation is not spec compliant, unless the browser is running on Windows. On every other operating system, `performance.now()` does not properly keep ticking while the operating system is suspended / sleeping. There isn't much that we can do. What we can do is we calculate the initial difference between `performance.now()` and `Date.now()` and store it in a thread local. Later, when the phone gets locked, `performance.now()` starts to break. However, we can detect when the phone gets unlocked again by listening to the `visibilitychange` event. This is where we can update the difference again. This of course isn't ideal, as `Date.now()` gets adjusted by NTP synchronizations, but it's the best we can do. More information: https://developer.mozilla.org/en-US/docs/Web/API/Performance/now#ticking_during_sleep https://www.igvita.com/2015/11/20/dont-lose-user-and-app-state-use-page-visibility/
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Every browser's
performance.now()implementation is not spec compliant, unless the browser is running on Windows. On every other operating system,performance.now()does not properly keep ticking while the operating system is suspended / sleeping. There isn't much that we can do. What we can do is we calculate the initial difference betweenperformance.now()andDate.now()and store it in a thread local. Later, when the phone gets locked,performance.now()starts to break. However, we can detect when the phone gets unlocked again by listening to thevisibilitychangeevent. This is where we can update the difference again. This of course isn't ideal, asDate.now()gets adjusted by NTP synchronizations, but it's the best we can do.More information:
https://developer.mozilla.org/en-US/docs/Web/API/Performance/now#ticking_during_sleep https://www.igvita.com/2015/11/20/dont-lose-user-and-app-state-use-page-visibility/