After some time of inactivity my laptop screen will darken and then turn off, as specified by my power saving settings. However if a YouTube video is playing then this doesn't happen. So either youtube.com is preventing this or my OS disables this power save feature when a webpage is playing a video.
I'm making a web application exercise timer. As the user is exercising when using it, they don't touch the mouse or keyboard meaning that the energy save kicks in and turns off the display. From test usage I can say this is very annoying!
How can I disable this behaviour while a exercise timer is running? I suppose I could hack it with a hidden video playing in the background but I was hoping for a better solution.
This question is a duplicate of: Can I prevent phone from sleep on a webpage
However it's a bit out of date, there is now a Wake Lock API but it's still experimental: http://boiler23.github.io/screen-wake/
Ive decided to go with a library, this seems the most popular: https://github.com/richtr/NoSleep.js