How can I check if somebody opens other applications apart from a specific page

[ekeskini]

I want to check if somebody who has open my page in a browser ,opens other applications at the same time.
Does anybody knows how can I check it in javascript.
I have thought about lostfocus but I dont know how can I use it.

[Rabbit]

Javascript does not have that kind of access to a user's system. It can't know if the user opens another application.

[gits]

may be you can specify the goal a bit more - basicly your webpage doesn't need to bother with any application a user opens besides it - so what do you exactly want to achieve with such a check?

[ekeskini]

I want to make an adaptive learning enviroment so that it can check if the user, when he studies, opens other applications and he is not focus on the subject.

[r035198x]

What if they have moved away from the site to open a pdf document with more notes on the subject?

Monitoring computer user activity is frowned upon. You'd only be able to get away with it in controlled environment like controlled computer labs.
For that, web applications are not a good choice. Browsers have lots of restrictions on what a loaded page can do. Identify the tasks you want your application to monitor and then research what technologies can do what you want to achieve, that should tell you which tech stacks to consider.

[gits]

yea - what r035198x suggests looks much more promising - something like an OS-service that monitors the user-activities on the current system. from a webpage you cannot observe such things - imagine you could - then a webpage could spy all your activities. you never ever really want that - so browsers don't support such access to the OS - at least not without extended and user-approved permissions.

[ekeskini]

ok thanks for your answer