Only change read status if in the same tab

[Pythonix]

I changed the code, so that the read status of the message is only changed if the tab with the chat opened is the active browser window.

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✅ Pythonix
❌ Raphael Husistein

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[dbrgn]

Hi

Thanks for your contribution! I assume that this intends to fix #17.

We already have a pull request open against one of the libraries we use to detect whether a message is in the viewport or not: thenikso/angular-inview#122 It has some advantages over your solutions, for example that it doesn't require setting timeouts and that the visibilityState attribute is also considered.

Since that pull request hasn't been merged for almost two months now, I'll vendorize the angular-inview library with the fix until something happens upstream. I'll close your PR, but will create another PR soon with a fix for #17.