Add view once viewing

[IsaacHatton]

This adds view once viewing functionality, note that none of the security/only view once functionality is present. Also, the image/video cannot be enlarged into the main viewer like other images/videos.

[IsaacHatton]

This fixes issue #128

[tomer8007]

Do you want to also mark the restored message in red, similarly to deleted messages?

[IsaacHatton]

I could as long as you think the view once logo will be enough for people to understand that it's a view once rather than a deleted normal message?

[tomer8007]

Can you post a screenshot of how the view once message usually looks like after you've already viewed it?

[IsaacHatton]

It doesn't change how it looks, my code never deletes the image once its viewed, the images are viewable unlimited times

[tomer8007]

I meant how does the user see a view-once message he's already viewed, without any modifications (the natural way)

[IsaacHatton]

Do you want it to enforce view once?

[tomer8007]

No, I was just wondering if it'll be clear to the user that the extension is enabling him to view the message twice even though it's a view-once message

[IsaacHatton]

IIRC the web has no change once a view once is opened on mobile, it always displays the default text about only viewable on mobile.

[tomer8007]

Oh I understand. So with the extension on, you will see view-once messages in the web, and you could view them unlimited times. Correct?

[IsaacHatton]

Yes, this is the functionality without this (chrome ext from store version)

[tomer8007]

Finally, is everything working?

[IsaacHatton]

As far as I can tell, but I'm not confident with how the IndexedDB will behave when it has to create the database as I havent used indexedDB before.

[tomer8007]

I think it'll work, but you can just delete the IndexedDB / uninstall the extension and install it again to see.

[IsaacHatton]

I did that but my concern is that what happens if it gets created by the injection script as in my test account it always is created by UI because there are view once messages in the chat history.

[tomer8007]

I don't understand why you can't check the injection script flow.

[IsaacHatton]

Apologies, my earlier comment was incorrect, I just tested the injection script flow by sending myself before opening any chats, and it worked fine.

I forgot that the UI script would only run once a chat was opened, as there aren't any messages to check on the first screen (the one that recommends downloading the desktop app).

[tomer8007]

OK, Thank you for this pull request, your time is appreciated

[IsaacHatton]

Did you want the text added, if not don't worry:

[tomer8007]

I think it's a good text, you can have another pull request for it