Replace image caching system with Glide 4

[tobiasKaminsky]

This replaces our old image caching system with Glide 4.
I first updated Glide 3 to 4 and then replaced our old system step by step.
Unfortunately it was not really possible to have this in smaller steps :-(

Info:

• cache defaults to 250mb (by glide) http://bumptech.github.io/glide/doc/configuration.html#disk-cache
• removing of column (FILE_UPDATE_THUMBNAIL) is not working on sqlite on android, but this will not created on new installations anylonger

TODO:

• video play icon overlay: on grid view bigger @AndyScherzinger maybe you have a nice idea?
• video without generated thumbnail also has "play button", which then overlays the dummy thumbnail, @AndyScherzinger maybe?
• external links:
  • not parsed correctly with svg, image is too small. But this is working correctly on activity stream, so this must be a problem with MenuItem
• check if we can transfer the old thumbnails

After finishing, I will squash and rebase.

[tobiasKaminsky]

This is first published to see what Codacy/Findbugs complain…

[nachoparker]

keep up the good work guys, let me know if I can help test this

[tobiasKaminsky]

Thanks @nachoparker. This will be soon in dev version, so you can then give us feedback (you can install it in parallel):
https://github.com/nextcloud/android/blob/master/CONTRIBUTING.md#dev-release

[tobiasKaminsky]

@AndyScherzinger @mario I tried again to get this SVG working in external links, but I do not know why it fails.
When debugging it, it sometimes returns a SVG, but then it is too small.

So I would go on with review & merge it and keep the issue separate.

[AndyScherzinger]

So I would go on with review & merge it and keep the issue separate.

fine by me, I'll just run another test and then I think we would be good to go.

[AndyScherzinger]

@tobiasKaminsky Just tested, so the thumbnails now seems to be the right ones but scrolling+fetching doesn't seem to work. So if I scroll slowly so that some thumbnails on the shown list are already there, the next ones get fetched, if I scroll faster and stop then the thumbnails aren't fetched anymore :(

[AndyScherzinger]

If you leave the folder and navigate back into it the thumbnails previously not shown do show up now but only the ones from the scroll-positions where I have been before. So it seems the fetching gets triggered but they don't get displayed navigating back/forth they are shown (i guess because they are now in the cache).

[nachoparker]

@tobiasKaminsky please, let me know when this is out in dev

[mario]

@tobiasKaminsky what about the usage comments by @AndyScherzinger ?

[mario]

@tobiasKaminsky not ready?

[tobiasKaminsky]

No :(
It has one nasty bug found by @AndyScherzinger. If you scroll through a very long list of images, at some point glide just stops trying to generate new thumbnails.

Unfortunately I did not had any time to dive into it :/
But I hope to tackle it before christmas.

[AndyScherzinger]

needs a rebase (with lots of conflicts to be solved)

[codeRemark]

if this can use for newest server ?

[AndyScherzinger]

@codeRemark the branch should work with the latest server while this branch is very outdated (see conflicts) and has quite some bugs to iron out first (see todo list in original description). So the branch is in need of a proper rebase and bugfixing. Other than that given the UI revamp that is happening at the moment there might be even more code conflicts in the near future.