Download missing album art from Lastfm

[rivaldi8]

If an album's art isn't found in the disk or something fails while loading it, this adds downloading it from Lastfm as a fallback. It does so only when listing the albums of an artist (ArtistMusicFragment) and when showing the album (AlbumDetailFragment).

There are some more places where album art is displayed and could benefit from this change. As they are not as important, I've left them out to keep the pull request small. If this gets merged, I can work on them on another pull request. I would also like to implement downloading the images directly into the folder of the album instead of into the cache of the application.

[naman14]

This would need to be accompanied by a preference in settings similar to 'Load artist images' to disable this behaviour.

[rivaldi8]

Ok, I'll work on it.

[rivaldi8]

Sorry, I misunderstood you about the "Load artist images" preference. I thought you meant it as a new preference, but I've found it already exists. I guess you meant to create another preference for album images instead.

In my opinion, if a user wants to load artist images, he or she will want album covers too. Or at least they won't care if they are downloaded too. Otherwise, the user would have to check/uncheck two options instead of one, which is bad from a usability point of view.

Currently this preference is already affecting album images. The ImageLoader is initialized here and this same instance used in rest of the application. Then, from the point of view of the code, it would be simpler to leave it as is. Just change the preference string to "Load artist/album images". Otherwise we would have to check somehow whether we are loading an artist or an album image.

What do you think?

[naman14]

@rivaldi8 I forgot that the ImageLoaderConfiguration is already using the load image preference.

I think we can change the preference string to "load artist/album images" and that should be fine. But i think we should add another preference "Always load album images from Last.fm". Summary for that can be "If unchecked, album art will be fetched locally from song file if available". And if its checked, then we should ignore the local album art and always fetch from lastfm

Though, its just my opinion, if you have better idea than feel free to implement that way

[rivaldi8]

Done!

[naman14]

@rivaldi8 Thanks!