implement read_directory and is_directory for android asset reader

[deltanedas]

Objective

Fixes #9968

Solution

Uses open_dir to read files.
It's collected in a vector since the AssetDir cant be sent between threads.

For is_directory it uses a silly hack (trying to open it then if it succeeds it must be a directory) seems there is no better way.

It also ignores meta like the filesystem implementation does, no idea if this is needed on android.

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Changelog

• Fixed: Android's AssetReader implementation now supports read_directory and is_directory.

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[alice-i-cecile]

Do we have a way to unit test this? It's surprisingly complex for a "read files" operation, and I'd like to ensure it keeps working.

[deltanedas]

I don't know how bevy does tests but I imagine assets.load_folder("/") then get its LoadedFolder and assert!(!folder.handles.is_empty(), "Loading folder failed") would do the job (might also automatically see if loading assets fails im not sure)

[deltanedas]

also this will require an is_directory implementation of some kind, it seems that it still refuses to work without it

[mockersf]

Do we have a way to unit test this? It's surprisingly complex for a "read files" operation, and I'd like to ensure it keeps working.

probably not easily, you need to be in an Android environment...

also this will require an is_directory implementation of some kind, it seems that it still refuses to work without it

Yup, you need to implement it... looking at the asset manager doc, it seems your "silly hack" is the best we can do

[deltanedas]

ok this will definitely require a test, on my device apparently after the folder's loadstate is loaded it has 0 handles???

[esensar]

ok this will definitely require a test, on my device apparently after the folder's loadstate is loaded it has 0 handles???

I have tried working on this, not knowing about this PR (#11495). That happened to me when I used open_dir for is_directory, since open_dir works on files too for some reason (and treats them as empty directories). I changed it to open and I tested it in mobile example and it returns all assets in the directory as expected.

[deltanedas]

yeah closing in favour of your one