Implement picture in picture for iOS

[aalzanki]

Test Plan:

• Run on ipad
• test out onIsPictureInPictureSupported, onIsPictureInPictureActive, restoreUserInterfaceForPictureInPictureStop, startPictureInPicture, stopPictureInPicture.

[cobarx]

This is a very cool feature, thanks for submitting and providing all the documentation!

I'd like to see if we can condense the interface so that it's as simple as possible.

onIsPictureInPictureSupported - React Native only supports iOS >= 9.0 so I don't think we need this.
onIsPictureInPictureActive - This gets called whenever the state changes, so it should be onPictureInPictureChanged or onPictureInPictureStatusChanged. The payload should be similar to other events: isActive or isPictureInPictureActive
restoreUserInterfaceForPictureInPictureStop - Given that this is mandatory to be called, how about just calling this automatically when we exit picture in picture
startPictureInPicture / stopPictureInPicture - I'm trying to use props wherever possible and avoid functions unless absolutely necessary. I'd suggest changing this to a boolean prop like pictureInPicture.

[aalzanki]

Ops, didn't realize my debug commits were showing up here. This is not ready to be reviewed again. There are some issues. I'll resolve them when I get a chance.

In terms of restoreUserInterfaceForPictureInPictureStop, I don't think we can just always call it when PIP stops. I think the idea behind restoreUserInterfaceForPictureInPictureStopWithCompletionHandler is that when the user moves away from the screen they were on when they started the PIP, and then taps the restore button from the PIP controls (left most button in this picture) the video wouldn't just disappear, but rather, it'd give your app a chance to navigate to the screen that the video is on, and then the little PIP will animate back into the video player's area. Defaulting to always calling restoreUserInterfaceForPictureInPictureStop means that the video will always immediately disappear, instead of animating back into place.

[aalzanki]

@cobarx I made 4 of the 5 changes you mentioned. Please let me know what you think about the restoration piece. I tried to mirror Apple's restoration function with: onRestoreUserInterfaceForPictureInPictureStop and restoreUserInterfaceForPictureInPictureStopCompleted.

[aalzanki]

@cobarx any feedback about the updated code?

[cobarx]

Sorry for the delay in getting to review this. This is working great, I'm going to merge it.

Two things I noticed:
Do we need the true/false argument to restoreUserInterfaceForPictureInPictureStopCompleted? If not, you could just pass true automatically and remove the argument from the README / JS function. If it is needed, please document when it's appropriate to use true vs. false.

Also, I'm not seeing events when I put the video in fullscreen and then engage PiP from there. If possible, can you add a PR to capture those using the same framework you've done here.

[cobarx]

Btw this works great. Thanks so much for putting it together, great feature.

It would be wonderful to be able to support this on ExoPlayer as well.

[danielmarino24i]

I think this PR breaks compatibility with tvOS, as PiP is only on AVKit (ios)

Probably is can be fixed with a solution like this (probably some condition has to be added also on AVPictureInPictureControllerDelegate delegate's methods ) or __TVOS_PROHIBITED:

#if __has_include(<react-native-video/RCTVideoCache.h>)
@interface RCTVideo : UIView <RCTVideoPlayerViewControllerDelegate, DVAssetLoaderDelegatesDelegate, AVAssetResourceLoaderDelegate>
#elif TARGET_OS_TV
@interface RCTVideo : UIView <RCTVideoPlayerViewControllerDelegate>
#else
@interface RCTVideo : UIView <RCTVideoPlayerViewControllerDelegate, AVPictureInPictureControllerDelegate>
#endif

[danielmarino24i]

Also it fails if initial value is set to true (it should be UI/JS triggered) of it is set as initial value, trigger the function on onLoad or sth like this

[FullstackJack]

@cobarx As noted by @danielmarino24i, this created a regression on tvOS. We'll need to get a PR up to hotfix it.

[FullstackJack]

I've spun up a work branch to complete this work for Android, we'll see how it goes.