android scrollview - Reproducir/Pausar video cuando listitem sea visible en recyclerview

android-scrollview android-recyclerview

Question

He implementado una vista de reciclador en la que estoy agregando vistas de texturas como elementos de lista para reproducir videos desde la url. Ahora, al igual que la aplicación Vine and Instagram, quiero reproducir un video cuando esté visible en la vista del reciclador y detener / pausar el video cuando listitem se sale de la pantalla. Lo siguiente es mi código:

Clase de videosAdapter:

public class VideosAdapter extends RecyclerView.Adapter<VideosAdapter.ViewHolder> {

private static String TAG = "VideosAdapter";

Context context;
private ArrayList<String> urls;
RecyclerView recyclerView;

public static class ViewHolder extends RecyclerView.ViewHolder {

    public TextureView textureView;
    public TextView textView;

    public ViewHolder(View v) {
        super(v);
        textureView = (TextureView) v.findViewById(R.id.textureView);
        textView = (TextView) v.findViewById(R.id.textView);

    }
}

public VideosAdapter(Context context, RecyclerView recyclerView, final ArrayList<String> urls) {

    this.context = context;
    this.recyclerView = recyclerView;
    this.urls = urls;

    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);
        }

        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);

            if(newState == RecyclerView.SCROLL_STATE_IDLE) {

                LinearLayoutManager layoutManager = ((LinearLayoutManager) recyclerView.getLayoutManager());
                int firstVisiblePosition = layoutManager.findFirstVisibleItemPosition();
                int findFirstCompletelyVisibleItemPosition = layoutManager.findFirstCompletelyVisibleItemPosition();
                int findLastVisibleItemPosition = layoutManager.findLastVisibleItemPosition();
                int findLastCompletelyVisibleItemPosition = layoutManager.findLastCompletelyVisibleItemPosition();

                *//*Log.i(TAG, "firstVisiblePosition = " + String.valueOf(firstVisiblePosition));
                Log.i(TAG, "findFirstCompletelyVisibleItemPosition = " + String.valueOf(findFirstCompletelyVisibleItemPosition));
                Log.i(TAG, "findLastVisibleItemPosition = " + String.valueOf(findLastVisibleItemPosition));
                Log.i(TAG, "findLastCompletelyVisibleItemPosition = " + String.valueOf(findLastCompletelyVisibleItemPosition));*//*

                Log.i(TAG, "//////////////////////////////////////////////////////////////");

                if(findFirstCompletelyVisibleItemPosition>=0) {
                    Log.i(TAG, "Playing_URl = " + urls.get(findFirstCompletelyVisibleItemPosition));
                    int tempPreviousUrl = findFirstCompletelyVisibleItemPosition - 1;
                    if(tempPreviousUrl>=0)
                        Log.i(TAG, "Stop_Playing_URl = " + urls.get(tempPreviousUrl));

                }
                else
                {
                    Log.i(TAG, "Playing_URl = " + urls.get(firstVisiblePosition));
                    int tempPreviousUrl = firstVisiblePosition - 1;
                    if(tempPreviousUrl>=0)
                        Log.i(TAG, "Stop_Playing_URl = " + urls.get(tempPreviousUrl));
                }
            }
        }
    });
}

// Create new views (invoked by the layout manager)
@Override
public VideosAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    // create a new view
    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.view_main, parent, false);
    ViewHolder viewHolder = new ViewHolder(v);
    return viewHolder;
}

// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, int position) {

    String url = urls.get(position);
    holder.textView.setText(url);

    //Log.i("BindViewHolderCalledFor", position + " = " + url);

    VideoPlayController videoPlayController = new VideoPlayController(context, recyclerView, holder.textureView, url);

    if(position==0) {
        videoPlayController.loadVideo();
    }

}

@Override
public int getItemCount() {
    return urls.size();
}

}

Clase VideoPlayController:

public class VideoPlayController implements TextureView.SurfaceTextureListener {

private static String TAG = "VideoPlayController";

Context context;
String url;
MediaPlayer mp;
Surface surface;
SurfaceTexture s;
RecyclerView recyclerView;
TextureView textureView;

public VideoPlayController(Context context, RecyclerView recyclerView, TextureView textureView, final String url) {

    this.context = context;
    this.recyclerView = recyclerView;
    this.textureView = textureView;
    this.url = url;

    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);

            if(newState == RecyclerView.SCROLL_STATE_IDLE) {

                Log.i(TAG, "OnScrollStateChangedCalled For: " + url);

                //When scroll is at idol position check if item is visible

            }
        }
    });

}

public void loadVideo() {

    textureView.setSurfaceTextureListener(this);
}

@Override
public void onSurfaceTextureAvailable(final SurfaceTexture surface, int width, int height) {
    Log.d("surface_available-url", this.url);
    startVideo(surface);
}

@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
    Log.d("surface_destroyed-url", this.url);
}

@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
    Log.d("surface_destroyed-url", this.url);
    this.mp.stop();
    this.mp.reset();
    this.mp.release();
    this.mp = null;
    return false;
}

@Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {

}

public void startVideo(SurfaceTexture t)
{
    this.surface = new Surface(t);
    this.mp = new MediaPlayer();
    this.mp.setSurface(this.surface);
    try {
        Uri uri = Uri.parse(this.url);
        this.mp.setDataSource(url);
        this.mp.prepareAsync();

        this.mp.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            public void onPrepared(MediaPlayer mp) {

                mp.setLooping(true);
                mp.start();

            }
        });
    } catch (IllegalArgumentException e1) {
        e1.printStackTrace();
    } catch (SecurityException e1) {
        e1.printStackTrace();
    } catch (IllegalStateException e1) {
        e1.printStackTrace();
    } catch (IOException e1) {
        e1.printStackTrace();
    }
    try {

    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (SecurityException e) {
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    }
    try {

    } catch (IllegalStateException e) {
        e.printStackTrace();
    }
}

public void changePlayState()
{
    if(this.mp.isPlaying())
        this.mp.stop();
    else
        this.mp.start();
}

public static boolean isViewVisible(View subView, View parentView) {
    Rect scrollBounds = new Rect();
    parentView.getHitRect(scrollBounds);
    if (subView.getLocalVisibleRect(scrollBounds)) {
        return true;
    }
    return false;
}

}

Para lograr esto, obtengo posiciones de artículos visibles como se discutió en este hilo. Pero no sé cómo pasar la posición de desplazamiento visible a mi clase VideoPlayController y cómo rastrear y acceder al objeto correcto en función de la posición de desplazamiento.