android-scrollview – 当listitem在recyclerview中可见时播放/暂停视频

我已经实现了一个recyclerview,我在其中添加纹理视图作为列表项来播放来自url的视频.现在像藤蔓和Instagram应用程序我想播放视频,当它在recyclerview中可见,并在listitem离开屏幕时停止/暂停视频.以下是我的代码：

VideosAdapter类：

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();
}

}

VideoPlayController类：

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,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,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 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;
}

}

为了实现这一点,我得到了this线程中讨论的可见项目位置.但我不知道如何将可见滚动位置传递给我的VideoPlayController类以及如何根据滚动位置跟踪和访问正确的对象.