028-TrackPlayCoverUpdate.md

#028: 播放器封面设置

#首页

##1. 创建一个播放器封面适配器用于加载封面图像

TrackPlayPageAdapter.java:

public class TrackPlayPageAdapter extends PagerAdapter {
    @Override
    public int getCount() {
        return 0;
    }

    @Override
    public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
        return view == object;
    }
}

##2. 绑定到播放器封面控件

TrackPlayerActivity.java:

private void initView() {
	...
	playCoverViewPager = findViewById(R.id.vp_track_cover);
    trackPlayPageAdapter = new TrackPlayPageAdapter();
    playCoverViewPager.setAdapter(trackPlayPageAdapter);
}

##3. 获取播放器列表并传递给适配器

PlayerPresenter.java:

public void getPlayList() {
    if (xmPlayerManager != null) {
        List<Track> playList = xmPlayerManager.getPlayList();
        for (IPlayerCallback playerCallback : playerCallbacks) {
            playerCallback.onPlayList(playList);
        }
    }
}

TrackPlayerActivity.java:

public void onPlayList(List<Track> tracks) {
    if (trackPlayPageAdapter != null) {
        trackPlayPageAdapter.setData(tracks);
    }
}

TrackPlayPageAdapter.java:

public void setData(List<Track> tracks) {
    this.tracks.clear();
    this.tracks.addAll(tracks);
    notifyDataSetChanged();
}

##4. 设置适配器布局文件

item_play_cover.xml

<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">

<ImageView
    android:id="@+id/iv_play_cover"
    android:layout_width="300dp"
    android:layout_height="300dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    tools:srcCompat="@tools:sample/avatars" />
</androidx.constraintlayout.widget.ConstraintLayout>

##5.适配器绑定布局文件并更新封面

TrackPlayPageAdapter.java:

public Object instantiateItem(@NonNull ViewGroup container, int position) {

    View view = LayoutInflater.from(container.getContext()).inflate(R.layout.item_play_cover, container, false);
    container.addView(view);
    ImageView imageView = view.findViewById(R.id.iv_play_cover);
    Track track = tracks.get(position);
    String playCoverImage = track.getCoverUrlLarge();
    Picasso.with(view.getContext()).load(playCoverImage).into(imageView);
    return view;
}

@Override
public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
    container.removeView((View) object);
}

##6. 效果图