在 RecyclerView 中实现 OnItemLongClickLister

Question

我正在开发一个使用开源代码的项目，但有一次我被卡住了，在这段代码中，我使用的是 RecyclerView，其中 onRecycleItemClickListener 已经实现，但现在我需要在现有代码中实现 onItemLongClickListener

public abstract class BaseRecyclerViewAdapter<T, VH extends BaseClickListenerViewHolder> extends RecyclerView.Adapter<VH> {

private List<T> objectsList;
protected final BaseActivity baseActivity;
protected final LayoutInflater layoutInflater;
protected final Resources resources;
protected QBUser currentQbUser;

// Package private because we need access in BaseViewHolder but not in child classes
OnRecycleItemClickListener<T> onRecycleItemClickListener;
AdapterView.OnItemLongClickListener onItemLongClickListener;

public BaseRecyclerViewAdapter(BaseActivity baseActivity) {
    this.baseActivity = baseActivity;
    this.layoutInflater = LayoutInflater.from(baseActivity);
    resources = baseActivity.getResources();
    objectsList = new ArrayList<>();
}

public BaseRecyclerViewAdapter(BaseActivity baseActivity, List<T> objectsList) {
    this(baseActivity);
    this.objectsList = objectsList;
    currentQbUser = AppSession.getSession().getUser();
}

public void setList(List<T> items) {
    objectsList = items;
    notifyDataSetChanged();
}

public void addItem(T item) {
    objectsList.add(item);
    notifyItemInserted(objectsList.size() - 1);
}

public void addItem(int position, T item) {
    objectsList.add(position, item);
    notifyItemInserted(position);
}

public void addAll(Collection<T> collection) {
    objectsList.addAll(collection);
    notifyItemRangeChanged(objectsList.size() - collection.size(), collection.size());
}

public void removeItem(int position) {
    objectsList.remove(position);
    notifyItemRemoved(position);
}

public void removeItem(T item) {
    int position = objectsList.indexOf(item);
    if (position != -1) {
        objectsList.remove(item);
        notifyItemRemoved(position);
    }
}

public void clear() {
    objectsList.clear();
    notifyDataSetChanged();
}

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

public T getItem(int position) {
    return objectsList.get(position);
}

public List<T> getAllItems() {
    return objectsList;
}

public boolean isEmpty() {
    return objectsList.size() == 0;
}

public void setOnRecycleItemClickListener(OnRecycleItemClickListener<T> onRecycleItemClickListener) {
    this.onRecycleItemClickListener = onRecycleItemClickListener;
}

protected void displayAvatarImage(String uri, ImageView imageView) {
    ImageLoader.getInstance().displayImage(uri, imageView, ImageLoaderUtils.UIL_USER_AVATAR_DISPLAY_OPTIONS);
}
}

Answer 1

您可以在代码中使用此类 ItemTouchListenerAdapter 轻松添加对项目点击和长按的支持。

用法：

recyclerView.addOnItemTouchListener(new ItemTouchListenerAdapter(recyclerView, this));

代码：

public class ItemTouchListenerAdapter extends GestureDetector.SimpleOnGestureListener implements RecyclerView.OnItemTouchListener {

    public interface RecyclerViewOnItemClickListener {
        void onItemClick(RecyclerView parent, View clickedView, int position);

        void onItemLongClick(RecyclerView parent, View clickedView, int position);
    }

    private RecyclerViewOnItemClickListener listener;
    private RecyclerView recyclerView;
    private GestureDetector gestureDetector;

    public ItemTouchListenerAdapter(RecyclerView recyclerView, RecyclerViewOnItemClickListener listener) {
        if (recyclerView == null || listener == null) {
            throw new IllegalArgumentException("RecyclerView and Listener arguments can not be null");
        }
        this.recyclerView = recyclerView;
        this.listener = listener;
        this.gestureDetector = new GestureDetector(recyclerView.getContext(), this);
    }

    @Override
    public boolean onInterceptTouchEvent(RecyclerView recyclerView, MotionEvent motionEvent) {
        gestureDetector.onTouchEvent(motionEvent);
        return false;
    }

    @Override
    public void onTouchEvent(RecyclerView recyclerView, MotionEvent motionEvent) {
    }

    @Override
    public void onShowPress(MotionEvent e) {
        View view = getChildViewUnder(e);
        if (view != null) {
            view.setPressed(true);
        }
    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        View view = getChildViewUnder(e);
        if (view == null) return false;

        view.setPressed(false);
        int position = recyclerView.getChildPosition(view);
        listener.onItemClick(recyclerView, view, position);
        return true;
    }

    public void onLongPress(MotionEvent e) {
        View view = getChildViewUnder(e);
        if (view == null) return;
        int position = recyclerView.getChildPosition(view);
        listener.onItemLongClick(recyclerView, view, position);
        view.setPressed(false);
    }

    @Nullable
    private View getChildViewUnder(MotionEvent e) {
        return recyclerView.findChildViewUnder(e.getX(), e.getY());
    }
}