使用字符串筛选嵌套RecyclerView中的项

Question

序言-我的目标是能够使用字段搜索NestedRecyclerView中的项。

在我的应用程序中，我有一个HomeFragment。在上述片段中，我有一个回收器视图(父回收视图)，这个视图又包含一个recyclerView(进一步的子级或嵌套的recyclerview)。以下是分别用于家长和儿童回收视图的适配器。

public class HomeFragmentRvParentAdapter extends RecyclerView.Adapter<HomeFragmentRvParentAdapter.ParentRvViewHolder> {
    private Context context;
    private Map<String, ArrayList<Product>> products;
    private FragmentChangeCallback fragmentChangeCallback;
    ArrayList<String> categories;
    public HomeFragmentRvParentAdapter(Context context, Map<String, ArrayList<Product>> products, FragmentChangeCallback callback){
        this.context = context;
        this.fragmentChangeCallback = callback;
        this.products = products;
    }

    @NonNull
    @Override
    public ParentRvViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.home_fragment_recyclerview_item_parent, parent, false);
        categories = new ArrayList<>(products.keySet());
        return new ParentRvViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ParentRvViewHolder holder, int position) {
        holder.itemCategoryName.setText(categories.get(position));
        setChildAdapter(holder.itemChildRecyclerView, products.get(categories.get(position)));
    }

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

    public class ParentRvViewHolder extends RecyclerView.ViewHolder {
        TextView itemCategoryName;
        RecyclerView itemChildRecyclerView;
        public ParentRvViewHolder(@NonNull View itemView) {
            super(itemView);
            itemCategoryName = itemView.findViewById(R.id.category_name);
            itemChildRecyclerView = itemView.findViewById(R.id.child_recycler);
        }
    }
private void setChildAdapter(RecyclerView recyclerView, ArrayList<Product> products){
        HomeFragmentRvChildAdapter adapter = new HomeFragmentRvChildAdapter(context ,products, fragmentChangeCallback);
        recyclerView.setLayoutManager(new LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false));
        recyclerView.setAdapter(adapter);

    }
}

public class HomeFragmentRvChildAdapter extends RecyclerView.Adapter<HomeFragmentRvChildAdapter.ChildViewHolder> {
    ArrayList<Product> products;
    Context context;
    FragmentChangeCallback fragmentChangeCallback;
    public HomeFragmentRvChildAdapter(Context context, ArrayList<Product>products, FragmentChangeCallback callback){
        this.products = products;
        this.context = context;
        this.fragmentChangeCallback = callback;
    }

    @NonNull
    @Override
    public ChildViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.home_fragment_recyclerview_item_child, parent, false);
        return new ChildViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ChildViewHolder holder, int position) {
        Glide.with(context).load(products.get(position).getIcon()).into(holder.iconView);
        holder.name.setText(products.get(position).getName());
        holder.description.setText(products.get(position).getDescription());
        holder.itemView.setOnClickListener(view -> {
            fragmentChangeCallback.fragmentChange(products.get(position).getPackageName());
        });
    }

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

    public class ChildViewHolder extends RecyclerView.ViewHolder {
        public ImageView iconView;
        public TextView name;
        public TextView description;
        public CardView cardView;
        public ChildViewHolder(@NonNull View itemView) {
            super(itemView);
            cardView = itemView.findViewById(R.id.cardView);
            iconView = itemView.findViewById(R.id.hf_item_icon_image);
            name = itemView.findViewById(R.id.app_title);
            description = itemView.findViewById(R.id.app_description);
        }
    }
}

public class Product{
    private String name;
    private String icon;
    private String category;
    private String description;
}

用于填充儿童回收器的Product的^字段。

我传递数据的方式是--在我的HomeFragmentViewModel中，我得到数据。然后，我将数据分类为一个HashMap，其中键是类别。然后，我将said映射传递给我的ParentRecyclerViewAdapter，该映射将category_title设置为键的值，并将链接的ArrayList传递给ChildRecyclerViewAdapter，然后将其分割为显示。

我的目标是，如前所述，能够使用EditText在HomeFragment中搜索儿童回收商中的物品。我尝试过只获取整个数据库，并使用项目的名称对其进行排序，然后在recyclerView中显示它，但我认为可能有一种更优雅的方法。

我能想到的唯一更好的方法是，也许只是将View.GONE应用于名称不包含用于搜索的字符串的视图。这将需要子项目的名称，但我不知道如何获得。

Answer 1

我解决这个问题的方法是:创建一个自定义的CardView类，其中有一个字段作为名称。

public class CustomCardView extends CardView {
    private String name;
    private String description;
    private String icon;
    public CustomCardView(@NonNull Context context) {
        super(context);
    }

    public CustomCardView(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CustomCardView, 0,0);
        try{
            name = a.getString(R.styleable.CustomCardView_appName);
            description = a.getString(R.styleable.CustomCardView_descriptionText);
        }finally {
            a.recycle();
        }
    }

    public CustomCardView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CustomCardView, 0,0);
        try{
            name = a.getString(R.styleable.CustomCardView_appName);
            description = a.getString(R.styleable.CustomCardView_descriptionText);
        }finally {
            a.recycle();
        }
    }

    public String getName(){
        return name;
    }

    public String getDescription(){
        return description;
    }

    public void setName(String name){
        this.name = name;
        invalidate();
        requestLayout();
    }

    public void setDescription(String description){
        this.description = description;
        invalidate();
        requestLayout();
    }
}

然后，我创建了一个静态ArrayList，它可以容纳所有的子对象。

public class RecyclerViewItemHolder {
    public static ArrayList<CustomCardView> childViews = new ArrayList<>();
    private static RecyclerViewItemHolder instance = null;
    private RecyclerViewItemHolder(){

    }
    public static RecyclerViewItemHolder getInstance(){
        if (instance == null){
            instance = new RecyclerViewItemHolder();
        }
        return instance;
    }
    public static ArrayList<CustomCardView> getChildViews(){
        return childViews;
    }
}

在onBindViewHolder of ChildRecyclerViewAdapter中，我将每个CustomCardView添加到ArrayList中。

@Override
    public void onBindViewHolder(@NonNull ChildViewHolder holder, int position) {
RecyclerViewItemHolder.getInstance().childViews.add(holder.cardView);
}

然后，从设置为ArrayList的TextWatcher的afterTextChanged方法访问EditText。我使用for循环检查cardView的名称是否包含搜索查询，如果不包含，则应用View.GONE。

private void initListeners() {
        binding.searchView.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void afterTextChanged(Editable editable) {
                for (CustomCardView cardView: RecyclerViewItemHolder.getChildViews()) {
                    if (!cardView.getName().contains(editable.toString())) {
                        cardView.setVisibility(View.GONE);
                    }else{
                        cardView.setVisibility(View.VISIBLE);
                    }
                }
            }
        });

剩下的唯一问题是，空类别不会消失，而是保持在空的状态。

现在，这可能不是最好的方法，所以我仍然感激任何关于如何改进这个解决方案的答案或评论。