make - android: adaptador genérico recyclerview con enlace de datos

recyclerview android studio

Question

Intenté crear un adaptador Recyclerview genérico como el siguiente:

BaseRecyclerAdapter:

public class BaseRecyclerAdapter<T, MVH extends BaseViewHolder<T>, EVH extends BaseViewHolder<T>> extends RecyclerView.Adapter<BaseViewHolder<T>> {

    private static final int VIEW_TYPE_EMPTY = 0;
    private static final int VIEW_TYPE_DATA = 1;
    private List<T> list = new ArrayList<>();
    @LayoutRes
    private int emptyViewLayoutResource;
    private Class<EVH> emptyViewHolder;
    @LayoutRes
    private int dataLayoutResource;
    private Class<MVH> dataViewHolder;

    public BaseRecyclerAdapter(int emptyViewLayoutResource, Class<EVH> emptyViewHolder, int dataLayoutResource, Class<MVH> dataViewHolder) {
        this.emptyViewLayoutResource = emptyViewLayoutResource;
        this.emptyViewHolder = emptyViewHolder;
        this.dataLayoutResource = dataLayoutResource;
        this.dataViewHolder = dataViewHolder;
    }

    @Override
    public BaseViewHolder<T> onCreateViewHolder(ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        ViewDataBinding binding = DataBindingUtil.inflate(layoutInflater, viewType == VIEW_TYPE_EMPTY ? emptyViewLayoutResource : dataLayoutResource, parent, false);
        try {
            return viewType == VIEW_TYPE_EMPTY ? emptyViewHolder.getConstructor(ViewDataBinding.class).newInstance(binding) : dataViewHolder.getConstructor(View.class).newInstance(binding);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        } catch (InstantiationException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void onBindViewHolder(BaseViewHolder<T> holder, int position) {
        int viewType = getItemViewType(position);
        if (viewType == VIEW_TYPE_EMPTY) {

        } else {
            holder.bind(list.get(position));
        }
    }

    @Override
    public int getItemCount() {
        return list.size() == 0 ? 1 : list.size();
    }

    @Override
    public int getItemViewType(int position) {
        return list.size() == 0 ? VIEW_TYPE_EMPTY : VIEW_TYPE_DATA;
    }
}

BaseViewHolder:

public class BaseViewHolder<T> extends RecyclerView.ViewHolder {
    private final ViewDataBinding binding;

    public BaseViewHolder(ViewDataBinding binding) {
        super(binding.getRoot());
        this.binding = binding;
    }

    public void bind(T t) {
        binding.setVariable(BR.obj, t);
        binding.executePendingBindings();
    }
}

¿Alguien puede intentarlo y sugerirme cómo inicializar esta clase para usarla con RecyclerView?

Answer 1

Lo que quería: Necesitaba que el Modelo pasara a Diseño, obviamente necesitábamos usar sus propiedades para enlazar. Es por eso que pensé en hacer de BaseViewHolder una clase genérica.

Problema real: no puede obtener Clase de clase genérica. Significa que no puedo inicializar BaseRecyclerAdapter de la siguiente manera:

private BaseRecyclerAdapter1<Model, EmptyViewHolder, ModelViewHolder> baseRecyclerAdapter1 = new BaseRecyclerAdapter1<>(R.layout.layout_empty, EmptyViewHolder<Model>.class, R.layout.list_item, ModelViewHolder<Model>.class);

Solución: gracias al enlace de datos. <variable /> etiqueta <variable /> hace el tipo de conversión para usted.

public class BaseViewHolder extends RecyclerView.ViewHolder {
    private final ViewDataBinding binding;

    public BaseViewHolder(ViewDataBinding binding) {
        super(binding.getRoot());
        this.binding = binding;
    }

    public void bind(Object object) {
        binding.setVariable(BR.obj, object);
        binding.executePendingBindings();
    }
}

Entonces, ahora puedo inicializar BaseRecyclerAdapter como:

private BaseRecyclerAdapter1<Model, EmptyViewHolder, ModelViewHolder> baseRecyclerAdapter1 = new BaseRecyclerAdapter1<>(R.layout.layout_empty, EmptyViewHolder.class, R.layout.list_item, ModelViewHolder.class);

En diseño:

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>

        <import type="android.view.View" />

        <variable
            name="obj"
            type="com.xxx.Model" />
    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

    </LinearLayout>
</layout>

Happy Coding .. !!