create - recyclerview android studio

RecyclerView onBindViewHolder solo se invoca cuando cambia getItemViewType

Question

Tengo un punto de vista con múltiples tipos de vista.

Al desplazarse onBindViewHolder solo se llama cuando getItemViewType cambia de valor. Esto hace que los elementos de mi lista no se actualicen correctamente.

¿Es esto un error? O estoy haciendo algo mal aquí. Esto parece un comportamiento muy extraño de la nueva clase recyclerView .

Aquí está mi adaptador:

package se.davison.smartrecycleradapter;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.util.SparseIntArray;
import android.view.LayoutInflater;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;

/**
 * Created by richard on 10/11/14.
 */
public class SectionAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {


    private static final String TAG = SectionAdapter.class.getSimpleName();
    private final LayoutInflater inflater;
    private final int sectionLayoutId;
    private SparseIntArray positionSection;
    private LinkedHashMap<AdapterItem, List<AdapterItem>> items = new LinkedHashMap<AdapterItem, List<AdapterItem>>();
    private List<Class<? extends AdapterItem>> itemTypes = new ArrayList<Class<? extends AdapterItem>>(20);

    public SectionAdapter(Context context, int sectionLayoutId, LinkedHashMap<AdapterItem, List<AdapterItem>> items) {
        this.inflater = LayoutInflater.from(context);
        this.sectionLayoutId = sectionLayoutId;
        this.items = items;
        initList(items);
    }

    public SectionAdapter(Context context, int sectionLayoutId) {
        this.inflater = LayoutInflater.from(context);
        this.sectionLayoutId = sectionLayoutId;
        this.items = new LinkedHashMap<AdapterItem, List<AdapterItem>>();
        initList(items);
    }


    @Override
    public int getItemViewType(int position) {
        AdapterItem item = getItem(position);
        Log.d(TAG, position + ": class " + item.getClass());
        return itemTypes.indexOf(item.getClass());
    }

    @Override
    public int getItemCount() {
        int count = 0;
        if (items == null) {
            return 0;
        }

        for (AdapterItem key : items.keySet()) {
            count++;
            List<AdapterItem> childItems = items.get(key);
            if (childItems != null) {
                count += childItems.size();
            }
        }
        return count;
    }

    private void initList(HashMap<AdapterItem, List<AdapterItem>> items) {
        positionSection = new SparseIntArray(items.size());
        int count = 0;
        int sectionIndex = -1;
        for (AdapterItem key : items.keySet()) {
            Class headerClass = key.getClass();
            if (!itemTypes.contains(headerClass)) {
                itemTypes.add(headerClass);
            }
            List<AdapterItem> childItems = items.get(key);
            sectionIndex = count;
            if (childItems != null) {
                for (AdapterItem item : childItems) {
                    Class clazz = item.getClass();
                    if (!itemTypes.contains(clazz)) {
                        itemTypes.add(clazz);
                    }
                    positionSection.put(count, sectionIndex);
                    count++;
                }

            }
            count++;
        }
        setHasStableIds(true);
    }

    private AdapterItem getItem(int position) {

        int totalChildCount = 0;
        int separatorCount = 0;
        for (AdapterItem key : items.keySet()) {
            if (position == 0 || position == totalChildCount + separatorCount) {
                return key;
            }
            separatorCount++;
            List<AdapterItem> list = items.get(key);
            int couldCount = countList(list);
            if (position < totalChildCount + separatorCount + couldCount) {
                return list.get(position - (totalChildCount + separatorCount));
            }

            totalChildCount += couldCount;
        }

        return null;
    }

    public void setItems(LinkedHashMap<AdapterItem, List<AdapterItem>> items) {
        this.items = items;
        notifyDataSetChanged();
    }

    public void setItemsAtHeader(int id, List<AdapterItem> items) {
        AdapterItem header = null;
        for (AdapterItem key : this.items.keySet()) {
            if (key.headerId() == id) {
                header = key;
                break;
            }
        }
        if (header == null) {
            throw new IllegalArgumentException(String.format("No header with id %s is found", id));
        }
        setItemsAtHeader(header, items);
    }

    private void setItemsAtHeader(AdapterItem header, List<AdapterItem> items) {
        this.items.put(header, items);
    }

    private int countList(List<?> list) {
        return list == null ? 0 : list.size();
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        AdapterItem firstItem = getFirstItemWithClass(itemTypes.get(viewType));
        return firstItem.onCreateViewHolder(inflater, viewGroup);
    }

    private AdapterItem getFirstItemWithClass(Class<? extends AdapterItem> clazz) {

        for (AdapterItem key : items.keySet()) {
            if (key.getClass() == clazz) {
                return key;
            }
            List<AdapterItem> childItems = items.get(key);
            if (childItems != null) {
                for (AdapterItem item : childItems) {
                    if (item.getClass() == clazz) {
                        return item;
                    }
                }
            }
        }
        throw new IllegalStateException("Something is wrong, you dont have any items with that class in your list");
    }


    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
        AdapterItem item = getItem(position);
        Log.d(TAG, "ITEM = " + item.getClass().getSimpleName());
        Log.d(TAG, "POS = " + position);
        if (item instanceof OneLineAdapterItem) {
            Log.d(TAG, "TEXT = " + ((OneLineAdapterItem) item).getText());
        }

        item.onBindViewHolder(viewHolder, position);
    }
}

También he abstraído los artículos así:

public abstract class AdapterItem<VH extends RecyclerView.ViewHolder> {


    public boolean isHeader(){
        return false;
    }

    public int headerId(){
        return -1;
    }

    public abstract VH onCreateViewHolder(LayoutInflater inflater, ViewGroup parent);

    public abstract void onBindViewHolder(VH viewHolder, int position);
}

Y para secciones

public class SectionAdapterItem extends AdapterItem<SectionAdapterItem.ViewHolder> {

    private String text;
    private boolean dividerVisible = false;

    public static class ViewHolder extends RecyclerView.ViewHolder{

        TextView titel;
        ImageView divider;

        public ViewHolder(View itemView) {
            super(itemView);
            titel = (TextView) itemView.findViewById(android.R.id.title);
            divider = (ImageView) itemView.findViewById(android.R.id.icon);
        }
    }

    public void setDividerVisible(boolean dividerVisible) {
        this.dividerVisible = dividerVisible;
    }

    public boolean isDividerVisible() {
        return dividerVisible;
    }

    @Override
    public boolean isHeader() {
        return true;
    }

    @Override
    public int headerId() {
        return super.headerId();
    }

    public SectionAdapterItem(String text) {
        this.text = text;
    }

    @Override
    public ViewHolder onCreateViewHolder(LayoutInflater inflater, ViewGroup parent) {
        return new ViewHolder(inflater.inflate(R.layout.top_header, parent, false));
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int position) {
        viewHolder.titel.setText(text);
        viewHolder.divider.setVisibility(dividerVisible?View.VISIBLE:View.GONE);
    }
}

Funciona bien para las primeras filas visibles, pero luego falla.

Answer 1

Cuando establece setHasStableIds(true) significa que si solicitamos una ID para una ubicación, cualquier elemento específico siempre devolverá la misma ID independientemente de su posición dentro de la lista. Esto nos permite identificar un elemento específico incluso si su posición cambia, lo que será útil más adelante.

Para eso necesita getItemId método getItemId en el adaptador y simplemente devolver sus posiciones.

@Override
    public long getItemId(int position) {
        return position;
    }

Answer 2

Olvidé implementar getItemId cuando uso setHasStableIds(true);

Implementando eso resolvió el problema!