Butterknife is unable to bind inside my Adapter Class

remedy. picture remedy. · Jul 16, 2015 · Viewed 18.4k times · Source

I have an Adapter that draws the layouts for my Navigation Drawer. My navigation drawer contains two inner xml files: One being the Header and the other being the Row. I draw these out in a single adapter, but when I'm trying to setText() on my header, I get failure to bind. Here is my adapter class:

public class DrawerAdapter extends RecyclerView.Adapter<DrawerAdapter.ViewHolder> {

private static final int HEADER_TYPE = 0;
private static final int ROW_TYPE = 1;
private static Context context;
private static DatabaseHelper databaseHelper;

private List<String> rows;
private List<Integer> icons;
private String driverName;

public DrawerAdapter(Context context, List<String> rows, List<Integer> icons, String driverName, DatabaseHelper databaseHelper) {
    this.icons = icons;
    this.rows = rows;
    this.context = context;
    this.driverName = driverName;
    this.databaseHelper = databaseHelper;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    if (viewType == HEADER_TYPE) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.drawer_header, parent, false);
        return new ViewHolder(view, viewType);

    } else if (viewType == ROW_TYPE) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.drawer_row, parent, false);
        return new ViewHolder(view, viewType);
    }
    return null;
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    if (holder.viewType == ROW_TYPE) {
        String rowText = rows.get(position - 1);
        int imageView = icons.get(position - 1);
        holder.textView.setText(rowText);
        holder.imageView.setImageResource(imageView);
    } else if (holder.viewType == HEADER_TYPE) {
        holder.driverNameText.setText(driverName);
    }
}

@Override
public int getItemCount() {
    return rows.size() + 1;
}

@Override
public int getItemViewType(int position) {
    if (position == 0)
        return HEADER_TYPE;
    return ROW_TYPE;
}

public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    protected int viewType;
    @Bind(R.id.drawer_row_icon)
    ImageView imageView;
    @Bind(R.id.drawer_row_text)
    TextView textView;
    @Bind(R.id.drawer_row_id)
    FrameLayout listRow;
    @Bind(R.id.driverName)
    TextView driverNameText;

    public ViewHolder(View itemView, int viewType) {
        super(itemView);

        this.viewType = viewType;

        if (viewType == ROW_TYPE) {
            ButterKnife.bind(this, itemView);
            imageView.setOnClickListener(this);
            textView.setOnClickListener(this);
            listRow.setOnClickListener(this);
        } else {
            ButterKnife.bind(this, itemView);
        }
    }


 }

As you can see in my onCreateViewHolder method, I'm checking for both viewType's so I know which layout to draw. This in turn will create a new object for the ViewHolder class in which I "TRY" to bind the elements inside my xml depending on the viewType. Am I missing something, or doing something wrongly?

Answer

remedy. picture remedy. · Jul 16, 2015

I was able to solve this problem by doing the following:

First, the api docs stated the following

Be default, views are required to be present in the layout for both field and method bindings. If a view is optional add a @Nullable annotation such as the one in the support-annotations library.

@Nullable @Bind(R.id.title) TextView subtitleView;

http://jakewharton.github.io/butterknife/javadoc/

Now since I had different elements to bind coming from different xml files, I had to tag them as @Nullable because it's possible that they won't even be bindable to begin with. I changed my code to do the following :

@Nullable @Bind(R.id.drawer_row_icon)
ImageView imageView;
@Nullable @Bind(R.id.drawer_row_text)
TextView textView;
@Nullable @Bind(R.id.drawer_row_id)
FrameLayout listRow;
@Nullable @Bind(R.id.driverName)
TextView driverNameText;

While also moving the ButterKnife.bind() outside of my IF-ELSE Block.