ModelAdapter.java

package com.uservoice.uservoicesdk.ui;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.uservoice.uservoicesdk.R;
import com.uservoice.uservoicesdk.rest.Callback;

import java.util.List;

public abstract class ModelAdapter<T> extends SearchAdapter<T> {

    protected static final int MODEL = 0;
    protected static final int LOADING = 1;

    protected final int layoutId;
    protected LayoutInflater inflater;
    protected List<T> objects;
    protected int addedObjects = 0;

    public ModelAdapter(Context context, int layoutId, List<T> objects) {
        this.context = context;
        this.layoutId = layoutId;
        this.objects = objects;
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    @SuppressWarnings("unchecked")
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;
        int type = getItemViewType(position);
        if (view == null) {
            view = inflater.inflate(type == LOADING ? R.layout.uv_loading_item : layoutId, null);
        }

        if (type == MODEL) {
            T model = (T) getItem(position);
            customizeLayout(view, model);
        }

        return view;
    }

    @Override
    public boolean isEnabled(int position) {
        return getItemViewType(position) == MODEL;
    }

    @Override
    public int getItemViewType(int position) {
        return position == getObjects().size() ? LOADING : MODEL;
    }

    @Override
    public int getViewTypeCount() {
        return 2;
    }

    @Override
    public int getCount() {
        return getObjects().size() + (loading ? 1 : 0);
    }

    @Override
    public Object getItem(int position) {
        return position < getObjects().size() ? getObjects().get(position) : null;
    }

    @Override
    public long getItemId(int position) {
        return getItemViewType(position) == LOADING ? -1 : position;
    }

    protected List<T> getObjects() {
        return objects;
    }

    public void add(int location, T object) {
        objects.add(location, object);
        addedObjects += 1;
        notifyDataSetChanged();
    }

    protected abstract void customizeLayout(View view, T model);

    protected abstract void loadPage(int page, Callback<List<T>> callback);
}