PhotoModel.java

package com.konifar.materialcat.models;

import android.content.Context;

import com.konifar.materialcat.MainApplication;
import com.konifar.materialcat.events.PhotoSearchCallbackEvent;
import com.konifar.materialcat.models.pojo.PhotoSource;
import com.konifar.materialcat.network.FlickrApiService;

import de.greenrobot.event.EventBus;
import retrofit.Callback;
import retrofit.RetrofitError;
import retrofit.client.Response;

public class PhotoModel {

    private static final String CAT_SEARCH_TEXT = "cat";
    private static final int PER_PAGE = 36;
    private static PhotoModel instance;

    FlickrApiService flickerApiService;

    private PhotoModel(Context context) {
        flickerApiService = MainApplication.FLICKR_API;
    }

    public static PhotoModel getInstance(Context context) {
        if (instance == null) {
            instance = new PhotoModel(context);
        }
        return instance;
    }

    public void getCatPhotos(int page, final String sort) {
        flickerApiService.photosSearch(CAT_SEARCH_TEXT, page, PER_PAGE, sort,
                new Callback<PhotoSource>() {
                    @Override
                    public void success(PhotoSource photoSource, Response response) {
                        EventBus.getDefault().post(new PhotoSearchCallbackEvent(true, photoSource.getPhotos(), sort));
                    }

                    @Override
                    public void failure(RetrofitError error) {
                        EventBus.getDefault().post(new PhotoSearchCallbackEvent(false, sort));
                    }
                });
    }

}