com.royclarkson.springagram.HomeFragment.java Source code

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Here is the source code for com.royclarkson.springagram.HomeFragment.java

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/*
 * Copyright 2014 Roy Clarkson
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.royclarkson.springagram;

import android.app.Activity;
import android.app.Fragment;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.royclarkson.springagram.model.ApiResource;

import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.ResourceAccessException;
import org.springframework.web.client.RestTemplate;

/**
 * @author Roy Clarkson
 */
public class HomeFragment extends Fragment {

    public static final String TAG = HomeFragment.class.getSimpleName();

    private static final String ARG_API_URL = "api_url";

    private String apiUrl;

    private HomeFragmentListener homeFragmentListener;

    public HomeFragment() {
        // Required empty public constructor
    }

    public static HomeFragment newInstance(String apiUrl) {
        HomeFragment fragment = new HomeFragment();
        Bundle args = new Bundle();
        args.putString(ARG_API_URL, apiUrl);
        fragment.setArguments(args);
        return fragment;
    }

    //***************************************
    // Fragment methods
    //***************************************

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            this.apiUrl = getArguments().getString(ARG_API_URL);
        }
        new DownloadRootResourceTask().execute(this.apiUrl);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_home, container, false);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        setRetainInstance(true);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            homeFragmentListener = (HomeFragmentListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString() + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        homeFragmentListener = null;
    }

    //***************************************
    // Listener interface
    //***************************************

    public interface HomeFragmentListener {

        public void onResourceDownloadComplete(ApiResource resource);

        public void onNetworkError(String message);

    }

    // ***************************************
    // Private classes
    // ***************************************

    private class DownloadRootResourceTask extends AsyncTask<String, Void, ApiResource> {

        Exception exception;

        @Override
        protected ApiResource doInBackground(String... params) {
            try {
                final String url = params[0];
                RestTemplate restTemplate = RestUtils.getInstance();
                ResponseEntity<ApiResource> responseEntity = restTemplate.exchange(url, HttpMethod.GET,
                        RestUtils.getRequestEntity(), ApiResource.class);
                return responseEntity.getBody();
            } catch (Exception e) {
                this.exception = e;
                Log.e(TAG, e.getMessage(), e);
            }

            return null;
        }

        @Override
        protected void onPostExecute(ApiResource apiResource) {
            if (homeFragmentListener != null) {
                if (this.exception != null && this.exception instanceof ResourceAccessException) {
                    homeFragmentListener.onNetworkError(this.exception.getMessage());
                } else {
                    homeFragmentListener.onResourceDownloadComplete(apiResource);
                }
            }
        }

    }

}