path: root/Android/06-Notifications/Notifications/src/course/labs/notificationslab/MainActivity.java

package course.labs.notificationslab;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.widget.Toast;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends Activity implements SelectionListener {

    public static final String TWEET_FILENAME = "tweets.txt";
    public static final String[] FRIENDS = { "taylorswift13", "msrebeccablack", "ladygaga" };
    public static final String DATA_REFRESHED_ACTION = "course.labs.notificationslab.DATA_REFRESHED";

    private static final int NUM_FRIENDS = 3;
    private static final String URL_LGAGA = "https://d396qusza40orc.cloudfront.net/android%2FLabs%2FUserNotifications%2Fladygaga.txt";
    private static final String URL_RBLACK = "https://d396qusza40orc.cloudfront.net/android%2FLabs%2FUserNotifications%2Frebeccablack.txt";
    private static final String URL_TSWIFT = "https://d396qusza40orc.cloudfront.net/android%2FLabs%2FUserNotifications%2Ftaylorswift.txt";
    private static final String TAG = "Lab-Notifications";
    private static final long TWO_MIN = 2 * 60 * 1000;
    private static final int UNSELECTED = -1;

    private FragmentManager mFragmentManager;
    private FriendsFragment mFriendsFragment;
    private boolean mIsFresh;
    private BroadcastReceiver mRefreshReceiver;
    private int mFeedSelected = UNSELECTED;
    private FeedFragment mFeedFragment;
    private String[] mRawFeeds = new String[3];
    private String[] mProcessedFeeds = new String[3];

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mFragmentManager = getFragmentManager();
        addFriendsFragment();
        // The feed is fresh if it was downloaded less than 2 minutes ago
        mIsFresh = (System.currentTimeMillis() - getFileStreamPath( TWEET_FILENAME).lastModified()) < TWO_MIN;
        ensureData();
    }

    // Add Friends Fragment to Activity
    private void addFriendsFragment() {
        mFriendsFragment = new FriendsFragment();
        mFriendsFragment.setArguments(getIntent().getExtras());
        FragmentTransaction transaction = mFragmentManager.beginTransaction();
        transaction.add(R.id.fragment_container, mFriendsFragment);
        transaction.commit();
    }

    // If stored Tweets are not fresh, reload them from network
    // Otherwise, load them from file
    private void ensureData() {

        log("In ensureData(), mIsFresh:" + mIsFresh);

        if (!mIsFresh) {
            log ("Issuing Toast Message");
            Toast.makeText(MainActivity.this, "Downloading Tweets from Network", Toast.LENGTH_SHORT).show();

            new DownloaderTask(MainActivity.this).execute(URL_LGAGA, URL_RBLACK, URL_TSWIFT);

            // Set up a BroadcastReceiver to receive an Intent when download
            // finishes.
            mRefreshReceiver = new BroadcastReceiver() {
                @Override
                public void onReceive(Context context, Intent intent) {
                    log("BroadcastIntent received in MainActivity");
                    if (isOrderedBroadcast()) {
                        setResultCode(RESULT_OK);
                    }
                }
            };
        } else {
            loadTweetsFromFile();
            parseJSON();
            updateFeed();
        }
    }

    // Called when new Tweets have been downloaded
    public void setRefreshed(String[] feeds) {
        mRawFeeds[0] = feeds[0];
        mRawFeeds[1] = feeds[1];
        mRawFeeds[2] = feeds[2];

        parseJSON();
        updateFeed();
        mIsFresh = true;
    };

    // Called when a Friend is clicked on
    @Override
    public void onItemSelected(int position) {
        mFeedSelected = position;
        mFeedFragment = addFeedFragment();

        if (mIsFresh) {
            updateFeed();
        }
    }

    // Calls FeedFragement.update, passing in the
    // the tweets for the currently selected friend
    void updateFeed() {
        if (null != mFeedFragment)
            mFeedFragment.update(mProcessedFeeds[mFeedSelected]);
    }

    // Add FeedFragment to Activity
    private FeedFragment addFeedFragment() {
        FeedFragment feedFragment;
        feedFragment = new FeedFragment();

        FragmentTransaction transaction = mFragmentManager.beginTransaction();

        transaction.replace(R.id.fragment_container, feedFragment);
        transaction.addToBackStack(null);

        transaction.commit();
        mFragmentManager.executePendingTransactions();
        return feedFragment;
    }

    // Register the BroadcastReceiver
    @Override
    protected void onResume() {
        super.onResume();
        if(mRefreshReceiver != null) {
            registerReceiver(mRefreshReceiver, new IntentFilter(DATA_REFRESHED_ACTION));
        }
    }

    @Override
    protected void onPause() {
        if(mRefreshReceiver != null) {
            unregisterReceiver(mRefreshReceiver);
        }
        super.onPause();
    }

    // Convert raw Tweet data (in JSON format) into text for display
    public void parseJSON() {

        JSONArray[] JSONFeeds = new JSONArray[NUM_FRIENDS];

        for (int i = 0; i < NUM_FRIENDS; i++) {
            try {
                JSONFeeds[i] = new JSONArray(mRawFeeds[i]);
            } catch (JSONException e) {
                e.printStackTrace();
            }

            String name = "";
            String tweet = "";

            JSONArray tmp = JSONFeeds[i];

            // string buffer for twitter feeds
            StringBuffer tweetRec = new StringBuffer("");

            for (int j = 0; j < tmp.length(); j++) {
                try {
                    tweet = tmp.getJSONObject(j).getString("text");
                    JSONObject user = (JSONObject) tmp.getJSONObject(j).get(
                            "user");
                    name = user.getString("name");

                } catch (JSONException e) {
                    e.printStackTrace();
                }

                tweetRec.append(name + " - " + tweet + "\n\n");
            }
            mProcessedFeeds[i] = tweetRec.toString();
        }
    }

    // Retrieve feeds text from a file
    // Store them in mRawTextFeed[]
    private void loadTweetsFromFile() {
        BufferedReader reader = null;

        try {
            FileInputStream fis = openFileInput(TWEET_FILENAME);
            reader = new BufferedReader(new InputStreamReader(fis));
            String s = null;
            int i = 0;
            while (null != (s = reader.readLine()) && i < NUM_FRIENDS) {
                mRawFeeds[i] = s;
                i++;
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (null != reader) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    // Simplified log output method
    private void log(String msg) {
        try {
            Thread.sleep(500);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        Log.i(TAG, msg);
    }
}