com.irahul.worldclock.WorldClockData.java Source code

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Here is the source code for com.irahul.worldclock.WorldClockData.java

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/*
 * Copyright (C) 2012 Rahul Agarwal
 *
 * This file is part of the World Clock
 * World Clock is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * World Clock is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with World Clock.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.irahul.worldclock;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.HashSet;
import java.util.Set;
import java.util.TimeZone;

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

import android.content.Context;
import android.util.Log;

/**
 * Data storage model - translate this to/from JSON
 * 
 * @author rahul
 * 
 */
public class WorldClockData {
    private static final String TAG = WorldClockData.class.getName();
    private static final String DISPLAY_NAME = "displayName";
    private static final String TIMEZONE_ID = "timezoneId";
    private static final String FILENAME = "WorldClockData";
    private Set<WorldClockTimeZone> selectedTimeZones = null;
    private Context context;

    public WorldClockData(Context context) {
        this.context = context;

        // load timezones if not available
        if (this.selectedTimeZones == null) {
            try {
                FileInputStream fis = context.openFileInput(FILENAME);
                StringBuilder fileData = new StringBuilder();

                byte[] buffer = new byte[1];
                while (fis.read(buffer) != -1) {
                    fileData.append(new String(buffer));
                }

                Log.d(TAG, "RAW - Loaded from file:" + fileData.toString());
                selectedTimeZones = deserialize(fileData.toString());

            } catch (FileNotFoundException e) {
                // no file exists - treat as empty list and create file
                createFile();
                this.selectedTimeZones = new HashSet<WorldClockTimeZone>();

            } catch (IOException e) {
                throw new WorldClockException(e);
            } catch (JSONException e) {
                throw new WorldClockException(e);
            }
        }
    }

    public Set<WorldClockTimeZone> getSavedTimeZones() {
        return selectedTimeZones;
    }

    public void deleteZone(WorldClockTimeZone wcTimeZone) {
        Log.d(TAG, "Removing zone: " + wcTimeZone);

        selectedTimeZones.remove(wcTimeZone);

        updateFile();
    }

    public void addZone(WorldClockTimeZone wcTimeZone) {
        Log.d(TAG, "Adding zone: " + wcTimeZone);

        //TODO - what to do if someone attempts to add same zone with a diff name?

        selectedTimeZones.add(wcTimeZone);

        updateFile();
    }

    /**
     * Creates a blank file
     */
    private void createFile() {
        Log.d(TAG, "Creating new file");

        // write empty array into file
        writeToFile(new JSONArray().toString());
    }

    /**
     * Writes set to file (assume not null)
     */
    private void updateFile() {
        try {
            JSONArray arr = serialize();
            writeToFile(arr.toString());

        } catch (JSONException e) {
            throw new WorldClockException(e);
        }
    }

    private void writeToFile(String jsonString) {
        Log.d(TAG, "Writing JSON to file: " + jsonString);
        try {
            FileOutputStream fos = context.openFileOutput(FILENAME, Context.MODE_PRIVATE);
            OutputStreamWriter osw = new OutputStreamWriter(fos);

            osw.write(jsonString);
            osw.flush();
            osw.close();
            fos.close();

        } catch (FileNotFoundException e) {
            throw new WorldClockException(e);
        } catch (IOException e) {
            throw new WorldClockException(e);
        }
    }

    private JSONArray serialize() throws JSONException {
        JSONArray jsonArr = new JSONArray();
        for (WorldClockTimeZone tz : selectedTimeZones) {
            JSONObject jsonTz = new JSONObject();
            jsonTz.put(TIMEZONE_ID, tz.getId());
            jsonTz.put(DISPLAY_NAME, tz.getDisplayName());
            jsonArr.put(jsonTz);
        }
        return jsonArr;
    }

    private Set<WorldClockTimeZone> deserialize(String jsonString) throws JSONException {
        JSONArray jsonArr = new JSONArray(jsonString);

        Set<WorldClockTimeZone> arr = new HashSet<WorldClockTimeZone>();
        for (int i = 0; i < jsonArr.length(); i++) {
            JSONObject jsonObj = jsonArr.getJSONObject(i);

            WorldClockTimeZone tz = new WorldClockTimeZone(TimeZone.getTimeZone(jsonObj.getString(TIMEZONE_ID)));
            tz.setDisplayName(jsonObj.getString(DISPLAY_NAME));

            arr.add(tz);
        }

        return arr;
    }

}