ControlPoints.java

/*
 * Copyright © 2012 Nokia Corporation. All rights reserved.
 * Nokia and Nokia Connecting People are registered trademarks of Nokia Corporation.
 * Oracle and Java are trademarks or registered trademarks of Oracle and/or its
 * affiliates. Other product and company names mentioned herein may be trademarks
 * or trade names of their respective owners.
 * See LICENSE.TXT for license information.
 */
package com.nokia.example.location.touristroute.model;

import java.io.IOException;
import java.util.Enumeration;

import javax.microedition.location.Coordinates;
import javax.microedition.location.Landmark;
import javax.microedition.location.LandmarkException;
import javax.microedition.location.LandmarkStore;

/**
 * Model class that handles landmark store actions.
 */
public class ControlPoints
{
    private LandmarkStore store = null;

    private static final String STORENAME = "TOURIST_DEMO";

    private static final String DEFAULT_CATEGORY = null;

    private static ControlPoints INSTANCE = null;

    /**
     * Constructs instance of this class. Makes sure that landmark store
     * instance exists.
     */
    private ControlPoints()
    {
        String name = null;
        // Try to find landmark store called "TOURIST_DEMO".
        try
        {
            store = LandmarkStore.getInstance(STORENAME);
        }
        catch (NullPointerException npe)
        {
            // This should never occur.
        }

        // Check whether landmark store exists.
        if (store == null)
        {
            // Landmark store does not exist.

            try
            {
                // Try to create landmark store named "TOURIST_DEMO".
                LandmarkStore.createLandmarkStore(STORENAME);
                name = STORENAME;
            }
            catch (IllegalArgumentException iae)
            {
                // Name is too long or landmark store with the specified
                // name already exists. This Exception should not occur,
                // because we have earlier tryed to created instance of
                // this landmark store.
            }
            catch (IOException e)
            {
                // Landmark store couldn't be created due to an I/O error
            }
            catch (LandmarkException e)
            {
                // Implementation does not support creating new landmark
                // stores.
            }

            store = LandmarkStore.getInstance(name);
        }
    }

    /**
     * Singleton patterns getInstance method. Makes sure that only one instance
     * of this class is alive at once.
     *
     * @return instance of this class.
     */
    public static ControlPoints getInstance()
    {
        if (INSTANCE == null)
        {
            INSTANCE = new ControlPoints();
        }

        return INSTANCE;
    }

    /**
     * Find a Landmark from the landmark store using a index.
     *
     * @param index -
     *            the landmark in the store.
     * @return Landmark from landmark store.
     */
    public Landmark findLandmark(int index)
    {
        Landmark lm = null;

        Enumeration cps = ControlPoints.getInstance().getLandMarks();
        int counter = 0;

        while (cps.hasMoreElements())
        {
            lm = (Landmark) cps.nextElement();

            if (counter == index)
            {
                break;
            }
            counter++;
        }

        return lm;
    }

    /**
     * Find nearest landmark to coordinate parameter from the landmarkstore.
     */
    public Landmark findNearestLandMark(Coordinates coord)
    {
        Landmark landmark = null;

        double latRadius = 0.1;
        double lonRadius = 0.1;

        float dist = Float.MAX_VALUE;

        try
        {
            // Generate enumeration of Landmarks that are close to coord.
            Enumeration enu = store.getLandmarks(null, coord.getLatitude()
                    - latRadius, coord.getLatitude() + latRadius, coord
                    .getLongitude() - lonRadius, coord.getLongitude()
                    + lonRadius);
            float tmpDist;
            Landmark tmpLandmark = null;

            while (enu.hasMoreElements())
            {
                tmpLandmark = (Landmark) enu.nextElement();
                tmpDist = tmpLandmark.getQualifiedCoordinates().distance(coord);

                if (tmpDist < dist)
                {
                    landmark = tmpLandmark;
                }
            }
        }
        catch (IOException ioe)
        {
            // I/O error happened when accessing the landmark store.
            return null;
        }

        return landmark;
    }

    public Enumeration getLandMarks()
    {
        Enumeration enu = null;

        try
        {
            enu = store.getLandmarks();
        }
        catch (IOException ioe)
        {
            // I/O error happened when accessing the landmark store.
        }

        return enu;
    }

    public void addLandmark(Landmark landmark) throws IOException
    {
        store.addLandmark(landmark, DEFAULT_CATEGORY);
    }

    public void updateLandmark(Landmark landmark) throws IOException,
            LandmarkException
    {
        store.updateLandmark(landmark);
    }

    public void removeLandmark(Landmark landmark) throws IOException,
            LandmarkException
    {
        store.deleteLandmark(landmark);
    }

}