mainclass.java

A "Time To First Fix" duration evaluation (J2ME application) on Nokia S60

package org.mcyrrer.ttff;

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.location.Location;
import javax.microedition.location.LocationException;
import javax.microedition.location.LocationListener;
import javax.microedition.location.LocationProvider;
import javax.microedition.midlet.MIDlet;
import java.util.Calendar;
import javax.microedition.midlet.MIDletStateChangeException;


/**
 * Main class that sets up an JSR179 locationprovider and use it to calculate Time To First Fix that is presentated in Class MIDPCanvas
 * @version 1.0
 * @author Mattias Gustavsson
 */
public class MainClass extends MIDlet implements CommandListener, LocationListener {

    private MIDPCanvas appCanvas;
    private Display display;
    private boolean ttffDone = false;
    private long timerStarted;
    LocationProvider myLocationProvider;
    Calendar date = Calendar.getInstance();
    final Command exitCommand = new Command("Exit", Command.EXIT, 1);

    protected void startApp() throws MIDletStateChangeException {
        /*
         *Set up the Canvas we use and adds softkeys and sets a commandlistener 
         */ 
        try {
            appCanvas = new MIDPCanvas();
            display = Display.getDisplay(this);
            display.setCurrent(appCanvas);

            // Set up this canvas to listen to command events
            this.appCanvas.setCommandListener(this);
            // Add the Exit command
            this.appCanvas.addCommand(exitCommand);
        } catch (Exception e) {
            e.printStackTrace();
        }

        /*
         * Set up the location provider and sets a listener to update the signal every 1 second.
         */
        try {
            myLocationProvider = LocationProvider.getInstance(null);
            myLocationProvider.setLocationListener(this, 1, 1, 1);
            //Timer started. This is the base time that we use later on to calculate the TTFF
            timerStarted = System.currentTimeMillis();
        } catch (LocationException ex) {
            ex.printStackTrace();
        }

    }

    protected void pauseApp() {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
        throw new UnsupportedOperationException("Not supported yet.");
    }

    public void locationUpdated(LocationProvider arg0, Location locaction) {
        

        if (!ttffDone) {
            /*
             * myLocationProvider need to up and running (state=AVAILABLE). Otherwise we will not get any signal to work with
             */
            if (myLocationProvider.getState() == LocationProvider.AVAILABLE) {
                /*
                 * our location need to have all gps data (isValid) to be used for determin TTFF
                 */
                if (locaction.isValid()) {

                    long timeresult = (System.currentTimeMillis() - timerStarted) / 1000;

                    appCanvas.setText("TTFF=" + Long.toString(timeresult) + "sec");
                    ttffDone = true;
                } else {
                    long timeresult = (System.currentTimeMillis() - timerStarted) / 1000;
                    appCanvas.setText(Long.toString(timeresult) + "sec");
                }
            }

            if (myLocationProvider.getState() == LocationProvider.TEMPORARILY_UNAVAILABLE) {
                appCanvas.setText("Location TEMPORARILY_UNAVAILABLE:");

            }
            if (myLocationProvider.getState() == LocationProvider.OUT_OF_SERVICE) {
                appCanvas.setText("Location OUT_OF_SERVICE:");
            }
        }
        appCanvas.repaint();

    }

    /**
     * 
     * @param arg0
     * @param arg1
     */
    public void providerStateChanged(LocationProvider arg0, int arg1) {
    }

    /**
     * 
     * @param c
     * @param arg1
     */
    public void commandAction(Command c, Displayable arg1) {
        if (c == exitCommand) {
            this.notifyDestroyed();
        }
    }
}