/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package laskin;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

/**
 * @author vesal
 */
public class Ynnaa extends MIDlet implements CommandListener, ItemStateListener {

    private boolean midletPaused = false;

    //<editor-fold defaultstate="collapsed" desc=" Generated Fields ">//GEN-BEGIN:|fields|0|
    private Command exitCommand;
    private Command laskeCommand;
    private Command screenCommand;
    private Form form;
    private TextField lasku;
    private TextField tulos;
    //</editor-fold>//GEN-END:|fields|0|

    /**
     * The HelloMIDlet constructor.
     */
    public Ynnaa() {
    }

    //<editor-fold defaultstate="collapsed" desc=" Generated Methods ">//GEN-BEGIN:|methods|0|
    //</editor-fold>//GEN-END:|methods|0|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: initialize ">//GEN-BEGIN:|0-initialize|0|0-preInitialize
    /**
     * Initilizes the application.
     * It is called only once when the MIDlet is started. The method is called before the <code>startMIDlet</code> method.
     */
    private void initialize() {//GEN-END:|0-initialize|0|0-preInitialize
        // write pre-initialize user code here
        exitCommand = new Command("Exit", Command.EXIT, 2);//GEN-BEGIN:|0-initialize|1|0-postInitialize
        laskeCommand = new Command("Laske", Command.OK, 0);
        screenCommand = new Command("Screen", Command.SCREEN, 0);
        lasku = new TextField("Lasku", "", 32, TextField.ANY);
        lasku.setItemCommandListener(this);
        lasku.setLayout(ImageItem.LAYOUT_LEFT);
        lasku.setPreferredSize(12, -1);
        tulos = new TextField("Tulos", "0", 32, TextField.ANY);
        tulos.setLayout(ImageItem.LAYOUT_DEFAULT | Item.LAYOUT_2);
        form = new Form("Welcome", new Item[] { lasku, tulos });
        form.addCommand(exitCommand);
        form.addCommand(laskeCommand);
        form.setCommandListener(this);//GEN-END:|0-initialize|1|0-postInitialize
        form.setItemStateListener(this);
    }//GEN-BEGIN:|0-initialize|2|
    //</editor-fold>//GEN-END:|0-initialize|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: startMIDlet ">//GEN-BEGIN:|3-startMIDlet|0|3-preAction
    /**
     * Performs an action assigned to the Mobile Device - MIDlet Started point.
     */
    public void startMIDlet() {//GEN-END:|3-startMIDlet|0|3-preAction
        // write pre-action user code here
        switchDisplayable(null, form);//GEN-LINE:|3-startMIDlet|1|3-postAction
        // write post-action user code here
    }//GEN-BEGIN:|3-startMIDlet|2|
    //</editor-fold>//GEN-END:|3-startMIDlet|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: resumeMIDlet ">//GEN-BEGIN:|4-resumeMIDlet|0|4-preAction
    /**
     * Performs an action assigned to the Mobile Device - MIDlet Resumed point.
     */
    public void resumeMIDlet() {//GEN-END:|4-resumeMIDlet|0|4-preAction
        // write pre-action user code here
        switchDisplayable(null, form);//GEN-LINE:|4-resumeMIDlet|1|4-postAction
        // write post-action user code here
    }//GEN-BEGIN:|4-resumeMIDlet|2|
    //</editor-fold>//GEN-END:|4-resumeMIDlet|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: switchDisplayable ">//GEN-BEGIN:|5-switchDisplayable|0|5-preSwitch
    /**
     * Switches a current displayable in a display. The <code>display</code> instance is taken from <code>getDisplay</code> method. This method is used by all actions in the design for switching displayable.
     * @param alert the Alert which is temporarily set to the display; if <code>null</code>, then <code>nextDisplayable</code> is set immediately
     * @param nextDisplayable the Displayable to be set
     */
    public void switchDisplayable(Alert alert, Displayable nextDisplayable) {//GEN-END:|5-switchDisplayable|0|5-preSwitch
        // write pre-switch user code here
        Display display = getDisplay();//GEN-BEGIN:|5-switchDisplayable|1|5-postSwitch
        if (alert == null) {
            display.setCurrent(nextDisplayable);
        } else {
            display.setCurrent(alert, nextDisplayable);
        }//GEN-END:|5-switchDisplayable|1|5-postSwitch
        // write post-switch user code here
    }//GEN-BEGIN:|5-switchDisplayable|2|
    //</editor-fold>//GEN-END:|5-switchDisplayable|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Displayables ">//GEN-BEGIN:|7-commandAction|0|7-preCommandAction
    /**
     * Called by a system to indicated that a command has been invoked on a particular displayable.
     * @param command the Command that was invoked
     * @param displayable the Displayable where the command was invoked
     */
    public void commandAction(Command command, Displayable displayable) {//GEN-END:|7-commandAction|0|7-preCommandAction
        // write pre-action user code here
        if (displayable == form) {//GEN-BEGIN:|7-commandAction|1|19-preAction
            if (command == exitCommand) {//GEN-END:|7-commandAction|1|19-preAction
                // write pre-action user code here
                exitMIDlet();//GEN-LINE:|7-commandAction|2|19-postAction
                // write post-action user code here
            } else if (command == laskeCommand) {//GEN-LINE:|7-commandAction|3|40-preAction

                laske();//GEN-LINE:|7-commandAction|4|40-postAction
                // write post-action user code here
            }//GEN-BEGIN:|7-commandAction|5|7-postCommandAction
        }//GEN-END:|7-commandAction|5|7-postCommandAction
        // write post-action user code here
    }//GEN-BEGIN:|7-commandAction|6|
    //</editor-fold>//GEN-END:|7-commandAction|6|

    /**
     * Returns a display instance.
     * @return the display instance.
     */
    public Display getDisplay () {
        return Display.getDisplay(this);
    }

    /**
     * Exits MIDlet.
     */
    public void exitMIDlet() {
        switchDisplayable (null, null);
        destroyApp(true);
        notifyDestroyed();
    }

    /**
     * Called when MIDlet is started.
     * Checks whether the MIDlet have been already started and initialize/starts or resumes the MIDlet.
     */
    public void startApp() {
        if (midletPaused) {
            resumeMIDlet ();
        } else {
            initialize ();
            startMIDlet ();
        }
        midletPaused = false;
    }

    /**
     * Called when MIDlet is paused.
     */
    public void pauseApp() {
        midletPaused = true;
    }

    /**
     * Called to signal the MIDlet to terminate.
     * @param unconditional if true, then the MIDlet has to be unconditionally terminated and all resources has to be released.
     */
    public void destroyApp(boolean unconditional) {
    }


    /**
     * Mukaeltu erota-aliohjelma
     * @param jono   jono josta erotellaan seuraava pala, jono lyhenee
     * @param merkki merkki jonka kohdalta katkaistaan
     * @return seuraava jonon pala
     */
    public static String erota(StringBuffer jono, char merkki) {
        if ( jono == null ) return "";
        int p;
        String s = jono.toString();
        p = s.indexOf(""+merkki);
        String alku;
        if ( p < 0 ) {
          alku = jono.toString();
          jono.delete(0,jono.length());
          return alku;
        }
        alku = s.substring(0,p);
        jono.delete(0,p+1);
        return alku;
      }


    /**
     * Laskun suorittaminen
     */
    public void laske() {
        StringBuffer jono =  new StringBuffer(lasku.getString());
        double summa = 0;
        while ( jono.length() != 0 ) {
            String pala = erota(jono,' ');
            try {
                summa +=Double.parseDouble(pala);
            } catch (NumberFormatException e) {
            }
        }
        tulos.setString(""+summa);
    }

    public void itemStateChanged(Item item) {
            if ( item == lasku ) laske();
    }


}