package Clearer;

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

public final class Main extends MIDlet
    implements CommandListener
{

    private Display display;
    private final Command cmdClear = new Command("Очистить", 1, 1);
    private final Command cmdRefresh = new Command("Обновить", 1, 2);
    private final Command cmdExit = new Command("Выход", 7, 1);
    private long totalMem;
    private long freeMem;
    Form frm;

    public Main()
    {
        frm = new Form("heap-монитор");
    }

    protected void destroyApp(boolean flag)
        throws MIDletStateChangeException
    {
        exitApp();
    }

    protected void pauseApp()
    {
    }

    protected void startApp()
        throws MIDletStateChangeException
    {
        if(display == null)
            initApp();
        else
            refreshData();
    }

    private void initApp()
    {
        display = Display.getDisplay(this);
        frm.addCommand(cmdClear);
        frm.addCommand(cmdRefresh);
        frm.addCommand(cmdExit);
        frm.setCommandListener(this);
        totalMem = getTotalMem();
        freeMem = getFreeMem();
        frm.append("Всего памяти: " + Long.toString(totalMem) + "\n");
        frm.append("Свободно памяти: " + Long.toString(freeMem));
        display.setCurrent(frm);
    }

    public void exitApp()
    {
        notifyDestroyed();
    }

    private void refreshData()
    {
        display.setCurrent(null);
        frm.delete(1);
        freeMem = getFreeMem();
        frm.append("Свободно памяти: " + Long.toString(freeMem) + "\n");
        display.setCurrent(frm);
    }

    private long getTotalMem()
    {
        return Runtime.getRuntime().totalMemory();
    }

    private long getFreeMem()
    {
        return Runtime.getRuntime().freeMemory();
    }

    public void commandAction(Command command, Displayable displayable)
    {
        if(command == cmdClear)
        {
            System.gc();
            Runtime.getRuntime().gc();
            refreshData();
        } else
        if(command == cmdRefresh)
            refreshData();
        else
        if(command == cmdExit)
            exitApp();
    }
}