import javax.microedition.midlet.*;

import javax.microedition.lcdui.*;

public class CALCULATOR extends MIDlet implements CommandListener

{

private Display display;

private Form fmMain;

private Form fmb2;

private TextField tfNum1;

private TextField tfNum2;

private TextField tfx1;

private TextField tfx2;

private TextField tfInput;

private TextBox tbHelp;

private Command cmHelp;

private Command cmExit;

private Command cmBack;

private Command cmCong;

private Command cmTru;

private Command cmNhan;

private Command cmChia;

// private Command cmLuy_thua;

private Command cmTigia;

private Command cmUsd;

private Command cmb2;

private Command cmDapso;

private Form fmTigia;

private TextField tfUsd;

private TextField tfVnd;

private TextField tfb;

private TextField tfa;

private TextField tfc;

private TextField tfKetqua;

private TextBox tbVo_nghiem;

private Form fmNghiem_kep;

private TextField tfx12;

public CALCULATOR()

{

display=Display.getDisplay(this);

tfx12=new TextField("X1=X2","",6,TextField.NUMERIC);

fmNghiem_kep=new Form("PHUONG TRINH CO NGHIEM KEP");

tfa=new TextField("NHAP A","",5,TextField.NUMERIC);

tfb=new TextField("NHAP B","",5,TextField.NUMERIC);

tfc=new TextField("NHAP C","",5,TextField.NUMERIC);

tfNum1 = new TextField(" NUM 1","",17,TextField.NUMERIC);

tfNum2 = new TextField(" NUM 2","",17,TextField.NUMERIC);

tfx1 = new TextField("X1","",5,TextField.NUMERIC);

tfx2 = new TextField("X2","",5,TextField.NUMERIC);

tfInput = new TextField(" INPUT","",17,TextField.NUMERIC);

tfKetqua = new TextField("KET QUA","",17,TextField.NUMERIC);

tfVnd=new TextField("USD","",17,TextField.NUMERIC);

tfUsd=new TextField("VND","",17,TextField.NUMERIC);

tbHelp=new TextBox("HELP","My program is a Calculator.It help you to computing plus,minus,device and..." +

".The program is easy to use." +

"The program is developed by cu0n9bk." +

"The program is bought by Microsoft with price is 1,000$",250,0);

tbVo_nghiem=new TextBox("VO NGHIEM","PHUONG TRINH VO NGHIEM THUC",30,0);

fmTigia= new Form("QUY DOI TY GIA");

fmMain= new Form("CALCULATOR");

fmb2 = new Form("GIAI PHUONG TRINH BAC HAI");

cmExit = new Command("EXIT",Command.EXIT,1);

cmCong = new Command("CONG",Command.SCREEN,1);

cmTru = new Command("TRU",Command.SCREEN,2);

cmNhan = new Command("NHAN",Command.SCREEN,3);

cmChia = new Command("CHIA",Command.SCREEN,4);

// cmLuy_thua = new Command("LUY THUA",Command.SCREEN,5);

cmHelp = new Command("HELP",Command.HELP,7);

cmBack=new Command("BACK",Command.BACK,1);

cmTigia=new Command("TI GIA",Command.SCREEN,5);

cmUsd=new Command("USD2VND",Command.SCREEN,1);

cmb2=new Command("GIAI PTB2",Command.SCREEN,6);

cmDapso=new Command("DAP SO",Command.SCREEN,1);

tbHelp.addCommand(cmBack);

tbHelp.addCommand(cmExit);

tbHelp.setCommandListener(this);

fmMain.addCommand(cmExit);

fmMain.addCommand(cmCong);

fmMain.addCommand(cmTru);

fmMain.addCommand(cmNhan);

fmMain.addCommand(cmChia);

// fmMain.addCommand(cmLuy_thua);

fmMain.addCommand(cmHelp);

fmMain.append(tfNum1);

fmMain.append(tfNum2);

fmMain.append(tfInput);

fmMain.append(tfKetqua);

fmMain.addCommand(cmb2);

fmMain.addCommand(cmTigia);

fmMain.addCommand(cmb2);

fmMain.setCommandListener(this);

fmTigia.addCommand(cmBack);

fmTigia.addCommand(cmUsd);

fmTigia.addCommand(cmExit);

fmTigia.append(tfVnd);

fmTigia.append(tfUsd);

fmTigia.setCommandListener(this);

fmb2.addCommand(cmBack);

fmb2.addCommand(cmExit);

fmb2.addCommand(cmDapso);

fmb2.append(tfa);

fmb2.append(tfb);

fmb2.append(tfc);

fmb2.append(tfx1);

fmb2.append(tfx2);

fmb2.setCommandListener(this);

fmNghiem_kep.addCommand(cmBack);

fmNghiem_kep.addCommand(cmExit);

fmNghiem_kep.append(tfx12);

fmNghiem_kep.setCommandListener(this);

tbVo_nghiem.addCommand(cmExit);

tbVo_nghiem.addCommand(cmBack);

tbVo_nghiem.setCommandListener(this);

}

public void startApp()

{

display.setCurrent(fmMain);

}

public void pauseApp()

{

}

public void destroyApp(boolean unconditional) {

}

public void commandAction(Command c, Displayable d)

{

if(c==cmExit)

{

destroyApp(false);

notifyDestroyed();

}

if(c==cmHelp)

{

display.setCurrent(tbHelp);

}

if(c==cmBack)

{

display.setCurrent(fmMain);

}

if(c==cmCong)

{

int a,b;

a=Integer.parseInt(tfNum1.getString());

b=Integer.parseInt(tfNum2.getString());

tfKetqua.setString(String.valueOf(a+b));

}

if(c==cmTru)

{

int a,b;

a=Integer.parseInt(tfNum1.getString());

b=Integer.parseInt(tfNum2.getString());

tfKetqua.setString(String.valueOf(a-b));

}

if(c==cmNhan)

{

int a,b;

a=Integer.parseInt(tfNum1.getString());

b=Integer.parseInt(tfNum2.getString());

tfKetqua.setString(String.valueOf(a*b));

}

if(c==cmChia)

{

int a,b;

a=Integer.parseInt(tfNum1.getString());

b=Integer.parseInt(tfNum2.getString());

tfKetqua.setString(String.valueOf(a/b));

}

if(c==cmTigia)

{

display.setCurrent(fmTigia);

}

if(c==cmUsd)

{

int a;

a=Integer.parseInt(tfVnd.getString());

tfUsd.setString(String.valueOf(16*a));

}

if(c==cmb2)

{

display.setCurrent(fmb2);

}

if(c==cmDapso)

{

int a,b,q,delta;

a=Integer.parseInt(tfa.getString());

b=Integer.parseInt(tfb.getString());

q=Integer.parseInt(tfc.getString());

delta=b*b-4*a*q;

if(delta<0)

{

display.setCurrent(tbVo_nghiem);

}

if(delta==0)

{

display.setCurrent(fmNghiem_kep);

int x12;

a=Integer.parseInt(tfa.getString());

b=Integer.parseInt(tfb.getString());

x12=-b/(2*a);

double t=(double) x12;

tfx12.setString(String.valueOf(x12));

}

}

}

}