Question: Hello, I need some assistance in writing a java pr... Hello, I need so
ID: 3924153 • Letter: Q
Question
Question: Hello, I need some assistance in writing a java pr...
Hello, I need some assistance in writing a java program using stacks (LIFO).
Create a Calculator w/ GUI
Write a program that graphically displays a working calculator for simple infix expressions that consist of: single-digit operands, the operators: +, -, *, and /, and parentheses.
Make the following assumptions:
unary operators (e.g. -2) are illegal
all operations, including division, are integer operations (and results are integers)
the input expression contains no embedded spaces and no illegal characters
the input expression is a syntactically correct infix expression
division by zero will not occur (consider how you can remove this restriction)
Create a GUI application, the calculator has a display and a keypad of 20 keys, which are arranged as follows:
C
<
Q
/
7
8
9
*
4
5
6
-
1
2
3
+
0
(
)
=
As the user presses keys to enter an infix expression, the corresponding characters appear in the display. The C (Clear) key erases all input entered so far; the < (Backspace) key erases the last character entered. When the user presses the = key, the expression is evaluated and the result appended to the right end of the expression in the display window. The user can then press C and enter another expression. If the user presses the Q (Quit) key, the calculator ceases operation and is erased from the screen.
C
<
Q
/
7
8
9
*
4
5
6
-
1
2
3
+
0
(
)
=
Explanation / Answer
import java.awt.*;
import java.awt.event.*;
public class MyCalculator extends Frame
{
public boolean setClear=true;
double number, memValue;
char op;
String digitButtonText[] = {"7", "8", "9", "4", "5", "6", "1", "2", "3", "0", "+/-", "." };
String operatorButtonText[] = {"/", "sqrt", "*", "%", "-", "1/X", "+", "=" };
String memoryButtonText[] = {"MC", "MR", "MS", "M+" };
String specialButtonText[] = {"Backspc", "C", "CE" };
String buttonsText[]={"C","<","Q","/"};
String buttonText1[]={"7","8","9","*"};
String ButtonsText2[]={"4","5","6","-"};
String ButtonText3[]={"1","2","3","+"};
String ButtonText4[]={"0","(",")","="};
MyDigitButton digitButton[]=new MyDigitButton[digitButtonText.length];
MyOperatorButton operatorButton[]=new MyOperatorButton[operatorButtonText.length];
MyMemoryButton memoryButton[]=new MyMemoryButton[memoryButtonText.length];
MySpecialButton specialButton[]=new MySpecialButton[specialButtonText.length];
Label displayLabel=new Label("0",Label.RIGHT);
Label memLabel=new Label(" ",Label.RIGHT);
final int FRAME_WIDTH=325,FRAME_HEIGHT=325;
final int HEIGHT=30, WIDTH=30, H_SPACE=10,V_SPACE=10;
final int TOPX=30, TOPY=50;
///////////////////////////
MyCalculator(String frameText)//constructor
{
super(frameText);
int tempX=TOPX, y=TOPY;
displayLabel.setBounds(tempX,y,240,HEIGHT);
displayLabel.setBackground(Color.BLUE);
displayLabel.setForeground(Color.WHITE);
add(displayLabel);
memLabel.setBounds(TOPX, TOPY+HEIGHT+ V_SPACE,WIDTH, HEIGHT);
add(memLabel);
// set Co-ordinates for Memory Buttons
tempX=TOPX;
y=TOPY+2*(HEIGHT+V_SPACE);
for(int i=0; i<memoryButton.length; i++)
{
memoryButton[i]=new MyMemoryButton(tempX,y,WIDTH,HEIGHT,memoryButtonText[i], this);
memoryButton[i].setForeground(Color.RED);
y+=HEIGHT+V_SPACE;
}
//set Co-ordinates for Special Buttons
tempX=TOPX+1*(WIDTH+H_SPACE); y=TOPY+1*(HEIGHT+V_SPACE);
for(int i=0;i<specialButton.length;i++)
{
specialButton[i]=new MySpecialButton(tempX,y,WIDTH*2,HEIGHT,specialButtonText[i], this);
specialButton[i].setForeground(Color.RED);
tempX=tempX+2*WIDTH+H_SPACE;
}
//set Co-ordinates for Digit Buttons
int digitX=TOPX+WIDTH+H_SPACE;
int digitY=TOPY+2*(HEIGHT+V_SPACE);
tempX=digitX; y=digitY;
for(int i=0;i<digitButton.length;i++)
{
digitButton[i]=new MyDigitButton(tempX,y,WIDTH,HEIGHT,digitButtonText[i], this);
digitButton[i].setForeground(Color.BLUE);
tempX+=WIDTH+H_SPACE;
if((i+1)%3==0){tempX=digitX; y+=HEIGHT+V_SPACE;}
}
//set Co-ordinates for Operator Buttons
int opsX=digitX+2*(WIDTH+H_SPACE)+H_SPACE;
int opsY=digitY;
tempX=opsX; y=opsY;
for(int i=0;i<operatorButton.length;i++)
{
tempX+=WIDTH+H_SPACE;
operatorButton[i]=new MyOperatorButton(tempX,y,WIDTH,HEIGHT,operatorButtonText[i], this);
operatorButton[i].setForeground(Color.RED);
if((i+1)%2==0){tempX=opsX; y+=HEIGHT+V_SPACE;}
}
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent ev)
{System.exit(0);}
});
setLayout(null);
setSize(FRAME_WIDTH,FRAME_HEIGHT);
setVisible(true);
}
//////////////////////////////////
static String getFormattedText(double temp)
{
String resText=""+temp;
if(resText.lastIndexOf(".0")>0)
resText=resText.substring(0,resText.length()-2);
return resText;
}
////////////////////////////////////////
public static void main(String []args)
{
new MyCalculator("Calculator -Ravi");
}
}
/*******************************************/
class MyDigitButton extends Button implements ActionListener
{
MyCalculator cl;
//////////////////////////////////////////
MyDigitButton(int x,int y, int width,int height,String cap, MyCalculator clc)
{
super(cap);
setBounds(x,y,width,height);
this.cl=clc;
this.cl.add(this);
addActionListener(this);
}
////////////////////////////////////////////////
static boolean isInString(String s, char ch)
{
for(int i=0; i<s.length();i++) if(s.charAt(i)==ch) return true;
return false;
}
/////////////////////////////////////////////////
public void actionPerformed(ActionEvent ev)
{
String tempText=((MyDigitButton)ev.getSource()).getLabel();
if(tempText.equals("."))
{
if(cl.setClear)
{cl.displayLabel.setText("0.");cl.setClear=false;}
else if(!isInString(cl.displayLabel.getText(),'.'))
cl.displayLabel.setText(cl.displayLabel.getText()+".");
return;
}
int index=0;
try{
index=Integer.parseInt(tempText);
}catch(NumberFormatException e){return;}
if (index==0 && cl.displayLabel.getText().equals("0")) return;
if(cl.setClear)
{cl.displayLabel.setText(""+index);cl.setClear=false;}
else
cl.displayLabel.setText(cl.displayLabel.getText()+index);
}//actionPerformed
}//class defination
/********************************************/
class MyOperatorButton extends Button implements ActionListener
{
MyCalculator cl;
MyOperatorButton(int x,int y, int width,int height,String cap, MyCalculator clc)
{
super(cap);
setBounds(x,y,width,height);
this.cl=clc;
this.cl.add(this);
addActionListener(this);
}
///////////////////////
public void actionPerformed(ActionEvent ev)
{
String opText=((MyOperatorButton)ev.getSource()).getLabel();
cl.setClear=true;
double temp=Double.parseDouble(cl.displayLabel.getText());
if(opText.equals("1/x"))
{
try
{double tempd=1/(double)temp;
cl.displayLabel.setText(MyCalculator.getFormattedText(tempd));}
catch(ArithmeticException excp)
{cl.displayLabel.setText("Divide by 0.");}
return;
}
if(opText.equals("sqrt"))
{
try
{double tempd=Math.sqrt(temp);
cl.displayLabel.setText(MyCalculator.getFormattedText(tempd));}
catch(ArithmeticException excp)
{cl.displayLabel.setText("Divide by 0.");}
return;
}
if(!opText.equals("="))
{
cl.number=temp;
cl.op=opText.charAt(0);
return;
}
// process = button pressed
switch(cl.op)
{
case '+':
temp+=cl.number;break;
case '-':
temp=cl.number-temp;break;
case '*':
temp*=cl.number;break;
case '%':
try{temp=cl.number%temp;}
catch(ArithmeticException excp)
{cl.displayLabel.setText("Divide by 0."); return;}
break;
case '/':
try{temp=cl.number/temp;}
catch(ArithmeticException excp)
{cl.displayLabel.setText("Divide by 0."); return;}
break;
}//switch
cl.displayLabel.setText(MyCalculator.getFormattedText(temp));
//cl.number=temp;
}//actionPerformed
}//class
/****************************************/
class MyMemoryButton extends Button implements ActionListener
{
MyCalculator cl;
/////////////////////////////////
MyMemoryButton(int x,int y, int width,int height,String cap, MyCalculator clc)
{
super(cap);
setBounds(x,y,width,height);
this.cl=clc;
this.cl.add(this);
addActionListener(this);
}
////////////////////////////////////////////////
public void actionPerformed(ActionEvent ev)
{
char memop=((MyMemoryButton)ev.getSource()).getLabel().charAt(1);
cl.setClear=true;
double temp=Double.parseDouble(cl.displayLabel.getText());
switch(memop)
{
case 'C':
cl.memLabel.setText(" ");cl.memValue=0.0;break;
case 'R':
cl.displayLabel.setText(MyCalculator.getFormattedText(cl.memValue));break;
case 'S':
cl.memValue=0.0;
case '+':
cl.memValue+=Double.parseDouble(cl.displayLabel.getText());
if(cl.displayLabel.getText().equals("0") || cl.displayLabel.getText().equals("0.0") )
cl.memLabel.setText(" ");
else
cl.memLabel.setText("M");
break;
}//switch
}//actionPerformed
}//class
/*****************************************/
class MySpecialButton extends Button implements ActionListener
{
MyCalculator cl;
MySpecialButton(int x,int y, int width,int height,String cap, MyCalculator clc)
{
super(cap);
setBounds(x,y,width,height);
this.cl=clc;
this.cl.add(this);
addActionListener(this);
}
//////////////////////
static String backSpace(String s)
{
String Res="";
for(int i=0; i<s.length()-1; i++) Res+=s.charAt(i);
return Res;
}
//////////////////////////////////////////////////////////
public void actionPerformed(ActionEvent ev)
{
String opText=((MySpecialButton)ev.getSource()).getLabel();
//check for backspace button
if(opText.equals("Backspc"))
{
String tempText=backSpace(cl.displayLabel.getText());
if(tempText.equals(""))
cl.displayLabel.setText("0");
else
cl.displayLabel.setText(tempText);
return;
}
//check for "C" button i.e. Reset
if(opText.equals("C"))
{
cl.number=0.0; cl.op=' '; cl.memValue=0.0;
cl.memLabel.setText(" ");
}
//it must be CE button pressed
cl.displayLabel.setText("0");cl.setClear=true;
}//actionPerformed
}//class
Note:Just change Array as your required format
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