I've had enough. I just don't get what's wrong at all.
I coded a basic calculator program, and it compiled correctly, no exceptions thingy, sooo... it's probably my mistake --- nothing appears on the calculator's GUI. It's a blank window with just the title. And when executing programs like this, shouldn't something be happening in the command prompt before the program pops out (well, that's what happened in my previous not-so-good-yet-working-calculator)?
*** Note: I am actually very embarassed to even post this thing since I haven't checked on anything yet, like if the program does what it's supposed to >////<. Ugh.
Here it goes:
//Revised Calculator (I had previously made one but not-so-efficient)
//Made by Some Inexperience Wanna-Be Programmer
//My apologies, really.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class MyCalculator extends JFrame
{
private JLabel inputL, resultL;
private JTextField inputTF, resultTF;
private JButton buttons [] = new JButton[17];
private JPanel mainPane, editablePane, bottomPane;
//Handler for all buttons
private Handler bHandler;
private static final int WIDTH = 250;
private static final int HEIGHT = 350;
int i=0; // just a counter since I ought to use loops later
public MyCalculator()
{
//Create panels
mainPane = new JPanel();
editablePane = new JPanel();
bottomPane = new JPanel();
//Create the two labels
inputL = new JLabel ("Input : ", SwingConstants.RIGHT);
resultL = new JLabel ("Result: ", SwingConstants.RIGHT);
//Create two textfields
inputTF = new JTextField(10);
inputTF.setEditable(false);
resultTF = new JTextField(10);
resultTF.setEditable(false);
resultTF.setText("0.0");
inputTF.setText("0.0");
//Register event handlers
bHandler = new Handler();
//Create number buttons
for (int i = 0; i <=9; i++)
{
buttons[i] = new JButton (Integer.toString(i));
buttons[i].addActionListener(bHandler);
}
//Create functional buttons
buttons[10] = new JButton("."); // decimal button
buttons[11] = new JButton("+"); // addition button
buttons[12] = new JButton("-"); // subtraction button
buttons[13] = new JButton("*"); // multiplication button
buttons[14] = new JButton("/"); // division button
buttons[15] = new JButton("="); // equals button
buttons[16] = new JButton("C"); // clear button
//Set title of the window
setTitle("Simple Calculator");
//Made many JPanels, thinking I'll insert a panel in the "parent" panel, hopefully to get a more organized look
//There could really be something wrong here x______x
mainPane.setLayout(new GridLayout(2,1));
editablePane.setLayout(new GridLayout(2,2));
editablePane.add(inputL);
editablePane.add(inputTF);
editablePane.add(resultL);
editablePane.add(resultTF);
mainPane.add(editablePane);
bottomPane.setLayout(new GridLayout(1,2));
editablePane.setLayout(new GridLayout(4,3));
for (i=7; i<10; i++)
editablePane.add(buttons[i]);
for (i=4; i<7; i++)
editablePane.add(buttons[i]);
for (i=1; i<4; i++)
editablePane.add(buttons[i]);
editablePane.add(buttons[0]);
editablePane.add(buttons[10]);
bottomPane.add(editablePane);
editablePane.setLayout(new GridLayout(4,2));
for (i=11; i<17; i++)
editablePane.add(buttons[i]);
bottomPane.add(editablePane);
mainPane.add(bottomPane);
//Set the size of the window and display it
setSize(WIDTH,HEIGHT);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public class Handler implements ActionListener
{
double result = 0.0;
String displayedNum = "0.0";
double storedNum1 = 0.0;
double storedNum2 = 0.0;
String operation = null;
boolean contOperation = false;
public void assign (String number)
{
//this one here basically replaces the original text (which is 0.0) with the entered number
// in the input text field when the first number clicked on.
if ((inputTF.getText()).equals("0.0"))
inputTF.setText(number);
else
{
//this allows the concatenation of numbers when pressed
displayedNum = inputTF.getText();
inputTF.setText(displayedNum + number);
}
}
//I'm still unsure of this method, you know how I can't check the program since nothing comes out?
//I plan to use this method to check for, obviously, if the user has finished an equation and
//would still want to continue
//i.e. 8+8=16... is entered by a user and he/she presses the subtract button and enters the number 9
//16 would then be stored as the first number and 9 as the second number: 16-9
public void checkContinuousOperation (boolean continuedOperation)
{
if (continuedOperation == false)
{
storedNum1 = Double.parseDouble(inputTF.getText());
displayedNum = "";
inputTF.setText(""+displayedNum);
}
else
{
storedNum1 = Double.parseDouble(resultTF.getText());
displayedNum = "";
inputTF.setText(""+displayedNum);
}
}
public void actionPerformed(ActionEvent e)
{
Object source = e.getSource(); //gets the source of the event
// this ladderized if-else if checks which of the buttons is clicked
// the assign method basically handles concatenating the numbers together and displays 'em
for (i=0; i<10; i++)
{
if (source == buttons[i])
assign(Integer.toString(i));
}
if (source == buttons[10])
assign(".");
else if (source == buttons[11])
{
checkContinuousOperation(true);
operation = "add";
}
else if (source == buttons[12])
{
checkContinuousOperation(true);
operation = "sub";
}
else if (source == buttons[13])
{
checkContinuousOperation(true);
operation = "mult";
}
else if (source == buttons[14])
{
checkContinuousOperation(true);
operation = "div";
}
//checks if the "=" button is pressed
//performs calculations and prints result
//after showing the result, second number is to be reset-ed to 0
//BTW, I hadn't really placed what it's supposed to do if the equal button is pressed first
else if (source == buttons[15])
{
storedNum2 = Double.parseDouble(inputTF.getText());
if (operation == "add")
{
result = storedNum1 + storedNum2;
resultTF.setText("" + result);
storedNum2 = 0;
}
else if (operation == "sub")
{
result = storedNum1 - storedNum2;
resultTF.setText("" + result);
storedNum2 = 0;
}
else if (operation == "mult")
{
result = storedNum1 * storedNum2;
resultTF.setText("" + result);
storedNum2 = 0;
}
else if (operation == "div")
{
result = storedNum1 / storedNum2;
resultTF.setText("" + result);
storedNum2 = 0;
}
}
//Clear button
else if (source == buttons[16])
{
storedNum1 = 0;
storedNum2 = 0;
resultTF.setText("0.0");
inputTF.setText("0.0");
contOperation = false;
}
}
}
public static void main(String [] args)
{
MyCalculator calculatorObject = new MyCalculator();
}
}
I know it's still a lil' messed up but what matters to me right now is that I get it to appear... 200+ lines of code for a blank window makes me feel reaaaaally upset. Nope, it's not homework. I previously did this (that was my homework but that calculator has a messy interface and would not work with changing continuous operations... like if you press 8+7-3... it will result in random numbers, though with continuous same operations it would work fine). That one ran. I think their main difference is with the new method, checkContinuousOperation, added and oh... I used Container for that one, not JPanel, which I'm not familiar with at all yet. I'm still weak with Java, beginner level. And if there's anything else I need to work on, please do tell. Thank you!
