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Thread: Another Calculator Problem

  1. #1
    Member
    Join Date
    Feb 2010
    Posts
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    Thanked 1 Time in 1 Post

    Default Another Calculator Problem

    EDIT: Nevermind, solved it.


    Hi guys, another problem with my calculator program has arose. I have added a button which will make the input positive or negative depending on what it is (I have also added many other things). To make something positive from negative, I delete the first character (assuming it should be a -). The problem is, sometimes it deletes the first character when it is suppose to put a negative in front of the input. It seems random when it does this. For example, if you click the buttons in this order: 3, +/-, +, 6, +/- the 6 will be deleted instead of getting a - sign in front of it.

    Here is a runnable code:
    package JFrameClaculator;
     
    import java.awt.Color;
    import java.awt.Container;
    import java.awt.Dimension;
    import java.awt.Font;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.awt.event.KeyEvent;
     
    import javax.swing.AbstractButton;
    import javax.swing.ImageIcon;
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JOptionPane;
    import javax.swing.JPanel;
    import javax.swing.JScrollPane;
    import javax.swing.JTextField;
    import javax.swing.SpringLayout;
    import javax.swing.UIManager;
    import javax.swing.UnsupportedLookAndFeelException;
     
    import layout.testing2;
     
    public class Calculator extends JPanel implements ActionListener{
     
    	public static void main(String[] args) {
            javax.swing.SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    createAndShowGUI();
                }
            });
        }
    	static String textop;
    	static String textop1;
    	static int x;
    	static int x1;
    	static int x2;
    	static int x3;
    	static int y = 1;
    	public static final char LF = '\n';
    	public static final char CR = '\r';
    	static JTextField textField;
    	protected static JButton b1;
    	protected static JButton b2;
    	protected static JButton b3;
    	protected static JButton b4;
    	protected static JButton b5;
    	protected static JButton b6;
    	protected static JButton b7;
    	protected static JButton b8;
    	protected static JButton b9;
    	protected static JButton b10;
    	protected static JButton b11;
    	protected static JButton b12;
    	protected static JButton b13;
    	protected static JButton b14;
    	protected static JButton b15;
    	protected static JButton b16;
    	protected static JButton b17;
    	protected static JButton b18;
    	private static void createAndShowGUI() {
    		JFrame frame = new JFrame("Calculator v2.1");
    		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    		Container contentPane = frame.getContentPane();
            SpringLayout layout = new SpringLayout();
            contentPane.setLayout(layout);
            String lookAndFeel = "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";
            try {
    			UIManager.setLookAndFeel(lookAndFeel);
    		} catch (ClassNotFoundException e) {
    			String ErrorMessage = "Error: "+e; 
    			JScrollPane scrollPane = new JScrollPane(new JLabel(ErrorMessage));  
    			scrollPane.setPreferredSize(new Dimension(100, 50));  
    			Object message = scrollPane;  
    			JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);      
    			try {
    				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    			} catch (ClassNotFoundException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (InstantiationException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (IllegalAccessException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (UnsupportedLookAndFeelException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			}
    		} catch (InstantiationException e) {
    			String ErrorMessage = "Error: "+e; 
    			JScrollPane scrollPane = new JScrollPane(new JLabel(ErrorMessage));  
    			scrollPane.setPreferredSize(new Dimension(100, 50));  
    			Object message = scrollPane;  
    			JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);      
    			try {
    				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    			} catch (ClassNotFoundException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (InstantiationException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (IllegalAccessException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (UnsupportedLookAndFeelException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			}
    		} catch (IllegalAccessException e) {
    			String ErrorMessage = "Error: "+e; 
    			JScrollPane scrollPane = new JScrollPane(new JLabel(ErrorMessage));  
    			scrollPane.setPreferredSize(new Dimension(100, 50));  
    			Object message = scrollPane;  
    			JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);      
    			try {
    				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    			} catch (ClassNotFoundException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (InstantiationException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (IllegalAccessException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (UnsupportedLookAndFeelException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			}
    		} catch (UnsupportedLookAndFeelException e) {
    			String ErrorMessage = "Error: "+e; 
    			JScrollPane scrollPane = new JScrollPane(new JLabel(ErrorMessage));  
    			scrollPane.setPreferredSize(new Dimension(100, 50));  
    			Object message = scrollPane;  
    			JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);      
    			try {
    				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    			} catch (ClassNotFoundException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (InstantiationException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (IllegalAccessException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			} catch (UnsupportedLookAndFeelException e1) {
    				String ErrorMessage1 = "Error: "+e1; 
    				JScrollPane scrollPane1 = new JScrollPane(new JLabel(ErrorMessage1));  
    				scrollPane1.setPreferredSize(new Dimension(100, 50));  
    				Object message1 = scrollPane1;  
    				JOptionPane.showMessageDialog(null, message1, "Error", JOptionPane.ERROR_MESSAGE);      
    				System.exit(0);
    			}
    		}
            textField = new JTextField("", 23);
            textField.setEditable(false);
            textField.setBackground(Color.white);
            Font f = new Font("+/-", Font.PLAIN, 11);
            b1 = new JButton("1");
            b1.setVerticalTextPosition(AbstractButton.CENTER);
            b1.setHorizontalTextPosition(AbstractButton.LEADING);
            b1.addActionListener(new Calculator());
            b1.setActionCommand("1");
            b1.setForeground(Color.blue);
            b2 = new JButton("2");
            b2.setVerticalTextPosition(AbstractButton.CENTER);
            b2.setHorizontalTextPosition(AbstractButton.LEADING);
            b2.addActionListener(new Calculator());
            b2.setActionCommand("2");
            b2.setForeground(Color.blue);
            b3 = new JButton("3");
            b3.setVerticalTextPosition(AbstractButton.CENTER);
            b3.setHorizontalTextPosition(AbstractButton.LEADING);
            b3.addActionListener(new Calculator());
            b3.setActionCommand("3");
            b3.setForeground(Color.blue);
            b4 = new JButton("4");
            b4.setVerticalTextPosition(AbstractButton.CENTER);
            b4.setHorizontalTextPosition(AbstractButton.LEADING);
            b4.addActionListener(new Calculator());
            b4.setActionCommand("4");
            b4.setForeground(Color.blue);
            b5 = new JButton("5");
            b5.setVerticalTextPosition(AbstractButton.CENTER);
            b5.setHorizontalTextPosition(AbstractButton.LEADING);
            b5.addActionListener(new Calculator());
            b5.setActionCommand("5");
            b5.setForeground(Color.blue);
            b6 = new JButton("6");
            b6.setVerticalTextPosition(AbstractButton.CENTER);
            b6.setHorizontalTextPosition(AbstractButton.LEADING);
            b6.addActionListener(new Calculator());
            b6.setActionCommand("6");
            b6.setForeground(Color.blue);
            b7 = new JButton("7");
            b7.setVerticalTextPosition(AbstractButton.CENTER);
            b7.setHorizontalTextPosition(AbstractButton.LEADING);
            b7.addActionListener(new Calculator());
            b7.setActionCommand("7");
            b7.setForeground(Color.blue);
            b8 = new JButton("8");
            b8.setVerticalTextPosition(AbstractButton.CENTER);
            b8.setHorizontalTextPosition(AbstractButton.LEADING);
            b8.addActionListener(new Calculator());
            b8.setActionCommand("8");
            b8.setForeground(Color.blue);
            b9 = new JButton("9");
            b9.setVerticalTextPosition(AbstractButton.CENTER);
            b9.setHorizontalTextPosition(AbstractButton.LEADING);
            b9.addActionListener(new Calculator());
            b9.setActionCommand("9");
            b9.setForeground(Color.blue);
            b10 = new JButton("0");
            b10.setVerticalTextPosition(AbstractButton.CENTER);
            b10.setHorizontalTextPosition(AbstractButton.LEADING);
            b10.addActionListener(new Calculator());
            b10.setActionCommand("0");
            b10.setForeground(Color.blue);
            b11 = new JButton("+");
            b11.setVerticalTextPosition(AbstractButton.CENTER);
            b11.setHorizontalTextPosition(AbstractButton.LEADING);
            b11.addActionListener(new Calculator());
            b11.setActionCommand("+");
            b11.setForeground(Color.red);
            b12 = new JButton("-");
            b12.setVerticalTextPosition(AbstractButton.CENTER);
            b12.setHorizontalTextPosition(AbstractButton.LEADING);
            b12.addActionListener(new Calculator());
            b12.setActionCommand("-");
            b12.setForeground(Color.red);
            b13 = new JButton("x");
            b13.setVerticalTextPosition(AbstractButton.CENTER);
            b13.setHorizontalTextPosition(AbstractButton.LEADING);
            b13.addActionListener(new Calculator());
            b13.setActionCommand("x");
            b13.setForeground(Color.red);
            b14 = new JButton("/");
            b14.setVerticalTextPosition(AbstractButton.CENTER);
            b14.setHorizontalTextPosition(AbstractButton.LEADING);
            b14.addActionListener(new Calculator());
            b14.setActionCommand("/");
            b14.setForeground(Color.red);
            b15 = new JButton("C");
            b15.setVerticalTextPosition(AbstractButton.CENTER);
            b15.setHorizontalTextPosition(AbstractButton.LEADING);
            b15.addActionListener(new Calculator());
            b15.setActionCommand("C");
            b15.setForeground(Color.red);
            b16 = new JButton("=");
            b16.setVerticalTextPosition(AbstractButton.CENTER);
            b16.setHorizontalTextPosition(AbstractButton.LEADING);
            b16.addActionListener(new Calculator());
            b16.setActionCommand("=");
            b16.setForeground(Color.red);
            b17 = new JButton(".");
            b17.setVerticalTextPosition(AbstractButton.CENTER);
            b17.setHorizontalTextPosition(AbstractButton.LEADING);
            b17.addActionListener(new Calculator());
            b17.setActionCommand(".");
            b17.setForeground(Color.blue);
            b18 = new JButton("+/-");
            b18.setVerticalTextPosition(AbstractButton.CENTER);
            b18.setHorizontalTextPosition(AbstractButton.LEADING);
            b18.addActionListener(new Calculator());
            b18.setActionCommand("+/-");
            b18.setFont(f);
            b18.setForeground(Color.blue);
            contentPane.setBackground(new Color(240, 240, 240));
            contentPane.add(textField);
            contentPane.add(b1);
            contentPane.add(b2);
            contentPane.add(b3);
            contentPane.add(b4);
            contentPane.add(b5);
            contentPane.add(b6);
            contentPane.add(b7);
            contentPane.add(b8);
            contentPane.add(b9);
            contentPane.add(b10);
            contentPane.add(b11);
            contentPane.add(b12);
            contentPane.add(b13);
            contentPane.add(b14);
            contentPane.add(b15);
            contentPane.add(b16);
            contentPane.add(b17);
            contentPane.add(b18);
            b1.setPreferredSize(new Dimension(45, 30));
            b2.setPreferredSize(new Dimension(45, 30));
            b3.setPreferredSize(new Dimension(45, 30));
            b4.setPreferredSize(new Dimension(45, 30));
            b5.setPreferredSize(new Dimension(45, 30));
            b6.setPreferredSize(new Dimension(45, 30));
            b7.setPreferredSize(new Dimension(45, 30));
            b8.setPreferredSize(new Dimension(45, 30));
            b9.setPreferredSize(new Dimension(45, 30));
            b10.setPreferredSize(new Dimension(45, 30));
            b11.setPreferredSize(new Dimension(45, 30));
            b12.setPreferredSize(new Dimension(45, 30));
            b13.setPreferredSize(new Dimension(45, 30));
            b14.setPreferredSize(new Dimension(45, 30));
            b15.setPreferredSize(new Dimension(45, 30));
            b16.setPreferredSize(new Dimension(145, 30));
            b17.setPreferredSize(new Dimension(45, 30));
            b18.setPreferredSize(new Dimension(45, 30));
            //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, textField,
                                 30,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, textField,
                                 10,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b1,
                                 30,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b1,
                                 110,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
            //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b2,
                                 80,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b2,
                                 110,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b3,
                                 130,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b3,
                                 110,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b4,
                                 30,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b4,
                                 75,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b5,
                                 80,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b5,
                                 75,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b6,
                                 130,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b6,
                                 75,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b7,
                                 30,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b7,
                                 40,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b8,
                                 80,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b8,
                                 40,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b9,
                                 130,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b9,
                                 40,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b10,
                                 30,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b10,
                                 145,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b11,
                                 180,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b11,
                                 40,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b12,
                                 180,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b12,
                                 75,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b13,
                                 180,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b13,
                                 110,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b14,
                                 180,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b14,
                                 145,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b15,
                                 130,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b15,
                                 145,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b16,
                                 30,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b16,
                                 180,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b17,
                                 80,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b17,
                                 145,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
          //SET HEIGHT/WIDTH
            layout.putConstraint(SpringLayout.WEST, b18,
                                 180,
                                 SpringLayout.WEST, contentPane);
            layout.putConstraint(SpringLayout.NORTH, b18,
                                 180,
                                 SpringLayout.NORTH, contentPane);
            //END SET HEIGHT/WIDTH
            frame.pack();
            frame.setSize(263, 259);
            frame.setLocation(20, 20);
            frame.setVisible(true);
            frame.setResizable(false);
    	}
    	public void actionPerformed(ActionEvent e) {
    		if (e.getSource()==b1) {
    			String text = textField.getText();
    			textField.setText(text+"1");
    		}
    		if (e.getSource()==b2) {
    			String text = textField.getText();
    			textField.setText(text+"2");
    		}
    		if (e.getSource()==b3) {
    			String text = textField.getText();
    			textField.setText(text+"3");
    		}
    		if (e.getSource()==b4) {
    			String text = textField.getText();
    			textField.setText(text+"4");
    		}
    		if (e.getSource()==b5) {
    			String text = textField.getText();
    			textField.setText(text+"5");
    		}
    		if (e.getSource()==b6) {
    			String text = textField.getText();
    			textField.setText(text+"6");
    		}
    		if (e.getSource()==b7) {
    			String text = textField.getText();
    			textField.setText(text+"7");
    		}
    		if (e.getSource()==b8) {
    			String text = textField.getText();
    			textField.setText(text+"8");
    		}
    		if (e.getSource()==b9) {
    			String text = textField.getText();
    			textField.setText(text+"9");
    		}
    		if (e.getSource()==b10) {
    			String text = textField.getText();
    			textField.setText(text+"0");
    		}
    		if (e.getSource()==b11) {
    			textop = textField.getText();
    			textField.setText("");
    			x = x + 1;
    		}
    		if (e.getSource()==b12) {
    			textop = textField.getText();
    			textField.setText("");
    			x1 = x1 + 1;
    		}
    		if (e.getSource()==b13) {
    			textop = textField.getText();
    			textField.setText("");
    			x2 = x2 + 1;
    		}
    		if (e.getSource()==b14) {
    			textop = textField.getText();
    			textField.setText("");
    			x3 = x3 + 1;
    		}
    		if (e.getSource()==b15) {
    			String str = textField.getText();
    			if (str == null) {
     
    		      }
    		      int strLen = str.length();
    		      if(strLen != 0){
    		      if (strLen < 2) {
    		          textField.setText("");
    		      }
    		      int lastIdx = strLen - 1;
    		      String ret = str.substring(0, lastIdx);
    		      char last = str.charAt(lastIdx);
    		      if (last == LF) {
    		          if (ret.charAt(lastIdx - 1) == CR) {
    		              textField.setText(ret.substring(0, lastIdx - 1));
    		          }
    		      }
    		      textField.setText(ret);
    			}
    		}
    		if (e.getSource()==b16) {
    			try{
    			if(x % 2 != 0)
    			{
    				textop1 = textField.getText();
    				float op = Float.valueOf(textop).floatValue();
    				float op1 = Float.valueOf(textop1).floatValue();
    				float opFinal = op+op1;
    				String Final = Float.toString(opFinal);
    				textField.setText(Final);
    				x = x + 1;
    			}
    			if(x1 % 2 != 0)
    			{
    				textop1 = textField.getText();
    				float op = Float.valueOf(textop).floatValue();
    				float op1 = Float.valueOf(textop1).floatValue();
    				float opFinal = op-op1;
    				String Final = Float.toString(opFinal);
    				textField.setText(Final);
    				x1 = x1 + 1;
    			}
    			if(x2 % 2 != 0)
    			{
    				textop1 = textField.getText();
    				float op = Float.valueOf(textop).floatValue();
    				float op1 = Float.valueOf(textop1).floatValue();
    				float opFinal = op*op1;
    				String Final = Float.toString(opFinal);
    				textField.setText(Final);
    				x2 = x2 + 1;
    			}
    			if(x3 % 2 != 0)
    			{
    				textop1 = textField.getText();
    				float op = Float.valueOf(textop).floatValue();
    				float op1 = Float.valueOf(textop1).floatValue();
    				float opFinal = op/op1;
    				String Final = Float.toString(opFinal);
    				textField.setText(Final);
    				x3 = x3 + 1;
    			}
    			else
    			{
     
    			}
    			}catch(Exception e1){
    				String ErrorMessage = "Error: "+e1; 
    				JScrollPane scrollPane = new JScrollPane(new JLabel(ErrorMessage));  
    				scrollPane.setPreferredSize(new Dimension(100, 50));  
    				Object message = scrollPane;  
    				JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);      
    				textField.setText("");
    				x = 0;
    				x1 = 0;
    				x2 = 0;
    				x3 = 0;
    				y = 1;
    			}
    		}
    		if (e.getSource()==b17) {
    			String text = textField.getText();
    			textField.setText(text+".");
    		}
    		if (e.getSource()==b18) {
    			try{
    			if(y % 2 != 0)
    			{
    				String text = textField.getText();
    				textField.setText("-"+text);
    				y = y + 1;
    			}
    			else if(y % 2 == 0)
    			{
    				String text = textField.getText();
    				int pos = text.length()-text.length(); 
    		        String newValue  = text.substring(0,pos) + text.substring(pos+1);
    		        textField.setText(newValue);
    		        y = y + 1;
    			}
    			}catch(Exception e2)
    			{
    				String ErrorMessage = "Error: "+e2; 
    				JScrollPane scrollPane = new JScrollPane(new JLabel(ErrorMessage));  
    				scrollPane.setPreferredSize(new Dimension(100, 50));  
    				Object message = scrollPane;  
    				JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);      
    				textField.setText("");
    				x = 0;
    				x1 = 0;
    				x2 = 0;
    				x3 = 0;
    				y = 1;
    			}
    		}
    	}
     
    }

    Here is what I think the relevant code is:
    //y starts out as 1
    if (e.getSource()==b18) {
    			try{
    			if(y % 2 != 0)
    			{
    				String text = textField.getText();
    				textField.setText("-"+text);
    				y = y + 1;
    			}
    			else if(y % 2 == 0)
    			{
    				String text = textField.getText();
    				int pos = text.length()-text.length(); 
    		        String newValue  = text.substring(0,pos) + text.substring(pos+1);
    		        textField.setText(newValue);
    		        y = y + 1;
    			}
    			}catch(Exception e2)
    			{
    				String ErrorMessage = "Error: "+e2; 
    				JScrollPane scrollPane = new JScrollPane(new JLabel(ErrorMessage));  
    				scrollPane.setPreferredSize(new Dimension(100, 50));  
    				Object message = scrollPane;  
    				JOptionPane.showMessageDialog(null, message, "Error", JOptionPane.ERROR_MESSAGE);      
    				textField.setText("");
    				x = 0;
    				x1 = 0;
    				x2 = 0;
    				x3 = 0;
    				y = 1;
    			}
    Last edited by The_Mexican; December 4th, 2010 at 06:14 PM.


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