Como fazer multiplas leituras com um editor de texto?

[DarthVictor]

Preciso fazer uma calculadora, porêm só consigo atravez de uma "gambiarra"

Eu gostaria de fazer uma como a do Windows, com uma caixa de texto, porêm só consigo atravez de 3.

Alguém tem uma idéia de como fazer este tipo de leitura para funcionar com uma única caixa de texto?

Se quiserem ver minha "gambiarra" com 3 caixas, ela segue abaixo.

/*
 * Calc01View.java
 */

package calc01;

import org.jdesktop.application.Action;
import org.jdesktop.application.ResourceMap;
import org.jdesktop.application.SingleFrameApplication;
import org.jdesktop.application.FrameView;
import org.jdesktop.application.TaskMonitor;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;
import javax.swing.Icon;
import javax.swing.JDialog;
import javax.swing.JFrame;

/**
 * The application's main frame.
 */
public class Calc01View extends FrameView {

    String n1, n2;
    double num1, num2;

    public Calc01View(SingleFrameApplication app) {
        super(app);

        initComponents();

        // status bar initialization - message timeout, idle icon and busy animation, etc
        ResourceMap resourceMap = getResourceMap();
        int messageTimeout = resourceMap.getInteger("StatusBar.messageTimeout");
        messageTimer = new Timer(messageTimeout, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                statusMessageLabel.setText("");
            }
        });
        messageTimer.setRepeats(false);
        int busyAnimationRate = resourceMap.getInteger("StatusBar.busyAnimationRate");
        for (int i = 0; i < busyIcons.length; i++) {
            busyIcons[i] = resourceMap.getIcon("StatusBar.busyIcons[" + i + "]");
        }
        busyIconTimer = new Timer(busyAnimationRate, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                busyIconIndex = (busyIconIndex + 1) % busyIcons.length;
                statusAnimationLabel.setIcon(busyIcons[busyIconIndex]);
            }
        });
        idleIcon = resourceMap.getIcon("StatusBar.idleIcon");
        statusAnimationLabel.setIcon(idleIcon);
        progressBar.setVisible(false);

        // connecting action tasks to status bar via TaskMonitor
        TaskMonitor taskMonitor = new TaskMonitor(getApplication().getContext());
        taskMonitor.addPropertyChangeListener(new java.beans.PropertyChangeListener() {
            public void propertyChange(java.beans.PropertyChangeEvent evt) {
                String propertyName = evt.getPropertyName();
                if ("started".equals(propertyName)) {
                    if (!busyIconTimer.isRunning()) {
                        statusAnimationLabel.setIcon(busyIcons[0]);
                        busyIconIndex = 0;
                        busyIconTimer.start();
                    }
                    progressBar.setVisible(true);
                    progressBar.setIndeterminate(true);
                } else if ("done".equals(propertyName)) {
                    busyIconTimer.stop();
                    statusAnimationLabel.setIcon(idleIcon);
                    progressBar.setVisible(false);
                    progressBar.setValue(0);
                } else if ("message".equals(propertyName)) {
                    String text = (String)(evt.getNewValue());
                    statusMessageLabel.setText((text == null) ? "" : text);
                    messageTimer.restart();
                } else if ("progress".equals(propertyName)) {
                    int value = (Integer)(evt.getNewValue());
                    progressBar.setVisible(true);
                    progressBar.setIndeterminate(false);
                    progressBar.setValue(value);
                }
            }
        });
    }

    @Action
    public void showAboutBox() {
        if (aboutBox == null) {
            JFrame mainFrame = Calc01App.getApplication().getMainFrame();
            aboutBox = new Calc01AboutBox(mainFrame);
            aboutBox.setLocationRelativeTo(mainFrame);
        }
        Calc01App.getApplication().show(aboutBox);
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        mainPanel = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        jLabel3 = new javax.swing.JLabel();
        jTextField1 = new javax.swing.JTextField();
        jTextField2 = new javax.swing.JTextField();
        jTextField3 = new javax.swing.JTextField();
        jButton1 = new javax.swing.JButton();
        jButton2 = new javax.swing.JButton();
        jButton3 = new javax.swing.JButton();
        jButton4 = new javax.swing.JButton();
        menuBar = new javax.swing.JMenuBar();
        javax.swing.JMenu fileMenu = new javax.swing.JMenu();
        javax.swing.JMenuItem exitMenuItem = new javax.swing.JMenuItem();
        javax.swing.JMenu helpMenu = new javax.swing.JMenu();
        javax.swing.JMenuItem aboutMenuItem = new javax.swing.JMenuItem();
        statusPanel = new javax.swing.JPanel();
        javax.swing.JSeparator statusPanelSeparator = new javax.swing.JSeparator();
        statusMessageLabel = new javax.swing.JLabel();
        statusAnimationLabel = new javax.swing.JLabel();
        progressBar = new javax.swing.JProgressBar();

        mainPanel.setName("mainPanel"); // NOI18N

        org.jdesktop.application.ResourceMap resourceMap = org.jdesktop.application.Application.getInstance(calc01.Calc01App.class).getContext().getResourceMap(Calc01View.class);
        jLabel1.setText(resourceMap.getString("jLabel1.text")); // NOI18N
        jLabel1.setName("jLabel1"); // NOI18N

        jLabel2.setText(resourceMap.getString("jLabel2.text")); // NOI18N
        jLabel2.setName("jLabel2"); // NOI18N

        jLabel3.setText(resourceMap.getString("jLabel3.text")); // NOI18N
        jLabel3.setName("jLabel3"); // NOI18N

        jTextField1.setText(resourceMap.getString("jTextField1.text")); // NOI18N
        jTextField1.setName("jTextField1"); // NOI18N

        jTextField2.setText(resourceMap.getString("jTextField2.text")); // NOI18N
        jTextField2.setName("jTextField2"); // NOI18N

        jTextField3.setText(resourceMap.getString("jTextField3.text")); // NOI18N
        jTextField3.setName("jTextField3"); // NOI18N

        jButton1.setText(resourceMap.getString("jButton1.text")); // NOI18N
        jButton1.setName("jButton1"); // NOI18N
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jButton2.setText(resourceMap.getString("jButton2.text")); // NOI18N
        jButton2.setName("jButton2"); // NOI18N
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
            }
        });

        jButton3.setText(resourceMap.getString("jButton3.text")); // NOI18N
        jButton3.setName("jButton3"); // NOI18N
        jButton3.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton3ActionPerformed(evt);
            }
        });

        jButton4.setText(resourceMap.getString("jButton4.text")); // NOI18N
        jButton4.setName("jButton4"); // NOI18N
        jButton4.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton4ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout mainPanelLayout = new javax.swing.GroupLayout(mainPanel);
        mainPanel.setLayout(mainPanelLayout);
        mainPanelLayout.setHorizontalGroup(
            mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(mainPanelLayout.createSequentialGroup()
                .addGap(32, 32, 32)
                .addGroup(mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel1)
                    .addComponent(jLabel3)
                    .addGroup(mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                        .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 42, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(jLabel2)))
                .addGap(18, 18, 18)
                .addGroup(mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addGroup(mainPanelLayout.createSequentialGroup()
                        .addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 42, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(31, 31, 31)
                        .addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 42, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(18, 18, 18)
                        .addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 42, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addComponent(jTextField3)
                    .addComponent(jTextField2)
                    .addComponent(jTextField1))
                .addContainerGap(122, Short.MAX_VALUE))
        );
        mainPanelLayout.setVerticalGroup(
            mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(mainPanelLayout.createSequentialGroup()
                .addGap(21, 21, 21)
                .addGroup(mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel1)
                    .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(36, 36, 36)
                .addGroup(mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jButton1, javax.swing.GroupLayout.DEFAULT_SIZE, 39, Short.MAX_VALUE)
                    .addComponent(jButton3, javax.swing.GroupLayout.DEFAULT_SIZE, 39, Short.MAX_VALUE)
                    .addComponent(jButton4, javax.swing.GroupLayout.DEFAULT_SIZE, 39, Short.MAX_VALUE)
                    .addComponent(jButton2, javax.swing.GroupLayout.DEFAULT_SIZE, 39, Short.MAX_VALUE))
                .addGap(18, 18, 18)
                .addGroup(mainPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel3)
                    .addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(46, 46, 46))
        );

        menuBar.setName("menuBar"); // NOI18N

        fileMenu.setText(resourceMap.getString("fileMenu.text")); // NOI18N
        fileMenu.setName("fileMenu"); // NOI18N

        javax.swing.ActionMap actionMap = org.jdesktop.application.Application.getInstance(calc01.Calc01App.class).getContext().getActionMap(Calc01View.class, this);
        exitMenuItem.setAction(actionMap.get("quit")); // NOI18N
        exitMenuItem.setName("exitMenuItem"); // NOI18N
        fileMenu.add(exitMenuItem);

        menuBar.add(fileMenu);

        helpMenu.setText(resourceMap.getString("helpMenu.text")); // NOI18N
        helpMenu.setName("helpMenu"); // NOI18N

        aboutMenuItem.setAction(actionMap.get("showAboutBox")); // NOI18N
        aboutMenuItem.setName("aboutMenuItem"); // NOI18N
        helpMenu.add(aboutMenuItem);

        menuBar.add(helpMenu);

        statusPanel.setName("statusPanel"); // NOI18N

        statusPanelSeparator.setName("statusPanelSeparator"); // NOI18N

        statusMessageLabel.setName("statusMessageLabel"); // NOI18N

        statusAnimationLabel.setHorizontalAlignment(javax.swing.SwingConstants.LEFT);
        statusAnimationLabel.setName("statusAnimationLabel"); // NOI18N

        progressBar.setName("progressBar"); // NOI18N

        javax.swing.GroupLayout statusPanelLayout = new javax.swing.GroupLayout(statusPanel);
        statusPanel.setLayout(statusPanelLayout);
        statusPanelLayout.setHorizontalGroup(
            statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(statusPanelSeparator, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
            .addGroup(statusPanelLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(statusMessageLabel)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 376, Short.MAX_VALUE)
                .addComponent(statusAnimationLabel)
                .addContainerGap())
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, statusPanelLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(progressBar, javax.swing.GroupLayout.DEFAULT_SIZE, 376, Short.MAX_VALUE)
                .addContainerGap())
        );
        statusPanelLayout.setVerticalGroup(
            statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(statusPanelLayout.createSequentialGroup()
                .addComponent(statusPanelSeparator, javax.swing.GroupLayout.PREFERRED_SIZE, 2, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addGroup(statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(statusPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(statusMessageLabel)
                        .addComponent(statusAnimationLabel))
                    .addComponent(progressBar, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap())
        );

        setComponent(mainPanel);
        setMenuBar(menuBar);
        setStatusBar(statusPanel);
    }// </editor-fold>                        

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
n1 =   jTextField1.getText();
n2 = jTextField2.getText();
num1 = Double.parseDouble(n1);
num2= Double.parseDouble(n2);
jTextField3.setText(""+ (num1+num2));
    }                                        

    private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         
n1 =   jTextField1.getText();
n2 = jTextField2.getText();
num1 = Double.parseDouble(n1);
num2= Double.parseDouble(n2);
jTextField3.setText(""+ (num1-num2));        // TODO add your handling code here:
    }                                        

    private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                         
n1 =   jTextField1.getText();
n2 = jTextField2.getText();
num1 = Double.parseDouble(n1);
num2= Double.parseDouble(n2);
jTextField3.setText(""+ (num1/num2));        // TODO add your handling code here:
    }                                        

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
n1 =   jTextField1.getText();
n2 = jTextField2.getText();
num1 = Double.parseDouble(n1);
num2= Double.parseDouble(n2);
jTextField3.setText(""+ (num1*num2));        // TODO add your handling code here:
    }                                        

    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JButton jButton3;
    private javax.swing.JButton jButton4;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JTextField jTextField1;
    private javax.swing.JTextField jTextField2;
    private javax.swing.JTextField jTextField3;
    private javax.swing.JPanel mainPanel;
    private javax.swing.JMenuBar menuBar;
    private javax.swing.JProgressBar progressBar;
    private javax.swing.JLabel statusAnimationLabel;
    private javax.swing.JLabel statusMessageLabel;
    private javax.swing.JPanel statusPanel;
    // End of variables declaration                   

    private final Timer messageTimer;
    private final Timer busyIconTimer;
    private final Icon idleIcon;
    private final Icon[] busyIcons = new Icon[15];
    private int busyIconIndex = 0;

    private JDialog aboutBox;
}

/*
 * Calc01App.java
 */

package calc01;

import org.jdesktop.application.Application;
import org.jdesktop.application.SingleFrameApplication;

/**
 * The main class of the application.
 */
public class Calc01App extends SingleFrameApplication {

    /**
     * At startup create and show the main frame of the application.
     */
    @Override protected void startup() {
        show(new Calc01View(this));
    }

    /**
     * This method is to initialize the specified window by injecting resources.
     * Windows shown in our application come fully initialized from the GUI
     * builder, so this additional configuration is not needed.
     */
    @Override protected void configureWindow(java.awt.Window root) {
    }

    /**
     * A convenient static getter for the application instance.
     * @return the instance of Calc01App
     */
    public static Calc01App getApplication() {
        return Application.getInstance(Calc01App.class);
    }

    /**
     * Main method launching the application.
     */
    public static void main(String[] args) {
        launch(Calc01App.class, args);
    }
}

/*
 * Calc01AboutBox.java
 */

package calc01;

import org.jdesktop.application.Action;

public class Calc01AboutBox extends javax.swing.JDialog {

    public Calc01AboutBox(java.awt.Frame parent) {
        super(parent);
        initComponents();
        getRootPane().setDefaultButton(closeButton);
    }

    @Action public void closeAboutBox() {
        dispose();
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        closeButton = new javax.swing.JButton();
        javax.swing.JLabel appTitleLabel = new javax.swing.JLabel();
        javax.swing.JLabel versionLabel = new javax.swing.JLabel();
        javax.swing.JLabel appVersionLabel = new javax.swing.JLabel();
        javax.swing.JLabel appDescLabel = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
        org.jdesktop.application.ResourceMap resourceMap = org.jdesktop.application.Application.getInstance(calc01.Calc01App.class).getContext().getResourceMap(Calc01AboutBox.class);
        setTitle(resourceMap.getString("title")); // NOI18N
        setModal(true);
        setName("aboutBox"); // NOI18N
        setResizable(false);

        javax.swing.ActionMap actionMap = org.jdesktop.application.Application.getInstance(calc01.Calc01App.class).getContext().getActionMap(Calc01AboutBox.class, this);
        closeButton.setAction(actionMap.get("closeAboutBox")); // NOI18N
        closeButton.setName("closeButton"); // NOI18N

        appTitleLabel.setFont(appTitleLabel.getFont().deriveFont(appTitleLabel.getFont().getStyle() | java.awt.Font.BOLD, appTitleLabel.getFont().getSize()+4));
        appTitleLabel.setText(resourceMap.getString("Application.title")); // NOI18N
        appTitleLabel.setName("appTitleLabel"); // NOI18N

        versionLabel.setFont(versionLabel.getFont().deriveFont(versionLabel.getFont().getStyle() | java.awt.Font.BOLD));
        versionLabel.setText(resourceMap.getString("versionLabel.text")); // NOI18N
        versionLabel.setName("versionLabel"); // NOI18N

        appVersionLabel.setText(resourceMap.getString("Application.version")); // NOI18N
        appVersionLabel.setName("appVersionLabel"); // NOI18N

        appDescLabel.setText(resourceMap.getString("appDescLabel.text")); // NOI18N
        appDescLabel.setName("appDescLabel"); // NOI18N

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addGap(148, 148, 148)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
                                .addComponent(versionLabel)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(appVersionLabel)
                                .addGap(181, 181, 181))
                            .addComponent(appTitleLabel, javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(appDescLabel, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 315, Short.MAX_VALUE)))
                    .addGroup(layout.createSequentialGroup()
                        .addGap(178, 178, 178)
                        .addComponent(closeButton)))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(appTitleLabel)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(appDescLabel, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(versionLabel)
                    .addComponent(appVersionLabel))
                .addGap(32, 32, 32)
                .addComponent(closeButton)
                .addContainerGap(34, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        
    
    // Variables declaration - do not modify                     
    private javax.swing.JButton closeButton;
    // End of variables declaration                   
    
}