Name: skT45625			Date: 04/19/2000


java version "1.3.0rc2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0rc2-Y)
Java HotSpot(TM) Client VM (build 1.3.0rc2-Y, mixed mode)

I want to validate a JTextField (Number), so I put a FocusListener on it. If I
press the Dummy-Button, the focusLost-method starts running and while the
focusLost-Method is running the actionPerformed-Method starts.
This happens only sometimes, so please test it often.

Here is the code:
// @(#)EventProblem.java
// If you Insert into the first Textfield an a and then click on the Button
// first the focusLost-method starts and then (the focusLost-Methods isn't
// finished!) the actionPerformed-method starts. The behaviour happens only
sometimes.
//
// (C) 2000 PPI Financial Systems
//
// Manifest EventManifest.txt
/*
Main-Class: EventProblem
Implementation-Vendor: "PPI Financial Systems"
*/
//
// jar -cfm Event.jar EventManifest.txt EventProblem*
//


import javax.swing.*;
import javax.swing.text.JTextComponent;
import java.awt.*;
import java.awt.event.*;

public class EventProblem
    extends JFrame
    implements FocusListener, ActionListener {

    //Constants
    private final static String NUMBER_LB = "Nummer: ";
    private final static String NUMBER_CB = "Nummer: ";
    private final static String TEXT_LB = "Text: ";
    private final static String DUMMY_BT = "Dummy-Button";
    private final static String DUMMY_TF = "Dummy-Textfield";

    private final static String[] CB_VALUES = {"-1","0","1", "a"};

    //Some static variables and methods for trace.
    private static int indent = 0;

    private static void traceEnter(String method) {

        for (int i = 0; i < indent; i++) {
            System.out.print(" | ");
        }
        System.out.println("> "+method);
        indent++;
    }

    private static void traceLeave(String method) {
        indent--;

        for (int i = 0; i < indent; i++) {
            System.out.print(" | ");
        }
        System.out.println("< "+method);
    }

    private static void tracePut(String txt) {
        for (int i = 0; i < indent; i++) {
            System.out.print(" | ");
        }
        System.out.println(txt);
    }


    //Variables
    /** NumberTextfield */
    private JTextField numberTF;
    final private JComboBox  numberCB;

    /** TextTextField */
    private JTextField textTF;

    /** DUMMYTextfield */
    private JTextField dummyTF;

    /** DUMMY-Button */
    private JButton dummyBT;


    //Constructor

    public EventProblem()  {
        super("2Events - JRE-Version "+ System.getProperty("java.version"));


        // Instanziieren der Komponenten
        numberTF = new JTextField(5);
        numberTF.setActionCommand(NUMBER_LB);

        numberCB = new JComboBox(CB_VALUES);
        numberCB.setActionCommand(NUMBER_CB + "CB");
        numberCB.setEditable(true);

        textTF = new JTextField(1);
        textTF.setActionCommand(TEXT_LB);
        textTF.setEditable(false);

        dummyBT = new JButton(DUMMY_BT);
        dummyBT.setActionCommand(DUMMY_BT);

        dummyTF = new JTextField(5);
        dummyTF.setActionCommand(DUMMY_TF);


        getContentPane().setLayout(new GridLayout(4,2,10,15));

        getContentPane().add(new JLabel(NUMBER_LB));
        getContentPane().add(numberTF);
        getContentPane().add(new JLabel(NUMBER_CB));
        getContentPane().add(numberCB);
        getContentPane().add(new JLabel(TEXT_LB));
        getContentPane().add(textTF);
        getContentPane().add(dummyBT);
        getContentPane().add(dummyTF);

        //Set focus-order
        numberTF.setNextFocusableComponent(numberCB);
        numberCB.setNextFocusableComponent(dummyBT);
        dummyBT.setNextFocusableComponent(dummyTF);
        dummyTF.setNextFocusableComponent(numberTF);

        dummyBT.addActionListener(this);
        numberTF.addFocusListener(this);

        this.pack();
        this.setLocation(100,100);
        this.setVisible(true);
    }

    //main-method
    public static void main(String[] args) {
        new EventProblem();
    }

    //FocusListener-Methods
    public void focusGained (FocusEvent fE) {
    }

    public void focusLost (FocusEvent fE) {
        String strVal = "";
        double doubleVal = 0;

        traceEnter("focusLost");
        tracePut("temporary = " + fE.isTemporary());
        if (!fE.isTemporary()) {
            if (fE.getSource().equals(numberTF)) {
                try {
                    String txt;

                    strVal = numberTF.getText();
                    if (!strVal.equals("")) {
                        doubleVal = Double.parseDouble(strVal);
                    }

                    if (doubleVal < 0) {
                        txt = "f-f";
                    } else if (doubleVal > 0) {
                        txt = "f+f";
                    } else {
                        txt = "f f";
                    }
                    textTF.setText(txt);

                } catch (Exception dwE) {
                    //dwE.printStackTrace();
                    JOptionPane.showMessageDialog(this,
"FocusLost:\n>"+strVal+"< is not a number!",
                        "Exception", JOptionPane.ERROR_MESSAGE);
                    SwingUtilities.invokeLater(
                        new Runnable() {
                            public void run() {
                                numberTF.requestFocus();
                                numberTF.selectAll();
                            }
                        }
                        );
                }
            }
        }

        traceLeave("focusLost");
    }

    //ActionListener-Methods
    public void actionPerformed(ActionEvent aE) {
        String strVal = "";
        double doubleVal = 0;

        traceEnter("actionPerformed");
        //tracePut(aE.getSource().toString());
        //tracePut(aE.getActionCommand());
        if (aE.getActionCommand().equals(DUMMY_BT)) {
            try {
                String txt;

                strVal = numberTF.getText();
                if (!strVal.equals("")) {
                    doubleVal = Double.parseDouble(strVal);
                }

                if (doubleVal < 0) {
                    txt = "a-a";
                } else if (doubleVal > 0) {
                    txt = "a+a";
                } else {
                    txt = "a a";
                }
                textTF.setText(txt);

            } catch (Exception dwE) {
                //dwE.printStackTrace();
                JOptionPane.showMessageDialog(this,
"ActionPerformed:\n>"+strVal+"< is not a number!",
                    "Exception", JOptionPane.ERROR_MESSAGE);
                SwingUtilities.invokeLater(
                    new Runnable() {
                        public void run() {
                            numberTF.requestFocus();
                            numberTF.selectAll();
                        }
                    }
                    );
            }
        }
        traceLeave("actionPerformed");
    }
}
(Review ID: 103890) 
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