Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-4331775

the JRE starts 2EventHandlerMethods parallel

    XMLWordPrintable

    Details

      Description



      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)
      ======================================================================

        Attachments

          Issue Links

            Activity

              People

              Assignee:
              joutwatesunw Joshua Outwater (Inactive)
              Reporter:
              skondamasunw Suresh Kondamareddy (Inactive)
              Votes:
              0 Vote for this issue
              Watchers:
              0 Start watching this issue

                Dates

                Created:
                Updated:
                Resolved:
                Imported:
                Indexed: