Archived:Java ME Gauge progress bar disappears on S60 3rd Edition FP1 (Known Issue)

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This known issue was originally created by Cyberal and has been verified by Nokia Developer.

Article Metadata

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Tested with

Devices(s): Nokia N95 8GB, Emulator

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Compatibility

Platform(s): S60 3rd Edition FP1

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Article

Created: cyberal_ (02 Oct 2008)

Last edited: hamishwillee (28 Jun 2012)

Overview

The javax.microedition.lcdui.Gauge progress bar disappears from the form. The label and the space occupied by the progress bar remain on the screen.

Description

When instantiating a new non-interactive Gauge indicating an INDEFINITE maximum value (and possibly a CONTINUOUS_RUNNING value) and changing the Maximum value to make it a DEFINITE gauge, the progress bar disappears. However, if the gauge is instantiated as a DEFINITE value (that is, Max = 100, Val = 50) and changed to INDEFINITE and back, it works.

The same code works on the Sun Java Wireless Toolkit 2.5.2 platform emulator.

How to reproduce

 import javax.microedition.lcdui.*;
 import javax.microedition.midlet.MIDlet;
 import javax.microedition.midlet.MIDletStateChangeException;
 
 public class GaugeProblem extends MIDlet implements CommandListener {
 
   Form form = new Form("GaugeProblem");
   Gauge gauge = new Gauge("Indefinite", false, Gauge.INDEFINITE,
           Gauge.CONTINUOUS_RUNNING);
   Command exitCommand = new Command("Exit", Command.EXIT, 1);
   Command changeCommand = new Command("Change", Command.SCREEN, 2);
 
   public GaugeProblem() {
      form.append(gauge);
      form.addCommand(exitCommand);
      form.addCommand(changeCommand);
      form.setCommandListener(this);
   }
 
   void init() {
      Display.getDisplay(this).setCurrent(form);
   }
 
   void changeGauge() {
      if (gauge.getMaxValue() == Gauge.INDEFINITE) {
         gauge.setLabel("Definite");
         gauge.setMaxValue(100);
         gauge.setValue(50);
      } else {
         gauge.setLabel("Indefinite");
         gauge.setMaxValue(Gauge.INDEFINITE);
         gauge.setValue(Gauge.CONTINUOUS_RUNNING);
      }
   }
 
   void exitMIDlet() {
      try {
         destroyApp(true);
      } catch (MIDletStateChangeException ex) {
         ex.printStackTrace();
      }
      notifyDestroyed();
   }
 
   protected void startApp() throws MIDletStateChangeException {
      init();
   }
 
   protected void pauseApp() {
   }
 
   protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
   }
 
   public void commandAction(Command command, Displayable arg1) {
      if (command == exitCommand) {
         exitMIDlet();
      } else if (command == changeCommand) {
         changeGauge();
      }
   }
 }

Solution

A workaround to this issue is to instantiate the Gauge with a definite value, and immediately after creation/appending to form, change it to INDEFINITE, and then back to definite as needed.

 import javax.microedition.lcdui.*;
 import javax.microedition.midlet.MIDlet;
 import javax.microedition.midlet.MIDletStateChangeException;
 
 public class GaugeProblem extends MIDlet implements CommandListener {
 
   Form form = new Form("GaugeProblem");
   Gauge gauge = new Gauge("Indefinite", false, 
           100, //Gauge.INDEFINITE,
           50); //Gauge.CONTINUOUS_RUNNING);
 
   Command exitCommand = new Command("Exit", Command.EXIT, 1);
   Command changeCommand = new Command("Change", Command.SCREEN, 2);
 
   public GaugeProblem() {
      // PATCH TO SOLVE DISAPPEARING GAUGE
      gauge.setMaxValue(Gauge.INDEFINITE);
      gauge.setValue(Gauge.CONTINUOUS_RUNNING);
      // END OF PATCH
      form.append(gauge);
      form.addCommand(exitCommand);
      form.addCommand(changeCommand);
      form.setCommandListener(this);
   }
 
   void init() {
      Display.getDisplay(this).setCurrent(form);
   }
 
   void changeGauge() {
      if (gauge.getMaxValue() == Gauge.INDEFINITE) {
         gauge.setLabel("Definite");
         gauge.setMaxValue(100);
         gauge.setValue(50);
      } else {
         gauge.setLabel("Indefinite");
         gauge.setMaxValue(Gauge.INDEFINITE);
         gauge.setValue(Gauge.CONTINUOUS_RUNNING);
      }
   }
 
   void exitMIDlet() {
      try {
         destroyApp(true);
      } catch (MIDletStateChangeException ex) {
         ex.printStackTrace();
      }
      notifyDestroyed();
   }
 
   protected void startApp() throws MIDletStateChangeException {
      init();
   }
 
   protected void pauseApp() {
   }
 
   protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
   }
 
   public void commandAction(Command command, Displayable arg1) {
      if (command == exitCommand) {
         exitMIDlet();
      } else if (command == changeCommand) {
         changeGauge();
      }
   }
 }