Java Development

[colombus]

I nsuch case then there is no other thread . Is it because  i am not popping the screens this error is coming ??

[RexDoug]

AFAIK, a non-modal display does not create a thread. However, if you pushModal() this *DOES* create a thread for each screen pushed.

You can certainly identify where your threads are coming from if you open the Threads view in the debugger.

[colombus]

Hi

 I checked the thread view in JDE but i cudnt find the number of threads.

Even after popping the screen each time the exception is coming

I am using activeRichtextfield. Is it having any relation to the thread ??

other than that I am not able find from where the threads come

[mreed]

Are you creating a bunch of Timers?

[colombus]

No

I am not using Timer at all

[RexDoug]

Well, you are doing something to create threads. You say that you opened the Threads view in the debugger, yet you could not see your threads?

Are you creating a Player (also creates thread)?

Maybe you should tell us what your program is doing?

[pfiffi78]

It may be worth setting a break point. Sometimes, at least in Eclipse, the Thread view only shows all threads once the VM has been paused by or hit a break point. 

[colombus]

Sorry all

I got the issue. My application has a headerbar which shows device battery status time etc. to update that i was using timer task and the header bar is a custom field. in all screen i was creating instance of it so new threads get created. Now i have one more issue

I am not able to make single object of headerbar and setTitle for each screen. Its giving Uncaught exception: Field added to a manager while it is already parented

The code is as follows is there any way i can update this title field

import java.util.Timer;
import java.util.TimerTask;
import net.rim.device.api.i18n.SimpleDateFormat;
import net.rim.device.api.system.DeviceInfo;
import net.rim.device.api.system.RadioInfo;
import net.rim.device.api.ui.DrawStyle;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Font;
import net.rim.device.api.ui.FontFamily;
import net.rim.device.api.ui.Graphics;
//
public class HeaderBar extends Field implements DrawStyle{
private Font headerFont = SmallFont();
private SimpleDateFormat timeFormat = new SimpleDateFormat("HH:mm");
private SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
private String timeString;
private String dateString;
private String title;
private boolean showSignal;
private boolean showBattery;
private boolean showDate;
private boolean showTime;
private boolean showTitle;
private int fieldWidth;
private int fieldHeight;
private int fontColour;
private int backgroundColour;
private int batteryBackground;
private Timer headerTimer = new Timer();
private TimerTask headerTask;
//
public HeaderBar(String _title) {
super(Field.NON_FOCUSABLE);
title = _title;
showSignal = true;
showBattery = true;
showDate = true;
showTime = true;
showTitle = true;
fieldHeight = 12;
fieldWidth = Graphics.getScreenWidth();
fontColour = 0x888888;
backgroundColour = 0;
batteryBackground = 0x999999;
//
headerTask = new TimerTask() {
public void run() {
invalidate();
}
};
//
headerTimer.scheduleAtFixedRate(headerTask, 1000, 1000);
}
//
public void setTitle(String _title){
title = _title;
invalidate();
}
//
public void setFontColour(int _fontColour){
fontColour = _fontColour;
invalidate();
}
//
public void setBatteryBackground(int _batteryBackground){
batteryBackground = _batteryBackground;
invalidate();
}
//
public void setBackgroundColour(int _backgroundColour){
backgroundColour = _backgroundColour;
invalidate();
}
//
public void showSignal(boolean bool){
showSignal = bool;
invalidate();
}
//
public void showBattery(boolean bool){
showBattery = bool;
invalidate();
}
//
public void showDate(boolean bool){
showDate = bool;
invalidate();
}
//
public void showTime(boolean bool){
showTime = bool;
invalidate();
}
//
public void showTitle(boolean bool){
showTitle = bool;
invalidate();
}
//
protected void layout(int width, int height) {
setExtent(getPreferredWidth(), getPreferredHeight());
}
//
public int getPreferredWidth() {
return fieldWidth;
}
//
public int getPreferredHeight() {
return fieldHeight;
}
//
protected void paint(Graphics graphics) {
graphics.setFont(headerFont);
int graphicsDiff = 0;
//
if(backgroundColour != 0){
graphics.setColor(backgroundColour);
graphics.fillRect(0, 0, this.getPreferredWidth(), this.getPreferredHeight());
}
//
if(showSignal){
graphicsDiff = graphicsDiff + 28;
graphics.setColor(0x999999);
graphics.fillRect(this.getPreferredWidth() - 26, 8, 6, 4);
graphics.fillRect(this.getPreferredWidth() - 21, 6, 6, 6);
graphics.fillRect(this.getPreferredWidth() - 16, 4, 6, 8 );
graphics.fillRect(this.getPreferredWidth() - 11, 2, 6, 10);
graphics.fillRect(this.getPreferredWidth() - 6, 0, 6, 12);
int signalLevel = RadioInfo.getSignalLevel();
if(signalLevel > -77){
//5 bands
graphics.setColor(0xEFEFEF);
graphics.fillRect(this.getPreferredWidth() - 25,9,4,2);
graphics.fillRect(this.getPreferredWidth() - 20,7,4,4);
graphics.fillRect(this.getPreferredWidth() - 15,5,4,6);
graphics.fillRect(this.getPreferredWidth() - 10,3,4,8);
graphics.fillRect(this.getPreferredWidth() - 5, 1, 4, 10);
}else if(signalLevel > -86){
//4 bands
graphics.setColor(0xEFEFEF);
graphics.fillRect(this.getPreferredWidth() - 25,9,4,2);
graphics.fillRect(this.getPreferredWidth() - 20,7,4,4);
graphics.fillRect(this.getPreferredWidth() - 15,5,4,6);
graphics.fillRect(this.getPreferredWidth() - 10,3,4,8);
}else if(signalLevel > -92){
//3 bands
graphics.setColor(0xEFEFEF);
graphics.fillRect(this.getPreferredWidth() - 25,9,4,2);
graphics.fillRect(this.getPreferredWidth() - 20,7,4,4);
graphics.fillRect(this.getPreferredWidth() - 15,5,4,6);
}else if(signalLevel > -101){
//2 bands
graphics.setColor(0xEFEFEF);
graphics.fillRect(this.getPreferredWidth() - 25,9,4,2);
graphics.fillRect(this.getPreferredWidth() - 20,7,4,4);
}else if(signalLevel > -120){
//1 band
graphics.setColor(0xEFEFEF);
graphics.fillRect(this.getPreferredWidth() - 25,9,4,2);
}
}
if(showBattery){
//
int batteryLevel = DeviceInfo.getBatteryLevel();
graphics.setColor(batteryBackground);
graphics.fillRect(this.getPreferredWidth()-23-graphicsDiff,2,20,8);
graphics.fillRect(this.getPreferredWidth()-3-graphicsDiff,4,1,4);
if(batteryLevel > 75){
graphics.setColor(0x28f300);
}else if(batteryLevel > 50){
graphics.setColor(0x91dc00);
}else if(batteryLevel > 25){
graphics.setColor(0xefec00);
}else{
graphics.setColor(0xff2200);
}
double powerLong = ((18.00/100)*batteryLevel);
int power = (int)powerLong;
graphics.fillRect(this.getPreferredWidth()-22-graphicsDiff,3,power,6);
graphicsDiff = graphicsDiff + 24;
}
//
graphics.setColor(fontColour);
//
if(showTime){
timeString = " " + timeFormat.formatLocal(System.currentTimeMillis()) + " ";
}else{
timeString = "";
}
//
if(showDate){
dateString = " " + dateFormat.formatLocal(System.currentTimeMillis()) + " ";
}else{
dateString = "";
}
//
graphics.drawText(dateString + timeString, this.getPreferredWidth()-headerFont.getAdvance(dateString + timeString)-graphicsDiff, 1);
//
if(showTitle){
int limit = 0;
if(showSignal)limit = limit + 28;
if(showBattery)limit = limit + 25;
if(showTime)limit = limit + headerFont.getAdvance(timeString);
if(showDate)limit = limit + headerFont.getAdvance(dateString);
if(headerFont.getAdvance(title) > this.getPreferredWidth() - limit){
int elippsy = headerFont.getAdvance("...");
int availableWidth = this.getPreferredWidth() - limit - elippsy;
String _txt = "";
String shorterTitle = "";
for(int i = 1 ; i < title.length(); i++){
_txt = title.substring(0, i);
if(headerFont.getAdvance(_txt) < availableWidth){
shorterTitle = _txt;
}
}
title = shorterTitle + "...";
}
graphics.drawText(title, 1, 0);
}
}
//
public static Font SmallFont(){
try {
FontFamily theFam = FontFamily.forName("SYSTEM");
return theFam.getFont(net.rim.device.api.ui.Font.PLAIN, 10);
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
return null;
}
} 

[RexDoug]

A field can only belong to one manager.

You'll have to figure a different way to handle the status bar, or simply refrain from creating screens until they are needed.

[mreed · Accepted solution]

You do not need to create a new Timer instance everytime you want to schedule a task. One can handle what you need (make a static instance somewhere). This will get you down to one Timer Thread.