I want to write myself an AbstractSpinnerModel for a JSpinner that displays values of my custom-made class Time. I've extended JSpinner, which looks like this:
import javax.swing.AbstractSpinnerModel;
import javax.swing.JSpinner;
public class TimeSpinner extends JSpinner {
public TimeSpinner() {
super();
setModel(new TimeSpinnerModel());
((JSpinner.DefaultEditor) getEditor()).getTextField().setEditable(true);
}
public class TimeSpinnerModel extends AbstractSpinnerModel {
private Time t = new Time(0);
@Override
public Object getValue() {
return t;
}
@Override
public void setValue(Object o) {
try {
t = Time.parseTime(o.toString());
fireStateChanged();
} catch (NumberFormatException e) {}
}
@Override
public Object getNextValue() {
// next 10 seconds step
return new Time(((t.getSeconds() + 10) / 10) * 10);
}
@Override
public Object getPreviousValue() {
if (t.getSeconds() > 0) {
// previous 10 seconds step
return new Time(((t.getSeconds() - 1) / 10) * 10);
}
return t;
}
}
}
When I run the code, I get a StackOverflowError because there seems to be a loop of Listeners notifying each other. But in all code samples I looked through it was done exactly the way I did it, i.e. calling fireStateChanged() in setValue. Why does this happen?
My stack trace (up to the point where it starts repeating):
Exception in thread "main" java.lang.StackOverflowError
at sun.awt.SunHints$Value.hashCode(SunHints.java:163)
at java.awt.font.FontRenderContext.hashCode(FontRenderContext.java:352)
at sun.font.FontDesignMetrics$MetricsKey.init(FontDesignMetrics.java:217)
at sun.font.FontDesignMetrics.getMetrics(FontDesignMetrics.java:286)
at sun.swing.SwingUtilities2.getFontMetrics(SwingUtilities2.java:1113)
at javax.swing.JComponent.getFontMetrics(JComponent.java:1626)
at javax.swing.text.PlainView.calculateLongestLine(PlainView.java:639)
at javax.swing.text.PlainView.updateDamage(PlainView.java:574)
at javax.swing.text.PlainView.removeUpdate(PlainView.java:464)
at javax.swing.text.FieldView.removeUpdate(FieldView.java:307)
at javax.swing.plaf.basic.BasicTextUI$RootView.removeUpdate(BasicTextUI.java:1624)
at javax.swing.plaf.basic.BasicTextUI$UpdateHandler.removeUpdate(BasicTextUI.java:1884)
at javax.swing.text.AbstractDocument.fireRemoveUpdate(AbstractDocument.java:259)
at javax.swing.text.AbstractDocument.handleRemove(AbstractDocument.java:622)
at javax.swing.text.AbstractDocument.remove(AbstractDocument.java:590)
at javax.swing.text.AbstractDocument.replace(AbstractDocument.java:666)
at javax.swing.text.JTextComponent.setText(JTextComponent.java:1669)
at javax.swing.JFormattedTextField$AbstractFormatter.install(JFormattedTextField.java:948)
at javax.swing.text.DefaultFormatter.install(DefaultFormatter.java:125)
at javax.swing.JFormattedTextField.setFormatter(JFormattedTextField.java:464)
at javax.swing.JFormattedTextField.setValue(JFormattedTextField.java:788)
at javax.swing.JFormattedTextField.setValue(JFormattedTextField.java:501)
at javax.swing.JSpinner$DefaultEditor.stateChanged(JSpinner.java:717)
at javax.swing.JSpinner.fireStateChanged(JSpinner.java:458)
at javax.swing.JSpinner$ModelListener.stateChanged(JSpinner.java:386)
at javax.swing.AbstractSpinnerModel.fireStateChanged(AbstractSpinnerModel.java:119)
at TimeSpinner$TimeSpinnerModel.setValue(TimeSpinner.java:26)
at javax.swing.JSpinner.setValue(JSpinner.java:354)
at javax.swing.JSpinner$DefaultEditor.propertyChange(JSpinner.java:752)
at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
at java.awt.Component.firePropertyChange(Component.java:8430)
at javax.swing.JFormattedTextField.setValue(JFormattedTextField.java:798)
at javax.swing.JFormattedTextField.setValue(JFormattedTextField.java:501)
at javax.swing.JSpinner$DefaultEditor.stateChanged(JSpinner.java:717)
at javax.swing.JSpinner.fireStateChanged(JSpinner.java:458)
Here is my Time.java:
public class Time {
private int sec;
public Time() {
sec = 0;
}
public Time(int sec) {
this.sec = sec;
}
public void add(int sec) {
this.sec += sec;
}
public void add(Time other) {
this.sec += other.sec;
}
public int getSeconds() {
return this.sec;
}
@Override
public String toString() {
if (this.sec < 3600)
return String.format("%d:%02d", sec/60, sec%60);
return String.format("%d:%02d:%02d", sec/3600, (sec%3600)/60, sec%60);
}
public static Time parseTime(String str) throws NumberFormatException {
try {
int i = Integer.parseInt(str);
return new Time(i);
} catch (NumberFormatException e) {}
try {
double d = Double.parseDouble(str.replace(',', '.'));
return new Time((int)(d * 60.0));
} catch (NumberFormatException e) {}
String[] strs = str.split(":");
int l = strs.length;
int h, m, s;
if (l == 3) {
h = Integer.parseInt(strs[0]);
m = Integer.parseInt(strs[1]);
s = Integer.parseInt(strs[2]);
}
else if (l == 2) {
h = 0;
m = Integer.parseInt(strs[0]);
s = Integer.parseInt(strs[1]);
} else {
throw new NumberFormatException();
}
return new Time(3600 * h + 60 * m + s);
}
}
Here's your working code after some modification
TimeSpinnerModel Class
package com.test;
import javax.swing.AbstractSpinnerModel;
import javax.swing.JSpinner;
public class TimeSpinner extends JSpinner {
public TimeSpinner() {
super();
setModel(new TimeSpinnerModel());
((JSpinner.DefaultEditor) getEditor()).getTextField().setEditable(true);
}
public class TimeSpinnerModel extends AbstractSpinnerModel {
private Time t = new Time(0);
@Override
public Object getValue() {
return t;
}
@Override
public void setValue(Object o) {
try {
t.set(Time.parseTime(o.toString()));
fireStateChanged();
} catch (NumberFormatException e) {}
}
@Override
public Object getNextValue() {
// next 10 seconds step
return new Time(((t.getSeconds() + 10) / 10) * 10);
}
@Override
public Object getPreviousValue() {
if (t.getSeconds() > 0) {
// previous 10 seconds step
return new Time(((t.getSeconds() - 1) / 10) * 10);
}
return t;
}
}
}
Time Class
public class Time {
private int sec;
public Time() {
sec = 0;
}
public Time(int sec) {
System.out.println(Com.cnt.getAndIncrement());
this.sec = sec;
}
public void set(int sec){
this.sec = sec;
}
public void add(int sec) {
this.sec += sec;
}
public void add(Time other) {
this.sec += other.sec;
}
public int getSeconds() {
return this.sec;
}
@Override
public String toString() {
if (this.sec < 3600)
return String.format("%d:%02d", sec / 60, sec % 60);
return String.format("%d:%02d:%02d", sec / 3600, (sec % 3600) / 60,
sec % 60);
}
public static int parseTime(String str) throws NumberFormatException {
try {
String[] strs = str.split(":");
if (strs.length == 1) {
return Integer.parseInt(str);
} else if (strs.length == 2) {
return Integer.parseInt(strs[0]) * 60
+ Integer.parseInt(strs[1]);
} else {
int h, m, s;
h = Integer.parseInt(strs[0]);
m = Integer.parseInt(strs[1]);
s = Integer.parseInt(strs[2]);
return 3600 * h + 60 * m + s;
}
} catch (NumberFormatException e) {
throw e;
}
}
}
When you create new instance of Time, number of instance goes beyond limits and cause StackOverflowError.
Other way:
As mentioned by sergiy-medvynskyy, You can override equals and hashCode to Time class and generate state change event only if the value is really changed (if old time is equals to the new - then no change state).
Example code:
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + sec;
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (!(obj instanceof Time)) {
return false;
}
Time other = (Time) obj;
if (sec != other.sec) {
return false;
}
return true;
}