javax.swing
Class SpinnerNumberModel

java.lang.Object
  javax.swing.AbstractSpinnerModel
      javax.swing.SpinnerNumberModel

All Implemented Interfaces:

Serializable, SpinnerModel

public class SpinnerNumberModel

extends AbstractSpinnerModel

implements Serializable

A SpinnerModel for sequences of numbers. The upper and lower bounds of the sequence are defined by properties called minimum and maximum. The size of the increase or decrease computed by the nextValue and previousValue methods is defined by a property called stepSize. The minimum and maximum properties can be null to indicate that the sequence has no lower or upper limit. All of the properties in this class are defined in terms of two generic types: Number and Comparable, so that all Java numeric types may be accommodated. Internally, there's only support for values whose type is one of the primitive Number types: Double, Float, Long, Integer, Short, or Byte.

To create a SpinnerNumberModel for the integer range zero to one hundred, with fifty as the initial value, one could write:

 
 Integer value = new Integer(50); 
 Integer min = new Integer(0);
 Integer max = new Integer(100); 
 Integer step = new Integer(1); 
 SpinnerNumberModel model = new SpinnerNumberModel(value, min, max, step); 
 int fifty = model.getNumber().intValue(); 
 

Spinners for integers and doubles are common, so special constructors for these cases are provided. For example to create the model in the previous example, one could also write:

 
 SpinnerNumberModel model = new SpinnerNumberModel(50, 0, 100, 1); 
 

This model inherits a ChangeListener. The ChangeListeners are notified whenever the model's value, stepSize, minimum, or maximum properties changes.

Since:

1.4

Author:

Hans Muller

See Also:

JSpinner, SpinnerModel, AbstractSpinnerModel, SpinnerListModel, SpinnerDateModel, Serialized Form

Field Summary

private Comparable	maximum
private Comparable	minimum
private Number	stepSize
private Number	value

Fields inherited from class javax.swing.AbstractSpinnerModel

listenerList

Constructor Summary

SpinnerNumberModel()
Constructs a SpinnerNumberModel with no minimum or maximum value, stepSize equal to one, and an initial value of zero.

SpinnerNumberModel(double value, double minimum, double maximum, double stepSize)
Constructs a SpinnerNumberModel with the specified value, minimum/maximum bounds, and stepSize.

SpinnerNumberModel(int value, int minimum, int maximum, int stepSize)
Constructs a SpinnerNumberModel with the specified value, minimum/maximum bounds, and stepSize.

SpinnerNumberModel(Number value, Comparable minimum, Comparable maximum, Number stepSize)
Constructs a SpinnerModel that represents a closed sequence of numbers from minimum to maximum.

Method Summary

Comparable	getMaximum() Returns the last number in the sequence.
Comparable	getMinimum() Returns the first number in this sequence.
Object	getNextValue() Returns the next number in the sequence.
Number	getNumber() Returns the value of the current element of the sequence.
Object	getPreviousValue() Returns the previous number in the sequence.
Number	getStepSize() Returns the size of the value change computed by the getNextValue and getPreviousValue methods.
Object	getValue() Returns the value of the current element of the sequence.
private Number	incrValue(int dir)
void	setMaximum(Comparable maximum) Changes the upper bound for numbers in this sequence.
void	setMinimum(Comparable minimum) Changes the lower bound for numbers in this sequence.
void	setStepSize(Number stepSize) Changes the size of the value change computed by the getNextValue and getPreviousValue methods.
void	setValue(Object value) Sets the current value for this sequence.

Methods inherited from class javax.swing.AbstractSpinnerModel

addChangeListener, fireStateChanged, getChangeListeners, getListeners, removeChangeListener

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

stepSize

private Number stepSize

value

private Number value

minimum

private Comparable minimum

maximum

private Comparable maximum

Constructor Detail

SpinnerNumberModel

public SpinnerNumberModel(Number value,
                          Comparable minimum,
                          Comparable maximum,
                          Number stepSize)

Constructs a SpinnerModel that represents a closed sequence of numbers from minimum to maximum. The nextValue and previousValue methods compute elements of the sequence by adding or subtracting stepSize respectively. All of the parameters must be mutually Comparable, value and stepSize must be instances of Integer Long, Float, or Double.

The minimum and maximum parameters can be null to indicate that the range doesn't have an upper or lower bound. If value or stepSize is null, or if both minimum and maximum are specified and mininum > maximum then an IllegalArgumentException is thrown. Similarly if (minimum <= value <= maximum) is false, an IllegalArgumentException is thrown.

Parameters:

value - the current (non null) value of the model

minimum - the first number in the sequence or null

maximum - the last number in the sequence or null

stepSize - the difference between elements of the sequence

Throws:

IllegalArgumentException - if stepSize or value is null or if the following expression is false: minimum <= value <= maximum

SpinnerNumberModel

public SpinnerNumberModel(int value,
                          int minimum,
                          int maximum,
                          int stepSize)

Constructs a SpinnerNumberModel with the specified value, minimum/maximum bounds, and stepSize.

Parameters:

value - the current value of the model

minimum - the first number in the sequence

maximum - the last number in the sequence

stepSize - the difference between elements of the sequence

Throws:

IllegalArgumentException - if the following expression is false: minimum <= value <= maximum

SpinnerNumberModel

public SpinnerNumberModel(double value,
                          double minimum,
                          double maximum,
                          double stepSize)

Constructs a SpinnerNumberModel with the specified value, minimum/maximum bounds, and stepSize.

Parameters:

value - the current value of the model

minimum - the first number in the sequence

maximum - the last number in the sequence

stepSize - the difference between elements of the sequence

Throws:

IllegalArgumentException - if the following expression is false: minimum <= value <= maximum

SpinnerNumberModel

public SpinnerNumberModel()

Constructs a SpinnerNumberModel with no minimum or maximum value, stepSize equal to one, and an initial value of zero.

Method Detail

setMinimum

public void setMinimum(Comparable minimum)

Changes the lower bound for numbers in this sequence. If minimum is null, then there is no lower bound. No bounds checking is done here; the new minimum value may invalidate the (minimum <= value <= maximum) invariant enforced by the constructors. This is to simplify updating the model, naturally one should ensure that the invariant is true before calling the getNextValue, getPreviousValue, or setValue methods.

Typically this property is a Number of the same type as the value however it's possible to use any Comparable with a compareTo method for a Number with the same type as the value. For example if value was a Long, minimum might be a Date subclass defined like this:

 MyDate extends Date {  // Date already implements Comparable
     public int compareTo(Long o) {
         long t = getTime();
         return (t < o.longValue() ? -1 : (t == o.longValue() ? 0 : 1));
     }
 }
 

This method fires a ChangeEvent if the minimum has changed.

Parameters:

minimum - a Comparable that has a compareTo method for Numbers with the same type as value

See Also:

getMinimum(), setMaximum(java.lang.Comparable), SpinnerModel.addChangeListener(javax.swing.event.ChangeListener)

getMinimum

public Comparable getMinimum()

Returns the first number in this sequence.

Returns:

the value of the minimum property

See Also:

setMinimum(java.lang.Comparable)

setMaximum

public void setMaximum(Comparable maximum)

Changes the upper bound for numbers in this sequence. If maximum is null, then there is no upper bound. No bounds checking is done here; the new maximum value may invalidate the (minimum <= value < maximum) invariant enforced by the constructors. This is to simplify updating the model, naturally one should ensure that the invariant is true before calling the next, previous, or setValue methods.

Typically this property is a Number of the same type as the value however it's possible to use any Comparable with a compareTo method for a Number with the same type as the value. See setMinimum for an example.

This method fires a ChangeEvent if the maximum has changed.

Parameters:

maximum - a Comparable that has a compareTo method for Numbers with the same type as value

See Also:

getMaximum(), setMinimum(java.lang.Comparable), SpinnerModel.addChangeListener(javax.swing.event.ChangeListener)

getMaximum

public Comparable getMaximum()

Returns the last number in the sequence.

Returns:

the value of the maximum property

See Also:

setMaximum(java.lang.Comparable)

setStepSize

public void setStepSize(Number stepSize)

Changes the size of the value change computed by the getNextValue and getPreviousValue methods. An IllegalArgumentException is thrown if stepSize is null.

This method fires a ChangeEvent if the stepSize has changed.

Parameters:

stepSize - the size of the value change computed by the getNextValue and getPreviousValue methods

See Also:

getNextValue(), getPreviousValue(), getStepSize(), SpinnerModel.addChangeListener(javax.swing.event.ChangeListener)

getStepSize

public Number getStepSize()

Returns the size of the value change computed by the getNextValue and getPreviousValue methods.

Returns:

the value of the stepSize property

See Also:

setStepSize(java.lang.Number)

incrValue

private Number incrValue(int dir)

getNextValue

public Object getNextValue()

Returns the next number in the sequence.

Specified by:

getNextValue in interface SpinnerModel

Returns:

value + stepSize or null if the sum exceeds maximum.

See Also:

SpinnerModel.getNextValue(), getPreviousValue(), setStepSize(java.lang.Number)

getPreviousValue

public Object getPreviousValue()

Returns the previous number in the sequence.

Specified by:

getPreviousValue in interface SpinnerModel

Returns:

value - stepSize, or null if the sum is less than minimum.

See Also:

SpinnerModel.getPreviousValue(), getNextValue(), setStepSize(java.lang.Number)

getNumber

public Number getNumber()

Returns the value of the current element of the sequence.

Returns:

the value property

See Also:

setValue(java.lang.Object)

getValue

public Object getValue()

Returns the value of the current element of the sequence.

Specified by:

getValue in interface SpinnerModel

Returns:

the value property

See Also:

setValue(java.lang.Object), getNumber()

setValue

public void setValue(Object value)

Sets the current value for this sequence. If value is null, or not a Number, an IllegalArgumentException is thrown. No bounds checking is done here; the new value may invalidate the (minimum <= value <= maximum) invariant enforced by the constructors. It's also possible to set the value to be something that wouldn't naturally occur in the sequence, i.e. a value that's not modulo the stepSize. This is to simplify updating the model, and to accommodate spinners that don't want to restrict values that have been directly entered by the user. Naturally, one should ensure that the (minimum <= value <= maximum) invariant is true before calling the next, previous, or setValue methods.

This method fires a ChangeEvent if the value has changed.

Specified by:

setValue in interface SpinnerModel

Parameters:

value - the current (non null) Number for this sequence

Throws:

IllegalArgumentException - if value is null or not a Number

See Also:

getNumber(), getValue(), SpinnerModel.addChangeListener(javax.swing.event.ChangeListener)