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 = Integer.valueOf(50);
 Integer min = Integer.valueOf(0);
 Integer max = Integer.valueOf(100);
 Integer step = Integer.valueOf(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
See Also:: JSpinner, SpinnerModel, AbstractSpinnerModel, SpinnerListModel, SpinnerDateModel, Serialized Form

Field Summary

Fields declared in class javax.swing.AbstractSpinnerModel

listenerList

Constructor Summary

Constructors
Constructor	Description
`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

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`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.
`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 declared in class javax.swing.AbstractSpinnerModel

addChangeListener, fireStateChanged, getChangeListeners, getListeners, removeChangeListener

Methods declared in class java.lang.Object

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

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 minimum > 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(Comparable) 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)

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)