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.
*
* @see JSpinner
* @see SpinnerModel
* @see AbstractSpinnerModel
* @see SpinnerListModel
* @see SpinnerDateModel
*
* @author Hans Muller
* @since 1.4
*/
@SuppressWarnings("serial") // Superclass is not serializable across versions
public class SpinnerNumberModel extends AbstractSpinnerModel implements Serializable
{
private Number stepSize, value;
private Comparable minimum, maximum;
/**
* 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.
*
* @param value the current (non null) value of the model
* @param minimum the first number in the sequence or null
* @param maximum the last number in the sequence or null
* @param 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
*/
public SpinnerNumberModel(Number value, Comparable minimum, Comparable maximum, Number stepSize) {
if ((value == null) || (stepSize == null)) {
throw new IllegalArgumentException("value and stepSize must be non-null");
}
if (!(((minimum == null) || (minimum.compareTo(value) <= 0)) &&
((maximum == null) || (maximum.compareTo(value) >= 0)))) {
throw new IllegalArgumentException("(minimum <= value <= maximum) is false");
}
this.value = value;
this.minimum = minimum;
this.maximum = maximum;
this.stepSize = stepSize;
}
/**
* Constructs a SpinnerNumberModel with the specified
* value, minimum/maximum bounds,
* and stepSize.
*
* @param value the current value of the model
* @param minimum the first number in the sequence
* @param maximum the last number in the sequence
* @param stepSize the difference between elements of the sequence
* @throws IllegalArgumentException if the following expression is false:
* minimum <= value <= maximum
*/
public SpinnerNumberModel(int value, int minimum, int maximum, int stepSize) {
this(Integer.valueOf(value), Integer.valueOf(minimum), Integer.valueOf(maximum), Integer.valueOf(stepSize));
}
/**
* Constructs a SpinnerNumberModel with the specified
* value, minimum/maximum bounds,
* and stepSize.
*
* @param value the current value of the model
* @param minimum the first number in the sequence
* @param maximum the last number in the sequence
* @param stepSize the difference between elements of the sequence
* @throws IllegalArgumentException if the following expression is false:
* minimum <= value <= maximum
*/
public SpinnerNumberModel(double value, double minimum, double maximum, double stepSize) {
this(new Double(value), new Double(minimum), new Double(maximum), new Double(stepSize));
}
/**
* Constructs a SpinnerNumberModel with no
* minimum or maximum value,
* stepSize equal to one, and an initial value of zero.
*/
public SpinnerNumberModel() {
this(Integer.valueOf(0), null, null, Integer.valueOf(1));
}
/**
* 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.
*
* @param minimum a Comparable that has a
* compareTo method for Numbers with
* the same type as value
* @see #getMinimum
* @see #setMaximum
* @see SpinnerModel#addChangeListener
*/
public void setMinimum(Comparable minimum) {
if ((minimum == null) ? (this.minimum != null) : !minimum.equals(this.minimum)) {
this.minimum = minimum;
fireStateChanged();
}
}
/**
* Returns the first number in this sequence.
*
* @return the value of the minimum property
* @see #setMinimum
*/
public Comparable getMinimum() {
return minimum;
}
/**
* 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.
*
* @param maximum a Comparable that has a
* compareTo method for Numbers with
* the same type as value
* @see #getMaximum
* @see #setMinimum
* @see SpinnerModel#addChangeListener
*/
public void setMaximum(Comparable maximum) {
if ((maximum == null) ? (this.maximum != null) : !maximum.equals(this.maximum)) {
this.maximum = maximum;
fireStateChanged();
}
}
/**
* Returns the last number in the sequence.
*
* @return the value of the maximum property
* @see #setMaximum
*/
public Comparable getMaximum() {
return maximum;
}
/**
* 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.
*
* @param stepSize the size of the value change computed by the
* getNextValue and getPreviousValue methods
* @see #getNextValue
* @see #getPreviousValue
* @see #getStepSize
* @see SpinnerModel#addChangeListener
*/
public void setStepSize(Number stepSize) {
if (stepSize == null) {
throw new IllegalArgumentException("null stepSize");
}
if (!stepSize.equals(this.stepSize)) {
this.stepSize = stepSize;
fireStateChanged();
}
}
/**
* Returns the size of the value change computed by the
* getNextValue
* and getPreviousValue methods.
*
* @return the value of the stepSize property
* @see #setStepSize
*/
public Number getStepSize() {
return stepSize;
}
private Number incrValue(int dir)
{
Number newValue;
if ((value instanceof Float) || (value instanceof Double)) {
double v = value.doubleValue() + (stepSize.doubleValue() * (double)dir);
if (value instanceof Double) {
newValue = new Double(v);
}
else {
newValue = new Float(v);
}
}
else {
long v = value.longValue() + (stepSize.longValue() * (long)dir);
if (value instanceof Long) {
newValue = Long.valueOf(v);
}
else if (value instanceof Integer) {
newValue = Integer.valueOf((int)v);
}
else if (value instanceof Short) {
newValue = Short.valueOf((short)v);
}
else {
newValue = Byte.valueOf((byte)v);
}
}
if ((maximum != null) && (maximum.compareTo(newValue) < 0)) {
return null;
}
if ((minimum != null) && (minimum.compareTo(newValue) > 0)) {
return null;
}
else {
return newValue;
}
}
/**
* Returns the next number in the sequence.
*
* @return value + stepSize or null if the sum
* exceeds maximum.
*
* @see SpinnerModel#getNextValue
* @see #getPreviousValue
* @see #setStepSize
*/
public Object getNextValue() {
return incrValue(+1);
}
/**
* Returns the previous number in the sequence.
*
* @return value - stepSize, or
* null if the sum is less
* than minimum.
*
* @see SpinnerModel#getPreviousValue
* @see #getNextValue
* @see #setStepSize
*/
public Object getPreviousValue() {
return incrValue(-1);
}
/**
* Returns the value of the current element of the sequence.
*
* @return the value property
* @see #setValue
*/
public Number getNumber() {
return value;
}
/**
* Returns the value of the current element of the sequence.
*
* @return the value property
* @see #setValue
* @see #getNumber
*/
public Object getValue() {
return 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.
*
* @param value the current (non null) Number
* for this sequence
* @throws IllegalArgumentException if value is
* null or not a Number
* @see #getNumber
* @see #getValue
* @see SpinnerModel#addChangeListener
*/
public void setValue(Object value) {
if ((value == null) || !(value instanceof Number)) {
throw new IllegalArgumentException("illegal value");
}
if (!value.equals(this.value)) {
this.value = (Number)value;
fireStateChanged();
}
}
}