SpinnerModel whose
* values are defined by an array or a List.
* For example to create a model defined by
* an array of the names of the days of the week:
* * String[] days = new DateFormatSymbols().getWeekdays(); * SpinnerModel model = new SpinnerListModel(Arrays.asList(days).subList(1, 8)); ** This class only stores a reference to the array or
List
* so if an element of the underlying sequence changes, it's up
* to the application to notify the ChangeListeners by calling
* fireStateChanged.
*
* This model inherits a ChangeListener.
* The ChangeListeners are notified whenever the
* model's value or list properties changes.
*
* @see JSpinner
* @see SpinnerModel
* @see AbstractSpinnerModel
* @see SpinnerNumberModel
* @see SpinnerDateModel
*
* @author Hans Muller
* @since 1.4
*/
public class SpinnerListModel extends AbstractSpinnerModel implements Serializable
{
private List list;
private int index;
/**
* Constructs a SpinnerModel whose sequence of
* values is defined by the specified List.
* The initial value (current element)
* of the model will be values.get(0).
* If values is null or has zero
* size, an IllegalArugmentException is thrown.
*
* @param values the sequence this model represents
* @throws IllegalArugmentException if values is
* null or zero size
*/
public SpinnerListModel(List values) {
if (values == null || values.size() == 0) {
throw new IllegalArgumentException("SpinnerListModel(List) expects non-null non-empty List");
}
this.list = values;
this.index = 0;
}
/**
* Constructs a SpinnerModel whose sequence of values
* is defined by the specified array. The initial value of the model
* will be values[0]. If values is
* null or has zero length, an
* IllegalArugmentException is thrown.
*
* @param values the sequence this model represents
* @throws IllegalArugmentException if values is
* null or zero length
*/
public SpinnerListModel(Object[] values) {
if (values == null || values.length == 0) {
throw new IllegalArgumentException("SpinnerListModel(Object[]) expects non-null non-empty Object[]");
}
this.list = Arrays.asList(values);
this.index = 0;
}
/**
* Constructs an effectively empty SpinnerListModel.
* The model's list will contain a single
* "empty" string element.
*/
public SpinnerListModel() {
this(new Object[]{"empty"});
}
/**
* Returns the List that defines the sequence for this model.
*
* @return the value of the list property
* @see #setList
*/
public List getList() {
return list;
}
/**
* Changes the list that defines this sequence and resets the index
* of the models value to zero. Note that list
* is not copied, the model just stores a reference to it.
*
* This method fires a ChangeEvent if list is
* not equal to the current list.
*
* @param list the sequence that this model represents
* @throws IllegalArgumentException if list is
* null or zero length
* @see #getList
*/
public void setList(List list) {
if ((list == null) || (list.size() == 0)) {
throw new IllegalArgumentException("invalid list");
}
if (!list.equals(this.list)) {
this.list = list;
index = 0;
fireStateChanged();
}
}
/**
* Returns the current element of the sequence.
*
* @return the value property
* @see SpinnerModel#getValue
* @see #setValue
*/
public Object getValue() {
return list.get(index);
}
/**
* Changes the current element of the sequence and notifies
* ChangeListeners. If the specified
* value is not equal to an element of the underlying sequence
* then an IllegalArgumentException is thrown.
* In the following example the setValue call
* would cause an exception to be thrown:
*
* String[] values = {"one", "two", "free", "four"};
* SpinnerModel model = new SpinnerListModel(values);
* model.setValue("TWO");
*
*
* @param elt the sequence element that will be model's current value
* @throws IllegalArgumentException if the specified value isn't allowed
* @see SpinnerModel#setValue
* @see #getValue
*/
public void setValue(Object elt) {
int index = list.indexOf(elt);
if (index == -1) {
throw new IllegalArgumentException("invalid sequence element");
}
else if (index != this.index) {
this.index = index;
fireStateChanged();
}
}
/**
* Returns the next legal value of the underlying sequence or
* null if value is already the last element.
*
* @return the next legal value of the underlying sequence or
* null if value is already the last element
* @see SpinnerModel#getNextValue
* @see #getPreviousValue
*/
public Object getNextValue() {
return (index >= (list.size() - 1)) ? null : list.get(index + 1);
}
/**
* Returns the previous element of the underlying sequence or
* null if value is already the first element.
*
* @return the previous element of the underlying sequence or
* null if value is already the first element
* @see SpinnerModel#getPreviousValue
* @see #getNextValue
*/
public Object getPreviousValue() {
return (index <= 0) ? null : list.get(index - 1);
}
/**
* Returns the next object that starts with substring.
*
* @param substring the string to be matched
* @return the match
*/
Object findNextMatch(String substring) {
int max = list.size();
if (max == 0) {
return null;
}
int counter = index;
do {
Object value = list.get(counter);
String string = value.toString();
if (string != null && string.startsWith(substring)) {
return value;
}
counter = (counter + 1) % max;
} while (counter != index);
return null;
}
}