Java Swing, 2nd Edition

Spinner Models

The javax.swing package includes several pre-built models for many common data types suited to spinners. Figure 7-15 shows the hierarchy of these models.

Figure 7-15. SpinnerModel class diagram

The SpinnerModel Interface

The SpinnerModel interface includes methods required to successfully store and retrieve spinner data. It includes a read/write value and next and previous properties, and it forces implementing models (such as AbstractSpinnerModel) to support a ChangeListener.

Properties

Not surprisingly, the properties for SpinnerModel are centered on the value being shown in the spinner. Notice in Table 7-17 that the model stores only the current value and the next/previous values. The actual list (or other object) behind these values is not part of the model.

Table 7-17. SpinnerModel properties

Property	Data type	get	is	set	Default value
nextValue	Object	·
previousValue	Object	·
value	Object	·		·

Events

Any changes to the selected value should be reported through ChangeEvent objects.

public void addChangeListener(ChangeListener l)public void removeChangeListener(ChangeListener l)

Add or remove a specific listener for ChangeEvent notifications from the component.

The AbstractSpinnerModel Class

The AbstractSpinnerModel class implements the event parts of the SpinnerModel. Implementations of addChangeListener( ), removeChangeListener( ), and getChange-Listeners( ) are all present. ...