Spec-Zone .ru
спецификации, руководства, описания, API
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014 * version 2 for more details (a copy is included in the LICENSE file that
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025
026package javafx.beans.value;
027
028/**
029 * A {@code ChangeListener} is notified whenever the value of an
030 * {@link ObservableValue} changes. It can be registered and unregistered with
031 * {@link ObservableValue#addListener(ChangeListener)} respectively
032 * {@link ObservableValue#removeListener(ChangeListener)}
033 * <p>
034 * For an in-depth explanation of change events and how they differ from
035 * invalidation events, see the documentation of {@code ObservableValue}.
036 * <p>
037 * The same instance of {@code ChangeListener} can be registered to listen to
038 * multiple {@code ObservableValues}.
039 * 
040 * @see ObservableValue
041 * 
042 * 
043 */
044public interface ChangeListener<T> {
045
046    /**
047     * This method needs to be provided by an implementation of
048     * {@code ChangeListener}. It is called if the value of an
049     * {@link ObservableValue} changes.
050     * <p>
051     * In general is is considered bad practice to modify the observed value in
052     * this method.
053     * 
054     * @param observable
055     *            The {@code ObservableValue} which value changed
056     * @param oldValue
057     *            The old value
058     * @param newValue
059     *            The new value
060     */
061    void changed(ObservableValue<? extends T> observable, T oldValue, T newValue);
062}