BeanPathAdapter.java 文件源码

/**
 * Adds/Removes the {@link FieldProperty} as a collection listener
 * 
 * @param observable
 *            the {@link Observable} collection/map to listen for
 *            changes on
 * @param add
 *            true to add, false to remove
 */
protected void addRemoveCollectionListener(final Observable observable,
        final boolean add) {
    final boolean isCol = getCollectionObservable() == observable;
    if (isCol
            && ((this.isCollectionListening && add) || (this.isCollectionListening && !add))) {
        return;
    }
    Boolean change = null;
    if (observable instanceof ObservableList) {
        final ObservableList<?> ol = (ObservableList<?>) observable;
        if (add) {
            ol.addListener(this);
            change = true;
        } else {
            ol.removeListener(this);
            change = false;
        }
    } else if (observable instanceof ObservableSet) {
        final ObservableSet<?> os = (ObservableSet<?>) observable;
        if (add) {
            os.addListener(this);
            change = true;
        } else {
            os.removeListener(this);
            change = false;
        }
    } else if (observable instanceof ObservableMap) {
        final ObservableMap<?, ?> om = (ObservableMap<?, ?>) observable;
        if (add) {
            om.addListener(this);
            change = true;
        } else {
            om.removeListener(this);
            change = false;
        }
    } else if (observable == null) {
        throw new IllegalStateException(String.format(
                "Observable collection/map bound to %1$s (item path: %2$s) "
                        + "has been garbage collected",
                this.fieldHandle.getFieldName(),
                this.collectionItemPath, observable,
                this.getFieldType()));
    } else {
        throw new UnsupportedOperationException(String.format(
                "%1$s (item path: %2$s) of type \"%4$s\" "
                        + "must be bound to a supported "
                        + "observable collection/map type... "
                        + "Found observable: %3$s",
                this.fieldHandle.getFieldName(),
                this.collectionItemPath, observable,
                this.getFieldType()));
    }
    if (isCol && change != null) {
        this.isCollectionListening = change;
    }
}