All Downloads are FREE. Search and download functionalities are using the official Maven repository.

javafx.beans.Observable Maven / Gradle / Ivy

The newest version!
/*
 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javafx.beans;


/**
 * An {@code Observable} is an entity that wraps content and allows to
 * observe the content for invalidations.
 * 

* An implementation of {@code Observable} may support lazy evaluation, * which means that the content is not immediately recomputed after changes, but * lazily the next time it is requested. All bindings and properties in * this library support lazy evaluation. *

* Implementations of this class should strive to generate as few events as * possible to avoid wasting too much time in event handlers. Implementations in * this library mark themselves as invalid when the first invalidation event * occurs. They do not generate anymore invalidation events until their value is * recomputed and valid again. * * @see javafx.beans.value.ObservableValue * @see javafx.collections.ObservableList * @see javafx.collections.ObservableMap * * * @since JavaFX 2.0 */ public interface Observable { /** * Adds an {@link InvalidationListener} which will be notified whenever the * {@code Observable} becomes invalid. If the same * listener is added more than once, then it will be notified more than * once. That is, no check is made to ensure uniqueness. *

* Note that the same actual {@code InvalidationListener} instance may be * safely registered for different {@code Observables}. *

* The {@code Observable} stores a strong reference to the listener * which will prevent the listener from being garbage collected and may * result in a memory leak. It is recommended to either unregister a * listener by calling {@link #removeListener(InvalidationListener) * removeListener} after use or to use an instance of * {@link WeakInvalidationListener} avoid this situation. * * @see #removeListener(InvalidationListener) * * @param listener * The listener to register * @throws NullPointerException * if the listener is null */ void addListener(InvalidationListener listener); /** * Removes the given listener from the list of listeners, that are notified * whenever the value of the {@code Observable} becomes invalid. *

* If the given listener has not been previously registered (i.e. it was * never added) then this method call is a no-op. If it had been previously * added then it will be removed. If it had been added more than once, then * only the first occurrence will be removed. * * @see #addListener(InvalidationListener) * * @param listener * The listener to remove * @throws NullPointerException * if the listener is null */ void removeListener(InvalidationListener listener); }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy