1 /*
   2  * Copyright (c) 2010, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javafx.beans;
  27 
  28 import javafx.beans.value.ObservableValue;
  29 
  30 /**
  31  * An {@code InvalidationListener} is notified whenever an
  32  * {@link Observable} becomes invalid. It can be registered and
  33  * unregistered with {@link Observable#addListener(InvalidationListener)}
  34  * respectively {@link Observable#removeListener(InvalidationListener)}.
  35  * <p>
  36  * For an in-depth explanation of invalidation events and how they differ from
  37  * change events, see the documentation of {@code ObservableValue}.
  38  * <p>
  39  * The same instance of {@code InvalidationListener} can be registered to listen
  40  * to multiple {@code Observables}.
  41  *
  42  * @see Observable
  43  * @see ObservableValue
  44  *
  45  *
  46  * @since JavaFX 2.0
  47  */
  48 @FunctionalInterface
  49 public interface InvalidationListener {
  50 
  51     /**
  52      * This method needs to be provided by an implementation of
  53      * {@code InvalidationListener}. It is called if an {@link Observable}
  54      * becomes invalid.
  55      * <p>
  56      * In general, it is considered bad practice to modify the observed value in
  57      * this method.
  58      *
  59      * @param observable
  60      *            The {@code Observable} that became invalid
  61      */
  62     public void invalidated(Observable observable);
  63 }