1 /*
   2  * Copyright (c) 2010, 2013, 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 com.sun.javafx.event;
  27 
  28 import java.util.LinkedList;
  29 import java.util.List;
  30 
  31 import javafx.event.Event;
  32 import javafx.event.EventDispatchChain;
  33 import javafx.event.EventDispatcher;
  34 
  35 public final class StubEventDispatchChain implements EventDispatchChain {
  36     private final LinkedList<EventDispatcher> eventDispatchers;
  37 
  38     public static final EventDispatchChain EMPTY_CHAIN =
  39             new StubEventDispatchChain();
  40 
  41     private StubEventDispatchChain() {
  42         this(new LinkedList<EventDispatcher>());
  43     }
  44 
  45     private StubEventDispatchChain(
  46             final LinkedList<EventDispatcher> eventDispatchers) {
  47         this.eventDispatchers = eventDispatchers;
  48     }
  49 
  50     @Override
  51     public EventDispatchChain append(final EventDispatcher eventDispatcher) {
  52         final LinkedList<EventDispatcher> newDispatchers =
  53                 copyDispatchers(eventDispatchers);
  54         newDispatchers.addLast(eventDispatcher);
  55         return new StubEventDispatchChain(newDispatchers);
  56     }
  57 
  58     @Override
  59     public EventDispatchChain prepend(final EventDispatcher eventDispatcher) {
  60         final LinkedList<EventDispatcher> newDispatchers =
  61                 copyDispatchers(eventDispatchers);
  62         newDispatchers.addFirst(eventDispatcher);
  63         return new StubEventDispatchChain(newDispatchers);
  64     }
  65 
  66     @Override
  67     public Event dispatchEvent(final Event event) {
  68         if (eventDispatchers.isEmpty()) {
  69             return event;
  70         }
  71 
  72         final LinkedList<EventDispatcher> tailDispatchers =
  73                 copyDispatchers(eventDispatchers.subList(
  74                                     1, eventDispatchers.size()));
  75         return eventDispatchers.element().dispatchEvent(
  76                 event, new StubEventDispatchChain(tailDispatchers));
  77     }
  78 
  79     private static LinkedList<EventDispatcher> copyDispatchers(
  80             final List<EventDispatcher> dispatchers) {
  81         return new LinkedList<EventDispatcher>(dispatchers);
  82     }
  83 }