src/main/java/net/pterodactylus/demoscenemusic/data/AbstractBase.java

   1 /*
   2  * DemosceneMusic - Base.java - Copyright © 2012 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.demoscenemusic.data;
  19
  20 import java.util.HashMap;
  21 import java.util.Map;
  22 import java.util.Map.Entry;
  23
  24 /**
  25  * TODO
  26  *
  27  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  28  */
  29 public abstract class AbstractBase implements Base {
  30
  31         private final String id;
  32
  33         private final Map<String, Value<?>> attributes = new HashMap<String, Value<?>>();
  34
  35         protected AbstractBase(String id) {
  36                 this.id = id;
  37         }
  38
  39         public String id() {
  40                 return id;
  41         }
  42
  43         @SuppressWarnings({ "synthetic-access", "unchecked" })
  44         protected <T> Value<T> value(String name, Class<T> clazz) {
  45                 if (!attributes.containsKey(name)) {
  46                         attributes.put(name, new Value<T>());
  47                 }
  48                 return (Value<T>) attributes.get(name);
  49         }
  50
  51         protected boolean dirty() {
  52                 for (Value<?> value : attributes.values()) {
  53                         if (value.dirty()) {
  54                                 return true;
  55                         }
  56                 }
  57                 return false;
  58         }
  59
  60         //
  61         // OBJECT METHODS
  62         //
  63
  64         /**
  65          * {@inheritDoc}
  66          */
  67         @Override
  68         public int hashCode() {
  69                 return id().hashCode();
  70         }
  71
  72         /**
  73          * {@inheritDoc}
  74          */
  75         @Override
  76         public boolean equals(Object obj) {
  77                 if (!(obj instanceof Base)) {
  78                         return false;
  79                 }
  80                 return id().equals(((Base) obj).id());
  81         }
  82
  83         /**
  84          * {@inheritDoc}
  85          */
  86         @Override
  87         public String toString() {
  88                 StringBuilder stringBuilder = new StringBuilder();
  89                 stringBuilder.append(getClass().getName());
  90                 stringBuilder.append('[').append("id=").append(id());
  91                 for (Entry<String, Value<?>> attributeEntry : attributes.entrySet()) {
  92                         stringBuilder.append(',').append(attributeEntry.getKey()).append('=').append(attributeEntry.getValue().get());
  93                 }
  94                 stringBuilder.append(']');
  95                 return stringBuilder.toString();
  96         }
  97
  98         protected static class Value<T> {
  99
 100                 private T original;
 101
 102                 private boolean originalSet;
 103
 104                 private T current;
 105
 106                 public T get() {
 107                         return current;
 108                 }
 109
 110                 public Value<T> set(T value) {
 111                         if (!originalSet) {
 112                                 original = value;
 113                                 originalSet = true;
 114                         }
 115                         current = value;
 116                         return this;
 117                 }
 118
 119                 public boolean dirty() {
 120                         return (original != null) ? !original.equals(current) : current != null;
 121                 }
 122
 123                 public Value<T> commit() {
 124                         original = current;
 125                         return this;
 126                 }
 127
 128         }
 129
 130 }