/*
* Copyright 2012 Daniel Bechler
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package de.danielbechler.diff.access;
import de.danielbechler.diff.selector.ElementSelector;
import de.danielbechler.diff.selector.MapKeyElementSelector;
import de.danielbechler.util.Assert;
import java.util.Map;
/**
* @author Daniel Bechler
*/
public final class MapEntryAccessor implements Accessor
{
private final Object referenceKey;
public MapEntryAccessor(final Object referenceKey)
{
Assert.notNull(referenceKey, "referenceKey");
this.referenceKey = referenceKey;
}
public Object getKey(final Map<?, ?> target)
{
final Map<Object, Object> map = objectToMap(target);
if (map == null)
{
return null;
}
final Object referenceKey = this.referenceKey;
for (final Object key : map.keySet())
{
if (key == referenceKey || key.equals(referenceKey))
{
return key;
}
}
return null;
}
@Override
public int hashCode()
{
return referenceKey.hashCode();
}
@Override
public boolean equals(final Object o)
{
if (this == o)
{
return true;
}
if (o == null || getClass() != o.getClass())
{
return false;
}
return referenceKey.equals(((MapEntryAccessor) o).referenceKey);
}
@Override
public String toString()
{
return "map key " + getElementSelector();
}
public ElementSelector getElementSelector()
{
return new MapKeyElementSelector(referenceKey);
}
public Object get(final Object target)
{
final Map<?, ?> targetMap = objectToMap(target);
if (targetMap != null)
{
return targetMap.get(referenceKey);
}
return null;
}
public void set(final Object target, final Object value)
{
final Map<Object, Object> targetMap = objectToMap(target);
if (targetMap != null)
{
targetMap.put(referenceKey, value);
}
}
public void unset(final Object target)
{
final Map<?, ?> targetMap = objectToMap(target);
if (targetMap != null)
{
targetMap.remove(referenceKey);
}
}
private static Map<Object, Object> objectToMap(final Object object)
{
if (object == null)
{
return null;
}
if (object instanceof Map)
{
//noinspection unchecked
return (Map<Object, Object>) object;
}
throw new IllegalArgumentException(object.getClass().toString());
}
}