/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.wicket.examples.tree;
import java.io.Serializable;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.apache.wicket.MetaDataKey;
import org.apache.wicket.Session;
/**
* Example of a custom expansion state:
* <ul>
* <li>expanded {@link Foo}s are identified by their id</li>
* <li>efficient expansion of all {@link Foo}</li>
* <li>state is stored in the session</li>
* </ul>
*
* @author svenmeier
*/
public class FooExpansion implements Set<Foo>, Serializable
{
private static final long serialVersionUID = 1L;
private static MetaDataKey<FooExpansion> KEY = new MetaDataKey<FooExpansion>()
{
private static final long serialVersionUID = 1L;
};
private Set<String> ids = new HashSet<>();
private boolean inverse;
public void expandAll()
{
ids.clear();
inverse = true;
}
public void collapseAll()
{
ids.clear();
inverse = false;
}
@Override
public boolean add(Foo foo)
{
if (inverse)
{
return ids.remove(foo.getId());
}
else
{
return ids.add(foo.getId());
}
}
@Override
public boolean remove(Object o)
{
Foo foo = (Foo)o;
if (inverse)
{
return ids.add(foo.getId());
}
else
{
return ids.remove(foo.getId());
}
}
@Override
public boolean contains(Object o)
{
Foo foo = (Foo)o;
if (inverse)
{
return !ids.contains(foo.getId());
}
else
{
return ids.contains(foo.getId());
}
}
@Override
public void clear()
{
throw new UnsupportedOperationException();
}
@Override
public int size()
{
throw new UnsupportedOperationException();
}
@Override
public boolean isEmpty()
{
throw new UnsupportedOperationException();
}
@Override
public <A> A[] toArray(A[] a)
{
throw new UnsupportedOperationException();
}
@Override
public Iterator<Foo> iterator()
{
throw new UnsupportedOperationException();
}
@Override
public Object[] toArray()
{
throw new UnsupportedOperationException();
}
@Override
public boolean containsAll(Collection<?> c)
{
throw new UnsupportedOperationException();
}
@Override
public boolean addAll(Collection<? extends Foo> c)
{
throw new UnsupportedOperationException();
}
@Override
public boolean retainAll(Collection<?> c)
{
throw new UnsupportedOperationException();
}
@Override
public boolean removeAll(Collection<?> c)
{
throw new UnsupportedOperationException();
}
/**
* Get the expansion for the session.
*
* @return expansion
*/
public static FooExpansion get()
{
FooExpansion expansion = Session.get().getMetaData(KEY);
if (expansion == null)
{
expansion = new FooExpansion();
Session.get().setMetaData(KEY, expansion);
}
return expansion;
}
}