// Copyright 2004, 2005 The Apache Software Foundation
//
// 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 org.apache.tapestry.contrib.table.model.common;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.tapestry.contrib.table.model.CTableDataModelEvent;
import org.apache.tapestry.contrib.table.model.ITableDataModel;
import org.apache.tapestry.contrib.table.model.ITableDataModelListener;
/**
* An implementation of the listener support in the ITableDataModel interface
*
* @author mindbridge
*/
public abstract class AbstractTableDataModel implements ITableDataModel
{
private List m_arrListeners;
public AbstractTableDataModel()
{
m_arrListeners = new ArrayList();
}
/**
* Method fireTableDataModelEvent.
* Fires a change event to all listeners
* @param objEvent the event to pass to the listeners
*/
protected void fireTableDataModelEvent(CTableDataModelEvent objEvent)
{
synchronized (m_arrListeners) {
List arrEmptyReferences = null;
for (Iterator it = m_arrListeners.iterator(); it.hasNext();)
{
WeakReference objRef = (WeakReference) it.next();
ITableDataModelListener objListener =
(ITableDataModelListener) objRef.get();
if (objListener != null)
objListener.tableDataChanged(objEvent);
else {
if (arrEmptyReferences == null)
arrEmptyReferences = new ArrayList();
arrEmptyReferences.add(objRef);
}
}
if (arrEmptyReferences != null)
m_arrListeners.removeAll(arrEmptyReferences);
}
}
/**
* @see org.apache.tapestry.contrib.table.model.ITableDataModel#addTableDataModelListener(ITableDataModelListener)
*/
public void addTableDataModelListener(ITableDataModelListener objListener)
{
synchronized (m_arrListeners) {
m_arrListeners.add(new WeakReference(objListener));
}
}
/**
* @see org.apache.tapestry.contrib.table.model.ITableDataModel#removeTableDataModelListener(ITableDataModelListener)
*/
public void removeTableDataModelListener(ITableDataModelListener objListener)
{
synchronized (m_arrListeners) {
List arrEmptyReferences = null;
for (Iterator it = m_arrListeners.iterator(); it.hasNext();)
{
WeakReference objRef = (WeakReference) it.next();
ITableDataModelListener objStoredListener =
(ITableDataModelListener) objRef.get();
if (objListener == objStoredListener || objStoredListener == null) {
if (arrEmptyReferences == null)
arrEmptyReferences = new ArrayList();
arrEmptyReferences.add(objRef);
}
}
if (arrEmptyReferences != null)
m_arrListeners.removeAll(arrEmptyReferences);
}
}
}