| // Copyright 2004 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 |
| * |
| * @version $Id$ |
| * @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); |
| } |
| } |
| |
| } |