// 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.vlib.components;
import org.apache.tapestry.BaseComponent;
import org.apache.tapestry.IActionListener;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.vlib.ejb.SortColumn;
/**
* Comopnent for allowing a column to be sorted.
*
* @author Howard Lewis Ship
* @since 3.0
*/
public abstract class ColumnSorter extends BaseComponent
{
public abstract SortColumn getSortColumn();
public abstract SortColumn getSelected();
public abstract void setSelected(SortColumn selected);
public abstract boolean isDescending();
public abstract void setDescending(boolean descending);
public abstract IActionListener getListener();
public void handleClick(IRequestCycle cycle)
{
SortColumn selected = getSelected();
SortColumn sortColumn = getSortColumn();
if (selected != sortColumn)
{
setSelected(sortColumn);
setDescending(false);
}
else
{
boolean current = isDescending();
setDescending(!current);
}
IActionListener listener = getListener();
if (listener == null)
throw Tapestry.createRequiredParameterException(this, "listener");
listener.actionTriggered(this, cycle);
}
}