/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2001 - 2009 Object Refinery Ltd, Pentaho Corporation and Contributors.. All rights reserved.
*/
package org.pentaho.reporting.engine.classic.core.function;
import javax.swing.table.TableModel;
import org.pentaho.reporting.engine.classic.core.Band;
import org.pentaho.reporting.engine.classic.core.Element;
/**
* This functions checks the tablemodel and hides the named elements, if there is no data available.
*
* @author Thomas Morgner
* @deprecated Use a formula instead.
*/
public class ShowElementIfDataAvailableExpression
extends AbstractElementFormatFunction
{
/**
* Default Constructor.
*/
public ShowElementIfDataAvailableExpression()
{
}
/**
* Applies the computed visiblity to all elements with the name defined in this expression.
*
* @param b the band.
*/
protected void processRootBand(final Band b)
{
final boolean visible = isDataAvailable();
final Element[] elements = FunctionUtilities.findAllElements(b, getElement());
for (int i = 0; i < elements.length; i++)
{
final Element element = elements[i];
element.setVisible(visible);
}
}
/**
* Computes the visibility state.
*
* @return true, if there is data available, false otherwise.
*/
private boolean isDataAvailable()
{
final ExpressionRuntime runtime = getRuntime();
if (runtime == null)
{
return false;
}
final TableModel data = runtime.getData();
if (data == null)
{
return false;
}
if (data.getRowCount() == 0)
{
return false;
}
return true;
}
/**
* Return the current expression value. <P> The value depends (obviously) on the expression implementation.
*
* @return the value of the function.
*/
public Object getValue()
{
if (isDataAvailable())
{
return Boolean.TRUE;
}
return Boolean.FALSE;
}
}