net.sf.jasperreports.engine.component.FillComponent Maven / Gradle / Ivy
/*
* JasperReports - Free Java Reporting Library.
* Copyright (C) 2001 - 2013 Jaspersoft Corporation. All rights reserved.
* http://www.jaspersoft.com
*
* Unless you have purchased a commercial license agreement from Jaspersoft,
* the following license terms apply:
*
* This program is part of JasperReports.
*
* JasperReports is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* JasperReports 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.
*
* You should have received a copy of the GNU Lesser General Public License
* along with JasperReports. If not, see
* The fill component implementation is responsible for managing a component
* at fill time. A typical implementation would evaluate a set of expressions
* and create a print element to be included in the generated report.
*
* @author Lucian Chirita ([email protected])
* @version $Id: FillComponent.java 5878 2013-01-07 20:23:13Z teodord $
*/
public interface FillComponent
{
/**
* Initializes the fill component with the fill context.
*
*
* This method is called before the fill component is used.
*
* @param fillContext the fill context
*/
void initialize(FillContext fillContext);
/**
* Evaluates the fill component.
*
*
* This method would evaluate the component expressions and store the
* results to be used in {@link #fill()}.
*
*
* If the component needs to delay the evaluation of some of its
* expressions, it would call
* {@link FillContext#registerDelayedEvaluation(JRPrintElement, EvaluationTimeEnum, String)}
* to register a delayed evaluation print element, and perform the delayed
* evaluations on {@link #evaluateDelayedElement(JRPrintElement, byte)}.
*
* @param evaluation the evaluation type
* @throws JRException
* @see FillContext#evaluate(net.sf.jasperreports.engine.JRExpression, byte)
*/
void evaluate(byte evaluation) throws JRException;
/**
* Prepares to fill the component by deciding whether the component will
* print, and how much vertical space it will require.
*
* @param availableHeight the amount of vertical space available for the
* component, starting from the top of the component element.
* @return the result of the preparation, which specifies whether the
* component will print and how much it will stretch vertically.
*/
FillPrepareResult prepare(int availableHeight);
/**
* Fills the component by creating a print element which will be included
* in the generated report.
*
*
* This method will get called only if {@link #prepare(int)} returned
* a result that indicated that the component will print.
*
* @return the print element generated by the component
*/
JRPrintElement fill();
/**
* Rewinds the component.
*
*
* This method is called when filling the component has been canceled and
* is about to be restarted. The component needs to reset its state
* (if any) to initial values.
*/
void rewind();
/**
* Perform delayed evaluations and fill the print element with the
* resulting data.
*
* @param element the print element for which delayed evaluation has
* been registered
* @param evaluation the evaluation type
* @throws JRException
* @see #evaluate(byte)
*/
void evaluateDelayedElement(JRPrintElement element, byte evaluation) throws JRException;
}