/*
* Copyright (c) 2003-2007 JGoodies Karsten Lentzsch. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* o Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* o Neither the name of JGoodies Karsten Lentzsch nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.jgoodies.validation.extras;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import com.jgoodies.validation.ValidationResult;
import com.jgoodies.validation.ValidationResultModel;
import com.jgoodies.validation.util.DefaultValidationResultModel;
/**
* An implementation of {@link ValidationResultModel} that wraps another
* ValidationResultModel to limit the number of reported
* {@link com.jgoodies.validation.ValidationMessage}s.<p>
*
* <strong>Note:</strong> This class is not yet part of the binary Validation
* library; it comes with the Validation distributions as an extra.
* <strong>The API is work in progress and may change without notice;
* this class may even be completely removed from future distributions.</strong>
* If you want to use this class, you may consider copying it into
* your code base.
*
* @author Karsten Lentzsch
* @version $Revision: 1.14 $
*
* @see com.jgoodies.validation.ValidationResultModel
*/
public final class LimitedValidationResultModel extends DefaultValidationResultModel {
/**
* Holds the upper bound for the number of messages in
* ValidationResults this model reports.
*/
private final int limit;
// Instance Creation ******************************************************
/**
* Constructs an <code>LimitedValidationResultModel</code>
* on the given ValidationResultModel.
*
* @param model the underlying model that provides all validation messages
* @param limit the upper bound for the number of messages this model returns
*/
public LimitedValidationResultModel(ValidationResultModel model, int limit) {
if (model == null)
throw new NullPointerException("The ValidationResultModel must not be null.");
if (limit <= 0)
throw new IllegalArgumentException("The limit must be positive.");
this.limit = limit;
model.addPropertyChangeListener(ValidationResultModel.PROPERTYNAME_RESULT, new ValidationResultChangeHandler());
}
// Implementing the Limitation ********************************************
private ValidationResult limitedResult(ValidationResult result) {
return result.isEmpty()
? ValidationResult.EMPTY
: result.subResult(0, Math.min(limit, result.size()));
}
// Helper Class ***********************************************************
/**
* Updates the limited validation result if the underlying model changes.
*/
private final class ValidationResultChangeHandler implements PropertyChangeListener {
/**
* The underlying validation result model has changed.
* Updates this model's validation result to a limited version
* of the new full validation result.
*
* @param evt the property change event to handle
*/
public void propertyChange(PropertyChangeEvent evt) {
ValidationResult result = (ValidationResult) evt.getNewValue();
setResult(limitedResult(result));
}
}
}
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