com.jgoodies.validation.extras.LimitedValidationResultModel Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jgoodies-validation Show documentation
The JGoodies Validation helps you validate user input in Swing apps and report validation errors and warnings. It has been designed to work with different architectures and programming flavors.
The newest version!
/*
 * Copyright (c) 2003-2014 JGoodies Software GmbH. 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 Software GmbH 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 static com.jgoodies.common.base.Preconditions.checkArgument;
import static com.jgoodies.common.base.Preconditions.checkNotNull;

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.
 *
 * Note: This class is not yet part of the binary Validation
 * library; it comes with the Validation distributions as an extra.
 * The API is work in progress and may change without notice;
 * this class may even be completely removed from future distributions.
 * If you want to use this class, you may consider copying it into
 * your code base.
 *
 * @author  Karsten Lentzsch
 * @version $Revision: 1.17 $
 *
 * @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 a {@code LimitedValidationResultModel}
     * 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) {
        checkNotNull(model, "The ValidationResultModel must not be null.");
        checkArgument(limit > 0, "The limit must be positive.");
        this.limit = limit;
        model.addPropertyChangeListener(ValidationResultModel.PROPERTY_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
         */
        @Override
		public void propertyChange(PropertyChangeEvent evt) {
            ValidationResult result = (ValidationResult) evt.getNewValue();
            setResult(limitedResult(result));
        }

    }


}