cyclingspinnerlistmodel.java

java tutotrials or beginners

/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved.
 *
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 * modification, are permitted provided that the following conditions
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 *
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 *     notice, this list of conditions and the following disclaimer.
 *
 *   - 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.
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 *   - Neither the name of Sun Microsystems 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
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */ 

package components;

import javax.swing.SpinnerModel;
import javax.swing.SpinnerListModel;

/**
 * This 1.4 example is used by the various SpinnerDemos.
 * It implements a SpinnerListModel that works only with
 * an Object array and that implements cycling (the next
 * value and previous value are never null).  It also
 * lets you optionally associate a spinner model that's
 * linked to this one, so that when a cycle occurs the
 * linked spinner model is updated.

 * The SpinnerDemos use the CyclingSpinnerListModel for
 * a month spinner that (in SpinnerDemo3) is tied to the
 * year spinner, so that -- for example -- when the month
 * changes from December to January, the year increases.
 */
public class CyclingSpinnerListModel extends SpinnerListModel {
    Object firstValue, lastValue;
    SpinnerModel linkedModel = null;

    public CyclingSpinnerListModel(Object[] values) {
        super(values);
        firstValue = values[0];
        lastValue = values[values.length - 1];
    }

    public void setLinkedModel(SpinnerModel linkedModel) {
        this.linkedModel = linkedModel;
    }

    public Object getNextValue() {
        Object value = super.getNextValue();
        if (value == null) {
            value = firstValue;
            if (linkedModel != null) {
                linkedModel.setValue(linkedModel.getNextValue());
            }
        }
        return value;
    }

    public Object getPreviousValue() {
        Object value = super.getPreviousValue();
        if (value == null) {
            value = lastValue;
            if (linkedModel != null) {
                linkedModel.setValue(linkedModel.getPreviousValue());
            }
        }
        return value;
    }
}