Remove2.java

/*
 * RemoveObject2.java
 * Transform
 *
 * Copyright (c) 2001-2010 Flagstone Software Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright 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.
 *  * Neither the name of Flagstone Software Ltd. 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.flagstone.transform;

import java.io.IOException;

import com.flagstone.transform.coder.Coder;
import com.flagstone.transform.coder.Context;
import com.flagstone.transform.coder.SWFDecoder;
import com.flagstone.transform.coder.SWFEncoder;
import com.flagstone.transform.exception.IllegalArgumentRangeException;

/**
 * RemoveObject2 removes an object from the display list, requiring only the
 * layer number.
 *
 * @see Remove
 */
public final class Remove2 implements MovieTag {

    /** Format string used in toString() method. */
    private static final String FORMAT = "Remove2: { layer=%d}";

    /** The layer where the object is displayed. */
    private int layer;

    /**
     * Creates and initialises a Remove2 object using values encoded
     * in the Flash binary format.
     *
     * @param coder
     *            an SWFDecoder object that contains the encoded Flash data.
     *
     * @throws IOException
     *             if an error occurs while decoding the data.
     */
    public Remove2(final SWFDecoder coder) throws IOException {
        if ((coder.readUnsignedShort() & Coder.LENGTH_FIELD)
        		== Coder.IS_EXTENDED) {
            coder.readInt();
        }
        layer = coder.readUnsignedShort();
    }

    /**
     * Creates a RemoveObject2, specifying the layer in the display list where
     * the object to be removed is currently displayed.
     *
     * @param level
     *            the layer number on which the object is displayed. Must be in
     *            the range 1.65535.
     */
    public Remove2(final int level) {
        setLayer(level);
    }

    /**
     * Creates and initialises a Remove2 object using the values copied
     * from another Remove2 object.
     *
     * @param object
     *            a Remove2 object from which the values will be
     *            copied.
     */
    public Remove2(final Remove2 object) {
        layer = object.layer;
    }

    /**
     * Get the layer in the display list where the object to be removed is
     * currently displayed.
     *
     * @return the layer number.
     */
    public int getLayer() {
        return layer;
    }

    /**
     * Sets the layer in the display list from which the object will be removed.
     *
     * @param aLayer
     *            the layer number on which the object is displayed. Must be in
     *            the range 1.65535.
     */
    public void setLayer(final int aLayer) {
        if ((aLayer < 1) || (aLayer > Coder.USHORT_MAX)) {
            throw new IllegalArgumentRangeException(
                    1, Coder.USHORT_MAX, aLayer);
        }
        layer = aLayer;
    }

    /** {@inheritDoc} */
    @Override
	public Remove2 copy() {
        return new Remove2(this);
    }

    /** {@inheritDoc} */
    @Override
    public String toString() {
        return String.format(FORMAT, layer);
    }

    /** {@inheritDoc} */
    @Override
	public int prepareToEncode(final Context context) {
        // CHECKSTYLE:OFF
        return 4;
        // CHECKSTYLE:ON
    }

    /** {@inheritDoc} */
    @Override
	public void encode(final SWFEncoder coder, final Context context)
            throws IOException {
        coder.writeShort((MovieTypes.REMOVE_2
                << Coder.LENGTH_FIELD_SIZE) | 2);
        coder.writeShort(layer);
    }
}