/*
* DefineJPEGImage3.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.image;
import java.io.IOException;
import java.util.Arrays;
import com.flagstone.transform.Constants;
import com.flagstone.transform.MovieTypes;
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;
/**
* DefineJPEGImage3 is used to define a transparent JPEG encoded image.
*
* <p>
* It extends the DefineJPEGImage2 class by including a separate zlib compressed
* table of alpha channel values. This allows the transparency of existing JPEG
* encoded images to be changed without re-encoding the original image.
* </p>
*
* @see DefineJPEGImage2
*/
public final class DefineJPEGImage3 implements ImageTag {
/** Format string used in toString() method. */
private static final String FORMAT = "DefineJPEGImage3: { identifier=%d;"
+ "image=byte<%d> ...; alpha=byte<%d> ...}";
/** The unique identifier for this object. */
private int identifier;
/** The JPEG encoded image. */
private byte[] image;
/** The zlib compressed transparency values for the image. */
private byte[] alpha;
/** The length of the object, minus the header, when it is encoded. */
private transient int length;
/** The width of the image in pixels. */
private transient int width;
/** The height of the image in pixels. */
private transient int height;
/**
* Creates and initialises a DefineJPEGImage3 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 DefineJPEGImage3(final SWFDecoder coder) throws IOException {
length = coder.readUnsignedShort() & Coder.LENGTH_FIELD;
if (length == Coder.IS_EXTENDED) {
length = coder.readInt();
}
coder.mark();
identifier = coder.readUnsignedShort();
final int offset = coder.readInt();
image = coder.readBytes(new byte[offset]);
// CHECKSTYLE IGNORE MagicNumberCheck FOR NEXT 1 LINES
alpha = coder.readBytes(new byte[length - offset - 6]);
decodeInfo();
coder.check(length);
coder.unmark();
}
/**
* Creates a DefineJPEGImage3 object with the specified image data, and
* alpha channel data.
*
* @param uid
* the unique identifier for this object. Must be in the range
* 1..65535.
* @param img
* the JPEG encoded image data. Must not be null.
* @param transparency
* byte array containing the zlib compressed alpha channel data.
* Must not be null.
*/
public DefineJPEGImage3(final int uid, final byte[] img,
final byte[] transparency) {
setIdentifier(uid);
setImage(img);
setAlpha(transparency);
}
/**
* Creates and initialises a DefineJPEGImage3 object using the values copied
* from another DefineJPEGImage3 object.
*
* @param object
* a DefineJPEGImage3 object from which the values will be
* copied.
*/
public DefineJPEGImage3(final DefineJPEGImage3 object) {
identifier = object.identifier;
width = object.width;
height = object.height;
image = object.image;
alpha = object.alpha;
}
/** {@inheritDoc} */
public int getIdentifier() {
return identifier;
}
/** {@inheritDoc} */
public void setIdentifier(final int uid) {
if ((uid < 1) || (uid > Coder.USHORT_MAX)) {
throw new IllegalArgumentRangeException(
1, Coder.USHORT_MAX, uid);
}
identifier = uid;
}
/**
* Get the width of the image in pixels (not twips).
*
* @return the width of the image.
*/
public int getWidth() {
return width;
}
/**
* Get the height of the image in pixels (not twips).
*
* @return the height of the image.
*/
public int getHeight() {
return height;
}
/**
* Get a copy of the image.
*
* @return a copy of the data.
*/
public byte[] getImage() {
return Arrays.copyOf(image, image.length);
}
/**
* Get a copy of the alpha channel.
*
* @return a copy of the data.
*/
public byte[] getAlpha() {
return Arrays.copyOf(alpha, alpha.length);
}
/**
* Sets the image data.
*
* @param bytes
* a list of bytes containing the image table. Must not be
* null.
*/
public void setImage(final byte[] bytes) {
image = Arrays.copyOf(bytes, bytes.length);
decodeInfo();
}
/**
* Sets the alpha channel data with the zlib compressed data.
*
* @param bytes
* array of bytes containing zlib encoded alpha channel. Must not
* be null.
*/
public void setAlpha(final byte[] bytes) {
alpha = Arrays.copyOf(bytes, bytes.length);
}
/** {@inheritDoc} */
public DefineJPEGImage3 copy() {
return new DefineJPEGImage3(this);
}
/** {@inheritDoc} */
@Override
public String toString() {
return String.format(FORMAT, identifier, image.length, alpha.length);
}
/** {@inheritDoc} */
public int prepareToEncode(final Context context) {
// CHECKSTYLE IGNORE MagicNumberCheck FOR NEXT 1 LINES
length = 6;
length += image.length;
length += alpha.length;
return (length > Coder.HEADER_LIMIT ? Coder.LONG_HEADER
: Coder.SHORT_HEADER) + length;
}
/** {@inheritDoc} */
public void encode(final SWFEncoder coder, final Context context)
throws IOException {
if (length > Coder.HEADER_LIMIT) {
coder.writeShort((MovieTypes.DEFINE_JPEG_IMAGE_3
<< Coder.LENGTH_FIELD_SIZE) | Coder.IS_EXTENDED);
coder.writeInt(length);
} else {
coder.writeShort((MovieTypes.DEFINE_JPEG_IMAGE_3
<< Coder.LENGTH_FIELD_SIZE) | length);
}
if (Constants.DEBUG) {
coder.mark();
}
coder.writeShort(identifier);
coder.writeInt(image.length);
coder.writeBytes(image);
coder.writeBytes(alpha);
if (Constants.DEBUG) {
coder.check(length);
coder.unmark();
}
}
/**
* Decode the JPEG image to get the width and height.
*/
private void decodeInfo() {
final JPEGInfo info = new JPEGInfo();
info.decode(image);
width = info.getWidth();
height = info.getHeight();
}
}