SWFWriter.java

/*
 * JSwiff is an open source Java API for Macromedia Flash file generation
 * and manipulation
 *
 * Copyright (C) 2004-2006 Ralf Terdic (contact@jswiff.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package com.jswiff;

import com.jswiff.io.OutputBitStream;
import com.jswiff.swfrecords.tags.FileAttributes;
import com.jswiff.swfrecords.tags.Metadata;
import com.jswiff.swfrecords.tags.SetBackgroundColor;
import com.jswiff.swfrecords.tags.Tag;
import com.jswiff.swfrecords.tags.TagConstants;
import com.jswiff.swfrecords.tags.TagWriter;

import java.io.IOException;
import java.io.OutputStream;

import java.util.Iterator;

/**
 * This class writes an SWF document (an <code>SWFDocument</code> instance) to
 * an output stream. Usage:
 * 
 * <pre>
 * <code>
 * SWFWriter writer = new SWFWriter(doc, outputStream);
 * writer.write();
 * </code>
 * </pre>
 */
public class SWFWriter {
	private OutputBitStream bitStream;

	private SWFDocument document;

	private boolean japanese;

	/**
	 * Creates a new SWF writer which writes the specified SWF document to the
	 * stream supplied here.
	 * 
	 * @param document
	 *            the SWF document to be written
	 * @param stream
	 *            the output stream the SWF file is written to
	 */
	public SWFWriter(SWFDocument document, OutputStream stream) {
		bitStream = new OutputBitStream(stream);
		this.document = document;
	}

	/**
	 * Specifies whether strings should be encoded using Japanese encoding
	 * (Shift-JIS). This is relevant only for SWF 5 or earlier, where strings
	 * are encoded using either ANSI or Shift-JIS. In Flash Player, the decoding
	 * choice is made depending on the locale, as this information is not stored
	 * in the SWF. Later SWF versions use Unicode (UTF-8) and ignore this
	 * option.
	 * 
	 * @param japanese
	 *            <code>true</code> if Shift-JIS encoding is to be used
	 */
	public void setJapanese(boolean japanese) {
		this.japanese = japanese;
	}

	/**
	 * Writes the SWF to the stream passed to the constructor. The stream is
	 * then closed.
	 * 
	 * @throws IOException
	 *             if an I/O error occured
	 */
	public void write() throws IOException {
		try {
			byte[] docPropertiesTagsBuffer = getDocPropertiesTagsBuffer();
			byte[] tagsBuffer = TagWriter.writeTags(document.getTags(), document.getVersion(), japanese);
			byte[] headerEndData = getHeaderEndData();
			long fileLength = 8 + headerEndData.length + tagsBuffer.length + docPropertiesTagsBuffer.length;
			writeHeaderStart();
			bitStream.writeUI32(fileLength);
			if (document.isCompressed()) {
				bitStream.enableCompression();
			}
			bitStream.writeBytes(headerEndData);
			// header written, now write document property tags (background,
			// file attrs, metadata)
			bitStream.writeBytes(docPropertiesTagsBuffer);
			// write all remaining tags
			bitStream.writeBytes(tagsBuffer);
		} finally {
			try {
				bitStream.close();
			} catch (Exception e) {
				// empty on purpose - don't need to propagate errors which occur
				// while closing
			}
		}
	}

	protected byte[] getDocPropertiesTagsBuffer() throws IOException {
		OutputBitStream tagStream = new OutputBitStream();
		if (document.getVersion() >= 8) {
			FileAttributes fileAttributes = new FileAttributes();
			fileAttributes.setAllowNetworkAccess(document.getAccessMode() == SWFDocument.ACCESS_MODE_NETWORK);
			TagWriter.writeTag(tagStream, fileAttributes, document.getVersion());
			String metadata = document.getMetadata();
			if (metadata != null) {
				fileAttributes.setHasMetadata(true);
				TagWriter.writeTag(tagStream, new Metadata(metadata), document.getVersion());
			}
		}
		TagWriter.writeTag(tagStream, new SetBackgroundColor(document.getBackgroundColor()), document.getVersion());
		return tagStream.getData();
	}

	private int getFrameCount() {
		int count = 0;
		for (Iterator i = document.getTags().iterator(); i.hasNext();) {
			if (((Tag) i.next()).getCode() == TagConstants.SHOW_FRAME) {
				count++;
			}
		}
		return count;
	}

	private byte[] getHeaderEndData() throws IOException {
		OutputBitStream headerStream = new OutputBitStream();

		// frame size
		document.getFrameSize().write(headerStream);
		// frame rate
		headerStream.writeUI8((short) 0); // this byte is ignored
		headerStream.writeUI8(document.getFrameRate());
		// frame count
		headerStream.writeUI16(getFrameCount());
		byte[] headerData = headerStream.getData();
		return headerData;
	}

	private void writeHeaderStart() throws IOException {
		// writes CWS/FWS and version - that's 4 bytes
		// C (0x43) for compressed or F (0x46) for uncompressed files
		bitStream.writeUI8((short) (document.isCompressed() ? 0x43 : 0x46));
		// WS (0x57 0x53)
		bitStream.writeBytes(new byte[] { 0x57, 0x53 });
		// version
		bitStream.writeUI8(document.getVersion());
	}
}