cstring.java

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.poi.hslf.record;

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

import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.StringUtil;

/**
 * A CString (type 4026). Holds a unicode string, and the first two bytes
 *  of the record header normally encode the count. Typically attached to
 *  some complex sequence of records, eg Commetns.
 *
 * @author Nick Burch
 */

public class CString extends RecordAtom {
	private byte[] _header;
	private static long _type = 4026l;
	
	/** The bytes that make up the text */
	private byte[] _text;
	
	/** Grabs the text. */
	public String getText() { 
		return StringUtil.getFromUnicodeLE(_text);
	}

	/** Updates the text in the Atom. */
	public void setText(String text) {
		// Convert to little endian unicode
		_text = new byte[text.length()*2];
		StringUtil.putUnicodeLE(text,_text,0);

		// Update the size (header bytes 5-8)
		LittleEndian.putInt(_header,4,_text.length);
	}
	
	/** 
	 * Grabs the count, from the first two bytes of the header.
	 * The meaning of the count is specific to the type of the parent record 
	 */
	public int getCount() {
		return (int)LittleEndian.getShort(_header);
	}
	
	/** 
	 * Sets the count
	 * The meaning of the count is specific to the type of the parent record 
	 */
	public void setCount(int count) {
		LittleEndian.putShort(_header, (short)count);
	}

	/* *************** record code follows ********************** */

	/** 
	 * For the CStrubg Atom 
	 */
	protected CString(byte[] source, int start, int len) {
		// Sanity Checking
		if(len < 8) { len = 8; }

		// Get the header
		_header = new byte[8];
		System.arraycopy(source,start,_header,0,8);

		// Grab the text
		_text = new byte[len-8];
		System.arraycopy(source,start+8,_text,0,len-8);
	}
	/**
	 * Create an empty CString
	 */
	public CString() {
		// 0 length header
		_header = new byte[] {  0, 0, 0xBA-256, 0x0f, 0, 0, 0, 0 };
		// Empty text
		_text = new byte[0];
	}

	/**
	 * We are of type 4026
	 */
	public long getRecordType() { return _type; }

	/**
	 * Write the contents of the record back, so it can be written
	 *  to disk
	 */
	public void writeOut(OutputStream out) throws IOException {
		// Header - size or type unchanged
		out.write(_header);

		// Write out our text
		out.write(_text);
	}
}