org.apache.fop.afp.ptoca.TransparentDataControlSequence Maven / Gradle / Ivy
/*
* 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.
*/
/* $Id$ */
package org.apache.fop.afp.ptoca;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.apache.fop.afp.fonts.CharactersetEncoder.EncodedChars;
import org.apache.fop.afp.ptoca.TransparentDataControlSequence.TransparentData;
import static org.apache.fop.afp.ptoca.PtocaConstants.TRANSPARENT_DATA_MAX_SIZE;
/**
* This object represents a series of PTOCA TransparentData (TRN) control sequences. This implements
* {@link Iterable} to enable iteration through the TRNs.
*/
final class TransparentDataControlSequence implements Iterable {
private static final int MAX_SBCS_TRN_SIZE = TRANSPARENT_DATA_MAX_SIZE;
// The maximum size of a TRN must be an EVEN number so that we're splitting TRNs on character
// boundaries rather than in the middle of a double-byte character
private static final int MAX_DBCS_TRN_SIZE = MAX_SBCS_TRN_SIZE - 1;
static final class TransparentData {
private final int offset;
private final int length;
private final EncodedChars encodedChars;
private TransparentData(int offset, int length, EncodedChars encChars) {
this.offset = offset;
this.length = length;
this.encodedChars = encChars;
}
void writeTo(OutputStream outStream) throws IOException {
encodedChars.writeTo(outStream, offset, length);
}
}
private final List trns;
/**
* Converts an encoded String wrapped in an {@link EncodedChars} into a series of
* {@link TransparentData} control sequences.
*
* @param encChars the encoded characters to convert to TRNs
*/
public TransparentDataControlSequence(EncodedChars encChars) {
int maxTrnLength = encChars.isDBCS() ? MAX_DBCS_TRN_SIZE : MAX_SBCS_TRN_SIZE;
int numTransData = encChars.getLength() / maxTrnLength;
int currIndex = 0;
List trns = new ArrayList();
for (int transDataCnt = 0; transDataCnt < numTransData; transDataCnt++) {
trns.add(new TransparentData(currIndex, maxTrnLength, encChars));
currIndex += maxTrnLength;
}
int left = encChars.getLength() - currIndex;
trns.add(new TransparentData(currIndex, left, encChars));
this.trns = Collections.unmodifiableList(trns);
}
/**
* The {@link Iterator} for retrieving the series of TRN control sequences.
*/
public Iterator iterator() {
return trns.iterator();
}
}