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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.
- */
-
- /* $Id$ */
-
- package org.apache.fop.pdf;
-
- import java.io.ByteArrayOutputStream;
- import java.io.IOException;
- import java.io.OutputStream;
- import java.util.ArrayList;
- import java.util.List;
-
- import org.apache.fop.pdf.xref.CompressedObjectReference;
-
- /**
- * An object stream, as described in section 3.4.6 of the PDF 1.5 Reference.
- */
- public class ObjectStream extends PDFStream {
-
- private static final PDFName OBJ_STM = new PDFName("ObjStm");
-
- private List<CompressedObject> objects = new ArrayList<CompressedObject>();
-
- private int firstObjectOffset;
-
- ObjectStream() {
- super(false);
- }
-
- ObjectStream(ObjectStream previous) {
- this();
- put("Extends", previous);
- }
-
- CompressedObjectReference addObject(CompressedObject obj) {
- if (obj == null) {
- throw new NullPointerException("obj must not be null");
- }
- CompressedObjectReference reference = new CompressedObjectReference(obj.getObjectNumber(),
- getObjectNumber(), objects.size());
- objects.add(obj);
- return reference;
- }
-
- @Override
- protected void outputRawStreamData(OutputStream out) throws IOException {
- int currentOffset = 0;
- StringBuilder offsetsPart = new StringBuilder();
- ByteArrayOutputStream streamContent = new ByteArrayOutputStream();
- for (CompressedObject object : objects) {
- offsetsPart.append(object.getObjectNumber())
- .append(' ')
- .append(currentOffset)
- .append('\n');
- currentOffset += object.output(streamContent);
- }
- byte[] offsets = PDFDocument.encode(offsetsPart.toString());
- firstObjectOffset = offsets.length;
- out.write(offsets);
- streamContent.writeTo(out);
- }
-
- @Override
- protected void populateStreamDict(Object lengthEntry) {
- put("Type", OBJ_STM);
- put("N", objects.size());
- put("First", firstObjectOffset);
- super.populateStreamDict(lengthEntry);
- }
- }
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