de.intarsys.pdf.content.CSContent Maven / Gradle / Ivy
/*
* Copyright (c) 2007, intarsys consulting GmbH
*
* 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 intarsys 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 de.intarsys.pdf.content;
import java.io.IOException;
import java.util.Iterator;
import de.intarsys.pdf.content.common.CSCreator;
import de.intarsys.pdf.cos.COSArray;
import de.intarsys.pdf.cos.COSName;
import de.intarsys.pdf.cos.COSObject;
import de.intarsys.pdf.cos.COSRuntimeException;
import de.intarsys.pdf.cos.COSStream;
import de.intarsys.pdf.filter.Filter;
import de.intarsys.pdf.parser.COSLoadException;
import de.intarsys.pdf.parser.CSContentParser;
import de.intarsys.pdf.writer.COSWriter;
import de.intarsys.tools.randomaccess.RandomAccessByteArray;
/**
* Represents the tokenized content of a PDF rendering program which is called a
* "content stream".
*
*
* A PDF rendering program is a sequence of operations, each build by a list of
* operands followed by the operator.
*
*
*
* Any visual appearance in a PDF document is build on a content stream. For
* example a PDPage hosts a content stream (or a list of content streams) to
* define its appearance.
*
*
*
* A content stream has no access to indirect objects, this means object
* references are not valid operands for operations. Complex objects are used
* within a content stream via an indirection defined in a resource dictionary.
*
*
* The {@link CSContent} itself is decoupled from its source of creation, this
* means after manipulating the content stream you have to apply it where you
* want to (for example adding it to a page).
*
* You can work on the content stream directly, adding and removing operations.
* A more elegant way to manipulate this is using a {@link CSCreator}, providing
* high level methods for the different content stream operations.
*/
public class CSContent {
/**
* Create {@link CSContent} from a byte array containing a PDF content
* stream.
*
* @param data
* The bytes defining the PDF content stream.
*
* @return The new {@link CSContent}
*/
static public CSContent createFromBytes(byte[] data) {
try {
CSContentParser parser = new CSContentParser();
return parser.parseStream(data);
} catch (IOException e) {
throw new COSRuntimeException(e);
} catch (COSLoadException e) {
throw new COSRuntimeException(e);
}
}
/**
* Create {@link CSContent} from an array of {@link COSStream}, together
* defining a PDF content stream.
*
* @param streams
* An array of {@link COSStream} objects containing each a chunk
* of the content stream.
* @return The new {@link CSContent}.
*/
static public CSContent createFromCos(COSArray streams) {
RandomAccessByteArray data = new RandomAccessByteArray(null);
try {
for (Iterator it = streams.iterator(); it.hasNext();) {
COSStream stream = ((COSObject) it.next()).asStream();
if (stream != null) {
data.write(stream.getDecodedBytes());
// force at least a single space between streams
data.write(32);
}
}
CSContentParser parser = new CSContentParser();
data.seek(0);
return parser.parseStream(data);
} catch (IOException e) {
throw new COSRuntimeException(e);
} catch (COSLoadException e) {
throw new COSRuntimeException(e);
}
}
/**
* Create {@link CSContent} from a {@link COSStream} containing a PDF
* content stream.
*
* @param stream
* The stream defining containing the PDF content stream.
*
* @return The new {@link CSContent}
*/
static public CSContent createFromCos(COSStream stream) {
return createFromBytes(stream.getDecodedBytes());
}
/**
* Create a new {@link CSContent}.
*
* @return The new {@link CSContent}.
*/
static public CSContent createNew() {
CSContent result = new CSContent();
return result;
}
/**
* the tokenized elements of the content stream. The elements of this list
* are COSStreamOperation objects.
*/
private CSOperation[] operations = new CSOperation[100];
private int size = 0;
/**
* Create a new PDCContentStream.
*
* @param resourceDict
* The dictionary defining the external references of the content
* stream.
*/
protected CSContent() {
super();
}
/**
* Add "content" at the end of the "marked content" portion in the content
* stream of this.
*
* @param mark
* The type of marked content we search
* @param content
* The content we want to use.
*/
public void addMarkedContent(COSName mark, byte[] content) {
int i = 0;
for (; i < size; i++) {
CSOperation operation = operations[i];
if (operation.isOpBeginMarkedContent(mark)) {
i++;
break;
}
}
if (i < size) {
// found
int nesting = 0;
for (i++; i < size; i++) {
CSOperation operation = operations[i];
if (operation.isOpBeginMarkedContent(null)) {
nesting++;
}
if (operation.isOpEndMarkedContent()) {
if (nesting == 0) {
addOperation(i, new CSLiteral(content));
break;
}
nesting--;
}
}
} else {
CSOperation operation;
operation = new CSOperation(CSOperators.CSO_BMC);
operation.addOperand(CSOperation.OPERAND_Tx);
addOperation(operation);
addOperation(new CSLiteral(content));
operation = new CSOperation(CSOperators.CSO_EMC);
addOperation(operation);
}
}
/**
* Add another operation to the rendering program.
*
* @param op
* The new operation to append.
*/
public void addOperation(CSOperation op) {
if (size >= operations.length) {
CSOperation[] newOperations = new CSOperation[size * 2];
System.arraycopy(operations, 0, newOperations, 0, size);
operations = newOperations;
}
operations[size++] = op;
}
/**
* Add another operation to the rendering program.
*
* @param op
* The new operation to append.
*/
public void addOperation(int index, CSOperation op) {
if (size >= operations.length) {
CSOperation[] newOperations = new CSOperation[size * 2];
System.arraycopy(operations, 0, newOperations, 0, size);
operations = newOperations;
}
System
.arraycopy(operations, index, operations, index + 1, size
- index);
size++;
operations[index] = op;
}
public COSStream createStream() {
COSStream result = COSStream.create(null);
result.setDecodedBytes(toByteArray());
return result;
}
public COSStream createStreamFlate() {
COSStream result = COSStream.create(null);
byte[] bytes = toByteArray();
result.setDecodedBytes(bytes);
if (bytes.length > 10) {
// deflate large streams
result.addFilter(Filter.CN_Filter_FlateDecode);
}
return result;
}
/**
* remove last operation from the rendering program.
*
* @return the last operation, or null of no operations left
*/
public CSOperation getLastOperation() {
if (size == 0) {
return null;
}
return operations[size - 1];
}
public CSOperation getOperation(int index) {
return operations[index];
}
public CSOperation[] getOperations() {
CSOperation[] copy = new CSOperation[size];
System.arraycopy(operations, 0, copy, 0, size());
return copy;
}
/**
* remove last operation from the rendering program.
*/
public void removeLastOperation() {
removeOperation(size - 1);
}
public void removeOperation(int index) {
System.arraycopy(operations, index + 1, operations, index, size - index
- 1);
size--;
}
/**
* Set the "marked content" portion in the content stream of this. Marked
* content is enclosed between "BMC" and "EMC", the begin operation has an
* operand identifying the type of marked content.
*
*
* The portion between the marks is replaced with content.If no
* marks are found, the new content is appended as a marked content section.
*
*
* @param mark
* The type of marked content we search
* @param content
* The content we want to use.
*/
public void setMarkedContent(COSName mark, byte[] content) {
int i = 0;
for (; i < size; i++) {
CSOperation operation = operations[i];
if (operation.isOpBeginMarkedContent(mark)) {
i++;
break;
}
}
if (i < size) {
// found
addOperation(i, new CSLiteral(content));
int nesting = 0;
for (i++; i < size;) {
CSOperation operation = operations[i];
if (operation.isOpBeginMarkedContent(null)) {
nesting++;
}
if (operation.isOpEndMarkedContent()) {
if (nesting == 0) {
break;
}
nesting--;
}
removeOperation(i);
}
} else {
CSOperation operation;
operation = new CSOperation(CSOperators.CSO_BMC);
operation.addOperand(CSOperation.OPERAND_Tx);
addOperation(operation);
addOperation(new CSLiteral(content));
operation = new CSOperation(CSOperators.CSO_EMC);
addOperation(operation);
}
}
/**
* The number of operations in the content stream.
*
* @return The number of operations in the content stream.
*/
public int size() {
return size;
}
/**
* Create the byte representation from the list of operations.
*
* @return The byte representation from the list of operations.
*/
public byte[] toByteArray() {
RandomAccessByteArray randomAccess = new RandomAccessByteArray(null);
COSWriter writer = new COSWriter(randomAccess, null);
try {
writer.writeContentStream(this);
} catch (IOException e) {
// this should not happen
}
return randomAccess.toByteArray();
}
@Override
public String toString() {
return new String(toByteArray());
}
}