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f78ea057ca
qpdf/include/qpdf/QPDFObjectHandle.hh
Jay Berkenbilt f78ea057ca Switch annotation flattening to use the form xobjects 
Instead of directly putting the contents of the annotation appearance
streams into the page's content stream, add commands to render the
form xobjects directly. This is a more robust way to do it than the
original solution as it works properly with patterns and avoids
problems with resource name clashes between the pages and the form
xobjects.
2019-01-02 21:49:47 -05:00

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// Copyright (c) 2005-2018 Jay Berkenbilt
//
// This file is part of qpdf.
//
// Licensed 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.
//
// Versions of qpdf prior to version 7 were released under the terms
// of version 2.0 of the Artistic License. At your option, you may
// continue to consider qpdf to be licensed under those terms. Please
// see the manual for additional information.
#ifndef QPDFOBJECTHANDLE_HH
#define QPDFOBJECTHANDLE_HH
#include <qpdf/DLL.h>
#include <qpdf/Types.h>
#include <qpdf/Constants.h>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <qpdf/QPDFObjGen.hh>
#include <qpdf/PointerHolder.hh>
#include <qpdf/Buffer.hh>
#include <qpdf/InputSource.hh>
#include <qpdf/QPDFTokenizer.hh>
#include <qpdf/QPDFObject.hh>
class Pipeline;
class QPDF;
class QPDF_Dictionary;
class QPDF_Array;
class QPDFTokenizer;
class QPDFExc;
class Pl_QPDFTokenizer;
class QPDFObjectHandle
{
public:
// This class is used by replaceStreamData. It provides an
// alternative way of associating stream data with a stream. See
// comments on replaceStreamData and newStream for additional
// details.
class StreamDataProvider
{
public:
QPDF_DLL
virtual ~StreamDataProvider()
{
}
// The implementation of this function must write stream data
// to the given pipeline. The stream data must conform to
// whatever filters are explicitly associated with the stream.
// QPDFWriter may, in some cases, add compression, but if it
// does, it will update the filters as needed. Every call to
// provideStreamData for a given stream must write the same
// data. The object ID and generation passed to this method
// are those that belong to the stream on behalf of which the
// provider is called. They may be ignored or used by the
// implementation for indexing or other purposes. This
// information is made available just to make it more
// convenient to use a single StreamDataProvider object to
// provide data for multiple streams.
virtual void provideStreamData(int objid, int generation,
Pipeline* pipeline) = 0;
};
// The TokenFilter class provides a way to filter content streams
// in a lexically aware fashion. TokenFilters can be attached to
// streams using the addTokenFilter or addContentTokenFilter
// methods or can be applied on the spot by filterPageContents.
// You may also use Pl_QPDFTokenizer directly if you need full
// control.
//
// The handleToken method is called for each token, including the
// eof token, and then handleEOF is called at the very end.
// Handlers may call write (or writeToken) to pass data
// downstream. Please see examples/pdf-filter-tokens.cc and
// examples/pdf-count-strings.cc for examples of using
// TokenFilters.
//
// Please note that when you call token.getValue() on a token of
// type tt_string, you get the string value without any
// delimiters. token.getRawValue() will return something suitable
// for being written to output, or calling writeToken with a
// string token will also work. The correct way to construct a
// string token that would write the literal value (str) is
// QPDFTokenizer::Token(QPDFTokenizer::tt_string, "str").
class TokenFilter
{
public:
QPDF_DLL
TokenFilter()
{
}
QPDF_DLL
virtual ~TokenFilter()
{
}
virtual void handleToken(QPDFTokenizer::Token const&) = 0;
QPDF_DLL
virtual void handleEOF();
class PipelineAccessor
{
friend class Pl_QPDFTokenizer;
private:
static void setPipeline(TokenFilter* f, Pipeline* p)
{
f->setPipeline(p);
}
};
protected:
QPDF_DLL
void write(char const* data, size_t len);
QPDF_DLL
void write(std::string const& str);
QPDF_DLL
void writeToken(QPDFTokenizer::Token const&);
private:
void setPipeline(Pipeline*);
Pipeline* pipeline;
};
// This class is used by parse to decrypt strings when reading an
// object that contains encrypted strings.
class StringDecrypter
{
public:
QPDF_DLL
virtual ~StringDecrypter()
{
}
virtual void decryptString(std::string& val) = 0;
};
// This class is used by parsePageContents. Callers must
// instantiate a subclass of this with handlers defined to accept
// QPDFObjectHandles that are parsed from the stream.
class ParserCallbacks
{
public:
QPDF_DLL
virtual ~ParserCallbacks()
{
}
virtual void handleObject(QPDFObjectHandle) = 0;
virtual void handleEOF() = 0;
protected:
// Implementors may call this method during parsing to
// terminate parsing early. This method throws an exception
// that is caught by parsePageContents, so its effect is
// immediate.
QPDF_DLL
void terminateParsing();
};
// Convenience object for rectangles
class Rectangle
{
public:
Rectangle() :
llx(0.0),
lly(0.0),
urx(0.0),
ury(0.0)
{
}
Rectangle(double llx, double lly,
double urx, double ury) :
llx(llx),
lly(lly),
urx(urx),
ury(ury)
{
}
double llx;
double lly;
double urx;
double ury;
};
// Convenience object for transformation matrices
class Matrix
{
public:
Matrix() :
a(0.0),
b(0.0),
c(0.0),
d(0.0),
e(0.0),
f(0.0)
{
}
Matrix(double a, double b, double c,
double d, double e, double f) :
a(a),
b(b),
c(c),
d(d),
e(e),
f(f)
{
}
double a;
double b;
double c;
double d;
double e;
double f;
};
QPDF_DLL
QPDFObjectHandle();
QPDF_DLL
QPDFObjectHandle(QPDFObjectHandle const&);
QPDF_DLL
QPDFObjectHandle&
operator=(QPDFObjectHandle const&);
QPDF_DLL
bool isInitialized() const;
// Return type code and type name of underlying object. These are
// useful for doing rapid type tests (like switch statements) or
// for testing and debugging.
QPDF_DLL
QPDFObject::object_type_e getTypeCode();
QPDF_DLL
char const* getTypeName();
// Exactly one of these will return true for any object. Operator
// and InlineImage are only allowed in content streams.
QPDF_DLL
bool isBool();
QPDF_DLL
bool isNull();
QPDF_DLL
bool isInteger();
QPDF_DLL
bool isReal();
QPDF_DLL
bool isName();
QPDF_DLL
bool isString();
QPDF_DLL
bool isOperator();
QPDF_DLL
bool isInlineImage();
QPDF_DLL
bool isArray();
QPDF_DLL
bool isDictionary();
QPDF_DLL
bool isStream();
QPDF_DLL
bool isReserved();
// This returns true in addition to the query for the specific
// type for indirect objects.
QPDF_DLL
bool isIndirect();
// True for everything except array, dictionary, stream, word, and
// inline image.
QPDF_DLL
bool isScalar();
// Public factory methods
// Wrap an object in an array if it is not already an array. This
// is a helper for cases in which something in a PDF may either be
// a single item or an array of items, which is a common idiom.
QPDF_DLL
QPDFObjectHandle wrapInArray();
// Construct an object of any type from a string representation of
// the object. Throws QPDFExc with an empty filename and an
// offset into the string if there is an error. Any indirect
// object syntax (obj gen R) will cause a logic_error exception to
// be thrown. If object_description is provided, it will appear
// in the message of any QPDFExc exception thrown for invalid
// syntax.
QPDF_DLL
static QPDFObjectHandle parse(std::string const& object_str,
std::string const& object_description = "");
// Construct an object as above by reading from the given
// InputSource at its current position and using the tokenizer you
// supply. Indirect objects and encrypted strings are permitted.
// This method is intended to be called by QPDF for parsing
// objects that are ready from the object's input stream.
QPDF_DLL
static QPDFObjectHandle parse(PointerHolder<InputSource> input,
std::string const& object_description,
QPDFTokenizer&, bool& empty,
StringDecrypter* decrypter,
QPDF* context);
// Older method: stream_or_array should be the value of /Contents
// from a page object. It's more convenient to just call
// QPDFPageObjectHelper::parsePageContents on the page object, and
// error messages will also be more useful because the page object
// information will be known.
QPDF_DLL
static void parseContentStream(QPDFObjectHandle stream_or_array,
ParserCallbacks* callbacks);
// When called on a stream or stream array that is some page's
// content streams, do the same as pipePageContents. This method
// is a lower level way to do what
// QPDFPageObjectHelper::pipePageContents does, but it allows you
// to perform this operation on a contents object that is
// disconnected from a page object. The description argument
// should describe the containing page and is used in error
// messages. The all_description argument is initialized to
// something that could be used to describe the result of the
// pipeline. It is the description amended with the identifiers of
// the underlying objects.
QPDF_DLL
void pipeContentStreams(Pipeline* p, std::string const& description,
std::string& all_description);
// As of qpdf 8, it is possible to add custom token filters to a
// stream. The tokenized stream data is passed through the token
// filter after all original filters but before content stream
// normalization if requested. This is a low-level interface to
// add it to a stream. You will usually want to call
// QPDFPageObjectHelper::addContentTokenFilter instead, which can
// be applied to a page object, and which will automatically
// handle the case of pages whose contents are split across
// multiple streams.
void addTokenFilter(PointerHolder<TokenFilter> token_filter);
// Legacy helpers for parsing content streams. These methods are
// not going away, but newer code should call the correspond
// methods in QPDFPageObjectHelper instead. The specification and
// behavior of these methods are the same as the identically named
// methods in that class, but newer functionality will be added
// there.
QPDF_DLL
void parsePageContents(ParserCallbacks* callbacks);
QPDF_DLL
void filterPageContents(TokenFilter* filter, Pipeline* next = 0);
QPDF_DLL
void pipePageContents(Pipeline* p);
QPDF_DLL
void addContentTokenFilter(PointerHolder<TokenFilter> token_filter);
// End legacy content stream helpers
// Type-specific factories
QPDF_DLL
static QPDFObjectHandle newNull();
QPDF_DLL
static QPDFObjectHandle newBool(bool value);
QPDF_DLL
static QPDFObjectHandle newInteger(long long value);
QPDF_DLL
static QPDFObjectHandle newReal(std::string const& value);
QPDF_DLL
static QPDFObjectHandle newReal(double value, int decimal_places = 0);
QPDF_DLL
static QPDFObjectHandle newName(std::string const& name);
QPDF_DLL
static QPDFObjectHandle newString(std::string const& str);
// Create a string encoded in UTF-16 from the given utf8-encoded
// string. Such strings are appropriately encoded to appear in PDF
// files outside of content streams, such as in document metadata
// form field values, page labels, outlines, and similar locations.
QPDF_DLL
static QPDFObjectHandle newUnicodeString(std::string const& utf8_str);
QPDF_DLL
static QPDFObjectHandle newOperator(std::string const&);
QPDF_DLL
static QPDFObjectHandle newInlineImage(std::string const&);
QPDF_DLL
static QPDFObjectHandle newArray();
QPDF_DLL
static QPDFObjectHandle newArray(
std::vector<QPDFObjectHandle> const& items);
QPDF_DLL
static QPDFObjectHandle newArray(Rectangle const&);
QPDF_DLL
static QPDFObjectHandle newArray(Matrix const&);
QPDF_DLL
static QPDFObjectHandle newDictionary();
QPDF_DLL
static QPDFObjectHandle newDictionary(
std::map<std::string, QPDFObjectHandle> const& items);
// Create an array from a rectangle. Equivalent to the rectangle
// form of newArray.
QPDF_DLL
static QPDFObjectHandle newFromRectangle(Rectangle const&);
// Create an array from a matrix. Equivalent to the matrix
// form of newArray.
QPDF_DLL
static QPDFObjectHandle newFromMatrix(Matrix const&);
// Create a new stream and associate it with the given qpdf
// object. A subsequent call must be made to replaceStreamData()
// to provide data for the stream. The stream's dictionary may be
// retrieved by calling getDict(), and the resulting dictionary
// may be modified. Alternatively, you can create a new
// dictionary and call replaceDict to install it.
QPDF_DLL
static QPDFObjectHandle newStream(QPDF* qpdf);
// Create a new stream and associate it with the given qpdf
// object. Use the given buffer as the stream data. The stream
// dictionary's /Length key will automatically be set to the size
// of the data buffer. If additional keys are required, the
// stream's dictionary may be retrieved by calling getDict(), and
// the resulting dictionary may be modified. This method is just
// a convenient wrapper around the newStream() and
// replaceStreamData(). It is a convenience methods for streams
// that require no parameters beyond the stream length. Note that
// you don't have to deal with compression yourself if you use
// QPDFWriter. By default, QPDFWriter will automatically compress
// uncompressed stream data. Example programs are provided that
// illustrate this.
QPDF_DLL
static QPDFObjectHandle newStream(QPDF* qpdf, PointerHolder<Buffer> data);
// Create new stream with data from string. This method will
// create a copy of the data rather than using the user-provided
// buffer as in the PointerHolder<Buffer> version of newStream.
QPDF_DLL
static QPDFObjectHandle newStream(QPDF* qpdf, std::string const& data);
// A reserved object is a special sentinel used for qpdf to
// reserve a spot for an object that is going to be added to the
// QPDF object. Normally you don't have to use this type since
// you can just call QPDF::makeIndirectObject. However, in some
// cases, if you have to create objects with circular references,
// you may need to create a reserved object so that you can have a
// reference to it and then replace the object later. Reserved
// objects have the special property that they can't be resolved
// to direct objects. This makes it possible to replace a
// reserved object with a new object while preserving existing
// references to them. When you are ready to replace a reserved
// object with its replacement, use QPDF::replaceReserved for this
// purpose rather than the more general QPDF::replaceObject. It
// is an error to try to write a QPDF with QPDFWriter if it has
// any reserved objects in it.
QPDF_DLL
static QPDFObjectHandle newReserved(QPDF* qpdf);
// Provide an owning qpdf and object description. The library does
// this automatically with objects that are read from from the
// input PDF and with objects that are created programmatically
// and inserted into the QPDF by adding them to an array or a
// dictionary or creating a new indirect object. Most end user
// code will not need to call this. If an object has an owning
// qpdf and object description, it enables qpdf to give warnings
// with proper context in some cases where it would otherwise
// raise exceptions.
QPDF_DLL
void setObjectDescription(QPDF* owning_qpdf,
std::string const& object_description);
QPDF_DLL
bool hasObjectDescription();
// Accessor methods. If an accessor method that is valid for only
// a particular object type is called on an object of the wrong
// type, an exception is thrown.
// Methods for bool objects
QPDF_DLL
bool getBoolValue();
// Methods for integer objects
QPDF_DLL
long long getIntValue();
// Methods for real objects
QPDF_DLL
std::string getRealValue();
// Methods that work for both integer and real objects
QPDF_DLL
bool isNumber();
QPDF_DLL
double getNumericValue();
// Methods for name objects; see also name and array objects
QPDF_DLL
std::string getName();
// Methods for string objects
QPDF_DLL
std::string getStringValue();
// If a string starts with the UTF-16 marker, it is converted from
// UTF-16 to UTF-8. Otherwise, it is treated as a string encoded
// with PDF Doc Encoding. PDF Doc Encoding is identical to
// ISO-8859-1 except in the range from 0200 through 0240, where
// there is a mapping of characters to Unicode. QPDF versions
// prior to version erroneously left characters in that range
// unmapped.
QPDF_DLL
std::string getUTF8Value();
// Methods for content stream objects
QPDF_DLL
std::string getOperatorValue();
QPDF_DLL
std::string getInlineImageValue();
// Methods for array objects; see also name and array objects
QPDF_DLL
int getArrayNItems();
QPDF_DLL
QPDFObjectHandle getArrayItem(int n);
QPDF_DLL
std::vector<QPDFObjectHandle> getArrayAsVector();
QPDF_DLL
bool isRectangle();
// If the array an array of four numeric values, return as a
// rectangle. Otherwise, return the rectangle [0, 0, 0, 0]
QPDF_DLL
Rectangle getArrayAsRectangle();
QPDF_DLL
bool isMatrix();
// If the array an array of six numeric values, return as a
// matrix. Otherwise, return the matrix [1, 0, 0, 1, 0, 0]
QPDF_DLL
Matrix getArrayAsMatrix();
// Methods for dictionary objects
QPDF_DLL
bool hasKey(std::string const&);
QPDF_DLL
QPDFObjectHandle getKey(std::string const&);
QPDF_DLL
std::set<std::string> getKeys();
QPDF_DLL
std::map<std::string, QPDFObjectHandle> getDictAsMap();
// Methods for name and array objects
QPDF_DLL
bool isOrHasName(std::string const&);
// Merge resource dictionaries. Assumes resource dictionaries have
// the property that the collection of keys of all first-level
// dictionary members contains no duplicates. This method does
// nothing if both this object and the other object are not
// dictionaries. Otherwise, it has following behavior, where
// "object" refers to the object whose method is invoked, and
// "other" refers to the argument:
//
// * For each key in "other" whose value is an array:
// * If "object" does not have that entry, shallow copy it.
// * Otherwise, if "object" has an array in the same place,
// append to that array any objects in "other"'s array that
// are not already present.
// * For each key in "other" whose value is a dictionary:
// * If "object" does not have that entry, shallow copy it.
// * Otherwise, for each key in the subdictionary:
// * If key is not present in "object"'s entry, shallow copy it.
// * Otherwise, ignore. Conflicts are not detected.
//
// The primary purpose of this method is to facilitate merging of
// resource dictionaries that are supposed to have the same scope
// as each other. For example, this can be used to merge a form
// XObject's /Resources dictionary with a form field's /DR.
// Conflicts are not detected. If, in the future, there should be
// a need to detect conflicts, this method could detect them and
// return a mapping from old to new names. This mapping could be
// used for filtering the stream. This would be necessary, for
// example, to merge a form XObject's resources with a page's
// resources with the intention of concatenating the content
// streams.
QPDF_DLL
void mergeResources(QPDFObjectHandle other);
// Get all resource names from a resourcey dictionary. If this
// object is a dctionary, this method returns a set of all the
// keys in all top-level subdictionaries. For resources
// dictionaries, this is the collection of names that may be
// referenced in the content stream.
QPDF_DLL
std::set<std::string> getResourceNames();
// Return the QPDF object that owns an indirect object. Returns
// null for a direct object.
QPDF_DLL
QPDF* getOwningQPDF();
// Create a shallow of an object as a direct object, but do not
// traverse across indirect object boundaries. That means that,
// for dictionaries and arrays, any keys or items that were
// indirect objects will still be indirect objects that point to
// the same place.
QPDF_DLL
QPDFObjectHandle shallowCopy();
// Mutator methods. Use with caution.
// Recursively copy this object, making it direct. Throws an
// exception if a loop is detected or any sub-object is a stream.
QPDF_DLL
void makeDirect();
// Mutator methods for array objects
QPDF_DLL
void setArrayItem(int, QPDFObjectHandle const&);
QPDF_DLL
void setArrayFromVector(std::vector<QPDFObjectHandle> const& items);
// Insert an item before the item at the given position ("at") so
// that it has that position after insertion. If "at" is equal to
// the size of the array, insert the item at the end.
QPDF_DLL
void insertItem(int at, QPDFObjectHandle const& item);
QPDF_DLL
void appendItem(QPDFObjectHandle const& item);
// Remove the item at that position, reducing the size of the
// array by one.
QPDF_DLL
void eraseItem(int at);
// Mutator methods for dictionary objects
// Replace value of key, adding it if it does not exist
QPDF_DLL
void replaceKey(std::string const& key, QPDFObjectHandle);
// Remove key, doing nothing if key does not exist
QPDF_DLL
void removeKey(std::string const& key);
// If the object is null, remove the key. Otherwise, replace it.
QPDF_DLL
void replaceOrRemoveKey(std::string const& key, QPDFObjectHandle);
// Methods for stream objects
QPDF_DLL
QPDFObjectHandle getDict();
// If addTokenFilter has been called for this stream, then the
// original data should be considered to be modified. This means we
// should avoid optimizations such as not filtering a stream that
// is already compressed.
QPDF_DLL
bool isDataModified();
// Returns filtered (uncompressed) stream data. Throws an
// exception if the stream is filtered and we can't decode it.
QPDF_DLL
PointerHolder<Buffer> getStreamData(
qpdf_stream_decode_level_e level = qpdf_dl_generalized);
// Returns unfiltered (raw) stream data.
QPDF_DLL
PointerHolder<Buffer> getRawStreamData();
// Write stream data through the given pipeline. A null pipeline
// value may be used if all you want to do is determine whether a
// stream is filterable and would be filtered based on the
// provided flags. If flags is 0, write raw stream data and return
// false. Otherwise, the flags alter the behavior in the following
// way:
//
// encode_flags:
//
// qpdf_sf_compress -- compress data with /FlateDecode if no other
// compression filters are applied.
//
// qpdf_sf_normalize -- tokenize as content stream and normalize tokens
//
// decode_level:
//
// qpdf_dl_none -- do not decode any streams.
//
// qpdf_dl_generalized -- decode supported general-purpose
// filters. This includes /ASCIIHexDecode, /ASCII85Decode,
// /LZWDecode, and /FlateDecode.
//
// qpdf_dl_specialized -- in addition to generalized filters, also
// decode supported non-lossy specialized filters. This includes
// /RunLengthDecode.
//
// qpdf_dl_all -- in addition to generalized and non-lossy
// specialized filters, decode supported lossy filters. This
// includes /DCTDecode.
//
// If, based on the flags and the filters and decode parameters,
// we determine that we know how to apply all requested filters,
// do so and return true if we are successful.
//
// In all cases, a return value of true means that filtered data
// has been written successfully. If filtering is requested but
// this method returns false, it means there was some error in the
// filtering, in which case the resulting data is likely partially
// filtered and/or incomplete and may not be consistent with the
// configured filters. QPDFWriter handles this by attempting to
// get the stream data without filtering, but callers should
// consider a false return value when decode_level is not
// qpdf_dl_none to be a potential loss of data. If you intend to
// retry in that case, pass true as the value of will_retry. This
// changes the warning issued by the library to indicate that the
// operation will be retried without filtering to avoid data loss.
QPDF_DLL
bool pipeStreamData(Pipeline*,
unsigned long encode_flags,
qpdf_stream_decode_level_e decode_level,
bool suppress_warnings = false,
bool will_retry = false);
// Legacy pipeStreamData. This maps to the the flags-based
// pipeStreamData as follows:
// filter = false -> encode_flags = 0
// filter = true -> decode_level = qpdf_dl_generalized
// normalize = true -> encode_flags |= qpdf_sf_normalize
// compress = true -> encode_flags |= qpdf_sf_compress
QPDF_DLL
bool pipeStreamData(Pipeline*, bool filter,
bool normalize, bool compress);
// Replace a stream's dictionary. The new dictionary must be
// consistent with the stream's data. This is most appropriately
// used when creating streams from scratch that will use a stream
// data provider and therefore start with an empty dictionary. It
// may be more convenient in this case than calling getDict and
// modifying it for each key. The pdf-create example does this.
QPDF_DLL
void replaceDict(QPDFObjectHandle);
// Replace this stream's stream data with the given data buffer,
// and replace the /Filter and /DecodeParms keys in the stream
// dictionary with the given values. (If either value is empty,
// the corresponding key is removed.) The stream's /Length key is
// replaced with the length of the data buffer. The stream is
// interpreted as if the data read from the file, after any
// decryption filters have been applied, is as presented.
QPDF_DLL
void replaceStreamData(PointerHolder<Buffer> data,
QPDFObjectHandle const& filter,
QPDFObjectHandle const& decode_parms);
// Replace the stream's stream data with the given string.
// This method will create a copy of the data rather than using
// the user-provided buffer as in the PointerHolder<Buffer> version
// of replaceStreamData.
QPDF_DLL
void replaceStreamData(std::string const& data,
QPDFObjectHandle const& filter,
QPDFObjectHandle const& decode_parms);
// As above, replace this stream's stream data. Instead of
// directly providing a buffer with the stream data, call the
// given provider's provideStreamData method. See comments on the
// StreamDataProvider class (defined above) for details on the
// method. The data must be consistent with filter and
// decode_parms as provided. Although it is more complex to use
// this form of replaceStreamData than the one that takes a
// buffer, it makes it possible to avoid allocating memory for the
// stream data. Example programs are provided that use both forms
// of replaceStreamData.
// Note about stream length: for any given stream, the provider
// must provide the same amount of data each time it is called.
// This is critical for making linearization work properly.
// Versions of qpdf before 3.0.0 required a length to be specified
// here. Starting with version 3.0.0, this is no longer necessary
// (or permitted). The first time the stream data provider is
// invoked for a given stream, the actual length is stored.
// Subsequent times, it is enforced that the length be the same as
// the first time.
// If you have gotten a compile error here while building code
// that worked with older versions of qpdf, just omit the length
// parameter. You can also simplify your code by not having to
// compute the length in advance.
QPDF_DLL
void replaceStreamData(PointerHolder<StreamDataProvider> provider,
QPDFObjectHandle const& filter,
QPDFObjectHandle const& decode_parms);
// Access object ID and generation. For direct objects, return
// object ID 0.
// NOTE: Be careful about calling getObjectID() and
// getGeneration() directly as this can lead to the pattern of
// depending on object ID or generation without the other. In
// general, when keeping track of object IDs, it's better to use
// QPDFObjGen instead.
QPDF_DLL
QPDFObjGen getObjGen() const;
QPDF_DLL
int getObjectID() const;
QPDF_DLL
int getGeneration() const;
QPDF_DLL
std::string unparse();
QPDF_DLL
std::string unparseResolved();
// For strings only, force binary representation. Otherwise, same
// as unparse.
QPDF_DLL
std::string unparseBinary();
// Return encoded as JSON. For most object types, there is an
// obvious mapping. The JSON is generated as follows:
// * Names are encoded as strings representing the normalized value of
// getName()
// * Indirect references are encoded as strings containing "obj gen R"
// * Strings are encoded as UTF-8 strings with unrepresentable binary
// characters encoded as \uHHHH
// * Encoding streams just encodes the stream's dictionary; the stream
// data is not represented
// * Object types that are only valid in content streams (inline
// image, operator) as well as "reserved" objects are not
// representable and will be serialized as "null".
// If dereference_indirect is true and this is an indirect object,
// show the actual contents of the object. The effect of
// dereference_indirect applies only to this object. It is not
// recursive.
QPDF_DLL
JSON getJSON(bool dereference_indirect = false);
// Legacy helper methods for commonly performed operations on
// pages. Newer code should use QPDFPageObjectHelper instead. The
// specification and behavior of these methods are the same as the
// identically named methods in that class, but newer
// functionality will be added there.
QPDF_DLL
std::map<std::string, QPDFObjectHandle> getPageImages();
QPDF_DLL
std::vector<QPDFObjectHandle> getPageContents();
QPDF_DLL
void addPageContents(QPDFObjectHandle contents, bool first);
QPDF_DLL
void rotatePage(int angle, bool relative);
QPDF_DLL
void coalesceContentStreams();
// End legacy page helpers
// Issue a warning about this object if possible. If the object
// has a description, a warning will be issued. Otherwise, if
// throw_if_no_description is true, throw an exception. Otherwise
// do nothing. Objects read normally from the file have
// descriptions. See comments on setObjectDescription for
// additional details.
void warnIfPossible(std::string const& warning,
bool throw_if_no_description = false);
// Initializers for objects. This Factory class gives the QPDF
// class specific permission to call factory methods without
// making it a friend of the whole QPDFObjectHandle class.
class Factory
{
friend class QPDF;
private:
static QPDFObjectHandle newIndirect(QPDF* qpdf,
int objid, int generation)
{
return QPDFObjectHandle::newIndirect(qpdf, objid, generation);
}
// object must be dictionary object
static QPDFObjectHandle newStream(
QPDF* qpdf, int objid, int generation,
QPDFObjectHandle stream_dict, qpdf_offset_t offset, size_t length)
{
return QPDFObjectHandle::newStream(
qpdf, objid, generation, stream_dict, offset, length);
}
};
friend class Factory;
// Accessor for raw underlying object -- only QPDF is allowed to
// call this.
class ObjAccessor
{
friend class QPDF;
private:
static PointerHolder<QPDFObject> getObject(QPDFObjectHandle& o)
{
o.dereference();
return o.m->obj;
}
};
friend class ObjAccessor;
// Provide access to specific classes for recursive
// releaseResolved().
class ReleaseResolver
{
friend class QPDF_Dictionary;
friend class QPDF_Array;
friend class QPDF_Stream;
private:
static void releaseResolved(QPDFObjectHandle& o)
{
o.releaseResolved();
}
};
friend class ReleaseResolver;
// Convenience routine: Throws if the assumption is violated. Your
// code will be better if you call one of the isType methods and
// handle the case of the type being wrong, but these can be
// convenient if you have already verified the type.
QPDF_DLL
void assertInitialized() const;
QPDF_DLL
void assertNull();
QPDF_DLL
void assertBool();
QPDF_DLL
void assertInteger();
QPDF_DLL
void assertReal();
QPDF_DLL
void assertName();
QPDF_DLL
void assertString();
QPDF_DLL
void assertOperator();
QPDF_DLL
void assertInlineImage();
QPDF_DLL
void assertArray();
QPDF_DLL
void assertDictionary();
QPDF_DLL
void assertStream();
QPDF_DLL
void assertReserved();
QPDF_DLL
void assertIndirect();
QPDF_DLL
void assertScalar();
QPDF_DLL
void assertNumber();
// The isPageObject method checks the /Type key of the object.
// This is not completely reliable as there are some otherwise
// valid files whose /Type is wrong for page objects. qpdf is
// slightly more accepting but may still return false here when
// treating the object as a page would work. Use this sparingly.
QPDF_DLL
bool isPageObject();
QPDF_DLL
bool isPagesObject();
QPDF_DLL
void assertPageObject();
private:
QPDFObjectHandle(QPDF*, int objid, int generation);
QPDFObjectHandle(QPDFObject*);
enum parser_state_e
{
st_top,
st_start,
st_stop,
st_eof,
st_dictionary,
st_array
};
// Private object factory methods
static QPDFObjectHandle newIndirect(QPDF*, int objid, int generation);
static QPDFObjectHandle newStream(
QPDF* qpdf, int objid, int generation,
QPDFObjectHandle stream_dict, qpdf_offset_t offset, size_t length);
void typeWarning(char const* expected_type,
std::string const& warning);
void objectWarning(std::string const& warning);
void assertType(char const* type_name, bool istype);
void dereference();
void copyObject(std::set<QPDFObjGen>& visited, bool cross_indirect);
void releaseResolved();
static void setObjectDescriptionFromInput(
QPDFObjectHandle, QPDF*, std::string const&,
PointerHolder<InputSource>, qpdf_offset_t);
static QPDFObjectHandle parseInternal(
PointerHolder<InputSource> input,
std::string const& object_description,
QPDFTokenizer& tokenizer, bool& empty,
StringDecrypter* decrypter, QPDF* context,
bool content_stream);
void parseContentStream_internal(
std::string const& description,
ParserCallbacks* callbacks);
static void parseContentStream_data(
PointerHolder<Buffer>,
std::string const& description,
ParserCallbacks* callbacks);
std::vector<QPDFObjectHandle> arrayOrStreamToStreamArray(
std::string const& description, std::string& all_description);
static void warn(QPDF*, QPDFExc const&);
class Members
{
friend class QPDFObjectHandle;
public:
QPDF_DLL
~Members();
private:
Members();
Members(QPDF* qpdf, int objid, int generation);
Members(QPDFObject* data);
bool initialized;
QPDF* qpdf;
int objid; // 0 for direct object
int generation;
PointerHolder<QPDFObject> obj;
bool reserved;
};
PointerHolder<Members> m;
};
#endif // QPDFOBJECTHANDLE_HH
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