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qpdf/include/qpdf/QPDFObjectHandle.hh
Jay Berkenbilt ec778ef98b Add additional comments about new accessor methods
2022-02-08 16:49:43 -05:00

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// Copyright (c) 2005-2022 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 <functional>
#include <memory>
#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 QPDFMatrix;
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 QPDF_DLL_CLASS StreamDataProvider
{
public:
QPDF_DLL
StreamDataProvider(bool supports_retry = false);
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. Note that, when writing linearized files, qpdf will
// call your provideStreamData twice, and if it generates
// different output, you risk generating invalid output or
// having qpdf throw an exception. 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.
// A few things to keep in mind:
//
// * Stream data providers must not modify any objects since
// they may be called after some parts of the file have
// already been written.
//
// * Since qpdf may call provideStreamData multiple times when
// writing linearized files, if the work done by your stream
// data provider is slow or computationally intensive, you
// might want to implement your own cache.
//
// * Once you have called replaceStreamData, the original
// stream data is no longer directly accessible from the
// stream, but this is easy to work around by copying the
// stream to a separate QPDF object. The qpdf library
// implements this very efficiently without actually making
// a copy of the stream data. You can find examples of this
// pattern in some of the examples, including
// pdf-custom-filter.cc and pdf-invert-images.cc.
// Prior to qpdf 10.0.0, it was not possible to handle errors
// the way pipeStreamData does or to pass back success.
// Starting in qpdf 10.0.0, those capabilities have been added
// by allowing an alternative provideStreamData to be
// implemented. You must implement at least one of the
// versions of provideStreamData below. If you implement the
// version that supports retry and returns a value, you should
// pass true as the value of supports_retry in the base class
// constructor. This will cause the library to call that
// version of the method, which should also return a boolean
// indicating whether it ran without errors.
QPDF_DLL
virtual void provideStreamData(int objid, int generation,
Pipeline* pipeline);
QPDF_DLL
virtual bool provideStreamData(
int objid, int generation, Pipeline* pipeline,
bool suppress_warnings, bool will_retry);
QPDF_DLL
bool supportsRetry();
private:
bool supports_retry;
};
// 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 or tt_name, you get the canonical, "parsed"
// representation of the token. For a string, this means that
// there are no delimiters, and for a name, it means that all
// escaping (# followed by two hex digits) has been resolved.
// qpdf's internal representation of a name includes the leading
// slash. As such, you can't write the value of token.getValue()
// directly to output that is supposed to be valid PDF syntax. If
// you want to do that, you need to call writeToken() instead, or
// you can retrieve the token as it appeared in the input with
// token.getRawValue(). To construct a new string or name token
// from a canonical representation, use
// QPDFTokenizer::Token(QPDFTokenizer::tt_string, "parsed-str") or
// QPDFTokenizer::Token(QPDFTokenizer::tt_name,
// "/Canonical-Name"). Tokens created this way won't have a
// PDF-syntax raw value, but you can still write them with
// writeToken(). Example:
// writeToken(QPDFTokenizer::Token(QPDFTokenizer::tt_name, "/text/plain"))
// would write `/text#2fplain`, and
// writeToken(QPDFTokenizer::Token(QPDFTokenizer::tt_string, "a\\(b"))
// would write `(a\(b)`.
class QPDF_DLL_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 QPDF_DLL_CLASS ParserCallbacks
{
public:
QPDF_DLL
virtual ~ParserCallbacks()
{
}
// One of the handleObject methods must be overridden.
QPDF_DLL
virtual void handleObject(QPDFObjectHandle);
QPDF_DLL
virtual void handleObject(
QPDFObjectHandle, size_t offset, size_t length);
virtual void handleEOF() = 0;
// Override this if you want to know the full size of the
// contents, possibly after concatenation of multiple streams.
// This is called before the first call to handleObject.
QPDF_DLL
virtual void contentSize(size_t);
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. See also
// QPDFMatrix. Unfortunately we can't replace this with QPDFMatrix
// because QPDFMatrix's default constructor creates the identity
// transform matrix and this one is all zeroes.
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&) = default;
QPDF_DLL
QPDFObjectHandle&
operator=(QPDFObjectHandle const&) = default;
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 initialized
// 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();
// True for objects that are direct nulls. Does not attempt to
// resolve objects. This is intended for internal use, but it can
// be used as an efficient way to check for nulls that are not
// indirect objects.
QPDF_DLL
bool isDirectNull() const;
// 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();
// True if the object is a name object representing the provided name.
QPDF_DLL
bool isNameAndEquals(std::string const& name);
// True if the object is a dictionary of the specified type and
// subtype, if any.
QPDF_DLL
bool isDictionaryOfType(std::string const& type,
std::string const& subtype = "");
// True if the object is a stream of the specified type and
// subtype, if any.
QPDF_DLL
bool isStreamOfType(std::string const& type,
std::string const& subtype = "");
// 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. See also the global `operator ""_qpdf` defined below.
QPDF_DLL
static QPDFObjectHandle parse(std::string const& object_str,
std::string const& object_description = "");
// Construct an object of any type from a string representation of
// the object. Indirect object syntax (obj gen R) is allowed and
// will create indirect references within the passed-in context.
// If object_description is provided, it will appear in the
// message of any QPDFExc exception thrown for invalid syntax.
// Note that you can't parse an indirect object reference all by
// itself as parse will stop at the end of the first complete
// object, which will just be the first number and will report
// that there is trailing data at the end of the string.
QPDF_DLL
static QPDFObjectHandle parse(QPDF* context,
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);
// Return the offset where the object was found when parsed. A
// negative value means that the object was created without
// parsing. If the object is in a stream, the offset is from the
// beginning of the stream. Otherwise, the offset is from the
// beginning of the file.
QPDF_DLL
qpdf_offset_t getParsedOffset();
// 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. Please note that if there is an array
// of content streams, p->finish() is called after each stream. If
// you pass a pipeline that doesn't allow write() to be called
// after finish(), you can wrap it in an instance of
// Pl_Concatenate and then call manualFinish() on the
// Pl_Concatenate pipeline at the end.
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.
QPDF_DLL
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);
// See comments for QPDFPageObjectHelper::pipeContents.
QPDF_DLL
void pipePageContents(Pipeline* p);
QPDF_DLL
void addContentTokenFilter(PointerHolder<TokenFilter> token_filter);
// End legacy content stream helpers
// Called on a stream to filter the stream as if it were page
// contents. This can be used to apply a TokenFilter to a form
// XObject, whose data is in the same format as a content stream.
QPDF_DLL
void filterAsContents(TokenFilter* filter, Pipeline* next = 0);
// Called on a stream to parse the stream as page contents. This
// can be used to parse a form XObject.
QPDF_DLL
void parseAsContents(ParserCallbacks* callbacks);
// 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);
// ABI: combine with other newReal by adding trim_trailing_zeroes
// above as an optional parameter with a default of true.
QPDF_DLL
static QPDFObjectHandle newReal(double value, int decimal_places,
bool trim_trailing_zeroes);
// Note about name objects: qpdf's internal representation of a
// PDF name is a sequence of bytes, excluding the NUL character,
// and starting with a slash. Name objects as represented in the
// PDF specification can contain characters escaped with #, but
// such escaping is not of concern when calling QPDFObjectHandle
// methods not directly relating to parsing. For example,
// newName("/text/plain").getName() and
// parse("/text#2fplain").getName() both return "/text/plain",
// while newName("/text/plain").unparse() and
// parse("/text#2fplain").unparse() both return "/text#2fplain".
// When working with the qpdf API for creating, retrieving, and
// modifying objects, you want to work with the internal,
// canonical representation. For names containing alphanumeric
// characters, dashes, and underscores, there is no difference
// between the two representations. For a lengthy discussion, see
// https://github.com/qpdf/qpdf/discussions/625.
QPDF_DLL
static QPDFObjectHandle newName(std::string const& name);
QPDF_DLL
static QPDFObjectHandle newString(std::string const& str);
// Create a string encoded from the given utf8-encoded string
// 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. We try ASCII first,
// then PDFDocEncoding, then UTF-16 as needed to successfully
// encode all the characters.
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 newArray(QPDFMatrix 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&);
QPDF_DLL
static QPDFObjectHandle newFromMatrix(QPDFMatrix 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 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
//
// (Note: this comment is referenced in qpdf-c.h and the manual.)
//
// In PDF files, objects have specific types, but there is nothing
// that prevents PDF files from containing objects of types that
// aren't expected by the specification.
//
// There are two flavors of accessor methods:
//
// * getSomethingValue() returns the value and issues a type
// warning if the type is incorrect.
//
// * getValueAsSomething() returns false if the value is the wrong
// type. Otherwise, it returns true and initializes a reference
// of the appropriate type. These methods never issue type
// warnings.
//
// The getSomethingValue() accessors and some of the other methods
// expect objects of a particular type. Prior to qpdf 8, calling
// an accessor on a method of the wrong type, such as trying to
// get a dictionary key from an array, trying to get the string
// value of a number, etc., would throw an exception, but since
// qpdf 8, qpdf issues a warning and recovers using the following
// behavior:
//
// * Requesting a value of the wrong type (int value from string,
// array item from a scalar or dictionary, etc.) will return a
// zero-like value for that type: false for boolean, 0 for
// number, the empty string for string, or the null object for
// an object handle.
//
// * Accessing an array item that is out of bounds will return a
// null object.
//
// * Attempts to mutate an object of the wrong type (e.g.,
// attempting to add a dictionary key to a scalar or array) will
// be ignored.
//
// When any of these fallback behaviors are used, qpdf issues a
// warning. Starting in qpdf 10.5, these warnings have the error
// code qpdf_e_object. Prior to 10.5, they had the error code
// qpdf_e_damaged_pdf. If the QPDFObjectHandle is associated with
// a QPDF object (as is the case for all objects whose origin was
// a PDF file), the warning is issued using the normal warning
// mechanism (as described in QPDF.hh), making it possible to
// suppress or otherwise detect them. If the QPDFObjectHandle is
// not associated with a QPDF object (meaning it was created
// programmatically), an exception will be thrown.
//
// The way to avoid getting any type warnings or exceptions, even
// when working with malformed PDF files, is to always check the
// type of a QPDFObjectHandle before accessing it (for example,
// make sure that isString() returns true before calling
// getStringValue()) and to always be sure that any array indices
// are in bounds.
//
// For additional discussion and rationale for this behavior, see
// the section in the QPDF manual entitled "Object Accessor
// Methods".
// Methods for bool objects
QPDF_DLL
bool getBoolValue();
QPDF_DLL
bool getValueAsBool(bool&);
// Methods for integer objects. Note: if an integer value is too
// big (too far away from zero in either direction) to fit in the
// requested return type, the maximum or minimum value for that
// return type may be returned. For example, on a system with
// 32-bit int, a numeric object with a value of 2^40 (or anything
// too big for 32 bits) will be returned as INT_MAX.
QPDF_DLL
long long getIntValue();
QPDF_DLL
bool getValueAsInt(long long&);
QPDF_DLL
int getIntValueAsInt();
QPDF_DLL
bool getValueAsInt(int&);
QPDF_DLL
unsigned long long getUIntValue();
QPDF_DLL
bool getValueAsUInt(unsigned long long&);
QPDF_DLL
unsigned int getUIntValueAsUInt();
QPDF_DLL
bool getValueAsUInt(unsigned int&);
// Methods for real objects
QPDF_DLL
std::string getRealValue();
QPDF_DLL
bool getValueAsReal(std::string&);
// Methods that work for both integer and real objects
QPDF_DLL
bool isNumber();
QPDF_DLL
double getNumericValue();
QPDF_DLL
bool getValueAsNumber(double&);
// Methods for name objects. The returned name value is in qpdf's
// canonical form with all escaping resolved. See comments for
// newName() for details.
QPDF_DLL
std::string getName();
QPDF_DLL
bool getValueAsName(std::string&);
// Methods for string objects
QPDF_DLL
std::string getStringValue();
QPDF_DLL
bool getValueAsString(std::string&);
// 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 8.0.0 erroneously left characters in that range
// unmapped.
QPDF_DLL
std::string getUTF8Value();
QPDF_DLL
bool getValueAsUTF8(std::string&);
// Methods for content stream objects
QPDF_DLL
std::string getOperatorValue();
QPDF_DLL
bool getValueAsOperator(std::string&);
QPDF_DLL
std::string getInlineImageValue();
QPDF_DLL
bool getValueAsInlineImage(std::string&);
// Methods for array objects; see also name and array objects.
// Return an object that enables iteration over members. You can
// do
//
// for (auto iter: obj.aitems())
// {
// // iter is an array element
// }
class QPDFArrayItems;
QPDF_DLL
QPDFArrayItems aitems();
QPDF_DLL
int getArrayNItems();
QPDF_DLL
QPDFObjectHandle getArrayItem(int n);
// Note: QPDF arrays internally optimize memory for arrays
// containing lots of nulls. Calling getArrayAsVector may cause a
// lot of memory to be allocated for very large arrays with lots
// of nulls.
QPDF_DLL
std::vector<QPDFObjectHandle> getArrayAsVector();
QPDF_DLL
bool isRectangle();
// If the array is 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 is 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. In all dictionary methods, keys
// are specified/represented as canonical name strings starting
// with a leading slash and not containing any PDF syntax
// escaping. See comments for getName() for details.
// Return an object that enables iteration over members. You can
// do
//
// for (auto iter: obj.ditems())
// {
// // iter.first is the key
// // iter.second is the value
// }
class QPDFDictItems;
QPDF_DLL
QPDFDictItems ditems();
// Return true if key is present. Keys with null values are treated as if
// they are not present. This is as per the PDF spec.
QPDF_DLL
bool hasKey(std::string const&);
// Return the value for the key. If the key is not present, null is
// returned.
QPDF_DLL
QPDFObjectHandle getKey(std::string const&);
// If the object is null, return null. Otherwise, call getKey().
// This makes it easier to access lower-level dictionaries, as in
// auto font = page.getKeyIfDict("/Resources").getKeyIfDict("/Font");
QPDF_DLL
QPDFObjectHandle getKeyIfDict(std::string const&);
// Return all keys. Keys with null values are treated as if
// they are not present. This is as per the PDF spec.
QPDF_DLL
std::set<std::string> getKeys();
// Return dictionary as a map. Entries with null values are included.
QPDF_DLL
std::map<std::string, QPDFObjectHandle> getDictAsMap();
// Methods for name and array objects. The name value is in qpdf's
// canonical form with all escaping resolved. See comments for
// newName() for details.
QPDF_DLL
bool isOrHasName(std::string const&);
// Make all resources in a resource dictionary indirect. This just
// goes through all entries of top-level subdictionaries and
// converts any direct objects to indirect objects. This can be
// useful to call before mergeResources if it is going to be
// called multiple times to prevent resources from being copied
// multiple times.
QPDF_DLL
void makeResourcesIndirect(QPDF& owning_qpdf);
// Merge resource dictionaries. If the "conflicts" parameter is
// provided, conflicts in dictionary subitems are resolved, and
// "conflicts" is initialized to a map such that
// conflicts[resource_type][old_key] == [new_key]
//
// See also makeResourcesIndirect, which can be useful to call
// before calling this.
//
// 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 if direct or just add it if indirect.
// * Otherwise, if conflicts are being detected:
// * If there is a key (oldkey) already in the dictionary
// that points to the same indirect destination as key,
// indicate that key was replaced by oldkey. This would
// happen if these two resource dictionaries have
// previously been merged.
// * Otherwise pick a new key (newkey) that is unique within
// the resource dictionary, store that in the resource
// dictionary with key's destination as its destination,
// and indicate that key was replaced by newkey.
//
// 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 or to
// merge two /DR dictionaries. The "conflicts" parameter may be
// previously initialized. This method adds to whatever is already
// there, which can be useful when merging with multiple things.
QPDF_DLL
void mergeResources(
QPDFObjectHandle other,
std::map<std::string, std::map<std::string, std::string>>* conflicts);
// ABI: eliminate version without conflicts and make conflicts
// default to nullptr.
QPDF_DLL
void mergeResources(QPDFObjectHandle other);
// Get all resource names from a resource dictionary. If this
// object is a dictionary, 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();
// Find a unique name within a resource dictionary starting with a
// given prefix. This method works by appending a number to the
// given prefix. It searches starting with min_suffix and sets
// min_suffix to selected value upon return. This can be used to
// increase efficiency if adding multiple items with the same
// prefix. (Why doesn't it set min_suffix to the next number?
// Well, maybe you aren't going to actually use the name it
// returns.) If you are calling this multiple times on the same
// resource dictionary, you can initialize resource_names by
// calling getResourceNames(), incrementally update it as you add
// resources, and keep passing it in so that getUniqueResourceName
// doesn't have to traverse the resource dictionary each time it's
// called.
QPDF_DLL
std::string getUniqueResourceName(
std::string const& prefix,
int& min_suffix,
std::set<std::string>* resource_names);
// ABI: remove this version and make resource_names default to
// nullptr.
QPDF_DLL
std::string getUniqueResourceName(std::string const& prefix,
int& min_suffix);
// Return the QPDF object that owns an indirect object. Returns
// null for a direct object.
QPDF_DLL
QPDF* getOwningQPDF();
// Create a shallow copy 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. In the strictest sense, this is not a shallow
// copy because it recursively descends arrays and dictionaries;
// it just doesn't cross over indirect objects. See also
// unsafeShallowCopy(). You can't copy a stream this way. See
// copyStream() instead.
QPDF_DLL
QPDFObjectHandle shallowCopy();
// Create a true shallow copy of an array or dictionary, just
// copying the immediate items (array) or keys (dictionary). This
// is "unsafe" because, if you *modify* any of the items in the
// copy, you are modifying the original, which is almost never
// what you want. However, if your intention is merely to
// *replace* top-level items or keys and not to modify lower-level
// items in the copy, this method is much faster than
// shallowCopy().
QPDF_DLL
QPDFObjectHandle unsafeShallowCopy();
// Create a copy of this stream. The new stream and the old stream
// are independent: after the copy, either the original or the
// copy's dictionary or data can be modified without affecting the
// other. This uses StreamDataProvider internally, so no
// unnecessary copies of the stream's data are made. If the source
// stream's data is already being provided by a
// StreamDataProvider, the new stream will use the same one, so
// you have to make sure your StreamDataProvider can handle that
// case. But if you're already using a StreamDataProvider, you
// probably don't need to call this method.
QPDF_DLL
QPDFObjectHandle copyStream();
// Mutator methods. Use with caution.
// Recursively copy this object, making it direct. An exception is
// thrown if a loop is detected. With allow_streams true, keep
// indirect object references to streams. Otherwise, throw an
// exception if any sub-object is a stream. Note that, when
// allow_streams is true and a stream is found, the resulting
// object is still associated with the containing qpdf. When
// allow_streams is false, the object will no longer be connected
// to the original QPDF object after this call completes
// successfully.
QPDF_DLL
void makeDirect(bool allow_streams);
// Zero-arg version is equivalent to makeDirect(false).
// ABI: delete zero-arg version of makeDirect, and make
// allow_streams default to false.
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();
// By default, or if true passed, QPDFWriter will attempt to
// filter a stream based on decode level, whether compression is
// enabled, and its ability to filter. Passing false will prevent
// QPDFWriter from attempting to filter the stream even if it can.
// This includes both decoding and compressing. This makes it
// possible for you to prevent QPDFWriter from uncompressing and
// recompressing a stream that it knows how to operate on for any
// application-specific reason, such as that you have already
// optimized its filtering. Note that this doesn't affect any
// other ways to get the stream's data, such as pipeStreamData or
// getStreamData.
QPDF_DLL
void setFilterOnWrite(bool);
QPDF_DLL
bool getFilterOnWrite();
// 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.
//
// The exact meaning of the return value differs the different
// versions of this function, but for any version, the meaning has
// been the same. For the main version, added in qpdf 10, the
// return value indicates whether the overall operation succeeded.
// The filter parameter, if specified, will be set to whether or
// not filtering was attempted. If filtering was not requested,
// this value will be false even if the overall operation
// succeeded.
//
// 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.
// Return value is overall success, even if filtering is not
// requested.
QPDF_DLL
bool pipeStreamData(Pipeline*, bool* filtering_attempted,
int encode_flags,
qpdf_stream_decode_level_e decode_level,
bool suppress_warnings = false,
bool will_retry = false);
// Legacy version. Return value is whether filtering was
// attempted. There is no way to determine success if filtering
// was not attempted.
QPDF_DLL
bool pipeStreamData(Pipeline*,
int 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
// Return value is whether filtering was attempted.
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);
// Starting in qpdf 10.2, you can use C++-11 function objects
// instead of StreamDataProvider.
// The provider should write the stream data to the pipeline. For
// a one-liner to replace stream data with the contents of a file,
// pass QUtil::file_provider(filename) as provider.
QPDF_DLL
void replaceStreamData(std::function<void(Pipeline*)> provider,
QPDFObjectHandle const& filter,
QPDFObjectHandle const& decode_parms);
// The provider should write the stream data to the pipeline,
// returning true if it succeeded without errors.
QPDF_DLL
void replaceStreamData(
std::function<bool(Pipeline*,
bool suppress_warnings,
bool will_retry)> 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 name
// in PDF syntax as returned by unparse()
// * 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.
QPDF_DLL
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.obj;
}
};
friend class ObjAccessor;
// Provide access to specific classes for recursive
// releaseResolved().
class ReleaseResolver
{
friend class QPDF_Dictionary;
friend class QPDF_Stream;
friend class SparseOHArray;
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();
QPDF_DLL
bool isFormXObject();
// Indicate if this is an image. If exclude_imagemask is true,
// don't count image masks as images.
QPDF_DLL
bool isImage(bool exclude_imagemask=true);
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,
bool first_level_only, bool stop_at_streams);
void shallowCopyInternal(QPDFObjectHandle& oh, bool first_level_only);
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 setParsedOffset(qpdf_offset_t offset);
void parseContentStream_internal(
std::string const& description,
ParserCallbacks* callbacks);
static void parseContentStream_data(
PointerHolder<Buffer>,
std::string const& description,
ParserCallbacks* callbacks,
QPDF* context);
std::vector<QPDFObjectHandle> arrayOrStreamToStreamArray(
std::string const& description, std::string& all_description);
static void warn(QPDF*, QPDFExc const&);
void checkOwnership(QPDFObjectHandle const&) const;
bool initialized;
// Moving members of QPDFObjectHandle into a smart pointer incurs
// a substantial performance penalty since QPDFObjectHandle
// objects are copied around so frequently.
QPDF* qpdf;
int objid; // 0 for direct object
int generation;
PointerHolder<QPDFObject> obj;
bool reserved;
};
#ifndef QPDF_NO_QPDF_STRING
// This is short for QPDFObjectHandle::parse, so you can do
// auto oh = "<< /Key (value) >>"_qpdf;
// If this is causing problems in your code, define
// QPDF_NO_QPDF_STRING to prevent the declaration from being here.
QPDF_DLL
QPDFObjectHandle operator ""_qpdf(char const* v, size_t len);
#endif // QPDF_NO_QPDF_STRING
class QPDFObjectHandle::QPDFDictItems
{
// This class allows C++-style iteration, including range-for
// iteration, around dictionaries. You can write
// for (auto iter: QPDFDictItems(dictionary_obj))
// {
// // iter.first is a string
// // iter.second is a QPDFObjectHandle
// }
// See examples/pdf-name-number-tree.cc for a demonstration of
// using this API.
public:
QPDF_DLL
QPDFDictItems(QPDFObjectHandle const& oh);
class iterator
{
friend class QPDFDictItems;
public:
typedef std::pair<std::string, QPDFObjectHandle> T;
using iterator_category = std::bidirectional_iterator_tag;
using value_type = T;
using difference_type = long;
using pointer = T*;
using reference = T&;
QPDF_DLL
virtual ~iterator() = default;
QPDF_DLL
iterator& operator++();
QPDF_DLL
iterator operator++(int)
{
iterator t = *this;
++(*this);
return t;
}
QPDF_DLL
iterator& operator--();
QPDF_DLL
iterator operator--(int)
{
iterator t = *this;
--(*this);
return t;
}
QPDF_DLL
reference operator*();
QPDF_DLL
pointer operator->();
QPDF_DLL
bool operator==(iterator const& other) const;
QPDF_DLL
bool operator!=(iterator const& other) const
{
return ! operator==(other);
}
private:
iterator(QPDFObjectHandle& oh, bool for_begin);
void updateIValue();
class Members
{
friend class QPDFDictItems::iterator;
public:
QPDF_DLL
~Members() = default;
private:
Members(QPDFObjectHandle& oh, bool for_begin);
Members() = delete;
Members(Members const&) = delete;
QPDFObjectHandle& oh;
std::set<std::string> keys;
std::set<std::string>::iterator iter;
bool is_end;
};
PointerHolder<Members> m;
value_type ivalue;
};
QPDF_DLL
iterator begin();
QPDF_DLL
iterator end();
private:
QPDFObjectHandle oh;
};
class QPDFObjectHandle::QPDFArrayItems
{
// This class allows C++-style iteration, including range-for
// iteration, around arrays. You can write
// for (auto iter: QPDFArrayItems(array_obj))
// {
// // iter is a QPDFObjectHandle
// }
// See examples/pdf-name-number-tree.cc for a demonstration of
// using this API.
public:
QPDF_DLL
QPDFArrayItems(QPDFObjectHandle const& oh);
class iterator
{
friend class QPDFArrayItems;
public:
typedef QPDFObjectHandle T;
using iterator_category = std::bidirectional_iterator_tag;
using value_type = T;
using difference_type = long;
using pointer = T*;
using reference = T&;
QPDF_DLL
virtual ~iterator() = default;
QPDF_DLL
iterator& operator++();
QPDF_DLL
iterator operator++(int)
{
iterator t = *this;
++(*this);
return t;
}
QPDF_DLL
iterator& operator--();
QPDF_DLL
iterator operator--(int)
{
iterator t = *this;
--(*this);
return t;
}
QPDF_DLL
reference operator*();
QPDF_DLL
pointer operator->();
QPDF_DLL
bool operator==(iterator const& other) const;
QPDF_DLL
bool operator!=(iterator const& other) const
{
return ! operator==(other);
}
private:
iterator(QPDFObjectHandle& oh, bool for_begin);
void updateIValue();
class Members
{
friend class QPDFArrayItems::iterator;
public:
QPDF_DLL
~Members() = default;
private:
Members(QPDFObjectHandle& oh, bool for_begin);
Members() = delete;
Members(Members const&) = delete;
QPDFObjectHandle& oh;
int item_number;
bool is_end;
};
PointerHolder<Members> m;
value_type ivalue;
};
QPDF_DLL
iterator begin();
QPDF_DLL
iterator end();
private:
QPDFObjectHandle oh;
};
#endif // QPDFOBJECTHANDLE_HH
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