mirror of
https://github.com/qpdf/qpdf.git
synced 2024-11-15 17:17:08 +00:00
d71f05ca07
This makes all integer type conversions that have potential data loss explicit with calls that do range checks and raise an exception. After this commit, qpdf builds with no warnings when -Wsign-conversion -Wconversion is used with gcc or clang or when -W3 -Wd4800 is used with MSVC. This significantly reduces the likelihood of potential crashes from bogus integer values. There are some parts of the code that take int when they should take size_t or an offset. Such places would make qpdf not support files with more than 2^31 of something that usually wouldn't be so large. In the event that such a file shows up and is valid, at least qpdf would raise an error in the right spot so the issue could be legitimately addressed rather than failing in some weird way because of a silent overflow condition.
772 lines
22 KiB
C++
772 lines
22 KiB
C++
#include <qpdf/QPDFPageObjectHelper.hh>
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#include <qpdf/QTC.hh>
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#include <qpdf/QPDF.hh>
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#include <qpdf/Pl_Concatenate.hh>
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#include <qpdf/Pl_Buffer.hh>
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#include <qpdf/QUtil.hh>
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#include <qpdf/QPDFExc.hh>
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#include <qpdf/QPDFMatrix.hh>
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#include <qpdf/QIntC.hh>
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class ContentProvider: public QPDFObjectHandle::StreamDataProvider
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{
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public:
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ContentProvider(QPDFObjectHandle from_page) :
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from_page(from_page)
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{
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}
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virtual ~ContentProvider()
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{
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}
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virtual void provideStreamData(int objid, int generation,
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Pipeline* pipeline);
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private:
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QPDFObjectHandle from_page;
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};
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void
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ContentProvider::provideStreamData(int, int, Pipeline* p)
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{
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Pl_Concatenate concat("concatenate", p);
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std::string description = "contents from page object " +
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QUtil::int_to_string(from_page.getObjectID()) + " " +
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QUtil::int_to_string(from_page.getGeneration());
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std::string all_description;
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from_page.getKey("/Contents").pipeContentStreams(
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&concat, description, all_description);
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concat.manualFinish();
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}
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class InlineImageTracker: public QPDFObjectHandle::TokenFilter
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{
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public:
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InlineImageTracker(QPDF*, size_t min_size, QPDFObjectHandle resources);
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virtual ~InlineImageTracker()
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{
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}
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virtual void handleToken(QPDFTokenizer::Token const&);
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QPDFObjectHandle convertIIDict(QPDFObjectHandle odict);
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QPDF* qpdf;
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size_t min_size;
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QPDFObjectHandle resources;
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std::string dict_str;
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std::string bi_str;
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int min_suffix;
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bool any_images;
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enum { st_top, st_bi } state;
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};
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InlineImageTracker::InlineImageTracker(QPDF* qpdf, size_t min_size,
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QPDFObjectHandle resources) :
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qpdf(qpdf),
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min_size(min_size),
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resources(resources),
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min_suffix(1),
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any_images(false),
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state(st_top)
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{
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}
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QPDFObjectHandle
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InlineImageTracker::convertIIDict(QPDFObjectHandle odict)
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{
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QPDFObjectHandle dict = QPDFObjectHandle::newDictionary();
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dict.replaceKey("/Type", QPDFObjectHandle::newName("/XObject"));
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dict.replaceKey("/Subtype", QPDFObjectHandle::newName("/Image"));
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std::set<std::string> keys = odict.getKeys();
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for (std::set<std::string>::iterator iter = keys.begin();
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iter != keys.end(); ++iter)
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{
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std::string key = *iter;
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QPDFObjectHandle value = odict.getKey(key);
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if (key == "/BPC")
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{
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key = "/BitsPerComponent";
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}
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else if (key == "/CS")
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{
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key = "/ColorSpace";
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}
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else if (key == "/D")
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{
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key = "/Decode";
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}
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else if (key == "/DP")
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{
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key = "/DecodeParms";
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}
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else if (key == "/F")
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{
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key = "/Filter";
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}
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else if (key == "/H")
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{
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key = "/Height";
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}
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else if (key == "/IM")
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{
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key = "/ImageMask";
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}
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else if (key == "/I")
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{
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key = "/Interpolate";
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}
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else if (key == "/W")
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{
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key = "/Width";
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}
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if (key == "/ColorSpace")
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{
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if (value.isName())
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{
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std::string name = value.getName();
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if (name == "/G")
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{
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name = "/DeviceGray";
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}
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else if (name == "/RGB")
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{
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name = "/DeviceRGB";
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}
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else if (name == "/CMYK")
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{
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name = "/DeviceCMYK";
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}
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else if (name == "/I")
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{
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name = "/Indexed";
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}
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else
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{
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name.clear();
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}
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if (! name.empty())
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{
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value = QPDFObjectHandle::newName(name);
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}
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}
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}
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else if (key == "/Filter")
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{
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std::vector<QPDFObjectHandle> filters;
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if (value.isName())
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{
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filters.push_back(value);
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}
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else if (value.isArray())
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{
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filters = value.getArrayAsVector();
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}
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for (std::vector<QPDFObjectHandle>::iterator iter =
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filters.begin();
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iter != filters.end(); ++iter)
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{
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std::string name;
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if ((*iter).isName())
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{
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name = (*iter).getName();
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}
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if (name == "/AHx")
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{
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name = "/ASCIIHexDecode";
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}
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else if (name == "/A85")
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{
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name = "/ASCII85Decode";
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}
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else if (name == "/LZW")
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{
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name = "/LZWDecode";
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}
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else if (name == "/Fl")
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{
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name = "/FlateDecode";
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}
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else if (name == "/RL")
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{
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name = "/RunLengthDecode";
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}
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else if (name == "/CCF")
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{
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name = "/CCITTFaxDecode";
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}
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else if (name == "/DCT")
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{
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name = "/DCTDecode";
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}
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else
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{
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name.clear();
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}
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if (! name.empty())
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{
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*iter = QPDFObjectHandle::newName(name);
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}
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}
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if (value.isName() && (filters.size() == 1))
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{
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value = filters.at(0);
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}
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else if (value.isArray())
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{
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value = QPDFObjectHandle::newArray(filters);
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}
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}
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dict.replaceKey(key, value);
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}
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return dict;
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}
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void
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InlineImageTracker::handleToken(QPDFTokenizer::Token const& token)
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{
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if (state == st_bi)
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{
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if (token.getType() == QPDFTokenizer::tt_inline_image)
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{
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std::string image_data(token.getValue());
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size_t len = image_data.length();
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if (len >= this->min_size)
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{
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QTC::TC("qpdf", "QPDFPageObjectHelper externalize inline image");
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Pl_Buffer b("image_data");
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b.write(QUtil::unsigned_char_pointer(image_data), len);
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b.finish();
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QPDFObjectHandle dict =
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convertIIDict(QPDFObjectHandle::parse(dict_str));
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dict.replaceKey(
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"/Length",
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QPDFObjectHandle::newInteger(QIntC::to_longlong(len)));
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std::string name = resources.getUniqueResourceName(
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"/IIm", this->min_suffix);
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QPDFObjectHandle image = QPDFObjectHandle::newStream(
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this->qpdf, b.getBuffer());
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image.replaceDict(dict);
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resources.getKey("/XObject").replaceKey(name, image);
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write(name);
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write(" Do\n");
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any_images = true;
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}
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else
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{
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QTC::TC("qpdf", "QPDFPageObjectHelper keep inline image");
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write(bi_str);
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writeToken(token);
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state = st_top;
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}
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}
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else if (token == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "ID"))
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{
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bi_str += token.getValue();
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dict_str += " >>";
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}
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else if (token == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "EI"))
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{
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state = st_top;
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}
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else
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{
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bi_str += token.getValue();
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dict_str += token.getValue();
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}
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}
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else if (token == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "BI"))
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{
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bi_str = token.getValue();
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dict_str = "<< ";
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state = st_bi;
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}
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else
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{
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writeToken(token);
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}
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}
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QPDFPageObjectHelper::Members::~Members()
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{
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}
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QPDFPageObjectHelper::Members::Members()
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{
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}
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QPDFPageObjectHelper::QPDFPageObjectHelper(QPDFObjectHandle oh) :
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QPDFObjectHelper(oh)
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{
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}
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QPDFObjectHandle
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QPDFPageObjectHelper::getAttribute(std::string const& name,
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bool copy_if_shared)
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{
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bool inheritable = ((name == "/MediaBox") || (name == "/CropBox") ||
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(name == "/Resources") || (name == "/Rotate"));
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QPDFObjectHandle node = this->oh;
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QPDFObjectHandle result(node.getKey(name));
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std::set<QPDFObjGen> seen;
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bool inherited = false;
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while (inheritable && result.isNull() && node.hasKey("/Parent"))
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{
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seen.insert(node.getObjGen());
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node = node.getKey("/Parent");
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if (seen.count(node.getObjGen()))
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{
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break;
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}
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result = node.getKey(name);
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if (! result.isNull())
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{
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QTC::TC("qpdf", "QPDFPageObjectHelper non-trivial inheritance");
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inherited = true;
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}
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}
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if (copy_if_shared && (inherited || result.isIndirect()))
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{
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QTC::TC("qpdf", "QPDFPageObjectHelper copy shared attribute");
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result = result.shallowCopy();
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this->oh.replaceKey(name, result);
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}
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return result;
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}
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QPDFObjectHandle
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QPDFPageObjectHelper::getTrimBox(bool copy_if_shared)
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{
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QPDFObjectHandle result = getAttribute("/TrimBox", copy_if_shared);
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if (result.isNull())
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{
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result = getCropBox(copy_if_shared);
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}
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return result;
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}
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QPDFObjectHandle
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QPDFPageObjectHelper::getCropBox(bool copy_if_shared)
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{
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QPDFObjectHandle result = getAttribute("/CropBox", copy_if_shared);
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if (result.isNull())
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{
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result = getMediaBox();
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}
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return result;
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}
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QPDFObjectHandle
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QPDFPageObjectHelper::getMediaBox(bool copy_if_shared)
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{
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return getAttribute("/MediaBox", copy_if_shared);
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}
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std::map<std::string, QPDFObjectHandle>
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QPDFPageObjectHelper::getPageImages()
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{
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return this->oh.getPageImages();
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}
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void
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QPDFPageObjectHelper::externalizeInlineImages(size_t min_size)
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{
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QPDFObjectHandle resources = getAttribute("/Resources", true);
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// Calling mergeResources also ensures that /XObject becomes
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// direct and is not shared with other pages.
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resources.mergeResources(
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QPDFObjectHandle::parse("<< /XObject << >> >>"));
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InlineImageTracker iit(this->oh.getOwningQPDF(), min_size, resources);
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Pl_Buffer b("new page content");
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filterPageContents(&iit, &b);
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if (iit.any_images)
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{
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getObjectHandle().replaceKey(
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"/Contents",
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QPDFObjectHandle::newStream(
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this->oh.getOwningQPDF(), b.getBuffer()));
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}
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}
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std::vector<QPDFAnnotationObjectHelper>
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QPDFPageObjectHelper::getAnnotations(std::string const& only_subtype)
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{
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std::vector<QPDFAnnotationObjectHelper> result;
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QPDFObjectHandle annots = this->oh.getKey("/Annots");
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if (annots.isArray())
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{
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int nannots = annots.getArrayNItems();
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for (int i = 0; i < nannots; ++i)
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{
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QPDFObjectHandle annot = annots.getArrayItem(i);
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if (only_subtype.empty() ||
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(annot.isDictionary() &&
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annot.getKey("/Subtype").isName() &&
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(only_subtype == annot.getKey("/Subtype").getName())))
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{
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result.push_back(QPDFAnnotationObjectHelper(annot));
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}
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}
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}
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return result;
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}
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std::vector<QPDFObjectHandle>
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QPDFPageObjectHelper::getPageContents()
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{
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return this->oh.getPageContents();
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}
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void
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QPDFPageObjectHelper::addPageContents(QPDFObjectHandle contents, bool first)
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{
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this->oh.addPageContents(contents, first);
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}
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void
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QPDFPageObjectHelper::rotatePage(int angle, bool relative)
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{
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this->oh.rotatePage(angle, relative);
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}
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void
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QPDFPageObjectHelper::coalesceContentStreams()
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{
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this->oh.coalesceContentStreams();
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}
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void
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QPDFPageObjectHelper::parsePageContents(
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QPDFObjectHandle::ParserCallbacks* callbacks)
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{
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this->oh.parsePageContents(callbacks);
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}
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void
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QPDFPageObjectHelper::filterPageContents(
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QPDFObjectHandle::TokenFilter* filter,
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Pipeline* next)
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{
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this->oh.filterPageContents(filter, next);
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}
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void
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QPDFPageObjectHelper::pipePageContents(Pipeline* p)
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{
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this->oh.pipePageContents(p);
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}
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void
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QPDFPageObjectHelper::addContentTokenFilter(
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PointerHolder<QPDFObjectHandle::TokenFilter> token_filter)
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{
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this->oh.addContentTokenFilter(token_filter);
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}
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class NameWatcher: public QPDFObjectHandle::TokenFilter
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{
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public:
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NameWatcher() :
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saw_bad(false)
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{
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}
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virtual ~NameWatcher()
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{
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}
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virtual void handleToken(QPDFTokenizer::Token const&);
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std::set<std::string> names;
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bool saw_bad;
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};
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void
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NameWatcher::handleToken(QPDFTokenizer::Token const& token)
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{
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if (token.getType() == QPDFTokenizer::tt_name)
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{
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// Create a name object and get its name. This canonicalizes
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// the representation of the name
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this->names.insert(
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QPDFObjectHandle::newName(token.getValue()).getName());
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}
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else if (token.getType() == QPDFTokenizer::tt_bad)
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{
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saw_bad = true;
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}
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writeToken(token);
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}
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void
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QPDFPageObjectHelper::removeUnreferencedResources()
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{
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NameWatcher nw;
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try
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{
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filterPageContents(&nw);
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}
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catch (std::exception& e)
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{
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this->oh.warnIfPossible(
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std::string("Unable to parse content stream: ") + e.what() +
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"; not attempting to remove unreferenced objects from this page");
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return;
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}
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if (nw.saw_bad)
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{
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QTC::TC("qpdf", "QPDFPageObjectHelper bad token finding names");
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this->oh.warnIfPossible(
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"Bad token found while scanning content stream; "
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"not attempting to remove unreferenced objects from this page");
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return;
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}
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// Walk through /Font and /XObject dictionaries, removing any
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// resources that are not referenced. We must make copies of
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// resource dictionaries down into the dictionaries are mutating
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// to prevent mutating one dictionary from having the side effect
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// of mutating the one it was copied from.
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std::vector<std::string> to_filter;
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to_filter.push_back("/Font");
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to_filter.push_back("/XObject");
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QPDFObjectHandle resources = getAttribute("/Resources", true);
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for (std::vector<std::string>::iterator d_iter = to_filter.begin();
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d_iter != to_filter.end(); ++d_iter)
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{
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QPDFObjectHandle dict = resources.getKey(*d_iter);
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if (! dict.isDictionary())
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{
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continue;
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}
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dict = dict.shallowCopy();
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resources.replaceKey(*d_iter, dict);
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std::set<std::string> keys = dict.getKeys();
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for (std::set<std::string>::iterator k_iter = keys.begin();
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k_iter != keys.end(); ++k_iter)
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{
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if (! nw.names.count(*k_iter))
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{
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dict.removeKey(*k_iter);
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}
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}
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}
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}
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QPDFPageObjectHelper
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QPDFPageObjectHelper::shallowCopyPage()
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{
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QPDF* qpdf = this->oh.getOwningQPDF();
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if (! qpdf)
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{
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throw std::runtime_error(
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"QPDFPageObjectHelper::shallowCopyPage"
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" called with a direct object");
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}
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QPDFObjectHandle new_page = this->oh.shallowCopy();
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return QPDFPageObjectHelper(qpdf->makeIndirectObject(new_page));
|
|
}
|
|
|
|
QPDFObjectHandle::Matrix
|
|
QPDFPageObjectHelper::getMatrixForTransformations(bool invert)
|
|
{
|
|
QPDFObjectHandle::Matrix matrix(1, 0, 0, 1, 0, 0);
|
|
QPDFObjectHandle bbox = getTrimBox(false);
|
|
if (! bbox.isRectangle())
|
|
{
|
|
return matrix;
|
|
}
|
|
QPDFObjectHandle rotate_obj = getAttribute("/Rotate", false);
|
|
QPDFObjectHandle scale_obj = getAttribute("/UserUnit", false);
|
|
if (! (rotate_obj.isNull() && scale_obj.isNull()))
|
|
{
|
|
QPDFObjectHandle::Rectangle rect = bbox.getArrayAsRectangle();
|
|
double width = rect.urx - rect.llx;
|
|
double height = rect.ury - rect.lly;
|
|
double scale = (scale_obj.isNumber()
|
|
? scale_obj.getNumericValue()
|
|
: 1.0);
|
|
int rotate = (rotate_obj.isInteger()
|
|
? rotate_obj.getIntValueAsInt()
|
|
: 0);
|
|
if (invert)
|
|
{
|
|
if (scale == 0.0)
|
|
{
|
|
return matrix;
|
|
}
|
|
scale = 1.0 / scale;
|
|
rotate = 360 - rotate;
|
|
}
|
|
|
|
// Ignore invalid rotation angle
|
|
switch (rotate)
|
|
{
|
|
case 90:
|
|
matrix = QPDFObjectHandle::Matrix(
|
|
0, -scale, scale, 0, 0, width * scale);
|
|
break;
|
|
case 180:
|
|
matrix = QPDFObjectHandle::Matrix(
|
|
-scale, 0, 0, -scale, width * scale, height * scale);
|
|
break;
|
|
case 270:
|
|
matrix = QPDFObjectHandle::Matrix(
|
|
0, scale, -scale, 0, height * scale, 0);
|
|
break;
|
|
default:
|
|
matrix = QPDFObjectHandle::Matrix(
|
|
scale, 0, 0, scale, 0, 0);
|
|
break;
|
|
}
|
|
}
|
|
return matrix;
|
|
}
|
|
|
|
QPDFObjectHandle
|
|
QPDFPageObjectHelper::getFormXObjectForPage(bool handle_transformations)
|
|
{
|
|
QPDF* qpdf = this->oh.getOwningQPDF();
|
|
if (! qpdf)
|
|
{
|
|
throw std::runtime_error(
|
|
"QPDFPageObjectHelper::getFormXObjectForPage"
|
|
" called with a direct object");
|
|
}
|
|
QPDFObjectHandle result = QPDFObjectHandle::newStream(qpdf);
|
|
QPDFObjectHandle newdict = result.getDict();
|
|
newdict.replaceKey("/Type", QPDFObjectHandle::newName("/XObject"));
|
|
newdict.replaceKey("/Subtype", QPDFObjectHandle::newName("/Form"));
|
|
newdict.replaceKey("/Resources",
|
|
getAttribute("/Resources", false).shallowCopy());
|
|
newdict.replaceKey("/Group",
|
|
getAttribute("/Group", false).shallowCopy());
|
|
QPDFObjectHandle bbox = getTrimBox(false).shallowCopy();
|
|
if (! bbox.isRectangle())
|
|
{
|
|
this->oh.warnIfPossible(
|
|
"bounding box is invalid; form"
|
|
" XObject created from page will not work");
|
|
}
|
|
newdict.replaceKey("/BBox", bbox);
|
|
PointerHolder<QPDFObjectHandle::StreamDataProvider> provider =
|
|
new ContentProvider(this->oh);
|
|
result.replaceStreamData(
|
|
provider, QPDFObjectHandle::newNull(), QPDFObjectHandle::newNull());
|
|
QPDFObjectHandle rotate_obj = getAttribute("/Rotate", false);
|
|
QPDFObjectHandle scale_obj = getAttribute("/UserUnit", false);
|
|
if (handle_transformations &&
|
|
(! (rotate_obj.isNull() && scale_obj.isNull())))
|
|
{
|
|
newdict.replaceKey("/Matrix",
|
|
QPDFObjectHandle::newArray(
|
|
getMatrixForTransformations()));
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
std::string
|
|
QPDFPageObjectHelper::placeFormXObject(
|
|
QPDFObjectHandle fo, std::string name,
|
|
QPDFObjectHandle::Rectangle rect,
|
|
bool invert_transformations)
|
|
{
|
|
// Calculate the transformation matrix that will place the given
|
|
// form XObject fully inside the given rectangle, shrinking and
|
|
// centering if needed.
|
|
|
|
// When rendering a form XObject, the transformation in the
|
|
// graphics state (cm) is applied first (of course -- when it is
|
|
// applied, the PDF interpreter doesn't even know we're going to
|
|
// be drawing a form XObject yet), and then the object's matrix
|
|
// (M) is applied. The resulting matrix, when applied to the form
|
|
// XObject's bounding box, will generate a new rectangle. We want
|
|
// to create a transformation matrix that make the form XObject's
|
|
// bounding box land in exactly the right spot.
|
|
|
|
QPDFObjectHandle fdict = fo.getDict();
|
|
QPDFObjectHandle bbox_obj = fdict.getKey("/BBox");
|
|
if (! bbox_obj.isRectangle())
|
|
{
|
|
return "";
|
|
}
|
|
|
|
QPDFMatrix wmatrix; // work matrix
|
|
QPDFMatrix tmatrix; // "to" matrix
|
|
QPDFMatrix fmatrix; // "from" matrix
|
|
if (invert_transformations)
|
|
{
|
|
// tmatrix inverts scaling and rotation of the destination
|
|
// page. Applying this matrix allows the overlaid form
|
|
// XObject's to be absolute rather than relative to properties
|
|
// of the destination page. tmatrix is part of the computed
|
|
// transformation matrix.
|
|
tmatrix = QPDFMatrix(getMatrixForTransformations(true));
|
|
wmatrix.concat(tmatrix);
|
|
}
|
|
if (fdict.getKey("/Matrix").isMatrix())
|
|
{
|
|
// fmatrix is the transformation matrix that is applied to the
|
|
// form XObject itself. We need this for calculations, but we
|
|
// don't explicitly use it in the final result because the PDF
|
|
// rendering system automatically applies this last before
|
|
// drawing the form XObject.
|
|
fmatrix = QPDFMatrix(fdict.getKey("/Matrix").getArrayAsMatrix());
|
|
wmatrix.concat(fmatrix);
|
|
}
|
|
|
|
// The current wmatrix handles transformation from the form
|
|
// xobject and, if requested, the destination page. Next, we have
|
|
// to adjust this for scale and position.
|
|
|
|
// Step 1: figure out what scale factor we need to make the form
|
|
// XObject's bounding box fit within the destination rectangle.
|
|
|
|
// Transform bounding box
|
|
QPDFObjectHandle::Rectangle bbox = bbox_obj.getArrayAsRectangle();
|
|
QPDFObjectHandle::Rectangle T = wmatrix.transformRectangle(bbox);
|
|
|
|
// Calculate a scale factor, if needed. If the transformed
|
|
// rectangle is too big, shrink it. Never expand it.
|
|
if ((T.urx == T.llx) || (T.ury == T.lly))
|
|
{
|
|
// avoid division by zero
|
|
return "";
|
|
}
|
|
double rect_w = rect.urx - rect.llx;
|
|
double rect_h = rect.ury - rect.lly;
|
|
double t_w = T.urx - T.llx;
|
|
double t_h = T.ury - T.lly;
|
|
double xscale = rect_w / t_w;
|
|
double yscale = rect_h / t_h;
|
|
double scale = (xscale < yscale ? xscale : yscale);
|
|
if (scale > 1.0)
|
|
{
|
|
scale = 1.0;
|
|
}
|
|
|
|
// Step 2: figure out what translation is required to get the
|
|
// rectangle to the right spot: centered within the destination.
|
|
wmatrix = QPDFMatrix();
|
|
wmatrix.scale(scale, scale);
|
|
wmatrix.concat(tmatrix);
|
|
wmatrix.concat(fmatrix);
|
|
|
|
T = wmatrix.transformRectangle(bbox);
|
|
double t_cx = (T.llx + T.urx) / 2.0;
|
|
double t_cy = (T.lly + T.ury) / 2.0;
|
|
double r_cx = (rect.llx + rect.urx) / 2.0;
|
|
double r_cy = (rect.lly + rect.ury) / 2.0;
|
|
double tx = r_cx - t_cx;
|
|
double ty = r_cy - t_cy;
|
|
|
|
// Now we can calculate the final matrix. The final matrix does
|
|
// not include fmatrix because that is applied automatically by
|
|
// the PDF interpreter.
|
|
QPDFMatrix cm;
|
|
cm.translate(tx, ty);
|
|
cm.scale(scale, scale);
|
|
cm.concat(tmatrix);
|
|
return (
|
|
"q\n" +
|
|
cm.unparse() + " cm\n" +
|
|
name + " Do\n" +
|
|
"Q\n");
|
|
}
|