QPDF_pages.cc
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#include <qpdf/QPDF.hh>
#include <assert.h>
#include <qpdf/QTC.hh>
#include <qpdf/QUtil.hh>
#include <qpdf/QPDFExc.hh>
std::vector<QPDFObjectHandle> const&
QPDF::getAllPages()
{
if (this->all_pages.empty())
{
getAllPagesInternal(
this->trailer.getKey("/Root").getKey("/Pages"), this->all_pages);
}
return this->all_pages;
}
void
QPDF::getAllPagesInternal(QPDFObjectHandle cur_pages,
std::vector<QPDFObjectHandle>& result)
{
std::string type = cur_pages.getKey("/Type").getName();
if (type == "/Pages")
{
QPDFObjectHandle kids = cur_pages.getKey("/Kids");
int n = kids.getArrayNItems();
for (int i = 0; i < n; ++i)
{
getAllPagesInternal(kids.getArrayItem(i), result);
}
}
else if (type == "/Page")
{
result.push_back(cur_pages);
}
else
{
throw QPDFExc(qpdf_e_damaged_pdf, this->file->getName(),
this->last_object_description,
this->file->getLastOffset(),
": invalid Type in page tree");
}
}
// FIXXX here down
void
QPDF::clearPagesCache()
{
this->all_pages.clear();
this->pageobj_to_pages_pos.clear();
}
void
QPDF::flattenPagesTree()
{
clearPagesCache();
// FIXME: more specific method, we don't want to generate the extra stuff.
// We also need cheap fixup after addPage/removePage.
// no compressed objects to be produced here...
std::map<int, int> object_stream_data;
optimize(object_stream_data); // push down inheritance
std::vector<QPDFObjectHandle> kids = this->getAllPages();
QPDFObjectHandle pages = this->trailer.getKey("/Root").getKey("/Pages");
const int len = kids.size();
for (int pos = 0; pos < len; ++pos)
{
// populate pageobj_to_pages_pos
ObjGen og(kids[pos].getObjectID(), kids[pos].getGeneration());
if (! this->pageobj_to_pages_pos.insert(std::make_pair(og, pos)).second)
{
// insert failed: duplicate entry found
*out_stream << "WARNING: duplicate page reference found, "
<< "but currently not fully supported." << std::endl;
}
// fix parent links
kids[pos].replaceKey("/Parent", pages);
}
pages.replaceKey("/Kids", QPDFObjectHandle::newArray(kids));
// /Count has not changed
assert(pages.getKey("/Count").getIntValue() == len);
}
int
QPDF::findPage(int objid, int generation)
{
if (this->pageobj_to_pages_pos.empty())
{
flattenPagesTree();
}
std::map<ObjGen, int>::iterator it =
this->pageobj_to_pages_pos.find(ObjGen(objid, generation));
if (it != this->pageobj_to_pages_pos.end())
{
return (*it).second;
}
return -1; // throw?
}
int
QPDF::findPage(QPDFObjectHandle const& pageoh)
{
if (!pageoh.isInitialized())
{
return -1;
// TODO? throw
}
return findPage(pageoh.getObjectID(), pageoh.getGeneration());
}
void
QPDF::addPage(QPDFObjectHandle newpage, bool first)
{
if (this->pageobj_to_pages_pos.empty())
{
flattenPagesTree();
}
newpage.assertPageObject(); // FIXME: currently private
QPDFObjectHandle pages = this->trailer.getKey("/Root").getKey("/Pages");
QPDFObjectHandle kids = pages.getKey("/Kids");
newpage.replaceKey("/Parent", pages);
if (first)
{
kids.insertItem(0, newpage);
}
else
{
kids.appendItem(newpage);
}
pages.replaceKey("/Count",
QPDFObjectHandle::newInteger(kids.getArrayNItems()));
// FIXME: this is overkill, but cache is now stale
clearPagesCache();
}
void
QPDF::addPageAt(QPDFObjectHandle newpage, bool before,
QPDFObjectHandle const &refpage)
{
int refpos = findPage(refpage); // also ensures flat /Pages
if (refpos == -1)
{
throw "Could not find refpage";
}
newpage.assertPageObject();
QPDFObjectHandle pages = this->trailer.getKey("/Root").getKey("/Pages");
QPDFObjectHandle kids = pages.getKey("/Kids");
if (! before)
{
++refpos;
}
newpage.replaceKey("/Parent", pages);
kids.insertItem(refpos, newpage);
pages.replaceKey("/Count",
QPDFObjectHandle::newInteger(kids.getArrayNItems()));
// FIXME: this is overkill, but cache is now stale
clearPagesCache();
}
void
QPDF::removePage(QPDFObjectHandle const& pageoh)
{
int pos = findPage(pageoh); // also ensures flat /Pages
if (pos == -1)
{
throw "Can't remove non-existing page";
}
QPDFObjectHandle pages = this->trailer.getKey("/Root").getKey("/Pages");
QPDFObjectHandle kids = pages.getKey("/Kids");
kids.eraseItem(pos);
pages.replaceKey("/Count",
QPDFObjectHandle::newInteger(kids.getArrayNItems()));
// FIXME: this is overkill, but cache is now stale
clearPagesCache();
}