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333 lines
11 KiB
C++
333 lines
11 KiB
C++
#include <qpdf/QPDFAcroFormDocumentHelper.hh>
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#include <qpdf/QTC.hh>
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#include <qpdf/QPDFPageDocumentHelper.hh>
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QPDFAcroFormDocumentHelper::Members::~Members()
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{
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}
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QPDFAcroFormDocumentHelper::Members::Members() :
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cache_valid(false)
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{
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}
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QPDFAcroFormDocumentHelper::QPDFAcroFormDocumentHelper(QPDF& qpdf) :
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QPDFDocumentHelper(qpdf),
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m(new Members())
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{
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}
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void
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QPDFAcroFormDocumentHelper::invalidateCache()
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{
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this->m->cache_valid = false;
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this->m->field_to_annotations.clear();
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this->m->annotation_to_field.clear();
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}
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bool
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QPDFAcroFormDocumentHelper::hasAcroForm()
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{
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return this->qpdf.getRoot().hasKey("/AcroForm");
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}
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std::vector<QPDFFormFieldObjectHelper>
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QPDFAcroFormDocumentHelper::getFormFields()
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{
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analyze();
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std::vector<QPDFFormFieldObjectHelper> result;
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for (std::map<QPDFObjGen,
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std::vector<QPDFAnnotationObjectHelper> >::iterator iter =
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this->m->field_to_annotations.begin();
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iter != this->m->field_to_annotations.end(); ++iter)
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{
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result.push_back(this->qpdf.getObjectByObjGen((*iter).first));
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}
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return result;
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}
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std::vector<QPDFAnnotationObjectHelper>
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QPDFAcroFormDocumentHelper::getAnnotationsForField(QPDFFormFieldObjectHelper h)
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{
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analyze();
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std::vector<QPDFAnnotationObjectHelper> result;
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QPDFObjGen og(h.getObjectHandle().getObjGen());
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if (this->m->field_to_annotations.count(og))
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{
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result = this->m->field_to_annotations[og];
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}
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return result;
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}
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std::vector<QPDFAnnotationObjectHelper>
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QPDFAcroFormDocumentHelper::getWidgetAnnotationsForPage(QPDFPageObjectHelper h)
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{
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return h.getAnnotations("/Widget");
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}
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QPDFFormFieldObjectHelper
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QPDFAcroFormDocumentHelper::getFieldForAnnotation(QPDFAnnotationObjectHelper h)
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{
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QPDFObjectHandle oh = h.getObjectHandle();
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if (! (oh.isDictionary() &&
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oh.getKey("/Subtype").isName() &&
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(oh.getKey("/Subtype").getName() == "/Widget")))
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{
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throw std::logic_error(
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"QPDFAnnotationObjectHelper::getFieldForAnnotation called for"
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" non-/Widget annotation");
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}
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analyze();
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QPDFFormFieldObjectHelper result(QPDFObjectHandle::newNull());
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QPDFObjGen og(oh.getObjGen());
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if (this->m->annotation_to_field.count(og))
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{
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result = this->m->annotation_to_field[og];
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}
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return result;
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}
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void
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QPDFAcroFormDocumentHelper::analyze()
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{
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if (this->m->cache_valid)
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{
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return;
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}
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this->m->cache_valid = true;
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QPDFObjectHandle acroform = this->qpdf.getRoot().getKey("/AcroForm");
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if (! (acroform.isDictionary() && acroform.hasKey("/Fields")))
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{
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return;
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}
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QPDFObjectHandle fields = acroform.getKey("/Fields");
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if (! fields.isArray())
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{
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QTC::TC("qpdf", "QPDFAcroFormDocumentHelper fields not array");
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acroform.warnIfPossible(
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"/Fields key of /AcroForm dictionary is not an array; ignoring");
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fields = QPDFObjectHandle::newArray();
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}
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// Traverse /AcroForm to find annotations and map them
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// bidirectionally to fields.
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std::set<QPDFObjGen> visited;
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size_t nfields = fields.getArrayNItems();
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QPDFObjectHandle null(QPDFObjectHandle::newNull());
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for (size_t i = 0; i < nfields; ++i)
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{
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traverseField(fields.getArrayItem(i), null, 0, visited);
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}
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// All Widget annotations should have been encountered by
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// traversing /AcroForm, but in case any weren't, find them by
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// walking through pages, and treat any widget annotation that is
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// not associated with a field as its own field. This just ensures
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// that requesting the field for any annotation we find through a
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// page's /Annots list will have some associated field. Note that
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// a file that contains this kind of error will probably not
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// actually work with most viewers.
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QPDFPageDocumentHelper dh(this->qpdf);
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std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
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for (std::vector<QPDFPageObjectHelper>::iterator iter = pages.begin();
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iter != pages.end(); ++iter)
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{
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QPDFPageObjectHelper ph(*iter);
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std::vector<QPDFAnnotationObjectHelper> annots =
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getWidgetAnnotationsForPage(ph);
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for (std::vector<QPDFAnnotationObjectHelper>::iterator i2 =
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annots.begin();
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i2 != annots.end(); ++i2)
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{
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QPDFObjectHandle annot((*i2).getObjectHandle());
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QPDFObjGen og(annot.getObjGen());
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if (this->m->annotation_to_field.count(og) == 0)
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{
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QTC::TC("qpdf", "QPDFAcroFormDocumentHelper orphaned widget");
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// This is not supposed to happen, but it's easy
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// enough for us to handle this case. Treat the
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// annotation as its own field. This could allow qpdf
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// to sensibly handle a case such as a PDF creator
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// adding a self-contained annotation (merged with the
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// field dictionary) to the page's /Annots array and
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// forgetting to also put it in /AcroForm.
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annot.warnIfPossible(
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"this widget annotation is not"
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" reachable from /AcroForm in the document catalog");
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this->m->annotation_to_field[og] =
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QPDFFormFieldObjectHelper(annot);
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this->m->field_to_annotations[og].push_back(
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QPDFAnnotationObjectHelper(annot));
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}
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}
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}
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}
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void
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QPDFAcroFormDocumentHelper::traverseField(
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QPDFObjectHandle field, QPDFObjectHandle parent, int depth,
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std::set<QPDFObjGen>& visited)
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{
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if (depth > 100)
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{
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// Arbitrarily cut off recursion at a fixed depth to avoid
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// specially crafted files that could cause stack overflow.
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return;
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}
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if (! field.isIndirect())
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{
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QTC::TC("qpdf", "QPDFAcroFormDocumentHelper direct field");
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field.warnIfPossible(
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"encountered a direct object as a field or annotation while"
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" traversing /AcroForm; ignoring field or annotation");
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return;
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}
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if (! field.isDictionary())
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{
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QTC::TC("qpdf", "QPDFAcroFormDocumentHelper non-dictionary field");
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field.warnIfPossible(
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"encountered a non-dictionary as a field or annotation while"
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" traversing /AcroForm; ignoring field or annotation");
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return;
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}
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QPDFObjGen og(field.getObjGen());
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if (visited.count(og) != 0)
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{
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QTC::TC("qpdf", "QPDFAcroFormDocumentHelper loop");
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field.warnIfPossible("loop detected while traversing /AcroForm");
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return;
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}
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visited.insert(og);
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// A dictionary encountered while traversing the /AcroForm field
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// may be a form field, an annotation, or the merger of the two. A
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// field that has no fields below it is a terminal. If a terminal
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// field looks like an annotation, it is an annotation because
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// annotation dictionary fields can be merged with terminal field
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// dictionaries. Otherwise, the annotation fields might be there
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// to be inherited by annotations below it.
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bool is_annotation = false;
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bool is_field = (0 == depth);
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QPDFObjectHandle kids = field.getKey("/Kids");
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if (kids.isArray())
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{
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is_field = true;
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size_t nkids = kids.getArrayNItems();
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for (size_t k = 0; k < nkids; ++k)
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{
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traverseField(kids.getArrayItem(k), field, 1 + depth, visited);
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}
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}
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else
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{
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if (field.hasKey("/Parent"))
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{
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is_field = true;
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}
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if (field.hasKey("/Subtype") ||
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field.hasKey("/Rect") ||
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field.hasKey("/AP"))
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{
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is_annotation = true;
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}
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}
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QTC::TC("qpdf", "QPDFAcroFormDocumentHelper field found",
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(depth == 0) ? 0 : 1);
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QTC::TC("qpdf", "QPDFAcroFormDocumentHelper annotation found",
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(is_field ? 0 : 1));
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if (is_annotation)
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{
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QPDFObjectHandle our_field = (is_field ? field : parent);
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this->m->field_to_annotations[our_field.getObjGen()].push_back(
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QPDFAnnotationObjectHelper(field));
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this->m->annotation_to_field[og] =
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QPDFFormFieldObjectHelper(our_field);
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}
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}
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bool
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QPDFAcroFormDocumentHelper::getNeedAppearances()
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{
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bool result = false;
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QPDFObjectHandle acroform = this->qpdf.getRoot().getKey("/AcroForm");
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if (acroform.isDictionary() &&
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acroform.getKey("/NeedAppearances").isBool())
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{
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result = acroform.getKey("/NeedAppearances").getBoolValue();
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}
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return result;
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}
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void
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QPDFAcroFormDocumentHelper::setNeedAppearances(bool val)
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{
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QPDFObjectHandle acroform = this->qpdf.getRoot().getKey("/AcroForm");
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if (! acroform.isDictionary())
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{
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this->qpdf.getRoot().warnIfPossible(
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"ignoring call to QPDFAcroFormDocumentHelper::setNeedAppearances"
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" on a file that lacks an /AcroForm dictionary");
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return;
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}
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if (val)
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{
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acroform.replaceKey("/NeedAppearances",
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QPDFObjectHandle::newBool(true));
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}
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else
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{
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acroform.removeKey("/NeedAppearances");
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}
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}
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void
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QPDFAcroFormDocumentHelper::generateAppearancesIfNeeded()
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{
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if (! getNeedAppearances())
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{
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return;
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}
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QPDFPageDocumentHelper pdh(this->qpdf);
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std::vector<QPDFPageObjectHelper> pages = pdh.getAllPages();
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for (std::vector<QPDFPageObjectHelper>::iterator page_iter =
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pages.begin();
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page_iter != pages.end(); ++page_iter)
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{
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std::vector<QPDFAnnotationObjectHelper> annotations =
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getWidgetAnnotationsForPage(*page_iter);
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for (std::vector<QPDFAnnotationObjectHelper>::iterator annot_iter =
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annotations.begin();
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annot_iter != annotations.end(); ++annot_iter)
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{
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QPDFAnnotationObjectHelper& aoh = *annot_iter;
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QPDFFormFieldObjectHelper ffh =
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getFieldForAnnotation(aoh);
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if (ffh.getFieldType() == "/Btn")
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{
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// Rather than generating appearances for button
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// fields, rely on what's already there. Just make
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// sure /AS is consistent with /V, which we can do by
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// resetting the value of the field back to itself.
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// This code is referenced in a comment in
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// QPDFFormFieldObjectHelper::generateAppearance.
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if (ffh.isRadioButton() || ffh.isCheckbox())
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{
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ffh.setV(ffh.getValue());
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}
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}
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else
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{
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ffh.generateAppearance(aoh);
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}
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}
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}
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setNeedAppearances(false);
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}
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