octoleo/qpdf
2
1
Fork 0
mirror of https://github.com/qpdf/qpdf.git synced 2024-11-18 18:35:09 +00:00
Code Issues Releases Wiki Activity
71a4e66d99
qpdf/libqpdf/QPDFAnnotationObjectHelper.cc

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

227 lines
9.4 KiB
C++
Raw Normal View History

Implement helper class for interactive forms
2018-06-19 13:26:41 +00:00
#include <qpdf/QPDFAnnotationObjectHelper.hh>
Add a blank line after the first header included in each source
2022-02-04 21:31:31 +00:00
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
#include <qpdf/QPDF.hh>
#include <qpdf/QPDFMatrix.hh>
Implement helper class for interactive forms
2018-06-19 13:26:41 +00:00
#include <qpdf/QTC.hh>
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
#include <qpdf/QUtil.hh>
Implement helper class for interactive forms
2018-06-19 13:26:41 +00:00
QPDFAnnotationObjectHelper::QPDFAnnotationObjectHelper(QPDFObjectHandle oh) :
QPDFObjectHelper(oh)
{
}
std::string
QPDFAnnotationObjectHelper::getSubtype()
{
return this->oh.getKey("/Subtype").getName();
}
QPDFObjectHandle::Rectangle
QPDFAnnotationObjectHelper::getRect()
{
return this->oh.getKey("/Rect").getArrayAsRectangle();
}
QPDFObjectHandle
QPDFAnnotationObjectHelper::getAppearanceDictionary()
{
return this->oh.getKey("/AP");
}
std::string
QPDFAnnotationObjectHelper::getAppearanceState()
{
if (this->oh.getKey("/AS").isName()) {
QTC::TC("qpdf", "QPDFAnnotationObjectHelper AS present");
return this->oh.getKey("/AS").getName();
}
QTC::TC("qpdf", "QPDFAnnotationObjectHelper AS absent");
return "";
}
Add form fields to json output Also add some additional methods for detecting form field types to assist in the json creation and for later use.
2019-01-02 02:27:18 +00:00
int
QPDFAnnotationObjectHelper::getFlags()
{
QPDFObjectHandle flags_obj = this->oh.getKey("/F");
Fix sign and conversion warnings (major) 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.
2019-06-21 03:35:23 +00:00
return flags_obj.isInteger() ? flags_obj.getIntValueAsInt() : 0;
Add form fields to json output Also add some additional methods for detecting form field types to assist in the json creation and for later use.
2019-01-02 02:27:18 +00:00
}
Implement helper class for interactive forms
2018-06-19 13:26:41 +00:00
QPDFObjectHandle
QPDFAnnotationObjectHelper::getAppearanceStream(std::string const& which, std::string const& state)
{
QPDFObjectHandle ap = getAppearanceDictionary();
std::string desired_state = state.empty() ? getAppearanceState() : state;
if (ap.isDictionary()) {
QPDFObjectHandle ap_sub = ap.getKey(which);
Disregard appearance state when irrelevant (fixes #949) If /AP is a dictionary of streams rather than a dictionary of dictionaries, disregard /AS, which is supposed to point to a subkey of one of the dictionaries. This fix prevents qpdf's annotation flattening from discarding some annotations when /AS is erroneously set.
2023-05-13 20:27:07 +00:00
if (ap_sub.isStream()) {
// According to the spec, Appearance State is supposed to refer to a subkey of the
// appearance stream when /AP is a dictionary, but files have been seen in the wild
// where Appearance State is `/N` and `/AP` is a stream. Therefore, if `which` points to
// a stream, disregard state and just use the stream. See qpdf issue #949 for details.
Implement helper class for interactive forms
2018-06-19 13:26:41 +00:00
QTC::TC("qpdf", "QPDFAnnotationObjectHelper AP stream");
return ap_sub;
}
if (ap_sub.isDictionary() && (!desired_state.empty())) {
QTC::TC("qpdf", "QPDFAnnotationObjectHelper AP dictionary");
QPDFObjectHandle ap_sub_val = ap_sub.getKey(desired_state);
if (ap_sub_val.isStream()) {
Fix typos in coverage cases
2021-02-28 22:29:47 +00:00
QTC::TC("qpdf", "QPDFAnnotationObjectHelper AP sub stream");
Implement helper class for interactive forms
2018-06-19 13:26:41 +00:00
return ap_sub_val;
}
}
}
Fix typos in coverage cases
2021-02-28 22:29:47 +00:00
QTC::TC("qpdf", "QPDFAnnotationObjectHelper AP null");
Implement helper class for interactive forms
2018-06-19 13:26:41 +00:00
return QPDFObjectHandle::newNull();
}
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
std::string
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
QPDFAnnotationObjectHelper::getPageContentForAppearance(
Honor flags when flattening annotations
2019-01-03 16:51:58 +00:00
std::string const& name, int rotate, int required_flags, int forbidden_flags)
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
{
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
if (!getAppearanceStream("/N").isStream()) {
return "";
}
// The appearance matrix computed by this method is the transformation matrix that needs to be
// in effect when drawing this annotation's appearance stream on the page. The algorithm for
// computing the appearance matrix described in section 12.5.5 of the ISO-32000 PDF spec is
// similar but not identical to what we are doing here.
// When rendering an appearance stream associated with an annotation, there are four relevant
// components:
//
// * The appearance stream's bounding box (/BBox)
// * The appearance stream's matrix (/Matrix)
// * The annotation's rectangle (/Rect)
// * In the case of form fields with the NoRotate flag, the page's rotation
// When rendering a form xobject in isolation, just drawn with a /Do operator, there is no form
// field, so page rotation is not relevant, and there is no annotation, so /Rect is not
// relevant, so only /BBox and /Matrix are relevant. The effect of these are as follows:
// * /BBox is treated as a clipping region
// * /Matrix is applied as a transformation prior to rendering the appearance stream.
Code tidy - reflow comments and strings
2023-05-27 17:19:52 +00:00
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// There is no relationship between /BBox and /Matrix in this case.
Code tidy - reflow comments and strings
2023-05-27 17:19:52 +00:00
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// When rendering a form xobject in the context of an annotation, things are a little different.
// In particular, a matrix is established such that /BBox, when transformed by /Matrix, would
// fit completely inside of /Rect. /BBox is no longer a clipping region. To illustrate the
// difference, consider a /Matrix of [2 0 0 2 0 0], which is scaling by a factor of two along
// both axes. If the appearance stream drew a rectangle equal to /BBox, in the case of the form
// xobject in isolation, this matrix would cause only the lower-left quadrant of the rectangle
// to be visible since the scaling would cause the rest of it to fall outside of the clipping
// region. In the case of the form xobject displayed in the context of an annotation, such a
// matrix would have no effect at all because it would be applied to the bounding box first, and
// then when the resulting enclosing quadrilateral was transformed to fit into /Rect, the effect
// of the scaling would be undone.
Code tidy - reflow comments and strings
2023-05-27 17:19:52 +00:00
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// Our job is to create a transformation matrix that compensates for these differences so that
// the appearance stream of an annotation can be drawn as a regular form xobject.
Code tidy - reflow comments and strings
2023-05-27 17:19:52 +00:00
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// To do this, we perform the following steps, which overlap significantly with the algorithm
// in 12.5.5:
Code tidy - reflow comments and strings
2023-05-27 17:19:52 +00:00
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
// 1. Transform the four corners of /BBox by applying /Matrix to them, creating an arbitrarily
// transformed quadrilateral.
Code tidy - reflow comments and strings
2023-05-27 17:19:52 +00:00
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
// 2. Find the minimum upright rectangle that encompasses the resulting quadrilateral. This is
// the "transformed appearance box", T.
Code tidy - reflow comments and strings
2023-05-27 17:19:52 +00:00
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
// 3. Compute matrix A that maps the lower left and upper right corners of T to the annotation's
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// /Rect. This can be done by scaling so that the sizes match and translating so that the
// scaled T exactly overlaps /Rect.
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// If the annotation's /F flag has bit 4 set, this means that annotation is to be rotated about
// its upper left corner to counteract any rotation of the page so it remains upright. To
// achieve this effect, we do the following extra steps:
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// 1. Perform the rotation on /BBox box prior to transforming it with /Matrix (by replacing
// matrix with concatenation of matrix onto the rotation)
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// 2. Rotate the destination rectangle by the specified amount
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
// 3. Apply the rotation to A as computed above to get the final appearance matrix.
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
QPDFObjectHandle rect_obj = this->oh.getKey("/Rect");
QPDFObjectHandle as = getAppearanceStream("/N").getDict();
QPDFObjectHandle bbox_obj = as.getKey("/BBox");
QPDFObjectHandle matrix_obj = as.getKey("/Matrix");
Add form fields to json output Also add some additional methods for detecting form field types to assist in the json creation and for later use.
2019-01-02 02:27:18 +00:00
int flags = getFlags();
Honor flags when flattening annotations
2019-01-03 16:51:58 +00:00
if (flags & forbidden_flags) {
QTC::TC("qpdf", "QPDFAnnotationObjectHelper forbidden flags");
return "";
}
if ((flags & required_flags) != required_flags) {
QTC::TC("qpdf", "QPDFAnnotationObjectHelper missing required flags");
return "";
}
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
if (!(bbox_obj.isRectangle() && rect_obj.isRectangle())) {
return "";
}
QPDFMatrix matrix;
if (matrix_obj.isMatrix()) {
Annotation flattening including form fields Flatten annotations by integrating their appearance streams into the content stream of the containing page. In the case of form fields, only flatten if /NeedAppearance is false (or equivalently absent). If flattening form fields, also remove /AcroForm from the document catalog.
2019-01-01 04:08:57 +00:00
QTC::TC("qpdf", "QPDFAnnotationObjectHelper explicit matrix");
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
matrix = QPDFMatrix(matrix_obj.getArrayAsMatrix());
} else {
Annotation flattening including form fields Flatten annotations by integrating their appearance streams into the content stream of the containing page. In the case of form fields, only flatten if /NeedAppearance is false (or equivalently absent). If flattening form fields, also remove /AcroForm from the document catalog.
2019-01-01 04:08:57 +00:00
QTC::TC("qpdf", "QPDFAnnotationObjectHelper default matrix");
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
}
QPDFObjectHandle::Rectangle rect = rect_obj.getArrayAsRectangle();
Honor flags when flattening annotations
2019-01-03 16:51:58 +00:00
bool do_rotate = (rotate && (flags & an_no_rotate));
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
if (do_rotate) {
Fix comment formatting and update notes
2023-12-27 19:07:38 +00:00
// If the annotation flags include the NoRotate bit and the page is rotated, we have to
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
// rotate the annotation about its upper left corner by the same amount in the opposite
// direction so that it will remain upright in absolute coordinates. Since the semantics of
// /Rotate for a page are to rotate the page, while the effect of rotating using a
// transformation matrix is to rotate the coordinate system, the opposite directionality is
// explicit in the code.
QPDFMatrix mr;
mr.rotatex90(rotate);
mr.concat(matrix);
matrix = mr;
double rect_w = rect.urx - rect.llx;
double rect_h = rect.ury - rect.lly;
switch (rotate) {
case 90:
Annotation flattening including form fields Flatten annotations by integrating their appearance streams into the content stream of the containing page. In the case of form fields, only flatten if /NeedAppearance is false (or equivalently absent). If flattening form fields, also remove /AcroForm from the document catalog.
2019-01-01 04:08:57 +00:00
QTC::TC("qpdf", "QPDFAnnotationObjectHelper rotate 90");
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
rect = QPDFObjectHandle::Rectangle(
rect.llx, rect.ury, rect.llx + rect_h, rect.ury + rect_w);
break;
case 180:
Annotation flattening including form fields Flatten annotations by integrating their appearance streams into the content stream of the containing page. In the case of form fields, only flatten if /NeedAppearance is false (or equivalently absent). If flattening form fields, also remove /AcroForm from the document catalog.
2019-01-01 04:08:57 +00:00
QTC::TC("qpdf", "QPDFAnnotationObjectHelper rotate 180");
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
rect = QPDFObjectHandle::Rectangle(
rect.llx - rect_w, rect.ury, rect.llx, rect.ury + rect_h);
break;
case 270:
Annotation flattening including form fields Flatten annotations by integrating their appearance streams into the content stream of the containing page. In the case of form fields, only flatten if /NeedAppearance is false (or equivalently absent). If flattening form fields, also remove /AcroForm from the document catalog.
2019-01-01 04:08:57 +00:00
QTC::TC("qpdf", "QPDFAnnotationObjectHelper rotate 270");
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
rect = QPDFObjectHandle::Rectangle(
rect.llx - rect_h, rect.ury - rect_w, rect.llx, rect.ury);
break;
default:
// ignore
break;
}
}
// Transform bounding box by matrix to get T
QPDFObjectHandle::Rectangle bbox = bbox_obj.getArrayAsRectangle();
Move rectangle transformation into QPDFMatrix
2019-01-26 21:48:41 +00:00
QPDFObjectHandle::Rectangle T = matrix.transformRectangle(bbox);
if ((T.urx == T.llx) || (T.ury == T.lly)) {
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
// avoid division by zero
return "";
}
// Compute a matrix to transform the appearance box to the rectangle
QPDFMatrix AA;
AA.translate(rect.llx, rect.lly);
Move rectangle transformation into QPDFMatrix
2019-01-26 21:48:41 +00:00
AA.scale((rect.urx - rect.llx) / (T.urx - T.llx), (rect.ury - rect.lly) / (T.ury - T.lly));
AA.translate(-T.llx, -T.lly);
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
if (do_rotate) {
AA.rotatex90(rotate);
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
}
Switch annotation flattening to use the form xobjects Instead of directly putting the contents of the annotation appearance streams into the page's content stream, add commands to render the form xobjects directly. This is a more robust way to do it than the original solution as it works properly with patterns and avoids problems with resource name clashes between the pages and the form xobjects.
2019-01-03 02:44:10 +00:00
as.replaceKey("/Subtype", QPDFObjectHandle::newName("/Form"));
return ("q\n" + AA.unparse() + " cm\n" + name + " Do\n" + "Q\n");
Add matrix and annotation appearance stream handling Generate page content fragment for rendering appearance streams including all matrix calculation.
2018-12-24 22:54:48 +00:00
}
Copy Permalink