Honor flags when flattening annotations

3 files changed, 74 insertions, 4 deletions

diff --git a/include/qpdf/Constants.h b/include/qpdf/Constants.h
index cfd95bef..6daf2614 100644
--- a/include/qpdf/Constants.h
+++ b/include/qpdf/Constants.h
@@ -89,4 +89,53 @@ enum qpdf_r3_modify_e		/* Allowed changes: */
     qpdf_r3m_none		/* no modifications */
 };
 
+/* Form field flags from the PDF spec */
+
+enum pdf_form_field_flag_e
+{
+    /* flags that apply to all form fields */
+    ff_all_read_only = 1 << 0,
+    ff_all_required = 1 << 1,
+    ff_all_no_export = 1 << 2,
+
+    /* flags that apply to fields of type /Btn (button) */
+    ff_btn_no_toggle_off = 1 << 14,
+    ff_btn_radio = 1 << 15,
+    ff_btn_pushbutton = 1 << 16,
+    ff_btn_radios_in_unison = 1 << 17,
+
+    /* flags that apply to fields of type /Tx (text) */
+    ff_tx_multiline = 1 << 12,
+    ff_tx_password = 1 << 13,
+    ff_tx_file_select = 1 << 20,
+    ff_tx_do_not_spell_check = 1 << 22,
+    ff_tx_do_not_scroll = 1 << 23,
+    ff_tx_comb = 1 << 24,
+    ff_tx_rich_text = 1 << 25,
+
+    /* flags that apply to fields of type /Ch (choice) */
+    ff_ch_combo = 1 << 17,
+    ff_ch_edit = 1 << 18,
+    ff_ch_sort = 1 << 19,
+    ff_ch_multi_select = 1 << 21,
+    ff_ch_do_not_spell_check = 1 << 22,
+    ff_ch_commit_on_sel_change = 1 << 26
+};
+
+/* Annotation flags from the PDF spec */
+
+enum pdf_annotation_flag_e
+{
+    an_invisible = 1 << 0,
+    an_hidden = 1 << 1,
+    an_print = 1 << 2,
+    an_no_zoom = 1 << 3,
+    an_no_rotate = 1 << 4,
+    an_no_view = 1 << 5,
+    an_read_only = 1 << 6,
+    an_locked = 1 << 7,
+    an_toggle_no_view = 1 << 8,
+    an_locked_contents = 1 << 9
+};
+
 #endif /* QPDFCONSTANTS_H */
diff --git a/include/qpdf/QPDFAnnotationObjectHelper.hh b/include/qpdf/QPDFAnnotationObjectHelper.hh
index 47242499..c5d24334 100644
--- a/include/qpdf/QPDFAnnotationObjectHelper.hh
+++ b/include/qpdf/QPDFAnnotationObjectHelper.hh
@@ -23,6 +23,7 @@
 #define QPDFANNOTATIONOBJECTHELPER_HH
 
 #include <qpdf/QPDFObjectHelper.hh>
+#include <qpdf/Constants.h>
 
 #include <qpdf/DLL.h>
 
@@ -76,10 +77,20 @@ class QPDFAnnotationObjectHelper: public QPDFObjectHelper
     // content stream that draws this annotation's appearance stream
     // as a form XObject. The value "name" is the resource name that
     // will be used to refer to the form xobject. The value "rotate"
-    // should be set to the page's /Rotate value or 0 if none.
+    // should be set to the page's /Rotate value or 0 if none. The
+    // values of required_flags and forbidden_flags are constructed by
+    // logically "or"ing annotation flags of type
+    // pdf_annotation_flag_e defined in qpdf/Constants.h. Content will
+    // be returned only if all required_flags are set and no
+    // forbidden_flags are set. For example, including an_no_view in
+    // forbidden_flags could be useful for creating an on-screen view,
+    // and including an_print to required_flags could be useful if
+    // preparing to print.
     QPDF_DLL
     std::string getPageContentForAppearance(
-        std::string const& name, int rotate);
+        std::string const& name, int rotate,
+        int required_flags = 0,
+        int forbidden_flags = an_invisible | an_hidden);
 
   private:
     class Members
diff --git a/include/qpdf/QPDFPageDocumentHelper.hh b/include/qpdf/QPDFPageDocumentHelper.hh
index d5446c16..d7876557 100644
--- a/include/qpdf/QPDFPageDocumentHelper.hh
+++ b/include/qpdf/QPDFPageDocumentHelper.hh
@@ -24,6 +24,7 @@
 
 #include <qpdf/QPDFDocumentHelper.hh>
 #include <qpdf/QPDFPageObjectHelper.hh>
+#include <qpdf/Constants.h>
 
 #include <qpdf/DLL.h>
 
@@ -92,14 +93,23 @@ class QPDFPageDocumentHelper: public QPDFDocumentHelper
     // the annotation from the page. Handles widget annotations
     // associated with interactive form fields as a special case,
     // including removing the /AcroForm key from the document catalog.
+    // The values passed to required_flags and forbidden_flags are
+    // passed along to
+    // QPDFAnnotationObjectHelper::getPageContentForAppearance. See
+    // comments there in QPDFAnnotationObjectHelper.hh for meanings of
+    // those flags.
     QPDF_DLL
-    void flattenAnnotations();
+    void flattenAnnotations(
+        int required_flags = 0,
+        int forbidden_flags = an_invisible | an_hidden);
 
   private:
     void flattenAnnotationsForPage(
         QPDFPageObjectHelper& page,
         QPDFObjectHandle& resources,
-        QPDFAcroFormDocumentHelper& afdh);
+        QPDFAcroFormDocumentHelper& afdh,
+        int required_flags,
+        int forbidden_flags);
 
     class Members
     {