STY: Use IntFlag for permissions_flag / update_page_form_field_values (…

…py-pdf#1094)

CHANGELOG.md

@@ -38,7 +38,7 @@
 -  Apply black
 -  Typo in Changelog
 
-Full Changelog: https://github.com/py-pdf/PyPDF2/compare/2.4.2...2.4.3
+Full Changelog: https://github.com/py-pdf/PyPDF2/compare/2.4.2...2.5.0
 
 ## Version 2.4.2, 2022-07-05
 

PyPDF2/_writer.py

@@ -67,6 +67,7 @@
 from .constants import EncryptionDictAttributes as ED
 from .constants import (
     FieldDictionaryAttributes,
+    FieldFlag,
     FileSpecificationDictionaryEntries,
     GoToActionArguments,
     InteractiveFormDictEntries,
@@ -75,7 +76,7 @@
 from .constants import PagesAttributes as PA
 from .constants import StreamAttributes as SA
 from .constants import TrailerKeys as TK
-from .constants import TypFitArguments
+from .constants import TypFitArguments, UserAccessPermissions
 from .generic import (
     ArrayObject,
     BooleanObject,
@@ -110,6 +111,10 @@
 logger = logging.getLogger(__name__)
 
 
+OPTIONAL_READ_WRITE_FIELD = FieldFlag(0)
+ALL_DOCUMENT_PERMISSIONS = UserAccessPermissions((2**31 - 1) - 3)
+
+
 class PdfWriter:
     """
     This class supports writing PDF files out, given pages produced by another
@@ -576,7 +581,10 @@ def appendPagesFromReader(
         self.append_pages_from_reader(reader, after_page_append)
 
     def update_page_form_field_values(
-        self, page: PageObject, fields: Dict[str, Any], flags: int = 0
+        self,
+        page: PageObject,
+        fields: Dict[str, Any],
+        flags: FieldFlag = OPTIONAL_READ_WRITE_FIELD,
     ) -> None:
         """
         Update the form field values for a given page from a fields dictionary.
@@ -627,7 +635,10 @@ def update_page_form_field_values(
                     )
 
     def updatePageFormFieldValues(
-        self, page: PageObject, fields: Dict[str, Any], flags: int = 0
+        self,
+        page: PageObject,
+        fields: Dict[str, Any],
+        flags: FieldFlag = OPTIONAL_READ_WRITE_FIELD,
     ) -> None:  # pragma: no cover
         """
         .. deprecated:: 1.28.0
@@ -699,7 +710,7 @@ def encrypt(
         user_pwd: str,
         owner_pwd: Optional[str] = None,
         use_128bit: bool = True,
-        permissions_flag: int = -1,
+        permissions_flag: UserAccessPermissions = ALL_DOCUMENT_PERMISSIONS,
     ) -> None:
         """
         Encrypt this PDF file with the PDF Standard encryption handler.

PyPDF2/constants.py

@@ -8,6 +8,7 @@
 PDF Reference, sixth edition, Version 1.7, 2006.
 """
 
+from enum import IntFlag
 from typing import Dict, Tuple
 
 
@@ -47,6 +48,43 @@ class EncryptionDictAttributes:
     ENCRYPT_METADATA = "/EncryptMetadata"  # boolean flag, optional
 
 
+class UserAccessPermissions(IntFlag):
+    """TABLE 3.20 User access permissions"""
+
+    R1 = 1
+    R2 = 2
+    PRINT = 4
+    MODIFY = 8
+    EXTRACT = 16
+    ADD_OR_MODIFY = 32
+    R7 = 64
+    R8 = 128
+    FILL_FORM_FIELDS = 256
+    EXTRACT_TEXT_AND_GRAPHICS = 512
+    ASSEMBLE_DOC = 1024
+    PRINT_TO_REPRESENTATION = 2048
+    R13 = 2**12
+    R14 = 2**13
+    R15 = 2**14
+    R16 = 2**15
+    R17 = 2**16
+    R18 = 2**17
+    R19 = 2**18
+    R20 = 2**19
+    R21 = 2**20
+    R22 = 2**21
+    R23 = 2**22
+    R24 = 2**23
+    R25 = 2**24
+    R26 = 2**25
+    R27 = 2**26
+    R28 = 2**27
+    R29 = 2**28
+    R30 = 2**29
+    R31 = 2**30
+    R32 = 2**31
+
+
 class Ressources:
     """TABLE 3.30 Entries in a resource dictionary."""
 
@@ -294,6 +332,14 @@ def attributes_dict(cls) -> Dict[str, str]:
         }
 
 
+class FieldFlag(IntFlag):
+    """TABLE 8.70 Field flags common to all field types"""
+
+    READ_ONLY = 1
+    REQUIRED = 2
+    NO_EXPORT = 4
+
+
 class DocumentInformationAttributes:
     """TABLE 10.2 Entries in the document information dictionary."""