ENH: Wrap and align text in flattened PDF forms

docs/user/forms.md

@@ -30,6 +30,7 @@ writer.update_page_form_field_values(
     writer.pages[0],
     {"fieldname": "some filled in text"},
     auto_regenerate=False,
+    flatten=False,
 )
 
 with open("filled-out.pdf", "wb") as output_stream:
@@ -41,6 +42,12 @@ parameter is `True` by default for legacy compatibility, but this flags the PDF
 processor to recompute the field's rendering, and may trigger a "save changes"
 dialog for users who open the generated PDF.
 
+If you want to flatten your form, that is, keeping all form field contents while
+removing the form fields themselves, you can set `flatten=True` to convert form
+field contents to regular pdf content, and then use
+`writer.remove_annotations(subtypes="/Widget")` to remove all form fields. This
+will result in a flattened pdf.
+
 ## Some notes about form fields and annotations
 
 PDF forms have a dual-nature approach to the fields:

pypdf/_font.py

@@ -1,5 +1,4 @@
 from dataclasses import dataclass, field
-from typing import Optional
 
 from pypdf.generic import DictionaryObject
 
@@ -29,10 +28,16 @@ class FontDescriptor:
     character_widths: dict[str, int] = field(default_factory=dict)
 
     @classmethod
-    def from_font_resource(cls, pdf_font_dict: DictionaryObject) -> "Optional[FontDescriptor]":
+    def from_font_resource(cls, pdf_font_dict: DictionaryObject) -> "FontDescriptor":
         from pypdf._codecs.core_fontmetrics import CORE_FONT_METRICS  # noqa: PLC0415
         # Prioritize information from the PDF font dictionary
-        font_name = pdf_font_dict.get("/BaseFont", "Unknown")
-        if font_name[1:] in CORE_FONT_METRICS:
-            return CORE_FONT_METRICS.get(font_name[1:])
+        font_name = pdf_font_dict.get("/BaseFont", "Unknown").removeprefix("/")
+        if font_name in CORE_FONT_METRICS:
+            return CORE_FONT_METRICS[font_name]
         return cls(name=font_name)
+
+    def text_width(self, text: str) -> float:
+        """Sum of character widths specified in PDF font for the supplied text."""
+        return sum(
+            [self.character_widths.get(char, self.character_widths.get("default", 0)) for char in text], 0.0
+        )