MAINT: _appearance_stream: Move y_offset calculation

The y_offset calculation occurs very early on in the code,
necessitating carrying it across various methods. This
patch simplifies that logic.

Author: PJBrs

pypdf/generic/_appearance_stream.py

@@ -104,13 +104,9 @@ def from_text_annotation(
         else:
             default_appearance = default_appearance.get_object()
 
-        # Use regex to capture the font name and font size with the re.MULTILINE flag
+        # Get font name and font size from default appearance
         pattern = r"(/.*?)\s+(\S+)\s+Tf"
         font_match = re.search(pattern, default_appearance, re.MULTILINE)
-
-        font_name = ""
-        font_size = 0.0
-
         if font_match:
             font_name = font_match.group(1)
             font_size = float(font_match.group(2))
@@ -123,24 +119,16 @@ def from_text_annotation(
         else:
             # Handle the case where a font pattern isn't found
             font_name = "/Helv"
-            if field.get(FieldDictionaryAttributes.Ff, 0) & FieldDictionaryAttributes.FfBits.Multiline:
-                font_size = DEFAULT_FONT_HEIGHT_IN_MULTILINE
-            else:
-                font_size = rect.height - 2
-
         # If font_size is 0, apply the logic for multiline or large-as-possible font
         if font_size == 0:
             if field.get(FieldDictionaryAttributes.Ff, 0) & FieldDictionaryAttributes.FfBits.Multiline:
                 font_size = DEFAULT_FONT_HEIGHT_IN_MULTILINE
             else:
                 font_size = rect.height - 2
-
         # Replace the old font name and size with the new ones using re.sub
         if font_match:
             # The replacement string uses captured groups from the match
             replacement = f"{font_name} {font_size} Tf"
-
-            # Pass the re.MULTILINE flag to re.sub as well
             default_appearance = re.sub(pattern, replacement, default_appearance, flags=re.MULTILINE)
         else:
             # If no font was found, we need to create the new DA string from scratch
@@ -209,7 +197,7 @@ def from_text_annotation(
 
         # Create the TextStreamAppearance instance
         new_appearance_stream = cls(
-            text, selection, default_appearance, font_glyph_byte_map, rect, font_size, y_offset
+            text, selection, default_appearance, font_glyph_byte_map, rect, font_size
         )
 
         if AnnotationDictionaryAttributes.AP in annotation: