PPF-403: consolidate font and font size functions

PyPDFForm/core/filler.py

@@ -8,7 +8,7 @@
 from ..middleware.checkbox import Checkbox
 from ..middleware.constants import ELEMENT_TYPES
 from ..middleware.radio import Radio
-from . import font_size as font_size_core
+from .font import checkbox_radio_font_size
 from . import template, utils
 from . import watermark as watermark_core
 
@@ -34,7 +34,7 @@ def fill(
             needs_to_be_drawn = False
 
             if isinstance(elements[key], (Checkbox, Radio)):
-                font_size = font_size_core.checkbox_radio_font_size(_element)
+                font_size = checkbox_radio_font_size(_element)
                 _to_draw = utils.checkbox_radio_to_draw(elements[key], font_size)
                 x, y = template.get_draw_checkbox_radio_coordinates(_element, _to_draw)
                 if isinstance(elements[key], Checkbox) and elements[key].value:

PyPDFForm/core/font.py

@@ -3,14 +3,17 @@
 
 import re
 from io import BytesIO
+from typing import Union
+from math import sqrt
 
 import pdfrw
 from reportlab.pdfbase import pdfmetrics
 from reportlab.pdfbase.ttfonts import TTFError, TTFont
 
 from . import constants
 from .patterns import TEXT_FIELD_APPEARANCE_PATTERNS
-from .template import traverse_pattern
+from .template import traverse_pattern, is_text_multiline
+from .constants import DEFAULT_FONT_SIZE
 
 
 def register_font(font_name: str, ttf_stream: bytes) -> bool:
@@ -38,15 +41,16 @@ def auto_detect_font(element: pdfrw.PdfDict) -> str:
     for pattern in TEXT_FIELD_APPEARANCE_PATTERNS:
         text_appearance = traverse_pattern(pattern, element)
 
-        if not text_appearance:
-            return result
+        if text_appearance:
+            break
 
-        text_appearance = text_appearance.replace("(", "").replace(")", "").split(" ")
+    if not text_appearance:
+        return result
 
-        for each in text_appearance:
-            if not each.startswith("/"):
-                return result
+    text_appearance = text_appearance.replace("(", "").replace(")", "").split(" ")
 
+    for each in text_appearance:
+        if each.startswith("/"):
             text_segments = re.findall("[A-Z][^A-Z]*", each.replace("/", ""))
 
             for font in pdfmetrics.standardFonts:
@@ -63,3 +67,37 @@ def auto_detect_font(element: pdfrw.PdfDict) -> str:
                     return font
 
     return result
+
+
+def text_field_font_size(element: pdfrw.PdfDict) -> Union[float, int]:
+    """
+    Calculates the font size it should be drawn with
+    given a text field element.
+    """
+
+    if is_text_multiline(element):
+        return DEFAULT_FONT_SIZE
+
+    height = abs(
+        float(element[constants.ANNOTATION_RECTANGLE_KEY][1])
+        - float(element[constants.ANNOTATION_RECTANGLE_KEY][3])
+    )
+
+    return height * 2 / 3
+
+
+def checkbox_radio_font_size(element: pdfrw.PdfDict) -> Union[float, int]:
+    """
+    Calculates the font size it should be drawn with
+    given a checkbox/radio button element.
+    """
+
+    area = abs(
+        float(element[constants.ANNOTATION_RECTANGLE_KEY][0])
+        - float(element[constants.ANNOTATION_RECTANGLE_KEY][2])
+    ) * abs(
+        float(element[constants.ANNOTATION_RECTANGLE_KEY][1])
+        - float(element[constants.ANNOTATION_RECTANGLE_KEY][3])
+    )
+
+    return sqrt(area) * 72 / 96

PyPDFForm/core/template.py

@@ -199,7 +199,7 @@ def is_text_field_comb(element: pdfrw.PdfDict) -> bool:
 
     try:
         return "{0:b}".format(int(element[constants.FIELD_FLAG_KEY]))[::-1][24] == "1"
-    except (TypeError, IndexError):
+    except (IndexError, TypeError):
         return False
 
 
@@ -217,7 +217,7 @@ def is_text_multiline(element: pdfrw.PdfDict) -> bool:
 
     try:
         return "{0:b}".format(int(field_flag))[::-1][12] == "1"
-    except (TypeError, IndexError):
+    except (IndexError, TypeError):
         return False
 
 
@@ -234,6 +234,7 @@ def get_dropdown_choices(element: pdfrw.PdfDict) -> Union[Tuple[str], None]:
                 .replace(")", "")
                 for each in choices
             )
+            break
 
     return result
 

PyPDFForm/core/utils.py

@@ -12,8 +12,7 @@
 from ..middleware.radio import Radio
 from ..middleware.text import Text
 from . import constants
-from . import font as font_core
-from . import font_size as font_size_core
+from .font import auto_detect_font, text_field_font_size
 from . import template
 
 
@@ -45,11 +44,11 @@ def update_text_field_attributes(
 
             if isinstance(elements[key], Text):
                 if elements[key].font is None:
-                    elements[key].font = font_core.auto_detect_font(_element)
+                    elements[key].font = auto_detect_font(_element)
                 if elements[key].font_size is None:
                     elements[key].font_size = template.get_text_field_font_size(
                         _element
-                    ) or font_size_core.text_field_font_size(_element)
+                    ) or text_field_font_size(_element)
                 if elements[key].font_color is None:
                     elements[key].font_color = template.get_text_field_font_color(
                         _element