Merge pull request #507 from chinapandaman/PPF-506

PPF-506: fix filler logic for signature

PyPDFForm/core/filler.py

@@ -41,6 +41,7 @@ def fill(
         for _widget in _widgets:
             key = get_widget_key(_widget)
             text_needs_to_be_drawn = False
+            _to_draw = x = y = None
 
             if isinstance(widgets[key], (Checkbox, Radio)):
                 font_size = checkbox_radio_font_size(_widget)
@@ -69,7 +70,6 @@ def fill(
                             height,
                         ]
                     )
-                    text_needs_to_be_drawn = False
             else:
                 widgets[key].text_line_x_coordinates = get_text_line_x_coordinates(
                     _widget, widgets[key]
@@ -78,7 +78,14 @@ def fill(
                 _to_draw = widgets[key]
                 text_needs_to_be_drawn = True
 
-            if text_needs_to_be_drawn:
+            if all(
+                [
+                    text_needs_to_be_drawn,
+                    _to_draw is not None,
+                    x is not None,
+                    y is not None,
+                ]
+            ):
                 texts_to_draw[page].append(
                     [
                         _to_draw,

docs/fill.md

@@ -90,5 +90,5 @@ with open("output.pdf", "wb+") as output:
     output.write(signed.read())
 ```
 
-**NOTE:** As described [here](install.md/#create-a-pdf-wrapper), the value of the signature in your dictionary can be a file path shown above, but also an open file object and a file stream 
-that's in `bytes`.
+**NOTE:** As described [here](install.md/#create-a-pdf-wrapper), the value of the signature in your dictionary can be 
+a file path shown above, but also an open file object and a file stream that's in `bytes`.