PPF-707: support create center/right alignment text field

PyPDFForm/patterns.py

@@ -158,3 +158,14 @@ def simple_flatten_generic(annot: DictionaryObject) -> None:
         annot[NameObject(Ff)] = NumberObject(
             int(annot.get(NameObject(Ff), 0)) | READ_ONLY  # noqa
         )
+
+
+def update_created_text_field_alignment(annot: DictionaryObject, val: int) -> None:
+    """Patterns to update text alignment for text annotations created by the library."""
+
+    annot[NameObject(Q)] = NumberObject(val)
+
+
+NON_ACRO_FORM_PARAM_TO_FUNC = {
+    "alignment": update_created_text_field_alignment
+}

PyPDFForm/widgets/base.py

@@ -2,12 +2,16 @@
 """Contains base class for all widgets to create."""
 
 from io import BytesIO
-from typing import List
+from typing import List, cast
 
-from pypdf import PdfReader
+from pypdf import PdfReader, PdfWriter
+from pypdf.generic import DictionaryObject
 from reportlab.lib.colors import Color
 from reportlab.pdfgen.canvas import Canvas
 
+from ..constants import Annots
+from ..template import get_widget_key
+from ..patterns import NON_ACRO_FORM_PARAM_TO_FUNC
 from ..utils import stream_to_io
 
 
@@ -16,6 +20,7 @@ class Widget:
 
     USER_PARAMS = []
     COLOR_PARAMS = []
+    ALLOWED_NON_ACRO_FORM_PARAMS = []
     NONE_DEFAULTS = []
     ACRO_FORM_FUNC = ""
 
@@ -36,6 +41,7 @@ def __init__(
             "x": x,
             "y": y,
         }
+        self.non_acro_form_params = []
 
         for each in self.USER_PARAMS:
             user_input, param = each
@@ -51,6 +57,10 @@ def __init__(
             elif user_input in self.NONE_DEFAULTS:
                 self.acro_form_params[param] = None
 
+        for each in self.ALLOWED_NON_ACRO_FORM_PARAMS:
+            if each in kwargs:
+                self.non_acro_form_params.append((each, kwargs.get(each)))
+
     def watermarks(self, stream: bytes) -> List[bytes]:
         """Returns a list of watermarks after creating the widget."""
 
@@ -76,3 +86,26 @@ def watermarks(self, stream: bytes) -> List[bytes]:
             watermark.read() if i == self.page_number - 1 else b""
             for i in range(page_count)
         ]
+
+
+def handle_non_acro_form_params(pdf: bytes, key: str, params: list) -> bytes:
+    """Handles non acro form parameters when creating a widget."""
+
+    pdf_file = PdfReader(stream_to_io(pdf))
+    out = PdfWriter()
+    out.append(pdf_file)
+
+    for page in out.pages:
+        for annot in page.get(Annots, []):  # noqa
+            annot = cast(DictionaryObject, annot.get_object())
+            _key = get_widget_key(annot.get_object())
+
+            if _key == key:
+                for param in params:
+                    if param[0] in NON_ACRO_FORM_PARAM_TO_FUNC:
+                        NON_ACRO_FORM_PARAM_TO_FUNC[param[0]](annot, param[1])
+
+    with BytesIO() as f:
+        out.write(f)
+        f.seek(0)
+        return f.read()

PyPDFForm/widgets/text.py

@@ -19,5 +19,6 @@ class TextWidget(Widget):
         ("max_length", "maxlen"),
     ]
     COLOR_PARAMS = ["font_color", "bg_color", "border_color"]
+    ALLOWED_NON_ACRO_FORM_PARAMS = ["alignment"]
     NONE_DEFAULTS = ["max_length"]
     ACRO_FORM_FUNC = "textfield"

PyPDFForm/wrapper.py

@@ -22,6 +22,7 @@
 from .utils import (get_page_streams, merge_two_pdfs, preview_widget_to_draw,
                     remove_all_widgets)
 from .watermark import create_watermarks_and_draw, merge_watermarks_with_pdf
+from .widgets.base import handle_non_acro_form_params
 from .widgets.checkbox import CheckBoxWidget
 from .widgets.dropdown import DropdownWidget
 from .widgets.text import TextWidget
@@ -213,11 +214,17 @@ def create_widget(
         if _class is None:
             return self
 
-        watermarks = _class(
+        obj = _class(
             name=name, page_number=page_number, x=x, y=y, **kwargs
-        ).watermarks(self.read())
+        )
+        watermarks = obj.watermarks(self.read())
 
         self.stream = merge_watermarks_with_pdf(self.read(), watermarks)
+        if obj.non_acro_form_params:
+            self.stream = handle_non_acro_form_params(self.stream,
+                                                      name,
+                                                      obj.non_acro_form_params)
+
         new_widgets = build_widgets(self.read())
         for k, v in self.widgets.items():
             if k in new_widgets:

docs/prepare.md

@@ -40,7 +40,8 @@ new_form = PdfWrapper("dummy.pdf").create_widget(
     font_color=(1, 0, 0),   # optional
     bg_color=(0, 0, 1), # optional
     border_color=(1, 0, 0), # optional
-    border_width=5  # optional
+    border_width=5,  # optional
+    alignment=0 # optional, 0=left, 1=center, 2=right
 )
 
 with open("output.pdf", "wb+") as output:

tests/test_create_widget.py

@@ -198,6 +198,50 @@ def test_create_text_default(template_stream, pdf_samples, request):
         assert obj.stream == expected
 
 
+def test_create_text_align_center(template_stream, pdf_samples, request):
+    expected_path = os.path.join(pdf_samples, "widget", "create_text_align_center.pdf")
+    with open(expected_path, "rb+") as f:
+        obj = PdfWrapper(template_stream).create_widget(
+            "text",
+            "foo",
+            1,
+            100,
+            100,
+            alignment=1,
+        )
+        assert obj.schema["properties"]["foo"]["type"] == "string"
+
+        request.config.results["expected_path"] = expected_path
+        request.config.results["stream"] = obj.read()
+
+        expected = f.read()
+
+        assert len(obj.stream) == len(expected)
+        assert obj.stream == expected
+
+
+def test_create_text_align_right(template_stream, pdf_samples, request):
+    expected_path = os.path.join(pdf_samples, "widget", "create_text_align_right.pdf")
+    with open(expected_path, "rb+") as f:
+        obj = PdfWrapper(template_stream).create_widget(
+            "text",
+            "foo",
+            1,
+            100,
+            100,
+            alignment=2,
+        )
+        assert obj.schema["properties"]["foo"]["type"] == "string"
+
+        request.config.results["expected_path"] = expected_path
+        request.config.results["stream"] = obj.read()
+
+        expected = f.read()
+
+        assert len(obj.stream) == len(expected)
+        assert obj.stream == expected
+
+
 def test_create_text_default_filled(template_stream, pdf_samples, request):
     expected_path = os.path.join(
         pdf_samples, "widget", "create_text_default_filled.pdf"