Merge pull request #504 from chinapandaman/PPF-502

PPF-502: supports signature field

PyPDFForm/core/constants.py

@@ -9,6 +9,7 @@
 PARENT_KEY = "/Parent"
 FIELD_FLAG_KEY = "/Ff"
 TEXT_FIELD_IDENTIFIER = "/Tx"
+SIGNATURE_FIELD_IDENTIFIER = "/Sig"
 TEXT_FIELD_APPEARANCE_IDENTIFIER = "/DA"
 SELECTABLE_IDENTIFIER = "/Btn"
 TEXT_FIELD_MAX_LENGTH_KEY = "/MaxLen"

PyPDFForm/core/coordinate.py

@@ -44,6 +44,25 @@ def get_draw_checkbox_radio_coordinates(
     )
 
 
+def get_draw_sig_coordinates_resolutions(widget: dict) -> Tuple[float, float, float, float]:
+    """
+    Returns coordinates and resolutions to draw signature at given a PDF form signature widget.
+    """
+
+    x = float(widget[ANNOTATION_RECTANGLE_KEY][0])
+    y = float(widget[ANNOTATION_RECTANGLE_KEY][1])
+    width = abs(
+        float(widget[ANNOTATION_RECTANGLE_KEY][0])
+        - float(widget[ANNOTATION_RECTANGLE_KEY][2])
+    )
+    height = abs(
+        float(widget[ANNOTATION_RECTANGLE_KEY][1])
+        - float(widget[ANNOTATION_RECTANGLE_KEY][3])
+    )
+
+    return x, y, width, height
+
+
 def get_draw_text_coordinates(
     widget: dict, widget_middleware: Text
 ) -> Tuple[Union[float, int], Union[float, int]]:

PyPDFForm/core/filler.py

@@ -6,10 +6,13 @@
 from ..middleware.checkbox import Checkbox
 from ..middleware.constants import WIDGET_TYPES
 from ..middleware.radio import Radio
+from ..middleware.signature import Signature
 from .coordinate import (get_draw_checkbox_radio_coordinates,
                          get_draw_text_coordinates,
-                         get_text_line_x_coordinates)
+                         get_text_line_x_coordinates,
+                         get_draw_sig_coordinates_resolutions)
 from .font import checkbox_radio_font_size
+from .image import any_image_to_jpg
 from .template import get_widget_key, get_widgets_by_page
 from .utils import checkbox_radio_to_draw
 from .watermark import create_watermarks_and_draw, merge_watermarks_with_pdf
@@ -21,39 +24,61 @@ def fill(
 ) -> bytes:
     """Fills a PDF using watermarks."""
 
+    # pylint: disable=too-many-branches
     texts_to_draw = {}
+    images_to_draw = {}
+    any_image_to_draw = False
     text_watermarks = []
+    image_watermarks = []
 
     radio_button_tracker = {}
 
     for page, _widgets in get_widgets_by_page(template_stream).items():
         texts_to_draw[page] = []
+        images_to_draw[page] = []
         text_watermarks.append(b"")
+        image_watermarks.append(b"")
         for _widget in _widgets:
             key = get_widget_key(_widget)
-            needs_to_be_drawn = False
+            text_needs_to_be_drawn = False
 
             if isinstance(widgets[key], (Checkbox, Radio)):
                 font_size = checkbox_radio_font_size(_widget)
                 _to_draw = checkbox_radio_to_draw(widgets[key], font_size)
                 x, y = get_draw_checkbox_radio_coordinates(_widget, _to_draw)
                 if isinstance(widgets[key], Checkbox) and widgets[key].value:
-                    needs_to_be_drawn = True
+                    text_needs_to_be_drawn = True
                 elif isinstance(widgets[key], Radio):
                     if key not in radio_button_tracker:
                         radio_button_tracker[key] = 0
                     radio_button_tracker[key] += 1
                     if widgets[key].value == radio_button_tracker[key] - 1:
-                        needs_to_be_drawn = True
+                        text_needs_to_be_drawn = True
+            elif isinstance(widgets[key], Signature):
+                stream = widgets[key].stream
+                if stream is not None:
+                    any_image_to_draw = True
+                    stream = any_image_to_jpg(stream)
+                    x, y, width, height = get_draw_sig_coordinates_resolutions(_widget)
+                    images_to_draw[page].append(
+                            [
+                                stream,
+                                x,
+                                y,
+                                width,
+                                height,
+                                ]
+                            )
+                    text_needs_to_be_drawn = False
             else:
                 widgets[key].text_line_x_coordinates = get_text_line_x_coordinates(
                     _widget, widgets[key]
                 )
                 x, y = get_draw_text_coordinates(_widget, widgets[key])
                 _to_draw = widgets[key]
-                needs_to_be_drawn = True
+                text_needs_to_be_drawn = True
 
-            if needs_to_be_drawn:
+            if text_needs_to_be_drawn:
                 texts_to_draw[page].append(
                     [
                         _to_draw,
@@ -68,4 +93,14 @@ def fill(
             if watermark:
                 text_watermarks[i] = watermark
 
-    return merge_watermarks_with_pdf(template_stream, text_watermarks)
+    result = merge_watermarks_with_pdf(template_stream, text_watermarks)
+
+    if any_image_to_draw:
+        for page, images in images_to_draw.items():
+            _watermarks = create_watermarks_and_draw(template_stream, page, "image", images)
+            for i, watermark in enumerate(_watermarks):
+                if watermark:
+                    image_watermarks[i] = watermark
+        result = merge_watermarks_with_pdf(result, image_watermarks)
+
+    return result

PyPDFForm/core/patterns.py

@@ -5,16 +5,21 @@
 from ..middleware.dropdown import Dropdown
 from ..middleware.radio import Radio
 from ..middleware.text import Text
+from ..middleware.signature import Signature
 from .constants import (ANNOTATION_FIELD_KEY, BUTTON_IDENTIFIER,
                         BUTTON_STYLE_IDENTIFIER, CHOICE_FIELD_IDENTIFIER,
                         CHOICES_IDENTIFIER, FIELD_FLAG_KEY, PARENT_KEY,
                         SELECTABLE_IDENTIFIER, SUBTYPE_KEY,
                         TEXT_FIELD_ALIGNMENT_IDENTIFIER,
                         TEXT_FIELD_APPEARANCE_IDENTIFIER,
                         TEXT_FIELD_IDENTIFIER, WIDGET_SUBTYPE_KEY,
-                        WIDGET_TYPE_KEY)
+                        WIDGET_TYPE_KEY, SIGNATURE_FIELD_IDENTIFIER)
 
 WIDGET_TYPE_PATTERNS = [
+    (
+        ({WIDGET_TYPE_KEY: SIGNATURE_FIELD_IDENTIFIER},),
+        Signature,
+    ),
     (
         ({WIDGET_TYPE_KEY: TEXT_FIELD_IDENTIFIER},),
         Text,

PyPDFForm/middleware/constants.py

@@ -7,6 +7,7 @@
 from .dropdown import Dropdown
 from .radio import Radio
 from .text import Text
+from .signature import Signature
 
 VERSION_IDENTIFIERS = [
     b"%PDF-1.0",
@@ -21,6 +22,6 @@
 ]
 VERSION_IDENTIFIER_PREFIX = b"%PDF-"
 
-WIDGET_TYPES = Union[Text, Checkbox, Radio, Dropdown]
+WIDGET_TYPES = Union[Text, Checkbox, Radio, Dropdown, Signature]
 
 DEPRECATION_NOTICE = "{} will be deprecated soon. Use {} instead."

PyPDFForm/middleware/signature.py

@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+"""Contains signature middleware."""
+
+from typing import BinaryIO, Union
+from os.path import expanduser
+
+from .adapter import fp_or_f_obj_or_stream_to_stream
+from .widget import Widget
+
+
+class Signature(Widget):
+    """A class to represent a signature field widget."""
+
+    def __init__(
+        self,
+        name: str,
+        value: Union[bytes, str, BinaryIO] = None,
+    ) -> None:
+        """Constructs all attributes for the signature field."""
+
+        super().__init__(name, value)
+
+    @property
+    def schema_definition(self) -> dict:
+        """Json schema definition of the signature field."""
+
+        return {"type": "string"}
+
+    @property
+    def sample_value(self) -> str:
+        """Sample value of the signature field."""
+
+        return expanduser("~/Downloads/sample_image.jpg")
+
+    @property
+    def stream(self) -> Union[bytes, None]:
+        """Converts the value of the signature field image to a stream."""
+
+        return (
+                fp_or_f_obj_or_stream_to_stream(self.value)
+                if self.value is not None
+                else None
+                )

PyPDFForm/middleware/widget.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 """Contains widget middleware."""
 
-from typing import Any, Union
+from typing import Any
 
 
 class Widget:
@@ -10,7 +10,7 @@ class Widget:
     def __init__(
         self,
         name: str,
-        value: Union[str, bool, int] = None,
+        value: Any = None,
     ) -> None:
         """Constructs basic attributes for the object."""
 

tests/test_signature.py

@@ -0,0 +1,60 @@
+# -*- coding: utf-8 -*-
+
+import os
+
+from PyPDFForm import PdfWrapper
+
+
+def test_fill_signature(pdf_samples, image_samples, request):
+    expected_path = os.path.join(
+            pdf_samples, "signature", "test_fill_signature.pdf"
+            )
+    with open(expected_path, "rb+") as f:
+        obj = PdfWrapper(
+                os.path.join(pdf_samples, "signature", "sample_template_with_signature.pdf")
+                ).fill(
+                        {"signature": os.path.join(image_samples, "sample_signature.png")}
+                        )
+
+        request.config.results["expected_path"] = expected_path
+        request.config.results["stream"] = obj.read()
+
+        expected = f.read()
+
+        if os.name != "nt":
+            assert len(obj.read()) == len(expected)
+            assert obj.read() == expected
+
+
+def test_signature_schema(pdf_samples):
+    obj = PdfWrapper(os.path.join(pdf_samples, "signature", "sample_template_with_signature.pdf"))
+
+    assert obj.widgets["signature"].schema_definition == {"type": "string"}
+
+
+def test_signature_sample_value(pdf_samples):
+    obj = PdfWrapper(os.path.join(pdf_samples, "signature", "sample_template_with_signature.pdf"))
+
+    assert obj.widgets["signature"].sample_value == os.path.expanduser(
+            "~/Downloads/sample_image.jpg")
+
+
+def test_fill_signature_overlap(pdf_samples, image_samples, request):
+    expected_path = os.path.join(
+            pdf_samples, "signature", "test_fill_signature_overlap.pdf"
+            )
+    with open(expected_path, "rb+") as f:
+        obj = PdfWrapper(
+                os.path.join(pdf_samples, "signature", "sample_template_with_signature_overlap.pdf")
+                ).fill(
+                        {"signature": os.path.join(image_samples, "sample_signature.png")}
+                        )
+
+        request.config.results["expected_path"] = expected_path
+        request.config.results["stream"] = obj.read()
+
+        expected = f.read()
+
+        if os.name != "nt":
+            assert len(obj.read()) == len(expected)
+            assert obj.read() == expected