Custom paper sizes (#74)

* Implement custom paper sizes (#73)

* fix operand

* paper_size as tuple

* mm to py constant

* fix doc

* Move paper size code to Section class

* cosmetic

* add tests

---------

Co-authored-by: Jake Charman <jake@jakecharman.co.uk>

Author: vb64

README.md

@@ -131,7 +131,7 @@ The `Section` class can set the following attributes.
 
 - toc: whether to include the headers `<h1>` - `<h6>` of this section in the TOC. Default is True.
 - root: the name of the root directory from which the image file paths starts in markdown. Default ".".
-- paper_size: name of paper size, [as described here](https://pymupdf.readthedocs.io/en/latest/functions.html#paper_size). Default "A4".
+- paper_size: either the name of a paper size, [as described here](https://pymupdf.readthedocs.io/en/latest/functions.html#paper_size), or a list/tuple containing the width and height in mm. Default "A4".
 - borders: size of borders. Default (36, 36, -36, -36).
 
 The following document properties are available for assignment (dictionary `MarkdownPdf.meta`) with the default values indicated.

README_ru.md

@@ -124,7 +124,7 @@ assert out.getbuffer().nbytes > 0
 
 - toc: нужно ли включать заголовки `<h1>` - `<h6>` этой секции в TOC. По умолчанию True.
 - root: имя корневого каталога, от которого начинаются пути файлов картинок в markdown. По умолчанию ".".
-- paper_size: название размера бумаги, [как описано здесь](https://pymupdf.readthedocs.io/en/latest/functions.html#paper_size). По умолчанию "A4".
+- paper_size: название размера бумаги, [как описано здесь](https://pymupdf.readthedocs.io/en/latest/functions.html#paper_size), или list/tuple содержащий ширину и высоту в мм. По умолчанию "A4".
 - borders: размер полей. По умолчанию (36, 36, -36, -36).
 
 Для присвоения доступны следующие свойства документа (словарь `MarkdownPdf.meta`) с указанными значениями по умолчанию.

markdown_pdf/__init__.py

@@ -6,9 +6,11 @@
 import fitz
 from markdown_it import MarkdownIt
 from pymupdf import (
-  _as_pdf_document, mupdf, JM_embedded_clean, JM_ensure_identity, JM_new_output_fileptr, ASSERT_PDF,
+  _as_pdf_document, mupdf, JM_embedded_clean, JM_ensure_identity, JM_new_output_fileptr, ASSERT_PDF, Rect,
 )
 
+MM_2_PT = 2.835
+
 
 class Section:
     """Markdown section."""
@@ -18,15 +20,25 @@ def __init__(
       text: str,
       toc: bool = True,
       root: str = ".",
-      paper_size: str = "A4",
+      paper_size: str or list or tuple = "A4",
       borders: typing.Tuple[int, int, int, int] = (36, 36, -36, -36)
     ):
         """Create md section with given properties."""
         self.text = text
         self.toc = toc
         self.root = root
-        # https://pymupdf.readthedocs.io/en/latest/functions.html#paper_size
+
         self.paper_size = paper_size
+        if isinstance(paper_size, str):
+            # https://pymupdf.readthedocs.io/en/latest/functions.html#paper_size
+            self.rect = fitz.paper_rect(paper_size)
+        elif isinstance(paper_size, (list, tuple)):
+            # Other paper sizes are in pt, so need to times mm by 2.835.
+            width, height = paper_size
+            self.rect = Rect(0.0, 0.0, (width * MM_2_PT), (height * MM_2_PT))
+        else:
+            raise TypeError("paper_size must be 'str', 'tuple' or 'list'")
+
         self.borders = borders
 
 
@@ -81,14 +93,13 @@ def _recorder(elpos):
 
     def add_section(self, section: Section, user_css: typing.Optional[str] = None) -> str:
         """Add markdown section to pdf."""
-        rect = fitz.paper_rect(section.paper_size)
-        where = rect + section.borders
+        where = section.rect + section.borders
         html = self.m_d.render(section.text)
         story = fitz.Story(html=html, archive=section.root, user_css=user_css)
         more = 1
         while more:  # loop outputting the story
             self.page_num += 1
-            device = self.writer.begin_page(rect)
+            device = self.writer.begin_page(section.rect)
             more, _ = story.place(where)  # layout into allowed rectangle
             story.element_positions(self._recorder, {"toc": section.toc, "pdfile": self})
             story.draw(device)

tests/test/test_converter.py

@@ -3,6 +3,8 @@
 make test T=test_converter.py
 """
 import io
+import pytest
+
 from . import TestBase
 
 TABLE_TEXT = """# Section with Table
@@ -94,3 +96,19 @@ def test_bytes(self):
         assert out.getbuffer().nbytes > 0
         with open(self.build("as_bytes.pdf"), "wb") as i:
             i.write(out.getvalue())
+
+    def test_paper_size(self):
+        """Check paper_size arg for Section class."""
+        from markdown_pdf import Section
+
+        section = Section("Title")  # default paper size 'A4'
+        assert section.rect.height == 842.0
+        assert section.rect.width == 595.0
+
+        section = Section("Title", paper_size=(5, 10))  # 5x10 mm
+        assert section.rect.height == 28.35
+        assert section.rect.width == 14.175
+
+        with pytest.raises(TypeError) as err:
+            Section("Title", paper_size=111)
+        assert 'paper_size must be' in str(err.value)