Watermark test. (#96)

Author: vb64

tests/test/test_hooks.py

@@ -0,0 +1,43 @@
+"""Hook tests.
+
+https://pymupdf.readthedocs.io/en/latest/tutorial.html
+
+make test T=test_hooks.py
+"""
+import fitz
+from . import TestBase
+
+
+class TestHooks(TestBase):
+    """Hooks tests."""
+
+    def test_backcolor(self):
+        """Check page background color feature."""
+        from markdown_pdf import Section, MarkdownPdf
+
+        pdf = MarkdownPdf()
+        text = open(self.fixture("plantuml.md"), "rt", encoding='utf-8').read()
+        section = Section(text)
+
+        where = section.rect + section.borders
+        html = pdf.m_d.render(section.text)
+        story = fitz.Story(html=html, archive=section.root)
+
+        story.place(where)
+        device = pdf.writer.begin_page(section.rect)
+        story.draw(device)
+        pdf.writer.end_page()
+
+        fname = self.build('backcolor.pdf')
+        pdf.save(fname)
+
+        print("###")
+        doc = fitz.open(fname)
+        print("#", doc.page_count)
+        # https://pymupdf.readthedocs.io/en/latest/recipes-drawing-and-graphics.html
+        # https://pymupdf.readthedocs.io/en/latest/the-basics.html#adding-a-watermark-to-a-pdf
+        # insert an image watermark from a file name to fit the page bounds
+        page = doc[0]
+        page.insert_image(page.bound(), filename=self.fixture("plantuml.png"), overlay=False, keep_proportion=False)
+        # https://pypi.org/project/pypng/
+        doc.save(self.build('backcolor1.pdf'))