[Python] Tiny numbers in ReportLab's table of contents

I followed an example from the ReportLab documentation on how to add a table of contents, and it works fine in most situations. However, if a section title is very close to the full page width, then the page number gets shrunk to fit. Sometimes, it's shrunk to the point you can't see it at all.

Has anyone found a way to work around this by forcing the section title to wrap earlier, leaving enough room for the page number?

Here's a demonstration of the problem:



You can see that with 3, 4, and 5 i's the page number shrinks and disappears.

Here's my modified version of the example that generated the table of contents above:

from reportlab.lib.styles import ParagraphStyle as PS
from reportlab.platypus import PageBreak
from reportlab.platypus.paragraph import Paragraph
from reportlab.platypus.doctemplate import PageTemplate, BaseDocTemplate
from reportlab.platypus.tableofcontents import TableOfContents
from reportlab.platypus.frames import Frame
from reportlab.lib.units import cm


class MyDocTemplate(BaseDocTemplate):

def __init__(self, filename, **kw):
self.allowSplitting = 0
BaseDocTemplate.__init__(self, filename, **kw)
template = PageTemplate('normal', [Frame(2.5 * cm, 2.5 * cm, 15 * cm, 25 * cm, id='F1')])
self.addPageTemplates(template)

def afterFlowable(self, flowable):
"Registers TOC entries."
if flowable.__class__.__name__ == 'Paragraph':
text = flowable.getPlainText()
style = flowable.style.name
if style == 'Heading1':
self.notify('TOCEntry', (0, text, self.page))
if style == 'Heading2':
self.notify('TOCEntry', (1, text, self.page))


h1 = PS(name='Heading1',
fontSize=14,
leading=16)

h2 = PS(name='Heading2',
fontSize=12,
leading=14,
leftIndent=10)

# Build story.
story = []
toc = TableOfContents()
# For conciseness we use the same styles for headings and TOC entries
toc.levelStyles = [h1, h2]
story.append(toc)
story.append(PageBreak())
story.append(Paragraph('Table of Contents Test', h1))
for i in range(10):
story.append(Paragraph('XXXXX ' * 9 + 'i' * i, h2))

doc = MyDocTemplate('toc_test.pdf')
doc.multiBuild(story)


I looked in the ReportLab source code, and found that it really is just shrinking the page number until it fits or reaches a font size of 1 pixel.

Continue reading...