_scale_block_fonts rebuilt a block by constructing a plain Word(word.text, scaled_style) for every word. LinkedWord is a Word subclass, so the reconstruction downgraded it and dropped the link target: every hyperlink in the document disappeared the moment the reader changed font size. Nothing caught it because the function returns the block unchanged at scale 1.0 with no family override, which is what the tests exercised. Add Word.with_style(), overridden by LinkedWord to carry location, link type, callback, params and title across. Putting the copy behaviour on the word class means any future Word subclass either inherits a correct copy or overrides one, rather than being silently flattened by a constructor call in the layout engine. Also extend coverage beyond Paragraph and Heading. Quote, HList and Table were returned unscaled, so a font-size change left quoted text, list items and table cells at their original size while the surrounding text reflowed. Table rows are re-added to the section they came from, so a <thead> row does not become a body row. Image, HorizontalRule, PageBreak and CodeBlock still pass through: they carry no styled words. Scaled blocks are now memoised per (block, scale) for the life of the layouter. Previously a fresh Paragraph and Word were allocated for every word on every page render at any scale != 1.0, on the hot path, against the caching work in concrete/text.py. Tests cover with_style on both word classes, link survival and target preservation across all four container types, per-container scaling, table section preservation, memoisation, and that originals are never mutated. End-to-end: links remain tappable at 0.8x, 1.5x and 2.0x. Note: query_point's hit region is offset from LinkText.origin by roughly the ascent, so probing a link's own centre reports "empty". That reproduces identically at scale 1.0, predates this change, and is tracked separately as R9 - the end-to-end test scans instead of probing. 891 passed. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
PyWebLayout
Project Status
📋 Note: Badges show results from the commit referenced in the URLs. Red "error" badges indicate build failures for that specific step.
Description
PyWebLayout is a Python library for HTML-like layout and rendering to paginated images. It provides a flexible page rendering system with support for borders, padding, text layout, and HTML parsing.
Key Features
Page Rendering System
- 📄 Flexible Page Layouts - Create pages with customizable sizes, borders, and padding
- 🎨 Styling System - Control backgrounds, border colors, and spacing
- 📐 Multiple Layouts - Support for portrait, landscape, and square pages
- 🖼️ Image Output - Render pages to PIL Images (PNG, JPEG, etc.)
Text and HTML Support
- 📝 HTML Parsing - Parse HTML content into structured document blocks
- 🔤 Font Support - Multiple font sizes, weights, and styles
- 🎨 Dynamic Font Families - Switch between Sans, Serif, and Monospace fonts on-the-fly
- ↔️ Text Alignment - Left, center, right, and justified text
- 📖 Rich Content - Headings, paragraphs, bold, italic, and more
- 📊 Table Rendering - Full HTML table support with headers, borders, and styling
- 🔘 Interactive Elements - Buttons, forms, and links with callback support
Architecture
- Abstract/Concrete Separation - Clean separation between content structure and rendering
- Extensible Design - Easy to extend with custom renderables
- Type-safe - Comprehensive type hints throughout the codebase
Installation
pip install pyWebLayout
Quick Start
Basic Page Rendering
from pyWebLayout.concrete.page import Page
from pyWebLayout.style.page_style import PageStyle
# Create a styled page
page_style = PageStyle(
border_width=2,
border_color=(200, 200, 200),
padding=(30, 30, 30, 30), # top, right, bottom, left
background_color=(255, 255, 255)
)
page = Page(size=(600, 800), style=page_style)
# Render to image
image = page.render()
image.save("my_page.png")
HTML Content Parsing
from pyWebLayout.io.readers.html_extraction import parse_html_string
from pyWebLayout.style import Font
# Parse HTML to structured blocks
html = """
<h1>Document Title</h1>
<p>First paragraph with <b>bold</b> text.</p>
<p>Second paragraph with more content.</p>
"""
base_font = Font(font_size=14)
blocks = parse_html_string(html, base_font=base_font)
# blocks is a list of structured content (Paragraph, Heading, etc.)
Visual Examples
The library supports various page layouts and configurations:
Examples
The examples/ directory contains working demonstrations:
Getting Started
- 01_simple_page_rendering.py - Introduction to the Page system
- 02_text_and_layout.py - HTML parsing and text rendering
- 03_page_layouts.py - Different page configurations
- 04_table_rendering.py - HTML table rendering with styling
- 05_html_table_with_images.py - Tables with embedded images
- 06_functional_elements_demo.py - Interactive buttons and forms with callbacks
- 08_bundled_fonts_demo.py - Using the bundled DejaVu font families
🆕 Advanced Features (NEW)
- 08_pagination_demo.py - Multi-page documents with PageBreak (11 tests)
- 09_link_navigation_demo.py - All link types and navigation (10 tests)
- 10_forms_demo.py - All 14 form field types (9 tests)
- 11_font_family_switching_demo.py - 🆕 Dynamic font switching in ereader
Run any example:
cd examples
python 01_simple_page_rendering.py
python 08_pagination_demo.py # NEW: Multi-page documents
All new examples include comprehensive test coverage! Run tests with:
python -m pytest tests/examples/ -v # 30 tests, all passing ✅
Coverage Impact: The new examples fill critical documentation gaps:
- PageBreak: 0% → 100% (had NO examples before)
- LinkText: 14% → 100% (all 4 link types demonstrated)
- FormFields: 14% → 100% (all 14 field types demonstrated)
See examples/README.md for detailed documentation.
Font Family Switching (NEW ✨)
PyWebLayout now supports dynamic font family switching in the ereader, allowing readers to change fonts on-the-fly without losing their reading position!
Quick Example
from pyWebLayout.style.fonts import BundledFont
from pyWebLayout.layout.ereader_manager import create_ereader_manager
# Create an ereader
manager = create_ereader_manager(blocks, page_size=(600, 800))
# Switch to serif font
manager.set_font_family(BundledFont.SERIF)
# Switch to monospace font
manager.set_font_family(BundledFont.MONOSPACE)
# Restore original fonts
manager.set_font_family(None)
# Query current font
current = manager.get_font_family()
Features
- 3 Bundled Fonts: Sans, Serif, and Monospace (DejaVu font family)
- Instant Switching: Change fonts without recreating the document
- Position Preservation: Reading position maintained across font changes
- Attribute Preservation: Bold, italic, size, and color are preserved
- Smart Caching: Automatic cache invalidation for optimal performance
Learn more: See FONT_SWITCHING_FEATURE.md for complete documentation.
Documentation
- ARCHITECTURE.md - Abstract/Concrete architecture guide
- FONT_SWITCHING_FEATURE.md - 🆕 Font family switching guide
- examples/README.md - Complete examples guide with tests
- docs/images/README.md - Visual documentation index
- pyWebLayout/layout/README_EREADER_API.md - EbookReader API reference
- API Reference - See docstrings in source code
License
MIT License
Author
Duncan Tourolle - duncan@tourolle.paris








