pyWebLayout/EPUB_READER_README.md

EPUB Reader Documentation

Overview

This project implements two major enhancements to pyWebLayout:

1. Enhanced Page Class: Moved HTML rendering logic from the browser into the Page class for better separation of concerns
2. Tkinter EPUB Reader: A complete EPUB reader application with pagination support

Files Created/Modified

1. Enhanced Page Class (pyWebLayout/concrete/page.py)

New Features Added:

• load_html_string() - Load HTML content directly into a Page
• load_html_file() - Load HTML from a file
• Private conversion methods to transform abstract blocks to renderables
• Integration with existing HTML extraction system

Key Methods:

page = Page(size=(800, 600))
page.load_html_string(html_content)  # Load HTML string
page.load_html_file("file.html")     # Load HTML file
image = page.render()                # Render to PIL Image

Benefits:

• Reuses existing html_extraction.py infrastructure
• Converts abstract blocks to concrete renderables
• Supports headings, paragraphs, lists, images, etc.
• Proper error handling with fallback rendering

2. EPUB Reader Application (epub_reader_tk.py)

Features:

• Complete Tkinter-based GUI
• EPUB file loading using existing epub_reader.py
• Chapter navigation with dropdown selection
• Page-by-page display with navigation controls
• Adjustable font size (8-24pt)
• Keyboard shortcuts (arrow keys, Ctrl+O)
• Status bar with loading feedback
• Scrollable content display

GUI Components:

• File open dialog for EPUB selection
• Chapter dropdown and navigation buttons
• Page navigation controls
• Font size adjustment
• Canvas with scrollbars for content display
• Status bar for feedback

Navigation:

• Left/Right arrows: Previous/Next page
• Up/Down arrows: Previous/Next chapter
• Ctrl+O: Open file dialog
• Mouse: Dropdown chapter selection

3. Test Suite (test_enhanced_page.py)

Test Coverage:

• HTML string loading and rendering
• HTML file loading and rendering
• EPUB reader app import and instantiation
• Error handling verification

Technical Architecture

HTML Processing Flow

HTML String/File → parse_html_string() → Abstract Blocks → Page._convert_block_to_renderable() → Concrete Renderables → Page.render() → PIL Image

EPUB Reading Flow

EPUB File → read_epub() → Book → Chapters → Abstract Blocks → Page Conversion → Tkinter Display

Usage Examples

Basic HTML Page Rendering

from pyWebLayout.concrete.page import Page

# Create and load HTML
page = Page(size=(800, 600))
page.load_html_string("""
<h1>Hello World</h1>
<p>This is a <strong>test</strong> paragraph.</p>
""")

# Render to image
image = page.render()
image.save("output.png")

EPUB Reader Application

# Run the EPUB reader
python epub_reader_tk.py

# Or import and use programmatically
from epub_reader_tk import EPUBReaderApp
app = EPUBReaderApp()
app.run()

Features Demonstrated

HTML Parsing & Rendering

• ✅ Paragraphs with inline formatting (bold, italic)
• ✅ Headers (H1-H6) with proper sizing
• ✅ Lists (ordered and unordered)
• ✅ Images with alt text fallback
• ✅ Error handling for malformed content

EPUB Processing

• ✅ Full EPUB metadata extraction
• ✅ Chapter-by-chapter navigation
• ✅ Table of contents integration
• ✅ Multi-format content support

User Interface

• ✅ Intuitive navigation controls
• ✅ Responsive layout with scrolling
• ✅ Font size customization
• ✅ Keyboard shortcuts
• ✅ Status feedback

Dependencies

The EPUB reader leverages existing pyWebLayout infrastructure:

• pyWebLayout.io.readers.epub_reader - EPUB parsing
• pyWebLayout.io.readers.html_extraction - HTML to abstract blocks
• pyWebLayout.concrete.* - Renderable objects
• pyWebLayout.abstract.* - Abstract document model
• pyWebLayout.style.* - Styling system

Testing

Run the test suite to verify functionality:

python test_enhanced_page.py

Expected output:

• ✅ HTML String Loading: PASS
• ✅ HTML File Loading: PASS
• ✅ EPUB Reader Imports: PASS

Future Enhancements

1. Advanced Pagination: Break long chapters across multiple pages
2. Search Functionality: Full-text search within books
3. Bookmarks: Save reading position
4. Themes: Dark/light mode support
5. Export: Save pages as images or PDFs
6. Zoom: Variable zoom levels for accessibility

Integration with Existing Browser

The enhanced Page class can be used to improve the existing html_browser.py:

# Instead of complex parsing in the browser
parser = HTMLParser()
page = parser.parse_html_string(html_content)

# Use the new Page class
page = Page()
page.load_html_string(html_content)

This provides better separation of concerns and reuses the robust HTML extraction system.