Add animated word cloud tool with Archimedean spiral visualization

[simonw]

Fetch https://raw.githubusercontent.com/simonw/research/refs/heads/main/rust-wordcloud/walkthrough.md to /tmp using curl so you can read the whole thing

Inspired by that, build animated-word-cloud.html - a page that accepts pasted text (which it persists in the #fragment of the URL such that a page loaded with that # populated will use that text as input and auto-submit it) such that when you submit the text it builds a word cloud using the algorithm described in that document but does it animated, to make the algorithm as clear to understand. Include a slider for the animation which can be paused and the speed adjusted or even stepped through frame by frame while paused. At any stage the visible in-progress word cloud can be downloaded as a PNG.

Mae sure the text "placed X" is not visible in the final frame - I don't want it in the PNG download - also increase font size of textarea to 16px

Single-page HTML tool that accepts pasted text and builds a word cloud
using the algorithm from the Rust wordcloud walkthrough, animated to
make each step visible. Features include:

• Text persisted in URL #fragment (base64-encoded) for sharing
• Auto-submit when loaded with populated fragment
• Play/pause animation with adjustable speed slider
• Frame-by-frame stepping when paused
• Progress scrubber to jump to any point in the animation
• PNG download of the current canvas state at any time
• Visual indicators: ghost words for collision probes, bounding boxes,
  crosshairs, and status labels for placed/skipped words
• Grid-based spatial indexing for collision detection
• Logarithmic font scaling for balanced word sizes
• Stop word filtering matching the Rust implementation

https://claude.ai/code/session_01MSBSKkyGbhzjfybwnjRemt

[claude]

Claude finished @simonw's task —— View job

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PR Review: Animated Word Cloud Tool

Reviewing the animated word cloud implementation for code quality, best practices, potential issues, and security considerations.

Todo List

• Read and analyze the animated-word-cloud.html file
• Review code structure and organization
• Check JavaScript implementation for bugs and best practices
• Evaluate HTML/CSS quality and accessibility
• Assess security considerations (especially URL fragment handling)
• Review performance implications of canvas operations
• Consider test coverage recommendations
• Provide comprehensive feedback summary

Code Review Feedback

This is a well-implemented single-page word cloud tool with impressive animation features. Here's my detailed analysis:

✅ Strengths

Code Organization & Architecture:

• Clean separation of concerns with distinct modules (word counting, spatial indexing, rendering, animation)
• Proper encapsulation using IIFE pattern to avoid global scope pollution
• Well-structured class-based approach for SpatialGrid
• Consistent naming conventions throughout

Algorithm Implementation:

• Excellent implementation of Archimedean spiral placement algorithm
• Smart optimization with grid-based spatial indexing for collision detection (animated-word-cloud.html:209-249)
• Efficient frame pre-computation strategy that balances performance with animation smoothness
• Deterministic PRNG (mulberry32) ensures reproducible results

User Experience:

• Comprehensive animation controls (play/pause, stepping, progress scrubber)
• Visual debugging aids (ghost words, bounding boxes, crosshairs, status labels)
• URL fragment persistence for sharing
• PNG export functionality

⚠️ Areas for Improvement

1. Security Considerations:

• Low Risk: URL fragment handling in persistText() and loadTextFromHash() (animated-word-cloud.html:535-553) uses btoa/atob which is safe for this use case
• The fallback to raw encodeURIComponent could potentially create very long URLs, but no XSS risk identified

2. Performance Concerns:

• Canvas operations: Multiple font setting calls per frame could be optimized by caching font contexts
• Text measurement: Creates new canvas context on each measurement - consider reusing (animated-word-cloud.html:196-206)
• Frame computation: Could be memory-intensive for very large texts (limited to 200 words, which helps)

3. Accessibility Issues:

• Missing ARIA labels on interactive elements
• No keyboard navigation for controls
• Color-only visual indicators (consider adding text alternatives)
• Canvas content is not accessible to screen readers

4. Code Quality Suggestions:

// animated-word-cloud.html:453-457 - Magic numbers should be constants
const SPEED_MIN_DELAY = 5;
const SPEED_MAX_DELAY = 500;
const SPEED_CURVE_FACTOR = 0.954;

// animated-word-cloud.html:567-572 - Error handling could be more user-friendly
if (wordCounts.length === 0) {
    const errorMsg = document.createElement('div');
    errorMsg.className = 'error-message';
    errorMsg.textContent = 'No words found after filtering. Try longer or different text.';
    // Show in UI rather than alert()
}

🔍 Potential Bugs

Minor Issues:

• measureText() (animated-word-cloud.html:196) assumes font metrics without explicit validation
• Canvas dimensions are fixed (1200x800) - responsive sizing would improve mobile experience
• No validation for extremely long words that might exceed canvas bounds

Edge Cases:

• Empty text input after trimming should be handled more gracefully
• Very short texts might not provide enough words for meaningful visualization
• Browser compatibility for canvas toDataURL() in some contexts

🎯 Recommendations

High Priority:

1. Accessibility improvements: Add ARIA labels and keyboard navigation
2. Performance optimization: Cache font contexts and reuse canvas for measurements
3. Error handling: Replace alert() with inline UI feedback

Medium Priority:

1. Responsive design: Make canvas size adaptive to viewport
2. Input validation: Better handling of edge cases and empty inputs
3. Mobile optimization: Touch-friendly controls and proper viewport scaling

Low Priority:

1. Configuration options: Allow users to customize color palettes, word limits, etc.
2. Export formats: Consider SVG export for scalable graphics
3. Animation presets: Different speed/timing curves for various effects

📊 Test Coverage Considerations

Since this is a visual, interactive tool, traditional unit testing has limited applicability. Consider:

1. Integration tests: Automated screenshot comparison for different text inputs
2. Performance benchmarks: Measure frame computation time for various input sizes
3. Cross-browser testing: Ensure canvas operations work consistently
4. Accessibility testing: Verify keyboard navigation and screen reader compatibility

🔒 Security Assessment

Overall: Low Risk - No significant security concerns identified

• Text processing is safe (no innerHTML usage)
• URL fragment encoding/decoding is properly handled with fallbacks
• Canvas operations are isolated and don't expose sensitive data
• No external dependencies or dynamic script loading

Final Assessment

This is a high-quality implementation that demonstrates sophisticated algorithm understanding and solid JavaScript engineering. The code is clean, well-organized, and feature-rich. The main areas for improvement are accessibility, performance optimization, and user experience enhancements rather than fundamental issues.

Recommendation: ✅ Approve with suggested improvements

---

[cloudflare-workers-and-pages]

Deploying tools with    Cloudflare Pages

Latest commit:	3932d42
Status:	✅  Deploy successful!
Preview URL:	https://d80d29ca.tools-b1q.pages.dev
Branch Preview URL:	https://claude-animated-word-cloud-w.tools-b1q.pages.dev

View logs

[claude]

Claude finished @simonw's task —— View job

---

PR Review: Animated Word Cloud Tool

Reviewing the animated word cloud implementation for code quality, best practices, potential issues, and security considerations.

Todo List

• Read and analyze the animated-word-cloud.html file
• Review code structure and organization
• Check JavaScript implementation for bugs and best practices
• Evaluate HTML/CSS quality and accessibility
• Assess security considerations (especially URL fragment handling)
• Review performance implications of canvas operations
• Consider test coverage recommendations
• Provide comprehensive feedback summary

Code Review Feedback

This is a well-implemented single-page word cloud tool with impressive animation features. Here's my detailed analysis:

✅ Strengths

Code Organization & Architecture:

• Clean separation of concerns with distinct modules (word counting, spatial indexing, rendering, animation)
• Proper encapsulation using IIFE pattern to avoid global scope pollution
• Well-structured class-based approach for SpatialGrid
• Consistent naming conventions throughout

Algorithm Implementation:

• Excellent implementation of Archimedean spiral placement algorithm
• Smart optimization with grid-based spatial indexing for collision detection (animated-word-cloud.html:209-249)
• Efficient frame pre-computation strategy that balances performance with animation smoothness
• Deterministic PRNG (mulberry32) ensures reproducible results

User Experience:

• Comprehensive animation controls (play/pause, stepping, progress scrubber)
• Visual debugging aids (ghost words, bounding boxes, crosshairs, status labels)
• URL fragment persistence for sharing
• PNG export functionality

⚠️ Areas for Improvement

1. Security Considerations:

• Low Risk: URL fragment handling in persistText() and loadTextFromHash() (animated-word-cloud.html:535-553) uses btoa/atob which is safe for this use case
• The fallback to raw encodeURIComponent could potentially create very long URLs, but no XSS risk identified

2. Performance Concerns:

• Canvas operations: Multiple font setting calls per frame could be optimized by caching font contexts
• Text measurement: Creates new canvas context on each measurement - consider reusing (animated-word-cloud.html:196-206)
• Frame computation: Could be memory-intensive for very large texts (limited to 200 words, which helps)

3. Accessibility Issues:

• Missing ARIA labels on interactive elements
• No keyboard navigation for controls
• Color-only visual indicators (consider adding text alternatives)
• Canvas content is not accessible to screen readers

4. Code Quality Suggestions:

// animated-word-cloud.html:453-457 - Magic numbers should be constants
const SPEED_MIN_DELAY = 5;
const SPEED_MAX_DELAY = 500;
const SPEED_CURVE_FACTOR = 0.954;

// animated-word-cloud.html:567-572 - Error handling could be more user-friendly
if (wordCounts.length === 0) {
    const errorMsg = document.createElement('div');
    errorMsg.className = 'error-message';
    errorMsg.textContent = 'No words found after filtering. Try longer or different text.';
    // Show in UI rather than alert()
}

🔍 Potential Bugs

Minor Issues:

• measureText() (animated-word-cloud.html:196) assumes font metrics without explicit validation
• Canvas dimensions are fixed (1200x800) - responsive sizing would improve mobile experience
• No validation for extremely long words that might exceed canvas bounds

Edge Cases:

• Empty text input after trimming should be handled more gracefully
• Very short texts might not provide enough words for meaningful visualization
• Browser compatibility for canvas toDataURL() in some contexts

🎯 Recommendations

High Priority:

1. Accessibility improvements: Add ARIA labels and keyboard navigation
2. Performance optimization: Cache font contexts and reuse canvas for measurements
3. Error handling: Replace alert() with inline UI feedback

Medium Priority:

1. Responsive design: Make canvas size adaptive to viewport
2. Input validation: Better handling of edge cases and empty inputs
3. Mobile optimization: Touch-friendly controls and proper viewport scaling

Low Priority:

1. Configuration options: Allow users to customize color palettes, word limits, etc.
2. Export formats: Consider SVG export for scalable graphics
3. Animation presets: Different speed/timing curves for various effects

📊 Test Coverage Considerations

Since this is a visual, interactive tool, traditional unit testing has limited applicability. Consider:

1. Integration tests: Automated screenshot comparison for different text inputs
2. Performance benchmarks: Measure frame computation time for various input sizes
3. Cross-browser testing: Ensure canvas operations work consistently
4. Accessibility testing: Verify keyboard navigation and screen reader compatibility

🔒 Security Assessment

Overall: Low Risk - No significant security concerns identified

• Text processing is safe (no innerHTML usage)
• URL fragment encoding/decoding is properly handled with fallbacks
• Canvas operations are isolated and don't expose sensitive data
• No external dependencies or dynamic script loading

Final Assessment

This is a high-quality implementation that demonstrates sophisticated algorithm understanding and solid JavaScript engineering. The code is clean, well-organized, and feature-rich. The main areas for improvement are accessibility, performance optimization, and user experience enhancements rather than fundamental issues.

Recommendation: ✅ Approve with suggested improvements