Scroll to Top Button - Documentation
Technical Overview
Core Features
Dynamic Content Awareness
- Utilizes MutationObserver to detect DOM changes
- Automatically adjusts to dynamically loaded content
- Maintains button visibility based on real-time page height
Advanced Smooth Scrolling
- Multiple easing functions for different scrolling experiences:
easeInOutCubic
: Balanced acceleration/deceleration
easeOutQuad
: Natural deceleration
easeInOutExpo
: Dramatic easing for long scrolls
- Distance-based duration adjustment
- Frame-rate optimized animations
Intelligent Visibility Control
- Shows button after configurable scroll threshold
- Considers viewport height and total page length
- Smooth fade transitions for showing/hiding
- Prevents visibility during short page loads
Performance Optimizations
Event Handling
- Debounced scroll event processing
- Passive event listeners for touch events
- Optimized animation frames
- Efficient DOM queries and caching
Memory Management
- Single button instance enforcement
- Proper event listener cleanup
- Efficient style calculations
- Minimal DOM operations
Configuration Guide
Button Appearance
{
buttonSize: '40px',
fontSize: '16px',
backgroundColor: '#333',
hoverColor: '#444',
textColor: '#FFF',
borderRadius: '50%',
bottom: '20px',
right: '20px'
}
Scroll Settings
{
scroll: {
duration: 800, // Base duration in milliseconds
easing: 'easeInOutCubic',
fps: 60,
breakpoints: {
short: 500, // Quick scroll for short distances
medium: 1500, // Standard scroll for medium distances
long: 3000 // Slower scroll for long distances
}
}
}
Visibility Thresholds
{
showThreshold: 300, // Pixels scrolled before showing
minimumPageHeight: 1000, // Minimum page height to enable button
fadeSpeed: 300, // Transition duration
zIndex: 2147483647 // Maximum z-index value
}
Implementation Details
Animation System
The script uses a sophisticated animation system that:
- Calculates optimal scroll duration based on distance
- Applies appropriate easing for smooth motion
- Maintains consistent frame rate
- Adjusts to system performance
Compatibility Features
- Works with modern and legacy browsers
- Handles different scrolling containers
- Supports dynamic page modifications
- Adapts to various page layouts
Error Handling
- Prevents multiple button instances
- Graceful degradation in unsupported browsers
- Handles scroll interruption
- Manages edge cases in page structure
Best Practices
Integration
- Add to page early in load cycle
- Avoid conflicts with existing scroll handlers
- Consider z-index hierarchy
- Test with various page lengths
Customization
- Adjust thresholds for specific use cases
- Modify easing for desired feel
- Customize appearance for branding
- Configure breakpoints for content type
Performance
- Monitor scroll performance
- Adjust debounce timing if needed
- Consider page weight impact
- Optimize animation settings
Browser Support
- Chrome 61+
- Firefox 55+
- Safari 11+
- Edge 16+
- Opera 48+
Known Limitations
- Extremely long pages may require adjusted settings
- Complex dynamic content may need custom threshold adjustments
- Some legacy browsers may fall back to basic scrolling
- Heavy JavaScript execution may affect animation smoothness