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requestAnimationFrame - Efficient DOM Updates for Animations and UI

Core Idea:

requestAnimationFrame is a browser API that schedules a function to execute before the next repaint, providing a more efficient and smoother way to perform animations and DOM manipulations than traditional timing mechanisms.

Key Principles:

1. Browser Optimization:
   • Aligns code execution with the browser's natural render cycle.
2. Throttling:
   • Automatically pauses in inactive tabs or hidden iframes.
3. Performance Alignment:
   • Batches visual updates to prevent tearing and optimize rendering.

Why It Matters:

• Animation Smoothness:
  • Produces more consistent frame rates and smoother animations.
• Battery Efficiency:
  • Reduces power consumption by aligning with display refresh.
• Resource Management:
  • Automatically throttles in background tabs to conserve resources.

How to Implement:

1. Schedule Animation Frame:
   • const frameId = requestAnimationFrame(callback);
2. Create Animation Loop:
   • Recursively call within the callback for continuous animation.
3. Cancel When Done:
   • cancelAnimationFrame(frameId); when animation should stop.

Example:

• Scenario:

  • Creating a smooth scrolling animation to a specific element.

• Application:

  function smoothScrollTo(element) {  const start = window.pageYOffset;  const target = element.getBoundingClientRect().top + start;  const duration = 500; // ms  let startTime = null;    function animate(currentTime) {    if (!startTime) startTime = currentTime;    const timeElapsed = currentTime - startTime;    const progress = Math.min(timeElapsed / duration, 1);    const easeProgress = 0.5 - Math.cos(progress * Math.PI) / 2;        window.scrollTo(0, start + (target - start) * easeProgress);        if (timeElapsed < duration) {      requestAnimationFrame(animate);    }  }    requestAnimationFrame(animate);}
  

• Result:

  • Smooth scrolling animation that's synchronized with the browser's refresh rate.

Connections:

• Related React Concepts:
  • useEffect: Often used to manage rAF initialization and cleanup.
  • useRef: Used to store animation frame IDs for cancellation.
• Broader Programming Concepts:
  • Render Loop: Game/animation programming pattern.
  • Debouncing/Throttling: Controlling execution frequency.

References:

1. Primary Source:
   • MDN Web Docs, Window.requestAnimationFrame()
2. Additional Resources:
   • MDN requestAnimationFrame

Tags:

#JavaScript #Animation #Performance #DOM #requestAnimationFrame #Rendering

Connections:

Sources:

• From: AG Grid