This code defines and runs an animation on an HTML...

August 9, 2025 at 02:13 AM

  const anim = clone.animate([
    { // Start: Original state
      left: rect.left + 'px',
      top: rect.top + 'px',
      width: rect.width + 'px',
      height: rect.height + 'px',
      opacity: 1,
      fontSize: initialFontSize + 'px',
      lineHeight: rect.height + 'px'
    },
    { // Middle: Zoomed in, still opaque
      left: targetLeft + 'px',
      top: targetTop + 'px',
      width: targetWidth + 'px',
      height: targetHeight + 'px',
      opacity: 1,
      fontSize: finalFontSize + 'px',
      lineHeight: targetHeight + 'px',
      offset: zoomTiming
    },
    { // End: Faded out
      left: targetLeft + 'px',
      top: targetTop + 'px',
      width: targetWidth + 'px',
      height: targetHeight + 'px',
      opacity: 0,
      fontSize: finalFontSize + 'px',
      lineHeight: targetHeight + 'px'
    }
  ], {
    duration: duration,
    easing: 'cubic-bezier(0.25, 1, 0.5, 1)'
  });

  // Timed event to show clue screen behind the clone *before* it fades
  setTimeout(() => {
    clueScreen.style.display = 'flex';
  }, duration * zoomTiming);

  anim.onfinish = () => {
    clone.remove();
  };
}

This code defines and runs an animation on an HTML element (clone) and performs a few related actions. Here's what it does step by step:

1. Animate the element `clone`:

The clone.animate() function defines a sequence of animations applied to the clone element. The animation has keyframes and timing options:

Keyframes:
- First keyframe (start): The clone begins in its original state, defined by the position (left, top), size (width, height), opacity (opacity: 1), font size, and line height. These are set using the properties of a bounding rectangle (rect) and an initial font size (initialFontSize).
- Second keyframe (middle): The element transitions to a "zoomed-in" state. It moves to the targetLeft and targetTop position, changes size to targetWidth and targetHeight, and adjusts its font size and line height to match. It stays opaque (opacity: 1). The offset: zoomTiming specifies when this keyframe occurs during the animation duration (a fractional value between 0 and 1).
- Third keyframe (end): The element retains the same position and size as in the second keyframe but fades out (opacity: 0).
Timing options:
- The animation lasts for duration milliseconds.
- The easing function 'cubic-bezier(0.25, 1, 0.5, 1)' makes the animation smooth and natural, with a custom timing curve.

The animate() function returns an Animation object assigned to the constant anim.

2. Show the "clue screen" mid-animation:

A timed event using setTimeout() runs a callback after a delay of duration * zoomTiming milliseconds (i.e., when the animation reaches the "zoomed-in" state). At that moment:

The clueScreen element (another HTML element) is revealed by setting its style.display property to 'flex'.

This ensures the "clue screen" becomes visible before the clone element finishes fading out.

3. Remove the `clone` element once the animation finishes:

The onfinish event handler of the Animation object ensures that when the animation completes, the clone element is removed from the DOM via the clone.remove() method.

Final Summary:

This code animates the clone element by making it transition from its original state, zoom-in and stay opaque for a moment, and then fade out. During the zoom-in phase, the "clue screen" is displayed. Finally, once the animation is complete, the clone element is removed from the document. The animation also uses a smooth cubic-bezier easing for a polished effect.

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This code defines and runs an animation on an HTML...

1. Animate the element clone:

2. Show the "clue screen" mid-animation:

3. Remove the clone element once the animation finishes:

Final Summary:

1. Animate the element `clone`:

3. Remove the `clone` element once the animation finishes: