pinafore/routes/_utils/getRectFromEntry.js

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// Get the bounding client rect from an IntersectionObserver entry.
// This is to work around a bug in Chrome: https://crbug.com/737228
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let hasBoundingRectBug
function rectsAreEqual (rectA, rectB) {
return rectA.height === rectB.height &&
rectA.top === rectB.top &&
rectA.width === rectB.width &&
rectA.bottom === rectB.bottom &&
rectA.left === rectB.left &&
rectA.right === rectB.right
}
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export function getRectFromEntry (entry) {
if (typeof hasBoundingRectBug !== 'boolean') {
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const boundingRect = entry.target.getBoundingClientRect()
const observerRect = entry.boundingClientRect
hasBoundingRectBug = !rectsAreEqual(boundingRect, observerRect)
}
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return hasBoundingRectBug ? entry.target.getBoundingClientRect() : entry.boundingClientRect
}