26 lines
697 B
Plaintext
26 lines
697 B
Plaintext
// @flow
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import { isShadowRoot } from './instanceOf';
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export default function contains(parent: Element, child: Element) {
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const rootNode = child.getRootNode && child.getRootNode();
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// First, attempt with faster native method
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if (parent.contains(child)) {
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return true;
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}
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// then fallback to custom implementation with Shadow DOM support
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else if (rootNode && isShadowRoot(rootNode)) {
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let next = child;
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do {
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if (next && parent.isSameNode(next)) {
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return true;
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}
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// $FlowFixMe[prop-missing]: need a better way to handle this...
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next = next.parentNode || next.host;
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} while (next);
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}
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// Give up, the result is false
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return false;
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}
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