import { eventListenerOptionsSupported } from './utils';
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const defaultOptions = {
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passive: true,
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capture: false
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};
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const supportedPassiveTypes = [
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'scroll', 'wheel',
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'touchstart', 'touchmove', 'touchenter', 'touchend', 'touchleave',
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'mouseout', 'mouseleave', 'mouseup', 'mousedown', 'mousemove', 'mouseenter', 'mousewheel', 'mouseover'
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];
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const getDefaultPassiveOption = (passive, eventName) => {
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if (passive !== undefined) return passive;
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return supportedPassiveTypes.indexOf(eventName) === -1 ? false : defaultOptions.passive;
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};
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const getWritableOptions = (options) => {
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const passiveDescriptor = Object.getOwnPropertyDescriptor(options, 'passive');
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return passiveDescriptor && passiveDescriptor.writable !== true && passiveDescriptor.set === undefined
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? Object.assign({}, options)
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: options;
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};
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const overwriteAddEvent = (superMethod) => {
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EventTarget.prototype.addEventListener = function (type, listener, options) {
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const usesListenerOptions = typeof options === 'object' && options !== null;
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const useCapture = usesListenerOptions ? options.capture : options;
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options = usesListenerOptions ? getWritableOptions(options) : {};
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options.passive = getDefaultPassiveOption(options.passive, type);
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options.capture = useCapture === undefined ? defaultOptions.capture : useCapture;
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superMethod.call(this, type, listener, options);
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};
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EventTarget.prototype.addEventListener._original = superMethod;
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};
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const supportsPassive = eventListenerOptionsSupported();
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if (supportsPassive) {
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const addEvent = EventTarget.prototype.addEventListener;
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overwriteAddEvent(addEvent);
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}
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