woocommerce-paypal-payments/modules/ppcp-settings/resources/js/utils/Helper/ButtonDisabler.js

/**
 * @param  selectorOrElement
 * @return {Element}
 */
const getElement = ( selectorOrElement ) => {
	if ( typeof selectorOrElement === 'string' ) {
		return document.querySelector( selectorOrElement );
	}
	return selectorOrElement;
};

const triggerEnabled = ( selectorOrElement, element ) => {
	jQuery( document ).trigger( 'ppcp-enabled', {
		handler: 'ButtonsDisabler.setEnabled',
		action: 'enable',
		selector: selectorOrElement,
		element,
	} );
};

const triggerDisabled = ( selectorOrElement, element ) => {
	jQuery( document ).trigger( 'ppcp-disabled', {
		handler: 'ButtonsDisabler.setEnabled',
		action: 'disable',
		selector: selectorOrElement,
		element,
	} );
};

export const setEnabled = ( selectorOrElement, enable, form = null ) => {
	const element = getElement( selectorOrElement );

	if ( ! element ) {
		return;
	}

	if ( enable ) {
		jQuery( element )
			.removeClass( 'ppcp-disabled' )
			.off( 'mouseup' )
			.find( '> *' )
			.css( 'pointer-events', '' );

		triggerEnabled( selectorOrElement, element );
	} else {
		jQuery( element )
			.addClass( 'ppcp-disabled' )
			.on( 'mouseup', function ( event ) {
				event.stopImmediatePropagation();

				if ( form ) {
					// Trigger form submit to show the error message
					const $form = jQuery( form );
					if (
						$form
							.find( '.single_add_to_cart_button' )
							.hasClass( 'disabled' )
					) {
						$form.find( ':submit' ).trigger( 'click' );
					}
				}
			} )
			.find( '> *' )
			.css( 'pointer-events', 'none' );

		triggerDisabled( selectorOrElement, element );
	}
};

export const isDisabled = ( selectorOrElement ) => {
	const element = getElement( selectorOrElement );

	if ( ! element ) {
		return false;
	}

	return jQuery( element ).hasClass( 'ppcp-disabled' );
};

export const disable = ( selectorOrElement, form = null ) => {
	setEnabled( selectorOrElement, false, form );
};

export const enable = ( selectorOrElement ) => {
	setEnabled( selectorOrElement, true );
};