{"version":3,"file":"header.mjs","sources":["../../../../src/govuk/components/header/header.mjs"],"sourcesContent":["import { getBreakpoint } from '../../common/index.mjs'\nimport { ElementError } from '../../errors/index.mjs'\nimport { GOVUKFrontendComponent } from '../../govuk-frontend-component.mjs'\n\n/**\n * Header component\n *\n * @preserve\n */\nexport class Header extends GOVUKFrontendComponent {\n /** @private */\n $menuButton\n\n /** @private */\n $menu\n\n /**\n * Save the opened/closed state for the nav in memory so that we can\n * accurately maintain state when the screen is changed from small to big and\n * back to small\n *\n * @private\n */\n menuIsOpen = false\n\n /**\n * A global const for storing a matchMedia instance which we'll use to detect\n * when a screen size change happens. We rely on it being null if the feature\n * isn't available to initially apply hidden attributes\n *\n * @private\n * @type {MediaQueryList | null}\n */\n mql = null\n\n /**\n * Apply a matchMedia for desktop which will trigger a state sync if the\n * browser viewport moves between states.\n *\n * @param {Element | null} $root - HTML element to use for header\n */\n constructor($root) {\n super($root)\n\n const $menuButton = this.$root.querySelector('.govuk-js-header-toggle')\n\n // Headers don't necessarily have a navigation. When they don't, the menu\n // toggle won't be rendered by our macro (or may be omitted when writing\n // plain HTML)\n if (!$menuButton) {\n return this\n }\n\n const menuId = $menuButton.getAttribute('aria-controls')\n if (!menuId) {\n throw new ElementError({\n component: Header,\n identifier:\n 'Navigation button (`