+import {onSelect} from "../services/dom";
+
/**
* Dropdown
* Provides some simple logic to create simple dropdown menus.
constructor(elem) {
this.container = elem;
- this.menu = elem.querySelector('ul');
+ this.menu = elem.querySelector('.dropdown-menu, [dropdown-menu]');
+ this.moveMenu = elem.hasAttribute('dropdown-move-menu');
this.toggle = elem.querySelector('[dropdown-toggle]');
+ this.body = document.body;
+ this.showing = false;
this.setupListeners();
}
- show() {
+ show(event = null) {
+ this.hideAll();
+
this.menu.style.display = 'block';
this.menu.classList.add('anim', 'menuIn');
- this.container.addEventListener('mouseleave', this.hide.bind(this));
+ this.toggle.setAttribute('aria-expanded', 'true');
+
+ if (this.moveMenu) {
+ // Move to body to prevent being trapped within scrollable sections
+ this.rect = this.menu.getBoundingClientRect();
+ this.body.appendChild(this.menu);
+ this.menu.style.position = 'fixed';
+ this.menu.style.left = `${this.rect.left}px`;
+ this.menu.style.top = `${this.rect.top}px`;
+ this.menu.style.width = `${this.rect.width}px`;
+ }
+
+ // Set listener to hide on mouse leave or window click
+ this.menu.addEventListener('mouseleave', this.hide.bind(this));
+ window.addEventListener('click', event => {
+ if (!this.menu.contains(event.target)) {
+ this.hide();
+ }
+ });
// Focus on first input if existing
- let input = this.menu.querySelector('input');
+ const input = this.menu.querySelector('input');
if (input !== null) input.focus();
+
+ this.showing = true;
+
+ const showEvent = new Event('show');
+ this.container.dispatchEvent(showEvent);
+
+ if (event) {
+ event.stopPropagation();
+ }
+ }
+
+ hideAll() {
+ for (let dropdown of window.components.dropdown) {
+ dropdown.hide();
+ }
}
hide() {
this.menu.style.display = 'none';
this.menu.classList.remove('anim', 'menuIn');
+ this.toggle.setAttribute('aria-expanded', 'false');
+ if (this.moveMenu) {
+ this.menu.style.position = '';
+ this.menu.style.left = '';
+ this.menu.style.top = '';
+ this.menu.style.width = '';
+ this.container.appendChild(this.menu);
+ }
+ this.showing = false;
+ }
+
+ getFocusable() {
+ return Array.from(this.menu.querySelectorAll('[tabindex],[href],button,input:not([type=hidden])'));
+ }
+
+ focusNext() {
+ const focusable = this.getFocusable();
+ const currentIndex = focusable.indexOf(document.activeElement);
+ let newIndex = currentIndex + 1;
+ if (newIndex >= focusable.length) {
+ newIndex = 0;
+ }
+
+ focusable[newIndex].focus();
+ }
+
+ focusPrevious() {
+ const focusable = this.getFocusable();
+ const currentIndex = focusable.indexOf(document.activeElement);
+ let newIndex = currentIndex - 1;
+ if (newIndex < 0) {
+ newIndex = focusable.length - 1;
+ }
+
+ focusable[newIndex].focus();
}
setupListeners() {
// Hide menu on option click
this.container.addEventListener('click', event => {
- let possibleChildren = Array.from(this.menu.querySelectorAll('a'));
- if (possibleChildren.indexOf(event.target) !== -1) this.hide();
+ const possibleChildren = Array.from(this.menu.querySelectorAll('a'));
+ if (possibleChildren.includes(event.target)) {
+ this.hide();
+ }
});
- // Show dropdown on toggle click
- this.toggle.addEventListener('click', this.show.bind(this));
- // Hide menu on enter press
- this.container.addEventListener('keypress', event => {
- if (event.keyCode !== 13) return true;
+
+ onSelect(this.toggle, event => {
+ event.stopPropagation();
+ this.show(event);
+ if (event instanceof KeyboardEvent) {
+ this.focusNext();
+ }
+ });
+
+ // Keyboard navigation
+ const keyboardNavigation = event => {
+ if (event.key === 'ArrowDown' || event.key === 'ArrowRight') {
+ this.focusNext();
+ event.preventDefault();
+ } else if (event.key === 'ArrowUp' || event.key === 'ArrowLeft') {
+ this.focusPrevious();
+ event.preventDefault();
+ } else if (event.key === 'Escape') {
+ this.hide();
+ this.toggle.focus();
+ event.stopPropagation();
+ }
+ };
+ this.container.addEventListener('keydown', keyboardNavigation);
+ if (this.moveMenu) {
+ this.menu.addEventListener('keydown', keyboardNavigation);
+ }
+
+ // Hide menu on enter press or escape
+ this.menu.addEventListener('keydown ', event => {
+ if (event.key === 'Enter') {
event.preventDefault();
+ event.stopPropagation();
this.hide();
- return false;
+ }
});
}