+import {onSelect} from "../services/dom";
+
/**
* Dropdown
* Provides some simple logic to create simple dropdown menus.
this.moveMenu = elem.hasAttribute('dropdown-move-menu');
this.toggle = elem.querySelector('[dropdown-toggle]');
this.body = document.body;
+ this.showing = false;
this.setupListeners();
}
- show(event) {
+ show(event = null) {
this.hideAll();
this.menu.style.display = 'block';
this.menu.classList.add('anim', 'menuIn');
+ this.toggle.setAttribute('aria-expanded', 'true');
if (this.moveMenu) {
// Move to body to prevent being trapped within scrollable sections
});
// Focus on first input if existing
- let input = this.menu.querySelector('input');
+ const input = this.menu.querySelector('input');
if (input !== null) input.focus();
- event.stopPropagation();
+ this.showing = true;
+
+ const showEvent = new Event('show');
+ this.container.dispatchEvent(showEvent);
+
+ if (event) {
+ event.stopPropagation();
+ }
}
hideAll() {
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.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();
+ }
+ });
+
+ onSelect(this.toggle, event => {
+ event.stopPropagation();
+ this.show(event);
+ if (event instanceof KeyboardEvent) {
+ this.focusNext();
+ }
});
- // 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;
+
+ // 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();
- return false;
+ 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();
+ }
});
}