jenkins/src/main/js/util/keyboard.js

104 lines
3.2 KiB
JavaScript

/**
* @param {Element} container - the container for the items
* @param {function(): NodeListOf<Element>} itemsFunc - function which returns the list of items
* @param {string} selectedClass - the class to apply to the selected item
* @param {function()} additionalBehaviours - add additional keyboard shortcuts to the focused item
* @param hasKeyboardPriority - set if custom behaviour is needed to decide whether the element has keyboard priority
*/
export default function makeKeyboardNavigable(
container,
itemsFunc,
selectedClass,
additionalBehaviours = () => {},
hasKeyboardPriority = () =>
window.getComputedStyle(container).visibility === "visible",
) {
window.addEventListener("keyup", (e) => {
let items = Array.from(itemsFunc());
let selectedItem = items.find((a) => a.classList.contains(selectedClass));
if (container && hasKeyboardPriority(container)) {
if (e.key === "Tab") {
if (items.includes(document.activeElement)) {
if (selectedItem) {
selectedItem.classList.remove(selectedClass);
}
selectedItem = document.activeElement;
selectedItem.classList.add(selectedClass);
}
}
}
});
window.addEventListener("keydown", (e) => {
let items = Array.from(itemsFunc());
let selectedItem = items.find((a) => a.classList.contains(selectedClass));
// Only navigate through the list of items if the container is active on the screen
if (container && hasKeyboardPriority(container)) {
if (e.key === "ArrowDown") {
e.preventDefault();
if (selectedItem) {
selectedItem.classList.remove(selectedClass);
const next = items[items.indexOf(selectedItem) + 1];
if (next) {
selectedItem = next;
} else {
selectedItem = items[0];
}
} else {
selectedItem = items[0];
}
scrollAndSelect(selectedItem, selectedClass, items);
} else if (e.key === "ArrowUp") {
e.preventDefault();
if (selectedItem) {
selectedItem.classList.remove(selectedClass);
const previous = items[items.indexOf(selectedItem) - 1];
if (previous) {
selectedItem = previous;
} else {
selectedItem = items[items.length - 1];
}
} else {
selectedItem = items[items.length - 1];
}
scrollAndSelect(selectedItem, selectedClass, items);
} else if (e.key === "Enter") {
if (selectedItem) {
e.preventDefault();
selectedItem.click();
}
} else {
additionalBehaviours(selectedItem, e.key, e);
}
}
});
}
function scrollAndSelect(selectedItem, selectedClass, items) {
if (selectedItem !== null) {
if (!isInViewport(selectedItem)) {
selectedItem.scrollIntoView(false);
}
selectedItem.classList.add(selectedClass);
if (items.includes(document.activeElement)) {
selectedItem.focus();
}
}
}
function isInViewport(element) {
const rect = element.getBoundingClientRect();
return (
rect.top >= 0 &&
rect.left >= 0 &&
rect.bottom <= window.innerHeight &&
rect.right <= window.innerWidth
);
}