docbrown/app/javascript/shared/components/useKeyboardShortcuts.jsx
Andrew Bone b7dfb2495a
Allow keyboard shortcuts (#10713)
* Create keyboardShortcuts.jsx

Add handler for keyboard shortcuts

* Match github's hotkey style

Makes objects clearer.

* Update keyboardShortcuts.jsx

* Allow single character shortcuts

update to allow single character shortcuts/hotkeys

* Add component documentation

Add inline documentation for the component.

* Fix example typo

* Move keyboardShortcuts to a hook

* Fixed useKeyboardShortcuts example

* Rename keyboardShortcuts.jsx to useKeyboardShortcuts.jsx

* Rebuild

* Move isFormField outside render cycle

Move the isFormField function outside of the render cycle.

* Prevent event listener on empty object

Don't add an event listener if the shortcuts property is an empty object or is null

* Add tests for useKeyboardShortcuts

Initial pass for adding tests to useKeyboardShortcuts

* Missed unmount

Missed a whole word...

* Fix typos

* Convert function type

* Add new test cases.

* Missing brackets

* Typo

* Update useKeyboardShortcuts.test.jsx

* Move event listener to document

* Update tests

* Use testing-library/user-event

* Correct fireEvent

* Update keyDown

* Slight tidy

* Change order, just in case

* Swap to render

* Make function async

* Rerun travis

* Add rerender

* Fix render function

* check event.key for fallback
2020-10-22 13:45:42 +02:00

104 lines
2.8 KiB
JavaScript

import { useEffect } from "preact/hooks";
import PropTypes from 'prop-types';
import { h } from 'preact';
/**
* Checker that return true if element is a form element
*
* @param {node} element to be checked
*
* @returns {boolean} isFormField
*/
function isFormField(element) {
if ((element instanceof HTMLElement) === false) return false;
const name = element.nodeName.toLowerCase();
const type = (element.getAttribute("type") || "").toLowerCase();
return (
name === "select" ||
name === "textarea" ||
(name === "input" && ["submit", "reset", "checkbox", "radio"].indexOf(type) < 0) ||
element.isContentEditable
);
};
/**
* hook that can be added to a component to listen
* for keyboard presses
*
* @example
* const shortcuts = {
* "ctrl+alt+KeyG": (e) => {
* e.preventDefault();
* alert("Control Alt G has been pressed");
* },
* "?": (e) => {
* setIsHelpVisible(true);
* }
* }
*
* useKeyboardShortcuts(shortcuts, someElementOrWindowObject);
*
* @param {object} shortcuts List of keyboard shortcuts/event
* @param {EventTarget} [eventTarget=window] An event target.
*
*/
export function useKeyboardShortcuts(shortcuts, eventTarget = window) {
useEffect(() => {
if (!shortcuts || Object.keys(shortcuts).length === 0) return;
const keyEvent = (e) => {
if (e.defaultPrevented) return;
// Get special keys
const keys = `${e.ctrlKey || e.metaKey ? "ctrl+" : ""}${e.altKey ? "alt+" : ""}${e.shiftKey ? "shift+" : ""}`;
// If no special keys are pressed and focus is inside a field return
if (e.target instanceof Node && isFormField(e.target) && !keys) return;
const shortcut = shortcuts[`${keys}${e.code}`] || shortcuts[`${keys}${e.key.toLowerCase()}`];
if (shortcut) shortcut(e);
};
eventTarget.addEventListener("keydown", keyEvent);
return () => {
eventTarget.removeEventListener("keydown", keyEvent);
};
}, [shortcuts, eventTarget]);
}
/**
* compoent that can be added to a component to listen
* for keyboard presses using the useKeyboardShortcuts hook
*
* @example
* const shortcuts = {
* "ctrl+alt+KeyG": (e) => {
* e.preventDefault();
* alert("Control Alt G has been pressed")
* }
* }
*
* <KeyboardShortcuts shortcuts={shortcuts} />
* <KeyboardShortcuts shortcuts={shortcuts} eventTarget={ref.current} />
*
* @param {object} shortcuts List of keyboard shortcuts/event
* @param {EventTarget} [eventTarget=window] An event target.
*
*/
export function KeyboardShortcuts({ shortcuts, eventTarget }) {
useKeyboardShortcuts(shortcuts, eventTarget);
return null;
}
KeyboardShortcuts.propTypes = {
shortcuts: PropTypes.object.isRequired,
eventTarget: PropTypes.instanceOf(Element)
}
KeyboardShortcuts.defaultProps = {
shortcuts: {},
eventTarget: window
}