Function createKeybindingsHandler

src/tinykeys.ts:263–322

(
	keybindingsMap: KeybindingsMap,
	options: KeybindingHandlerOptions = {},
)

 * ```
 */
export function createKeybindingsHandler(
	keybindingsMap: KeybindingsMap,
	options: KeybindingHandlerOptions = {},
): EventListener {
	let timeout = options.timeout ?? DEFAULT_TIMEOUT
	let ignore = options.ignore ?? defaultKeybindingsHandlerIgnore

	let keybindings = Object.keys(keybindingsMap).map(input => {
		return [input, parseKeybinding(input), keybindingsMap[input]] as const
	})

	let pending = new Map<string, KeybindingPress[]>()
	let timer: number | null = null

	return event => {
		if (!isKeyboardEvent(event) || ignore(event)) {
			return
		}

		let conflicts: Array<string> = []
		for (let [input, sequence, handler] of keybindings) {
			let prev = pending.get(input)
			let expected = prev ? prev : sequence
			let [current, ...rest] = expected

			let matches = matchKeybindingPress(event, current)

			if (!matches) {
				// Modifier keydown events shouldn't break sequences
				// Note: This works because:
				// - non-modifiers will always return false
				// - if the current keypress is a modifier then it will return true when we check its state
				// MDN: https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/getModifierState
				if (!getModifierState(event, event.key)) {
					pending.delete(input)
				}
			} else if (rest.length > 0) {
				pending.set(input, rest)
				conflicts.push(input)
			} else {
				pending.delete(input)
				if (conflicts.length) {
					console.warn(
						`tinykeys: Conflict found, "${input}" did not fire, waiting for:`,
						conflicts,
					)
				} else {
					handler(event)
					break
				}
			}
		}

		if (timer) {
			clearTimeout(timer)
		}

		timer = setTimeout(() => pending.clear(), timeout)