Keyboard Input Typescript

keyboard-input.ts

type KeyboardState = 'pressed' | 'down' | 'released' | 'up'

class Keyboard {
	private _keys: Record<string, KeyboardState> = {}
	constructor(keys: string[]) {
		for (const _key of keys) {
			this._keys[_key] = 'up'
		}
	}

	onPress(key: string) {
		if (this._keys[key] === 'up') {
			this._keys[key] = 'pressed'
		}
	}

	onRelease(key: string) {
		if (this._keys[key] === 'down') {
			this._keys[key] = 'released'
		}
	}

	wasPressed(key: string) {
		return this._keys[key] === 'pressed'
	}
	wasReleased(key: string) {
		return this._keys[key] === 'released'
	}

	isDown(key: string) {
		return this._keys[key] === 'down'
	}
	isUp(key: string) {
		return this._keys[key] === 'up'
	}

	update() {
		for (const key in this._keys) {
			if (Object.prototype.hasOwnProperty.call(this._keys, key)) {
				const _key = this._keys[key]
				if (_key === 'pressed') this._keys[key] = 'down'
				if (_key === 'released') this._keys[key] = 'up'
			}
		}
	}
}

const keyboard = new Keyboard(['a', 'd', 'w'])


window.addEventListener('keydown', (e) => {
	keyboard.onPress(e.key)
})
window.addEventListener('keyup', (e) => {
	keyboard.onRelease(e.key)
})