The lock() method of the Keyboard interface returns a Promise after enabling the capture of keypresses for any or all of the keys on the physical keyboard. This method can only capture keys that are granted access by the underlying operating system.

keyCodes Optional

An Array of one or more key codes to lock. If no keycodes are provided all keys will be locked. A list of valid code values is found in the UI Events KeyboardEvent code Values spec.

A Promise.

Transient user activation is required. The user has to interact with the page or a UI element in order for this feature to work.

The following example captures all keypresses.

navigator.keyboard.lock();

The following example captures the "W", "A", "S", and "D" keys. It captures these keys regardless of which modifiers are used with the key press. Assuming a standard US QWERTY layout, registering "KeyW" ensures that "W", Shift+"W", Control+"W", Control+Shift+"W", and all other key modifier combinations with "W" are sent to the app. The same applies to for "KeyA", "KeyS" and "KeyD".

navigator.keyboard.lock(["KeyW", "KeyA", "KeyS", "KeyD"]);