Keyboard: lock() method

{{APIRef("Keyboard API")}} {{SeeCompatTable}} {{securecontext_header}} 

The lock() method of the {{domxref("Keyboard")}}  interface returns a {{jsxref('Promise')}}  that resolves 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.

If lock() is called multiple times then only the key codes specified in the most recent call will be locked. Any keys locked by a previous call to lock() are unlocked.

Syntax

lock()
lock(keyCodes)

Parameters

• keyCodes {{optional_inline}} 
  • : An {{jsxref('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.

Return value

A {{jsxref('Promise')}}  that resolves with {{jsxref('undefined')}}  when the lock was successful.

Exceptions

• AbortError {{domxref("DOMException")}} 
  • : Thrown if a new call to lock() is made before the current one has finished.
• InvalidAccessError {{domxref("DOMException")}} 
  • : Thrown if any key in keyCodes is not a valid key code attribute value.
• InvalidStateError {{domxref("DOMException")}} 
  • : Thrown if lock() is not called in an active top-level browsing context.

Security

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

Examples

Capturing all keys

The following example captures all keypresses.

navigator.keyboard.lock();

Capturing specific keys

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"]);

Specifications

{{Specifications}} 

Browser compatibility

{{Compat}}