Instance Property

queryElementValue

Obtains the current value of an element.

Declaration

IOReturn (*queryElementValue)(void *self, IOHIDElementCookie elementCookie, IOHIDEventStruct *valueEvent, uint32_t timeoutMS, IOHIDElementCallbackFunction callback, void *callbackTarget, void *callbackRefcon);

Parameters

elementCookie

The element of interest.

valueEvent

The event that will be filled. If a long value is present, it is up to the caller to deallocate it.

timeoutMS

UNSUPPORTED.

callback

UNSUPPORTED.

callbackTarget

UNSUPPORTED.

callbackRefcon

UNSUPPORTED.

Return Value

Returns an IOReturn code.

Discussion

This call is most useful for feature type elements. This method will poll the device for the current element value.

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

Learn more about using Apple's beta software