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# dispatchRelativeScrollWheelEvent

Dispatches a relative scroll wheel event to the system.

```
virtual kern_return_t dispatchRelativeScrollWheelEvent(uint64_t timeStamp, IOFixed dx, IOFixed dy, IOFixed dz, IOOptionBits options, bool accelerate);
```

## Parameters

`timeStamp`

The timestamp of the event. Use the timestamp of the report element that is the source of the event.

`dx`

The delta X value.

`dy`

The delta Y value.

`dz`

The delta Z value.

`options`

Additional options for scrolling-related events. Specify `0` for no options. For a list of other values, see [`IOHIDScrollEventOptions`](/documentation/HIDDriverKit/IOHIDScrollEventOptions).

`accelerate`

Scroll events are subject to an acceleration algorithm. Pass in `false` if you don’t wish to have acceleration logic applied to the scroll event.

## Return Value

<doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess> on success, or another value if an error occurs. See <doc://com.apple.documentation/documentation/DriverKit/error-codes>.

## Discussion

Call this method from your event service to dispatch a scroll-wheel event to the system. Typically, you call this method when handling a report from the device, after you determine that the report originated from scroll-wheel hardware or otherwise represents a scrolling event.

---

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