Instance Property


The phase of a gesture event, such as a magnify, scroll, or pressure change.


var phase: NSEvent.Phase { get }


A gesture phase corresponds to a fluid gesture event. As a gesture event occurs, its phase begins with began and ends with either ended or cancelled. All the gesture events are sent to the view under the cursor when the began occurred.

Technically, a gesture scroll event starts with a began phase and ends with a ended. However, when the user puts two fingers down on a trackpad, the trackpad issues mayBegin, followed by began, cancelled, or ended. The mayBegin event phase signals that scrolling is about to begin before the gesture has technically started. A Magic Mouse does not issue mayBegin scroll wheel events.

A pressure event (type NSEvent.EventType.pressure) is a fluid gesture. Like the other fluid gesture events, it has a phase that describes the sequence of the pressure gesture stream.

Legacy scroll wheel events (say from a Mighty Mouse) and momentum scroll wheel events both have a phase of none. (Legacy scroll wheel events also have a momentumPhase of none.) To learn more about scroll wheel events, see Handling Trackpad Events.

See NSEvent.Phase for possible values.

See Also

Scroll Wheel and Flick Events

var hasPreciseScrollingDeltas: Bool

A Boolean value that indicates whether precise scrolling deltas are available.

var scrollingDeltaX: CGFloat

The scroll wheel’s horizontal delta.

var scrollingDeltaY: CGFloat

The scroll wheel’s vertical delta.

var momentumPhase: NSEvent.Phase

The momentum phase for a scroll or flick gesture.

struct NSEvent.Phase

Constants that represent the possible phases during an event phase.

struct NSEvent.SwipeTrackingOptions

Constants that specify swipe-tracking options.

var isDirectionInvertedFromDevice: Bool

A Boolean value that indicates whether the user has changed the device inversion.