The phase of a gesture event, such as a magnify, scroll, or pressure change.
SDK
- macOS 10.7+
Framework
- App
Kit
Declaration
Discussion
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 may
, followed by began
, cancelled
, or ended
. The may
event phase signals that scrolling is about to begin before the gesture has technically started. A Magic Mouse does not issue may
scroll wheel events.
A pressure event (type NSEvent
) 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 momentum
of none
.) To learn more about scroll wheel events, see Handling Trackpad Events.
See NSEvent
for possible values.