Recognizes two-finger pinch and spread gestures by listening to touch events from an ITouchInput source. Raises PinchUpdated each time the distance between the two active contact points changes, providing a relative scale delta. More...

Inheritance diagram for Gondwana.Input.Touch.Gestures.PinchGestureRecognizer:

Public Member Functions
	PinchGestureRecognizer (ITouchInput touchInput)
	Initializes a new instance of the PinchGestureRecognizer class, subscribing to touch events from the specified ITouchInput source.
void	Dispose ()
	Releases all resources held by this recognizer and unsubscribes from the touch input source. After disposal, no further PinchUpdated events will be raised.

Events
EventHandler< PinchedEventArgs >?	PinchStarted
	Occurs when exactly two contacts establish a pinch gesture.
EventHandler< PinchedEventArgs >?	PinchUpdated
	Occurs whenever the distance between two active touch contact points changes during a pinch or spread gesture. The event data includes the relative scale delta and current distance.
EventHandler< PinchedEventArgs >?	PinchEnded
	Occurs when the current two-contact pinch ends or is interrupted.

Detailed Description

Recognizes two-finger pinch and spread gestures by listening to touch events from an ITouchInput source. Raises PinchUpdated each time the distance between the two active contact points changes, providing a relative scale delta.

Subscribe to the PinchUpdated event to receive incremental scale updates as the user moves two fingers together or apart. A PinchedEventArgs.ScaleDelta greater than 1.0 means the fingers spread apart (expand), while a value less than 1.0 means they moved closer (contract).

All simultaneous contacts are tracked. Pinch updates are emitted only when exactly two contacts are active. If a third finger lands while two are tracked, updates pause until one lifts and exactly two remain — at which point the baseline distance is recomputed so there is no jump.

Definition at line 23 of file PinchGestureRecognizer.cs.

Constructor & Destructor Documentation

◆ PinchGestureRecognizer()

Gondwana.Input.Touch.Gestures.PinchGestureRecognizer.PinchGestureRecognizer ( ITouchInput touchInput )

Initializes a new instance of the PinchGestureRecognizer class, subscribing to touch events from the specified ITouchInput source.

Parameters

touchInput The touch input source to monitor for pinch gestures. Must not be null.

Exceptions

ArgumentNullException Thrown when touchInput is null.

Definition at line 53 of file PinchGestureRecognizer.cs.

Member Function Documentation

◆ Dispose()

void Gondwana.Input.Touch.Gestures.PinchGestureRecognizer.Dispose ( )

Releases all resources held by this recognizer and unsubscribes from the touch input source. After disposal, no further PinchUpdated events will be raised.

Definition at line 178 of file PinchGestureRecognizer.cs.

Event Documentation

◆ PinchEnded

EventHandler<PinchedEventArgs>? Gondwana.Input.Touch.Gestures.PinchGestureRecognizer.PinchEnded

Occurs when the current two-contact pinch ends or is interrupted.

Definition at line 41 of file PinchGestureRecognizer.cs.

◆ PinchStarted

EventHandler<PinchedEventArgs>? Gondwana.Input.Touch.Gestures.PinchGestureRecognizer.PinchStarted

Occurs when exactly two contacts establish a pinch gesture.

Definition at line 32 of file PinchGestureRecognizer.cs.

◆ PinchUpdated

EventHandler<PinchedEventArgs>? Gondwana.Input.Touch.Gestures.PinchGestureRecognizer.PinchUpdated

Occurs whenever the distance between two active touch contact points changes during a pinch or spread gesture. The event data includes the relative scale delta and current distance.

Definition at line 38 of file PinchGestureRecognizer.cs.

Public Member Functions

Events