Package org.gnome.gtk

Interface Gesture.BeginCallback

All Superinterfaces:

FunctionPointer

Enclosing class:

Gesture

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public static interface Gesture.BeginCallback
extends FunctionPointer

Functional interface declaration of the BeginCallback callback.

See Also:

• run(org.gnome.gdk.EventSequence)

Method Summary

Modifier and Type	Method	Description
void	run(@Nullable EventSequence sequence)	Emitted when the gesture is recognized.
default MemorySegment	toCallback(Arena arena)	Creates a native function pointer to the upcall(java.lang.foreign.MemorySegment, java.lang.foreign.MemorySegment) method.
default void	upcall(MemorySegment sourceGesture, MemorySegment sequence)	The upcall method is called from native code.

Method Details

run

void run(@Nullable
 @Nullable EventSequence sequence)

Emitted when the gesture is recognized.

This means the number of touch sequences matches Gtk.Gesture:n-points.

Note: These conditions may also happen when an extra touch (eg. a third touch on a 2-touches gesture) is lifted, in that situation sequence won't pertain to the current set of active touches, so don't rely on this being true.

upcall

default void upcall(MemorySegment sourceGesture,
 MemorySegment sequence)

The upcall method is called from native code. The parameters are marshaled and run(org.gnome.gdk.EventSequence) is executed.

toCallback

default MemorySegment toCallback(Arena arena)

Creates a native function pointer to the upcall(java.lang.foreign.MemorySegment, java.lang.foreign.MemorySegment) method.

Specified by:

toCallback in interface FunctionPointer

Parameters:

arena - the function pointer will be allocated in this arena

Returns:

the native function pointer