Interface DropTargetAsync.DropCallback

All Superinterfaces:

FunctionPointer

Enclosing class:

DropTargetAsync

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 DropTargetAsync.DropCallback
extends FunctionPointer

Functional interface declaration of the DropCallback callback.

See Also:

• run(Drop, double, double)

Method Summary

Modifier and Type	Method	Description
boolean	run(@Nullable Drop drop, double x, double y)	Emitted on the drop site when the user drops the data onto the widget.
default MemorySegment	toCallback(Arena arena)	Creates a native function pointer to the upcall(MemorySegment, MemorySegment, double, double) method.
default int	upcall(MemorySegment sourceDropTargetAsync, MemorySegment drop, double x, double y)	The upcall method is called from native code.

Method Details

run

boolean run(@Nullable Drop drop,
 double x,
 double y)

Emitted on the drop site when the user drops the data onto the widget.

The signal handler must determine whether the pointer position is in a drop zone or not. If it is not in a drop zone, it returns false and no further processing is necessary.

Otherwise, the handler returns true. In this case, this handler will accept the drop. The handler must ensure that Drop#finish is called to let the source know that the drop is done. The call to Drop#finish must only be done when all data has been received.

To receive the data, use one of the read functions provided by Drop such as Drop#readAsync or Drop#readValueAsync.

upcall

default int upcall(MemorySegment sourceDropTargetAsync,
 MemorySegment drop,
 double x,
 double y)

The upcall method is called from native code. The parameters are marshaled and run(Drop, double, double) is executed.

toCallback

default MemorySegment toCallback(Arena arena)

Creates a native function pointer to the upcall(MemorySegment, MemorySegment, double, double) method.

Specified by:

toCallback in interface FunctionPointer

Parameters:

arena - the arena in which the function pointer is allocated

Returns:

the native function pointer