Interface DrawingArea.ResizeCallback

All Superinterfaces:

FunctionPointer

Enclosing class:

DrawingArea

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 DrawingArea.ResizeCallback
extends FunctionPointer

Functional interface declaration of the ResizeCallback callback.

See Also:

• run(int, int)

Method Summary

Modifier and Type	Method	Description
void	run(int width, int height)	Emitted once when the widget is realized, and then each time the widget is changed while realized.
default MemorySegment	toCallback(Arena arena)	Creates a native function pointer to the upcall(MemorySegment, int, int) method.
default void	upcall(MemorySegment sourceDrawingArea, int width, int height)	The upcall method is called from native code.

Method Details

run

void run(int width,
 int height)

Emitted once when the widget is realized, and then each time the widget is changed while realized.

This is useful in order to keep state up to date with the widget size, like for instance a backing surface.

upcall

default void upcall(MemorySegment sourceDrawingArea,
 int width,
 int height)

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

toCallback

default MemorySegment toCallback(Arena arena)

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

Specified by:

toCallback in interface FunctionPointer

Parameters:

arena - the arena in which the function pointer is allocated

Returns:

the native function pointer