Package org.gnome.gdk

Interface Toplevel.ComputeSizeCallback

All Superinterfaces:

FunctionPointer

Enclosing interface:

Toplevel

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 Toplevel.ComputeSizeCallback
extends FunctionPointer

Functional interface declaration of the ComputeSizeCallback callback.

See Also:

• run(org.gnome.gdk.ToplevelSize)

Method Summary

Modifier and Type	Method	Description
void	run(@Nullable ToplevelSize size)	Emitted when the size for the surface needs to be computed, when it is present.
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 sourceToplevel, MemorySegment size)	The upcall method is called from native code.

Method Details

run

void run(@Nullable ToplevelSize size)

Emitted when the size for the surface needs to be computed, when it is present.

This signal will normally be emitted during or after a call to Toplevel.present(org.gnome.gdk.ToplevelLayout), depending on the configuration received by the windowing system. It may also be emitted at any other point in time, in response to the windowing system spontaneously changing the configuration of the toplevel surface.

It is the responsibility of the toplevel user to handle this signal and compute the desired size of the toplevel, given the information passed via the Gdk.ToplevelSize object. Failing to do so will result in an arbitrary size being used as a result.

upcall

default void upcall(MemorySegment sourceToplevel,
 MemorySegment size)

The upcall method is called from native code. The parameters are marshaled and run(org.gnome.gdk.ToplevelSize) 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 arena in which the function pointer is allocated

Returns:

the native function pointer