WeakNotify (java-gi API)

All Superinterfaces:: FunctionPointer

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

@FunctionalInterface @Generated("io.github.jwharm.JavaGI") public interface WeakNotify extends FunctionPointer

Functional interface declaration of the WeakNotify callback.

See Also:

Method Summary

Modifier and Type

Method

Description

void

run(@Nullable MemorySegment data, GObject whereTheObjectWas)

A GWeakNotify function can be added to an object as a callback that gets triggered when the object is finalized.

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 data, MemorySegment whereTheObjectWas)

The upcall method is called from native code.

Method Details
- run
  
  void run(@Nullable @Nullable MemorySegment data, GObject whereTheObjectWas)
  
  A GWeakNotify function can be added to an object as a callback that gets triggered when the object is finalized.
  Since the object is already being disposed when the GWeakNotify is called, there's not much you could do with the object, apart from e.g. using its address as hash-index or the like.
  In particular, this means it’s invalid to call g_object_ref(), g_weak_ref_init(), g_weak_ref_set(), g_object_add_toggle_ref(), g_object_weak_ref(), g_object_add_weak_pointer() or any function which calls them on the object from this callback.
- upcall
  
  default void upcall(MemorySegment data, MemorySegment whereTheObjectWas)
  
  The upcall method is called from native code. The parameters are marshaled and run(java.lang.foreign.MemorySegment, org.gnome.gobject.GObject) 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