Interface DragSurface.ComputeSizeCallback

All Superinterfaces:
FunctionPointer
Enclosing interface:
DragSurface
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 DragSurface.ComputeSizeCallback extends FunctionPointer

Functional interface declaration of the ComputeSizeCallback callback.

See Also:

  • Method Details

    • run

      void run(@Nullable DragSurfaceSize size)

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

      This signal will normally be emitted during the native surface layout cycle when the surface size needs to be recomputed.

      It is the responsibility of the drag surface user to handle this signal and compute the desired size of the surface, storing the computed size in the Gdk.DragSurfaceSize object that is passed to the signal handler, using DragSurfaceSize.setSize(int, int).

      Failing to set a size so will result in an arbitrary size being used as a result.

      Since:
      4.12

    • upcall

      default void upcall(MemorySegment sourceDragSurface, MemorySegment size)
      The upcall method is called from native code. The parameters are marshaled and run(DragSurfaceSize) is executed.

    • toCallback

      default MemorySegment toCallback(Arena arena)
      Creates a native function pointer to the upcall(MemorySegment, MemorySegment) method.
      Specified by:
      toCallback in interface FunctionPointer
      Parameters:
      arena - the arena in which the function pointer is allocated
      Returns:
      the native function pointer