Interface MenuModel.ItemsChangedCallback

All Superinterfaces:
FunctionPointer
Enclosing class:
MenuModel
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 MenuModel.ItemsChangedCallback extends FunctionPointer

Functional interface declaration of the ItemsChangedCallback callback.

Since:
2.32
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    run(int position, int removed, int added)
    Emitted when a change has occurred to the menu.
    default MemorySegment
    toCallback(Arena arena)
    Creates a native function pointer to the upcall(MemorySegment, int, int, int) method.
    default void
    upcall(MemorySegment sourceMenuModel, int position, int removed, int added)
    The upcall method is called from native code.

  • Method Details

    • run

      void run(int position, int removed, int added)

      Emitted when a change has occurred to the menu.

      The only changes that can occur to a menu is that items are removed or added. Items may not change (except by being removed and added back in the same location). This signal is capable of describing both of those changes (at the same time).

      The signal means that starting at the index position, removed items were removed and added items were added in their place. If removed is zero then only items were added. If added is zero then only items were removed.

      As an example, if the menu contains items a, b, c, d (in that order) and the signal (2, 1, 3) occurs then the new composition of the menu will be a, b, \, \, \_, d (with each _ representing some new item).

      Signal handlers may query the model (particularly the added items) and expect to see the results of the modification that is being reported. The signal is emitted after the modification.

    • upcall

      default void upcall(MemorySegment sourceMenuModel, int position, int removed, int added)
      The upcall method is called from native code. The parameters are marshaled and run(int, int, int) is executed.

    • toCallback

      default MemorySegment toCallback(Arena arena)
      Creates a native function pointer to the upcall(MemorySegment, int, 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