Reference Manual - 0.9.25
IDirectFBDisplayLayer   GetLevel

Get the current display layer level.

GetLevel (
  IDirectFBDisplayLayer   * thiz,
  int   * ret_level
);

The level describes the z axis position of a layer. The primary layer is always on level zero unless a special driver adds support for level adjustment on the primary layer. Layers above have a positive level, e.g. video overlays. Layers below have a negative level, e.g. video underlays or background layers.