/** @brief The two groups where the children could be packed: the start-group and the end-group */typedef enum Etk_Box_Group{ ETK_BOX_START, /**< The start-group of children: the children in this group are displayed * at the start (left or top) of the box */ ETK_BOX_END, /**< The end-group of children: the children in this group are displayed * at the end (right or bottom) of the box */} Etk_Box_Group;/** @brief Describes how a child of the box expands and fills the space */typedef enum Etk_Box_Fill_Policy{ ETK_BOX_NONE = 1 << 0, /**< The child does not fill or expand */ ETK_BOX_EXPAND = 1 << 1, /**< The child will fill all the available space in its cell */ ETK_BOX_FILL = 1 << 2, /**< The cell containing the child will expand to take all the available space */}