gtk:label-angle (object)

object -- a gtk:label widget
angle -- a number coerced to a double float for the angle that the baseline of the label makes with the horizontal, in degrees, measured counterclockwise

The accessor for the angle slot gets or sets the angle of rotation for the label. An angle of 90 degrees reads from from bottom to top, an angle of 270 degrees, from top to bottom. The angle setting for the label is ignored if the label is selectable, wrapped, or ellipsized.