pango:layout-justify (layout)

layout -- a pango:layout object
justify -- a boolean whether the lines in the Pango layout should be justified

The pango:layout-justify function gets whether each complete line should be stretched to fill the entire width of the Pango layout. The (setf pango:layout-justify) function sets the justify. This stretching is typically done by adding whitespace, but for some scripts (such as Arabic), the justification may be done in more complex ways, like extending the characters.