Defines a set of edges for the anchor rectangle. These are used to
derive an anchor point that the child surface will be positioned
relative to. If two orthogonal edges are specified (e.g. 'top' and
'left'), then the anchor point will be the intersection of the edges
(e.g. the top left position of the rectangle); otherwise, the derived
anchor point will be centered on the specified edge, or in the center of
the anchor rectangle if no edge is specified.
If two parallel anchor edges are specified (e.g. 'left' and 'right'),
the invalid_input error is raised.
set anchor rectangle anchor edges
Defines a set of edges for the anchor rectangle. These are used to derive an anchor point that the child surface will be positioned relative to. If two orthogonal edges are specified (e.g. 'top' and 'left'), then the anchor point will be the intersection of the edges (e.g. the top left position of the rectangle); otherwise, the derived anchor point will be centered on the specified edge, or in the center of the anchor rectangle if no edge is specified.
If two parallel anchor edges are specified (e.g. 'left' and 'right'), the invalid_input error is raised.