generic function calculates the minimum and maximum size of a pane.
A CAPI pane or layout.
The generic function calculate-constraints calculates the minimum and maximum size for
according to the sizes of its children, and sets these values into
's geometry cache.
The CAPI calls calculate-constraints for each pane and layout that it displays.
When creating your own layout, you should define a method for
that sets the values of the following geometry slots based on the constraints of its children.
The minimum width of pane.
The maximum width of pane.
The minimum height of pane.
The maximum height of pane.
The constraints of any CAPI element can be found by calling get-constraints.
LispWorks CAPI Reference Manual - 17 Mar 2008