The calculate-constraints generic function calculates the minimum and maximum size of a pane.
This generic function calculates the minimum and maximum size for pane according to the sizes of its children, and sets these values into pane 's geometry cache.
When creating your own layout, you should define a method for calculate-constraints 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 .