The 'maxsize' property

Two-element numeric vector

Valid for: All displayable controls, but usually used for window-level objects (Form, Dialog, Document, Window). Under MacOS, valid only for window-level objects.

When you create a resizable window, you may want to limit the maximum size to which the user can enlarge it. The maxsize property allows you to define the upper limit. The first element is the maximum height, and the second is the maximum width, in the current scale of the object. A value of 0 means no constraint.

See also the minsize property.