Xojo.Core.Rect.Inset
From Xojo Documentation
Method
Xojo.Core.Rect.Inset(deltaX As Double, deltaY As Double) As Xojo.Core.Rect
Supported for all project types and targets.
Supported for all project types and targets.
Returns a new rect with the same center, but each side inset by the given amount. Specify a negative value to grow the rectangle.