shrink
Shrinks (or grows) the given rectangle by moving the 4 sides according to the offsets given.
The corner radii will be changed in a way that tries to keep the center of the corner circle intact. This emulates CSS behavior.
This function also works for growing rectangles if you pass negative values for the @top, @right, @bottom or @left.
Return
the resized GskRoundedRect
Parameters
top
How far to move the top side downwards
right
How far to move the right side to the left
bottom
How far to move the bottom side upwards
left
How far to move the left side to the right