Rectangle class seems kind of useless since it does not define many attributes or methods itself. However, objects of this type are frequently used in every application. They allow insertion of space to control MUI's layout process.
You can use the attributes of the super class to control the size and other attributes of the rectangle. E.g. you can use Area.FixWidth and Area.FixHeight to create rectangles of a fixed size.
Rectangle objects are also often necessary as padding
space next to objects which are not resizable themselves.
<label> object is e.g. not resizable. To
prevent these static label objects from blocking the
resizing feature of your whole GUI, you can simply pad
them with a
<rectangle> object. Here is an
example of a label next to a checkmark object, padded
using an invisible rectangle:
<hgroup> <label>Enable hardware acceleration</label> <checkmark/> <rectangle/> </hgroup>