iOS Programming: The Big Nerd Ranch Guide, 6th Edition

Views and Frames

When you initialize a view programmatically, you use its init(frame:) designated initializer. This method takes one argument, a CGRect, that will become the view’s frame, a property on UIView.

var frame: CGRect

A view’s frame specifies the view’s size and its position relative to its superview. Because a view’s size is always specified by its frame, a view is always a rectangle.

A CGRect contains the members origin and size. The origin is a structure of type CGPoint and contains two CGFloat properties: x and y. The size is a structure of type CGSize and has two CGFloat properties: width and height (Figure 3.5).

Figure 3.5  CGRect

The CGRect diagram shows the position of a target object. The origin ...