What Makes a Complete Specification
How do you know when you are done with your layout? For auto layout to unambiguously position all the views in an interface, it needs to find an origin and size for every view. To do that, every view must be part of one or more relationships that specify four constraints: two for the system to calculate the horizontal position and size, and two for the vertical position and size.
As you saw earlier in this chapter, constraints can be built using many parts of the view geometry. Table 4-1 shows what constraints unambiguously specify the Total Cars label. The completeness table is another example of an excellent tool for design. You can create tables like this for any level in the view hierarchy of a scene. Although ...
Get Learning iOS Development: A Hands-on Guide to the Fundamentals of iOS Programming now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
