Book Image

Swift Essentials - Second Edition

By : Alex Blewitt
Book Image

Swift Essentials - Second Edition

By: Alex Blewitt

Overview of this book

Swift was considered one of the biggest innovations last year, and certainly with Swift 2 announced at WWDC in 2015, this segment of the developer space will continue to be hot and dominating. This is a fast-paced guide to provide an overview of Swift programming and then walks you through in detail how to write iOS applications. Progress through chapters on custom views, networking, parsing and build a complete application as a Git repository, all by using Swift as the core language
Table of Contents (17 chapters)
Swift Essentials Second Edition
About the Author
About the Reviewer

Using Auto Layout

Auto Layout has been part of Xcode for the last few releases, and it was added to support an evolution from the previous springs-and-struts approach that predated Mac OS X. First released on iOS 6.0, it has evolved to the point where size-independent displays can now be created as the default.

Understanding constraints

In Xcode 5, interface builder enabled Auto Layout by default for the first time. When a label was dragged to the top or bottom of the parent view, a dotted blue line would indicate that the label was correctly spaced, and a constraint would be generated.

However, in many cases, the constraints weren't created correctly or had undesired effects. For example, positioning a button in the center at the top may not maintain the location depending on whether the constraint being added was absolute (200px from the right) or relative (in the center of the screen). In both cases, the button may look like it was positioned correctly, only to fail when the device's screen...