Learning Swift, 2nd Edition

Chapter 12. Supporting the iOS Ecosystem

In this chapter, we’ll add support for sharing, handoffs (so users can resume what they’re doing on other iOS devices or in the macOS app), and search (so the iOS search system can be used to find text within note documents). All three of these features help to integrate your app into the wider context of the user’s phone, which means that your app is no longer an island.

Sharing with UIActivityController

We’ll start by adding sharing support to the image attachment view controller, as shown in Figure 12-1.

Figure 12-1. The standard iOS share sheet

Sharing on iOS is handled by UIActivityViewController, which provides a standard view controller offering system services, such as copy and paste, as well as sharing to social media, email, or text messaging. Other apps can also provide share destinations.

1. Open Main.storyboard and go to the image attachment view controller.

2. Add a UIToolBar from the Object library to the view and place it at the bottom of the screen. This will also include a UIBarButtonItem, which works pretty much exactly like our old friend UIButton, but is customized to work in toolbars.

3. Resize the toolbar to make it fit the width of the screen. Next, click the Pin menu, and pin the left, right, and bottom edges of the view. This will keep it at the bottom of the screen and make it always fill the width of the screen. ...