WatchKit is a framework provided by

Apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

to develop applications for the

Apple Watch The Apple Watch is a brand of smartwatch products developed and marketed by Apple Inc., Apple. It incorporates activity tracker, fitness tracking, Health (Apple), health-oriented capabilities, and wireless telecommunication, and integrates wit ...

. The WatchKit framework is designed for the Swift programming language and also the Objective-C programming language and must be compiled in

Xcode Xcode is a suite of developer tools for building apps on Apple devices. It includes an integrated development environment (IDE) of the same name for macOS, used to develop software for macOS, iOS, iPadOS, watchOS, tvOS, and visionOS. It w ...

, similar to iOS applications.

History

WatchKit was first released in 2014, one year before the release of the Apple Watch. It was bundled in with the iOS 8.2 beta SDK. In 2015, Apple set up WatchKit labs in several different cities to allow for in-person development of Apple Watch applications before the product's official launch.

Functionality

WatchKit provides classes allows for development of applications on the Apple Watch. WatchKit also enables iOS applications to send notifications and "Glances," which are persistent notifications that are created using predefined templates made by Apple. The framework is designed to be used with either Swift or Objective-C, and must be compiled in Xcode. While it is designed for the Apple Watch, the watch itself only renders the user interface, and an

iPhone The iPhone is a line of smartphones developed and marketed by Apple that run iOS, the company's own mobile operating system. The first-generation iPhone was announced by then–Apple CEO and co-founder Steve Jobs on January 9, 2007, at ...

linked with the watch renders everything else. It also allows for Handoff support with the linked iPhone.

Classes

WatchKit provides some classes for general purposes, as representing controllers, interfaces, and alert actions. Also provides support for file management, through the following classes: And a set of classes that inherit from WKInterfaceObject and represents visual UI elements.

Protocols

WatchKit provides two protocols: WKExtensionDelegate and WKImageAnimatable. WKExtensionDelegate is intended to manage the behavior of the WatchKit extension and WKImageAnimatable controls the playback of animated images.

References

{{technology-stub Swift (programming language) software Objective-C software Software frameworks Apple Inc. software