Class

WKInterfaceDevice

An object that provides information about the user’s Apple Watch.

Overview

You can use the information from WKInterfaceDevice to make decisions about the content you display in your app. You can also use this object to play haptic feedback when your app is active.

Do not subclass or create instances of this class yourself. Always call the current() class method to get the shared device object.

Topics

Getting the Shared Device Object

class func current()

Returns the shared device object.

Getting the Screen Information

var screenBounds: CGRect

The bounding rectangle of the screen.

var screenScale: CGFloat

The number of pixels per point for the current screen.

Getting the Device Settings

var name: String

The name assigned to the underlying device.

var model: String

The model information for the device.

var localizedModel: String

The localized version of the model information.

var wristLocation: WKInterfaceDeviceWristLocation

The wrist on which the user wears the Apple Watch.

enum WKInterfaceDeviceWristLocation

Constants indicating the wrist on which the user wears the Apple Watch.

var crownOrientation: WKInterfaceDeviceCrownOrientation

The side on which the crown is positioned.

enum WKInterfaceDeviceCrownOrientation

Constants indicating the crown orientation from the user’s perspective.

var preferredContentSizeCategory: String

The preferred font-sizing option.

Getting the System Information

var systemName: String

The name of the operating system.

var systemVersion: String

The version of the operating system.

Getting the Layout Direction

var layoutDirection: WKInterfaceLayoutDirection

The layout direction of the user interface.

class func interfaceLayoutDirection(for: WKInterfaceSemanticContentAttribute)

Returns the user interface direction for the given semantic content attribute.

enum WKInterfaceSemanticContentAttribute

A semantic description of the view’s contents, used to determine whether the view should be flipped when switching between left-to-right and right-to-left layouts.

enum WKInterfaceLayoutDirection

Specifies the directional flow of the user interface.

Accessing Information about the Battery

var isBatteryMonitoringEnabled: Bool

A Boolean value that determines whether the app can monitor the device's battery.

var batteryLevel: Float

The battery's current percent charge.

enum WKInterfaceDeviceBatteryState

The battery's charging state.

Getting the Water Resistance

var waterResistanceRating: WKWaterResistanceRating

The Apple Watch water-resistance rating.

enum WKWaterResistanceRating

The Apple Watch water-resistance rating.

Playing Haptic Feedback

func play(WKHapticType)

Gives haptic feedback to the user.

enum WKHapticType

Constant indicating the style of feedback to deliver using haptics.

watchOS 1 Properties and Methods

var cachedImages: [String : NSNumber]

A dictionary containing the name and size (in bytes) of the cached images.

func addCachedImage(UIImage, name: String)

Caches the image using the provided name.

func addCachedImage(with: Data, name: String)

Caches the image data using the provided name.

func removeAllCachedImages()

Removes all the cached images from the cachedImages dictionary.

func removeCachedImage(withName: String)

Removes the cached image with the specified name.

Relationships

Inherits From

Conforms To

See Also

Extension Architecture

class WKExtension

An object that manages behaviors that are shared among all of your app’s interface controllers.

protocol WKExtensionDelegate

A collection of methods you can implement to manage the app-level behavior of your WatchKit extension.

Keeping Your watchOS App’s Content Up to Date

Ensure that your watchOS app has access to the most recent content available.