NEW: Learn SwiftUI with my free YouTube video series! >>

How to detect low power mode is enabled

Swift version: 5.0

Paul Hudson    @twostraws   

When a user has enabled low-power mode you probably want to avoid doing CPU-intensive work: not only is the system less able to give you resources, but you always want to respect the user's wishes and help their battery last as long as possible.

There are two ways of checking for low-power mode: you can read a property whenever you need it, or register for a notification. First, here's an example with the property:

func doComplicatedWork() {
    guard ProcessInfo.processInfo.isLowPowerModeEnabled == false else { return }

    // continue doing complicated work here
}

You can also register to be notified when the lower power mode state changes, like this:

NotificationCenter.default.addObserver(self, selector: #selector(powerStateChanged), name: Notification.Name.NSProcessInfoPowerStateDidChange, object: nil)

When that method is triggered, you can check the new value of isLowPowerModeEnabled to see what state the device is in:

@objc func powerStateChanged(_ notification: Notification) {
    let lowerPowerEnabled = ProcessInfo.processInfo.isLowPowerModeEnabled
    // take appropriate action
}

SPONSOR Meet the new Instabug – more than just bug reporting! We help you build better apps and minimize your debugging time. With each bug report, we automatically capture details like network requests, repro steps, and session details. Get real-time crash reports with stack trace details and session data to help you catch and fix issues easily. And with our customizable in-app surveys, you’ll gather insightful user feedback and much more. Instabug is the fastest and easiest way to release with confidence. Start your free trial now! Start your free trial now!

Available from iOS 9.0

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

MASTER SWIFT NOW
Buy Testing Swift Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Average rating: 3.7/5

Click here to visit the Hacking with Swift store >>