PatrickJahr.Blazor.ScreenWakeLock 1.0.0

PatrickJahr.Blazor.ScreenWakeLock

Introduction

A Blazor wrapper for the Screen Wake Lock API.

The Screen Wake Lock API allows web applications to request a screen wake lock. Under the right conditions, and if allowed, the screen wake lock prevents the system from turning off a device's screen.

Getting started

Prerequisites

You need .NET 7.0 or newer to use this library.

Download .NET 7 Download .NET 8

Platform support

Installation

You can install the package via NuGet with the Package Manager in your IDE or alternatively using the command line:

dotnet add package PatrickJahr.Blazor.ScreenWakeLock

Usage

The package can be used in Blazor WebAssembly projects.

Add to service collection

To make the ScreenWakeLockService available on all pages, register it at the IServiceCollection in Program.cs before the host is built:

builder.Services.AddScreenWakeLockService();

Checking for browser support

Before using the Screen Wake Lock API, you should first test if the API is supported on the target platform by calling the IsSupportedAsync() method. This method returns a boolean to indicate whether the Screen Wake Lock API is supported or not.

var isSupported = await screenWakeLock.IsSupportedAsync();
if (isSupported)
{
    // enable screen wake lock feature
}
else
{
    // use fallback mechanism or hide/disable feature
}

Request screen wake lock

To request a screen wake lock, you need to call the RequestWakeLockAsync() method from the IScreenWakeLockService service. The browser can refuse the request for various reasons (for example, because the battery charge level is too low), so it's a good practice to wrap the call in a try…catch statement. The exception's message will contain more details in case of failure.

try
{
    await _screenWakeLockService.RequestWakeLockAsync();
}
catch(Exception e)
{
    // Handle exxception
}

Release screen wake lock

You also need a way to release the screen wake lock, which is achieved by calling the ReleaseWakeLockAsync() method of the IScreenWakeLockService service.

await _screenWakeLockService.ReleaseWakeLockAsync();

As soon as the object was released the action WakeLockReleased will be fired.

protected override async Task OnInitializedAsync()
{
    //...

    _screenWakeLockService.WakeLockReleased = () =>
    {
       _wakeLockRequested = false;
    };

    //...
    await base.OnInitializedAsync();
}

Related articles

• Documentation on MDN
• Blog post on web.dev
• Browser support on caniuse.com

Acknowledgements

Thanks to Kristoffer Strube who provides a Blazor wrapper for the File System Access API. This library is inspired by Kristoffer's implementation and project setup.

License and Note

BSD-3-Clause.

This is a technical showcase, not an official PatrickJahr product.