A LiveData class that has null value.

The implementation of the Google Vision api is not that hard, but there are a few fixes you’ll need to make your app production ready. Most importantly: the default implementation does not support autofocus which makes it very hard to scan a barcode.

If you’re going to add a custom camera to your app, use these snippets to do it right. This recipe uses the Camera2 APIs, and hides all the weird code required for setting up a viewfinder and taking pictures.

Adds several features over the regular AndroidJUnitRunner:

A replacement for the mediator LiveData for triggering LiveData transformations.

A class that is using the “normal” shared preferences for any device with an sdk < M and the EncryptedSharedPreferences for M and above.

This recipe is outdated! We’ll keep it for now, because it might be useful when maintaining old apps, but the new prefered way is to use a FragmentContainerView instead.

Gets the MD5, SHA1 and SHA256 of a keystore. You’ll need this for many signin solutions, such as Google SignIn, Facebook, Twitter, etc.

All the methods below need the location permission:

Tiny snippet for reducing compatibility clutter.

The snippets below can lock access to the app whenever the user leaves the app and comes back, with an optional timeout.

Use LiveData to determine the status of any permission (in the sample code below: the location permission). If the user grants the permission at any point, then we will get notified.

Start the App Settings Activity so that the user can change settings related to the application, such as permissions.

A very complete recipe that implements a RecyclerView that pulls in paginated data, using Retrofit, LiveData. It includes example models, adapter, viewholders, and a viewholder for displaying the network state in case of an error.

Common type converters for the Room library.

Simple snippet for showing a notification. Tweak where needed.

It’s date formatting string time! This is the table you need for all simple date formatting in Java/Kotlin.

Detect when the keyboard is visible and when not.

Add a file file_paths.xml to the resources directory res/xml/ in order to grant access to the correct folders:

This recipe creates a “time ago” string from any timestamp, often used to display how long ago a comment was posted or a notification was received. We’re creating an extension method, so any Long timestamp can be converted like so: 12313131.timeAgo(arr) where arr is a list of labels. This list can be retrieved from a string-array in the strings.xml to make it localizable.

Copying and pasting from and to the system clipboard. Assuming text and/or html content.

For haptic feedback on button touches: