takusemba/spotlight

Spotlight is an Android library that helps app developers create onboarding tutorials or guided walkthroughs by highlighting specific parts of the screen. When you open an app for the first time and a dark overlay appears with a glowing circle pointing at a button to explain what it does, that kind of effect is what Spotlight produces. The library handles the animation, the overlay, and the step-by-step progression so the developer does not have to build it from scratch. To use it in an Android app, you add the library as a dependency and then define a series of targets, where each target is a specific spot on the screen you want to draw attention to. You position each target by coordinates or by anchoring it to an existing view, choose a shape for the spotlight ring (a circle or rounded rectangle are provided, or you can draw a custom shape), and optionally add a ripple or flicker visual effect around the highlighted area. You can also attach an overlay layout to each target to display explanatory text or illustrations next to the spotlight. Once you build the sequence of targets, you start the spotlight and step through them with next, previous, or jump-to-index calls. Callbacks let you run code when a spotlight starts or ends, which is useful for animating explanatory labels in sync with the highlight. The library works on Android API 14 and above, is written in Kotlin, and is released under the Apache 2.0 license, meaning it can be used freely in both personal and commercial projects. The repository includes a sample app module that demonstrates the features in a working app.