Introducing Ink API, a brand new Jetpack library for stylus apps

Posted by Chris Assigbe – Developer Relations Engineer and Tom Buckley – Product Supervisor

With stylus enter, Android apps on telephones, foldables, tablets, and Chromebooks grow to be much more highly effective instruments for productiveness and creativity. Whereas there’s already so much to consider when designing for big screens – see our full steerage and inspiration gallery – styluses are particularly impactful, reworking these units right into a digital pocket book or sketchbook. Customers count on stylus experiences to really feel as fluid and pure as writing on paper, which is why Android beforehand added APIs to cut back inking latency to as little as 4ms; just about imperceptible. Nevertheless, latency is only one side of an inking expertise – builders at the moment must generate stroke shapes from stylus enter, render these strokes shortly, and effectively run geometric queries over strokes for instruments like choice and eraser. These capabilities can require important funding in geometry and graphics simply to get began.

In the present day, we’re excited to share Ink API, an alpha Jetpack library that makes it simple to create, render, and manipulate lovely ink strokes, enabling builders to construct superb options on high of those APIs. Ink API builds upon the Android framework’s basis of low latency and prediction, offering you with a strong and intuitive toolkit for integrating wealthy inking options into your apps.

Writing with Ink API on a Samsung Tab S8, 4ms end-to-end latency

What’s Ink API?

Ink API is a complete stylus enter library that empowers you to shortly create revolutionary and expressive inking experiences. It presents a modular structure somewhat than a one-size-fits-all canvas, so you may tailor Ink API to your app’s stack and wishes. The modules embody key functionalities like:

• Strokes module: Represents the ink enter and its visible illustration.
• Geometry module: Helps manipulating and analyzing strokes, facilitating options like erasing, and deciding on strokes.
• Brush module: Supplies a declarative approach to outline the visible fashion of strokes, together with coloration, measurement, and the kind of device to attract with.
• Rendering module: Effectively shows ink strokes on the display screen, permitting them to be mixed with Jetpack Compose or Android Views.
• Stay Authoring module: Handles real-time inking enter to create easy strokes with the bottom latency a tool can present.

Ink API is suitable with units working Android 5.0 (API stage 21) or later, and presents advantages on all of those units. It might additionally benefit from latency enhancements in Android 10 (API 29) and improved rendering results and efficiency in Android 14 (API 34).

Why select Ink API?

Ink API supplies an out-of-the-box implementation for primary inking duties so you may create a novel drawing expertise to your personal app. Ink API presents a number of benefits over a totally customized implementation:

• Ease of Use: Ink API abstracts away the complexities of graphics and geometry, permitting you to focus in your app’s distinctive inking options.
• Efficiency: Constructed-in low latency help and optimized rendering guarantee a easy and responsive inking expertise.
• Flexibility: The modular design means that you can decide and select the parts you want, tailoring the library to your particular necessities.

Ink API has already been adopted throughout many Google apps due to these benefits, together with for markup in Docs and Circle-to-Search; and the underlying know-how additionally powers markup in Pictures, Drive, Meet, Preserve, and Classroom. For Circle to Search, the Ink API modular design empowered the staff to make the most of solely the parts they wanted. They leveraged the stay authoring and brush capabilities of Ink API to render a gorgeous stroke as customers circle (to go looking). The staff additionally constructed customized geometry instruments tailor-made to their ML fashions. That’s modularity at its best.

“Ink API was our first alternative for Circle-to-Search (CtS). Using their intensive documentation, integrating the Ink API was a breeze, permitting us to succeed in our first working prototype w/in only one week. Ink’s customized brush texture and animation help allowed us to shortly iterate on the stroke design.” 

– Jordan Komoda, Software program Engineer, Google

We’ve additionally designed Ink API with our Android app companions’ suggestions in thoughts to ensure it matches with their present app architectures and necessities.

With Ink API, constructing a pure and fluid inking expertise on Android is easier than ever. Ink API enables you to give attention to what differentiates your expertise somewhat than on the main points of paths, meshes, and shaders. Whether or not you might be exploring inking for note-taking, picture or doc markup, interactive studying, or one thing utterly completely different, we hope you’ll give Ink API a attempt!

Get began with Ink API

Able to dive into the effectively of Ink API? Take a look at the official developer information and discover the API reference to begin constructing your next-generation inking app. We’re wanting to see the revolutionary experiences you create!

Observe: This alpha launch is only the start for Ink API. We’re dedicated to constantly enhancing the library, including new options and functionalities based mostly in your suggestions. Keep tuned for updates and be a part of us in shaping the way forward for inking on Android!