Portfolio ticker inside Android Robinhood app

One of the guiding principles the Robinhood’s app engineering teams value above all else is user experience. We believe that a delightful and intuitive user experience helps distinguish our app from the others and highlight the shift from the traditional financial behemoths to the agile mobile-first brokerage that is Robinhood. We are thankful that our UI/UX-driven engineering efforts are well received by both our customers and the industry as a whole, and they resulted in two design awards for our iOS and Android apps in the first year of their respective launches. However, we are not done yet. We constantly look for ways to evolve and refactor our app in the face of new standards and expectations. We search for new open source and framework libraries and tools because we believe that the less code we write and thus need to maintain, the better and more flexible it is for us down the road. We listen to our customers’ suggestions and feedback in order to improve our app. We do all of these while at the same time maintaining the high standards that we set for, and our customers expect from, all of Robinhood engineering.

To this end, Robinhood app engineering teams focus on creating high-performance mobile architectures and UI modules so that our apps run smoothly and efficiently across all devices. One such module that we built pretty early on was the ticker text module, named after the stock price tickers that you normally see on Wall Street. When we were building the ticker module on Android, we had a few main requirements:

High performance: animation should not cause any lag in the UI, particularly during scroll and fling.

Low memory usage: e.g. do not use multiple views underneath.

Easily pluggable: the core logic should be properly encapsulated so the UI module can be easily reused across screens.

Simple, extensible API: very minimal efforts required to redefine how the text is rendered or animated.

Minimum possible Android SDK version requirement

With these goals in mind, we developed the first version of our ticker module and shipped it with our initial Android public release. After a few minor stumbles and some iterations, we are glad to announce that we are offering Ticker to the open source community!