Aspect Oriented Programming AOP is both a complex and quite simple thing. There has been a lot of buzz around AOP but recently the buzz has faded. The question that people still ask is “what do I do with it”. Hopefully you will have an idea of what it is and create your own thoughts on how you could use it. In this post I aim to describe what AOP actually is and how it works.

What is AOP Every time someone tries to explain AOP (Aspect Oriented Programming) they often use words like “magic” or “black magic”. And that’s understandable, especially if you come from an OOP world and come across AOP it really feels like “magic”: something is happening and you as a developer usually don’t know why, what or how. AspectJ is one of the more well-known implementations for AOP in Java and is developed by the Eclipse Foundation.

Today I’m going to create an android custom view to implement circular SeekBar like the mockup below, make it as a library, open source at GitHub, and publish it to JCenter. In this post, I will cover several fundamental concepts of android custom view, write a helpful README on GitHub, and how to publish your library. Before you start… Try to understand the requirement or design specification, take a look at this widget first, the user can touch the indicator icon through this arc to set the current progress level.