Prize winner in Competition "Android Development Competition"
I have been designing and developing mobile applications for less than 1 year, though I'm a professional software developer for 10 years or so, and this new mobile era makes me feel excited. As of today there are two and a half major platforms gaining pretty well reputation by the mobile users. Two of them are iOS (formerly known as iPhone OS) and Android and the half is long debated Windows Phone 7.
In this tutorial article I will try to introduce you to the general development principles of Android by building a real calculator application (TouchCalculator). By the end of this tutorial you will be able to build Android applications with simple user interfaces and backing business logic.
Preparing Yourself and The Development Environment
Before you get started, if you are totally new to Android I would suggest you to read the What is Android? section from the Android Developers site and I would also suggest you to have a look at Android Developers Blog.
If you have not configured an Android development environment already, please follow the instructions in this link.
TouchCalculator, our sample and simple calculator, is a standard calculator supporting four arithmetic operations and three mathematical functions (namely square root, reciprocle and percentage) along with a memory buffer.
Let's start with the mockup of our calculator. Below is a color coded sketch of our application. I've seperated the UI into locigal parts and each part is represented with a color highlight. There is a reasoning behind the conceptual seperation and this will be evident in the next sections of the tutorial.