Good afternoon!

This is an introductory lesson. We will not code anything here. In this lesson I will enlighten reasons why I decided to create this site.

To write programs we need a development environment. Google recommends to use Eclipse for this purpose with Android Development Tools (ADT) plugin. In this lesson we will have a look in detail how to install and configure this development environment.

To test our applications we will need an Android Virtual Device (AVD). It is an Android smartphone emulator, where Eclipse can install and launch our applications. Let’s create it.

Let’s have a look how is screen content composed in Android applications.

In the last lesson we have learnt that Activity reads a layout-file and displays what is configured in it. Now let’s find out how Activity knows which specific file to read.  

Positioning of View-elements on the screen depends on the ViewGroup (layout), inside which they are located. In this lesson we will observe main types of Layouts.

In this lesson we will:

- examine screen properties;
- explore layout parameters (height, width, margin, gravity, weight)

In this lesson we will:

- learn how to refer to View-elements on the screen from code and change their properties

In this lesson we will:

- learn how to process button clicks and find out what a listener is.

In this lesson we will:

- learn how to use one listener for several View-elements
- teach Activity to to act as a listener

In this lesson we will:

- find out what is res/values folder needed for, what can you store in it and how to use it.

In this lesson we will:

 - look through application logs and Toast messages

In this lesson we will:

 - create menu items

In this lesson we will:

- create menu items with IDs
- group and sort menu items

In this lesson we will:

- create a context menu

In this lesson we will:

- create layout programmatically, not using layout-files

In this lesson we will:

- add components to the screen while application is running

In the this lesson we will:

- change layout-parameters for already existing screen components

In the this lesson we will:

- write a calculator application

In the this lesson we will:

- explore animation of View-components