Tetris is a classic game. In this chapter, we will develop a version very similar to the original version. Seven figures of different shapes and colors fall down and the player's job is to move and rotate them into positions so that as many rows as possible are completely filled. When a row is filled, it disappears. Every removed row gives one point.

This application is the only one in this book that supports the single document interface, which implies that we have one document class object and one view class object. The other applications support the multiple document interface, they have one document class object and zero or more view class objects. The following screenshot depicts a classic example of the Tetris Application: