0.1 Pr0110-anatomy of the processing framework

Table of contents

• Preface
  • Viewing tip
    • Images
    • Listings
• Preview
• General background information
  • A software framework
    • Inversion of control
    • Create the body of a class
    • Default behavior
    • Extensibility
    • Non-modifiable framework code
  • Overall behavior of the Processing framework
• Discussion and sample code
  • A subclass of PApplet
  • Understanding the anatomy of the framework
  • The draw method
  • Code in the Cars class
  • Let's talk about color
  • Constructor for the Car class
  • The draw method of the Cars class
  • The display method of the Car class
  • The drive method of the Car class
  • Putting it all together
• Run the program
• Summary
• Miscellaneous

Preface

This module is one in a collection of modules designed to teach you about the Processing open source programming environment.

Processing is a Java-based OOP programming environment for people who want to create images, animations, and interactions.

The purpose of this module is to explore and explain the anatomy of the Processing framework by dissecting and explaining an animated sketch.

Click here to view the JavaScript version of the sketch in your HTML 5 compatible browser.

Acknowledgement: The sketch that I will explain in this module is almost an exact copy of the sketch presented in Object Oriented Programming by Daniel Shiffman. I recommend that you take a look at what Shiffman has to sayabout this sketch as he develops it from a non-OO syntax to an OO syntax.

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the imagesand listings while you are reading about them.

Images

• Image 1 . Default display window.
• Image 2 . The PDE.
• Image 3 . Screen shot of the sketch during execution.

Listings

• Listing 1 . Code for the class named Car.
• Listing 2 . Code for the class named Cars.
• Listing 3 . Beginning of the Car class.
• Listing 4 . The draw method of the Cars class
• Listing 5 . The display method of the Car class
• Listing 6 . The drive method of the Car class.

Preview

What you have learned

In the previous module, you learned how to download and install the Processing Development Environment (PDE) .

You also learned how to create an animated Processing sketch that can be run in any of three ways:

• Run directly from the PDE.
• Run in JavaScript mode.
• Export and run as an application.

What you will learn

In this module, you will learn about the structural anatomy of the Processing framework.

General background information

There's a good chance that your Java programming background is restricted to Java applications, (which always have a main method) or Java applets, (which don't have a main method but do have something similar) .

You may have noticed that the code in the previous module did not expose a main method or anything similar to a main method.

A software framework

The Processing Development Environment is really a software framework. What do I mean by that? Here is part of what Wikipedia has to say about a software framework: