Preliminaries

There's a few things to do before we dive into the tutorial itself. For example, to do Eclipse programming, you will have to get your hands on an Eclipse installation first. Read through the following sections to get ready for the tutorial tasks.

Required Software

Install Eclipse. For what we do, we recommend installing the Eclipse Modeling Tools.

Finding Documentation

During the tutorial, we will cover each topic only briefly, so it is always a good idea to find more information online. Here's some more resources that may prove helpful:

• Java™ Platform, Standard Edition 8 API Specification
  As Java programmers, you will already know this one, but it's so important and helpful that it's worth repeating. The API documentation contains just about everything you need to know about the API provided by Java.
• Eclipse Help System
  Eclipse comes with its own help system that contains a wealth of information. You will be spending most of your time in the Platform Plug-in Developer Guide, which contains the following three important sections:
  
  • Programmer's Guide
    When you encounter a new topic, such as SWT or JFace, the Programmer's Guide often contains helpful articles to give you a first overview. Recommended reading.
  • References -> API Reference
    One of the two most important parts of the Eclipse Help System, the API Reference contains the Javadoc documentation of all Eclipse framework classes. Extremely helpful.
  • References -> Extension Points Reference
    The other of the two most important parts of the Eclipse Help System, the Extension Point Reference lists all extension points of the Eclipse framework along with information about what they are and how to use them. Also extremely helpful.
• Eclipsepedia
  The official Eclipse Wiki. Contains a wealth of information on Eclipse programming.
• Eclipse Resources
  Provides forums, tutorials, articles, presentations, etc. on Eclipse and Eclipse-related topics.
• Eclipse Layout Kernel
  Documentation on how the layout infrastructure works and on how to write your own layout algorithms. This is our project, so if you find that something is unclear or missing, tell us about it!

You will find that despite of all of these resources Eclipse is still not as well commented and documented as we'd like it to be. Finding out how stuff works in the world of Eclipse can thus sometimes be a challenge. However, you are not alone: this also applies to many people who are conveniently connected by something called The Internet. It should go without saying that if all else fails, Google often turns up great tutorials or solutions to problems you may run into. And if it doesn't, your advisers will be happy to help.

As far as KIELER documentation is concerned, you will find documentation at the KIELER Confluence. The documentation is not as complete as we (and especially everyone else) would like it to be, however, so feel free to ask those responsible for help if you have questions that the documentation fails to answer.

Your First Steps with Eclipse

Starting Eclipse

1. Eclipse uses workspaces to store, for instance, user preferences. Upon the first start of eclipse you will be asked to specify a location. Select one as you like.
   
2. Switch to the workbench, you should see something like this
   

Importing Existing Plug-ins

1. Download the zip file with all our prepared tutorial plugins from our Stash. Unzip the file.
2. Open the context menu within the Package-Explorer (on the very left, right-click the empty space).
3. Select Import. Then chose General > Existing Projects into Workspace.
4. Browse to the location where you unzipped the downloaded plug-ins. Check the checkbox in front of the de.cau.cs.kieler.tutorials.plugins.shouter plug-in and press Finish.
   
   

Creating Your First Plug-in

1. Open the context menu within the Package-Explorer (on the very left, right-click the empty space).
2. New -> Project...
3. In the project wizard, choose Plug-in Project and click Next.
4. As the project name, enter de.cau.cs.rtprak.login.simple. Uncheck Use default location (which would put the project into your workspace), and put it into your local clone of the Git repository instead (the Location should read something like /path/to/git/repository/de.cau.cs.rtprak.login.simple). Click Next.
5. As the name, enter Simple (login). Also, make sure that Generate an activator and This plug-in will make contributions to the UI are both checked. Click Finish. (Eclipse might ask you whether you want to switch to the Plug-in Development Perspective, which configures Eclipse to provide the views that are important for plug-in development. Choose Yes. Or No. It won't have a big influence on your future...)
6. Eclipse has now created your new plug-in and was nice enough to open the Plug-in Manifest Editor, which allows you to graphically edit two important files of your plugin: plugin.xml and META-INF/MANIFEST.MF. (By the way, this would be a great time to research the editor and the two files online.) Basically, those two files provide information that tell Eclipse what other plug-ins your plug-in needs and how it works together with other plug-ins by providing extensions and extension points. Our new plug-in will depend on two other plug-ins, so switch to the Dependencies tab of the editor and add dependencies to org.eclipse.ui.editors and org.eclipse.jface.text. Save the editor and close it. (You can always reopen it by opening one of the two mentioned files from the Package Explorer.)

Extension Points

For the final part of the tutorial, we will now use the extension point mechanism of Eclipse to add some behavior to our Turing Machines. An extension point is basically a well-defined point where other plug-ins can register to add functionality. The extension point is basically defined by an XML Schema file that defines an interface; other plug-ins may access this interface using XML code in their plugin.xml file, so-called extensions. Our extension point will provide an interface for classes that define behavior of a Turing Machine, and we will call them head controllers (programs that control the tape head).