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Getting Started with Google Protobuf - 2

Fri Dec 7, 2012

Before starting with this tutorial, you should ensure that you have WindowBuilder Pro installed from the following update site: http://download.eclipse.org/windowbuilder/WB/release/R201206261200/4.2/ . This link is for Eclipse Juno/Kepler 4.2/4.3. If you are using an older version of Eclipse, you should see here on how to install WindowBuilder for that version.

 1. Install Protocol Buffer Editor and Set preferences

protobuf-dt is an eclipse plugin for creating, editing and compiling messages in Google Protobuf. You can install protobuf-dt from here: http://code.google.com/p/protobuf-dt/wiki/Installing . After the installation is complete, you should set some preferences for protobuf-dt as shown in the image below. The configuration shown in the image is specific for Mac OsX. 

2. Create an Eclipse RCP application with a form editor [Advanced]

This section is going to be a bit lengthy and advanced. Here, we create an Eclipse RCP application that has the following features:

  • Custom perspective
  • A Common Navigator View
  • A Form Editor for managing addresses i.e. An Address Book

In the project/package explorer right click and create a new Plug-in Project named contacts-manager. Continue pressing the next button until you reach the Templates page. Select Hello RCP template and press the Finish button. This will result in the manifest editor for the project to open automatically as shown in the image below. 

In the top right of the image, I’ve annotated the Run button. If you press the Run button, you should see an empty application window with the title Hello RCP. Next, We will add the Eclipse Common Navigator view in the application. Eclipse Common Navigator Framework  allows you to create and manage projects/files in the workspace of your RCP application.

In the Manifest editor, click on the Extensions **tab and Add the org.eclipse.ui.navigator.viewer as shown in the images below. Essentially, we are adding a view to our RCP. Therefore, the view id is important to note. The view id that I set is *contacts_manager.comnav. *We will use this view id later.**

* *

 Now, we need to write some codes to make the CNF show up properly in the RCP application. Open up ApplicationWorkbenchAdvisor.java and add the following two methods to it:

@Override
  public void initialize(IWorkbenchConfigurer configurer) {
    super.initialize(configurer);
    IDE.registerAdapters();
  }

@Override
public IAdaptable getDefaultPageInput() {
     IWorkspace workspace = ResourcesPlugin.getWorkspace();
     return workspace.getRoot();
}

Next, open up Perspective.java and add the following code to createInitialLayout method.

layout.addView("contacts_manager.comnav", IPageLayout.LEFT, 0.10f, layout.getEditorArea());

The code above adds the common navigator view to the perspective of our RCP application. If you run the RCP application now, it should look similar to the image below.

Next, we create an editor for managing simple contacts.

In the Dependencies tab of manifest editor, add org.eclipse.ui.forms as a dependency. Then, go to Extensions tab and add a new extension org.eclipse.ui.editors as shown in the images below. We’ll be using Multi-page Editor template, so don’t forget to select it as well.

The template creates two files: ContactEditor.java and ContactEditorContributor.java. Because we’re creating an editor for managing simple contacts, we’ll remove all the template code and start with our own. Remove all the template code from ContactEditor.java and use the following code as the starting point. You might as well delete ContactEditorContributor.java because we won’t be using it. If you do so, don’t forget to remove the corresponding reference to it in the manifest file.

public class ContactEditor extends FormEditor {

    @Override
    protected void addPages() {
    }

    @Override
    public void doSave(IProgressMonitor monitor) {
    }

    @Override
    public void doSaveAs() {
    }

    @Override
    public boolean isSaveAsAllowed() {
        return false;
    }

}

A Form editor is a collection of form pages. We’ll create a form page using Window Builder. As shown in the images below, create a new form page called ContactFormPage.java.

Using the Window Builder, we will create a simple form like below:

The following are the variable names for the text fields: txtFirstName, txtMiddleName, txtLastName, txtMobile, txtHomepage, and btnSave. We need to add this form page in the ContactEditor.java file. Update the ContactEditor.java file as below:

  public class ContactEditor extends FormEditor {

    ContactFormPage cfp;

    @Override
    protected void addPages() {
        try {
            cfp = new ContactFormPage(this, "ContactFormPage", "Contacts");

            addPage(cfp);
        } catch (PartInitException e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void setInput(IEditorInput input) {
        super.setInput(input);

        setPartName("Simple Contact Editor");
    }

    @Override
    public void doSave(IProgressMonitor monitor) {
    }

    @Override
    public void doSaveAs() {
    }

    @Override
    public boolean isSaveAsAllowed() {
        return false;
    }

  }

Testing what we have so far

In the last section we covered a lot of information related to creating a RCP application with a common navigator; and a simple form editor. To test what we have so far, run the application and create a new project called addresses. In this project, create a new file called supervisor.contact. This is shown in image below.

Click on the Finish button. You should now have the form editor open the contact file automatically as shown in the image below.

 

That’s it for this part. In the next and final part , we will focus on how to persist the data for the .contact file using Google Protobuf.

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