Let’s add an extended view to Astah

Astah Plug-in can add an extra view in Astah. For example, you can make a view to show a list of class summary or whatever you would like to show on Astah. So in this page, let’s create a Plug-in to add an extended view to Astah. And let’s make it show just a “hello world” text on there as an easy example.

Creating an extended view

To add an extended view, use IPluginExtraTabView interface. Below is a sample of the HelloWoroldView which implements the IPluginExtraTabView.

/*
 * Please change this class's package to your genearated Plug-in's package.
 * Plug-in's package namespace => com.example
 *   com.change_vision.astah.extension.plugin => X
 *   com.example                              => O
 *   com.example.internal                     => O
 *   learning                                 => X
 */
package com.example.internal;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;

import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

import com.change_vision.jude.api.inf.project.ProjectAccessor;
import com.change_vision.jude.api.inf.project.ProjectAccessorFactory;
import com.change_vision.jude.api.inf.project.ProjectEvent;
import com.change_vision.jude.api.inf.project.ProjectEventListener;
import com.change_vision.jude.api.inf.ui.IPluginExtraTabView;
import com.change_vision.jude.api.inf.ui.ISelectionListener;

public class HelloWorldView extends JPanel implements IPluginExtraTabView, ProjectEventListener {

    public HelloWorldView() {
        initComponents();
    }

    private void initComponents() {
        setLayout(new BorderLayout());
        add(createLabelPane(), BorderLayout.CENTER);
        addProjectEventListener();
    }

  private void addProjectEventListener() {
    try {
      ProjectAccessor projectAccessor = ProjectAccessorFactory.getProjectAccessor();
      projectAccessor.addProjectEventListener(this);
    } catch (ClassNotFoundException e) {
      e.getMessage();
    }
  }

  private Container createLabelPane() {
      JLabel label = new JLabel("hello world");
        JScrollPane pane = new JScrollPane(label);
        return pane;
    }

    @Override
    public void projectChanged(ProjectEvent e) {
    }

    @Override
    public void projectClosed(ProjectEvent e) {
    }

     @Override
    public void projectOpened(ProjectEvent e) {
    }

  @Override
  public void addSelectionListener(ISelectionListener listener) {
  }

  @Override
  public Component getComponent() {
    return this;
  }

  @Override
  public String getDescription() {
    return "Show Hello World here";
  }

  @Override
  public String getTitle() {
    return "Hello World View";
  }

  public void activated() {

  }

  public void deactivated() {

  }
}

The getComponent() tells Astah what to show on the extended tab view such as a table. In our sample, the instance of a JPanel with a JLabel is returned to Astah by the getComponent(). And the label on the extended tab should be defined in the getTitle().

A class implementing ProjectEventListener interface is an observer which keeps watching the models on current Astah. And the projectChanged() method will be called when there was a change in models such as adding/deleting of classes.

Adding an extended view to Astah

Next, let’s write the plugin.xml to add the extended view to Astah.

<?xml version="1.0" encoding="UTF-8"?>
<plugin>
   <extension point="com.change_vision.astah.ui.view">
        <view
            id="com.example.internal.HelloWorldView"
            type="extraTab"
            class="com.example.internal.HelloWorldView" />
   </extension>
</plugin>

Tag name	Attribute	Required	Description
extension		o	Specify extension point
	point	o	Specify com.change_vision.astah.ui.view
view		o	Specify view configuration
	id	o	View’s ID
	type	o	Specify the location of the view
			extraTab if you put the view on ExtraView
	class	o	Specify implementation of the class

Now an extended view has been added to Astah.