Starting Guide

Old initial set-up

In 2008, Chihiro Saito, a developer for Sun Microsystems, created a BD-J plugin for Netbeans. You could previously download it here, but the old Plugins site has been deleted. With some minor tweaks, it could be used today and took care of a lot of stuff for you.

I have not been able to get the plug-in working again, but I was able to transfer the example project I created to IntelliJ, and have been using its ant file to work with.

Fixing the ant file

Some essential tools apparently got reorganized during the move from Java 7 to Java 8. You will need to have JDK7 or earlier somewhere on your computer. I have edited the Ant build.xml to use VLC and take this into account.

You need to fill in the location of your JDK7 or earlier here:

 <property name="OldJavaLocation" value=" "/>

In order for the free software VLC to be able to play Blu-Ray, you require libbluray. Please refer to VLC guides to find out more. In order for VLC to play your self-crafted Blu-Ray Java project, you need to have a video file running.

Paste the contents of this directory in the /dist/DiscImage/BDMV/ directory of your project.

Finally, replace the HelloTVXlet.java with this file.

You should see this in VLC when you run the project:

User input

VLC unfortunately only recognizes a few of the many buttons you would find on a typical Blu-Ray Player remote. That's why we're going to focus on the arrow keys and the enter key for now.

First you need to make your Xlet implement UserEventListener.

Add the following to your initXlet():

        UserEventRepository repository = new UserEventRepository("Repository");
        repository.addAllArrowKeys();
        repository.addKey(HRcEvent.VK_ENTER);
        EventManager.getInstance().addUserEventListener((UserEventListener) this, repository);

Then add the userEventReceived method to your Xlet.

    public void userEventReceived(UserEvent e) {
        //The magic happens here.
    }

An example implementation expects the Xlet to have a member variable private int counter = 0. We will increment and decrement this counter with the left and right arrow keys, and redraw the gui in a different color depending on this counter.

    public void userEventReceived(UserEvent e) {
        if (e.getCode() == HRcEvent.VK_LEFT) {
            counter -= 20;
        } else if (e.getCode() == HRcEvent.VK_RIGHT) {
            counter += 20;
        }
        if (counter > 250 || counter < 0) {
            counter = 0;
        }
        scene.remove(gui);

        gui = new Container() {

            public void paint(Graphics graphics) {
                graphics.setFont(font);
                graphics.setColor(new Color(120, 120, counter));
                graphics.fillRect(150, 150, getWidth() - 300, getHeight() - 300);
                graphics.setColor(new Color(200, 200, 200));
                int message_width = graphics.getFontMetrics().stringWidth(message);
                graphics.drawString(message, (getWidth() - message_width) / 2, 500);
            }

        };

        scene.add(gui, BorderLayout.CENTER);
        gui.setSize(1920, 1080);  // BD screen size
        scene.add(gui, BorderLayout.CENTER);

        scene.validate();

    }

Displaying images

This won't work:

                Image img = Toolkit.getDefaultToolkit().getImage(getClass().getResource("/randomimage.png"));
                graphics.drawImage(img,150, 150, null);

Toolkit is threaded. I've been spoiled by modern Java, so I didn't really get that. But it was fortunately explained to me by our Japanese predecessors.

                Image img = Toolkit.getDefaultToolkit().getImage(getClass().getResource("/randomimage.png"));
                MediaTracker tracker= new MediaTracker(this);
                tracker.addImage(img, 0);
                try{
                    tracker.waitForAll();
                }
                catch (Exception e){
                }
                graphics.drawImage(img,150, 150, null);