“Bind” components’ size to a MediaView’s size in JavaFX
May 11, 2013 Leave a comment
The MediaView is a control allowing you to add videos and sounds to your JavaFX application. If you are playing a video, maybe you would like another control to have the same size. For example, you can have a video played next to an image that you would like to have the same height. The easy thing would like to do some property binding like this:
final MediaView mediaView = new MediaView(aPlayerInstance); mediaView.setFitWidth(200); final ImageView imageView = new ImageView(anImageInstance); imageView.fitHeightProperty().bind(mediaView.heightProperty());
But this code is wrong because the MediaView doesn’t have a height property. So in order to succeed in our goal, the MediaView has a boundsInLocalProperty which can be used to change the size of the ImageView in our case. Look at this code example:
final MediaView mediaView = new MediaView(aPlayerInstance);
mediaView.setFitWidth(200);
final ImageView imageView = new ImageView(anImageInstance);
mediaView.boundsInLocalProperty().addListener(new ChangeListener<Bounds>() {
@Override
public void changed(ObservableValue<? extends Bounds> observableValue, Bounds bounds, Bounds bounds2) {
imageView.setFitHeight(bounds2.getHeight());
}
});
Of course you have to do some nullity checks to make your code more robust.
My presentation was about JavaFX 2. If you’re following this blog, you won’t be surprised. Why JavaFX? Because since I discovered JavaFX 2, I’m very excited about it, and really enthusiast. I knew JavaFX 1 and I have to be honest, I was disappointed from it. I know Swing for many years and I think it suits no more the way we do UI today, in 2012. I know JSF (1 & 2) and some aspects are really great. I’ve always been someone who believes in desktop apps, despite of the great progress done in web, and all the great stuff you can do, I still believe in desktop apps. And JavaFX 2 is for me an absolutely great platform for developing desk apps in Java. Up to date in terms of development process (in comparison to Swing), easier, more powerful, UI & UX oriented, it takes nice concepts from the entire Java ecosystem. And I really wanted (still want) to share my enthusiast about it. So I did. My presentation was about an introduction to JavaFX 2, but I decided to give an overview of really important concepts like properties and bindings, as well as FXML, which for me are some really key features of JavaFX. And with which you do crazy things, believe me! And during the talk we switched from the slides to the code some times, in order to create a simple browser without pretensions, just to explore our key features. I think it’s important to explain important concepts but also to give a “real life” example. I could tell you many things about the properties during 30 minutes, but you won’t remember anything. So I kept it simple with a demo. And it’s fun to see Google and LinkedIn in our little browser. At the end we had a Q&A session which was really interesting because I felt some enthusiasm in the attendance about JavaFX and that was great! I really enjoyed the evening.
