Introduction to JavaFX on Raspberry Pi

Copyright © 2012, Oracle and/or its affiliates. All rights reserved.
Introduction to JavaFX
on Raspberry Pi
Bruno Borges
Oracle Product Manager for Latin America
Java Evangelist
bit.ly/javafxraspberrypij1

Copyright © 2012, Oracle and/or its affiliates. All rights reserved. Insert Information Protection Policy Classification from Slide 132
Bruno Borges
Oracle Product Manager / Evangelist
Developer, Gamer, Beer lover
JavaFX / Embedded Enthusiast
Twitter: @brunoborges

What do you need to build JavaFX apps?

JavaFX Scene Builder
●
Linux supported!

Java SE 6/7/8
●
SE 8 comes with JavaFX libs as part of JRE

NetBeans 7.3.1+
Some things, and coffee

JavaFX Scene Builder 1.1 GA
bit.ly/javafxdownload

Raspberry Pi Configurations
for JavaFX applications
CPU Overclock
900~950MHz
Memory split
128MB for video
Framebuffer
framebuffer_width=1280
framebuffer_height=720

CPU Overclock
$ cat /proc/cpuinfo
Processor : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS : 697.95
…
$ sudo raspi-config
bit.ly/raspioverclock

CPU Overclock
$ cat /proc/cpuinfo
Processor : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS : 697.95
…
$ sudo raspi-config

Memory Split
128mb best
performance
64mb may work
$ sudo raspi-config

Video Framebuffer
Edit /boot/config.txt
Enable (uncomment) these options, with these values:
framebuffer_width=1280
framebuffer_height=720

Exiting a JavaFX Application on Raspberry.Pi
Connect over SSH and kill the java process
$ killall -9 java
Enable the debug environment variable to enable control-C exit command
$ export JAVA_DEBUG=1
$ java -cp Stopwatch.jar stopwatch.MainScreen

Final parameters for JavaFX on Raspy
Do not show virtual keyboard (optional)
-Dcom.sun.javafx.isEmbedded=false
Send video to the framebuffer (required!)
-Djavafx.platform=eglfb

Building Your 1st
JavaFX App

Your First JavaFX App for RaspberryPi

Your First JavaFX App for RaspberryPi
public class MyApplication extends Application {
@Override
public void start(Stage stage) throws Exception {
URL fxml = getClass().getResource("MyApplication.fxml");
Parent root = FXMLLoader.load(fxml);
Scene scene = new Scene(root);
stage.setScene(scene);
stage.setFullScreen(true); // for Desktop. Not need for Pi
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}


Properties
// JavaFX
DoubleProperty value = new SimpleDoubleProperty(0);
public double getValue() {
return value.get();
}
public void setValue(double newValue){
value.set(newValue);
}
public DoubleProperty valueProperty() {
return value;
}


Bindings

Binding unidirecional
●
bind();

Binding bi-direcional
●
bindBidirectional();


Bindings
@FXML
private Label humidityLabel;
...
// HUMIDITY MONITOR
HumidityMonitor humidityMon = new HumidityMonitor(...);
humidityLabel.textProperty().bind(humidityMon.valueProperty());
humidityMonitor.start();


Bindings
IntegerProperty number1 = new SimpleIntegerProperty(1);
IntegerProperty number2 = new SimpleIntegerProperty(2);
DoubleProperty number3 = new SimpleDoubleProperty(0.5);
NumberBinding sum1 = number1.add(number2);
NumberBinding result1 = number1
.add(number2)
.multiply(number3);
NumberBinding sum2 = Bindings.add(number1, number2);
NumberBinding result2 = Bindings
.add(number1,
multiply(number2, number3));


JAX-RS 2.0 Client API
Download libs from here:
bit.ly/jersey-libs-javafx
https://jersey.java.net/


import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
...
Client client = ClientBuilder.newClient();


String uriTemplate = "http://{host}:{port}/things";
String host = System.getProperty(
"things.host",
"192.168.1.101");
String port = System.getProperty(
"things.port",
"8080");


Map<String, Object> params = new HashMap<>();
params.put("host", host);
params.put("port", port);
UriBuilder uriBuilder = UriBuilder.fromUri(uriTemplate);
Client thingsServerURI = uriBuilder.buildFromMap(params);


Using the things REST client
String sHumidity = thingsServerURI
.path("/humidity")
.request()
.get(String.class);


Working with Threads
Using the things REST client with threads
class MonitorService extends TimerTask {
public void run() {
String sval = thingsHumidyPath
.request().get(String.class);
final float humidity = new Float(sval);
Platform.runLater(new Runnable() {
@Override
public void run() {
floatValue.set(humidity);
value.set(Float.toString(humidity));
}
});
}
}


class MonitorService extends TimerTask {
public void run() {
String sval = thingsHumidyPath
.request().get(String.class);
final float humidity = new Float(sval);
Platform.runLater(new Runnable() {
@Override
public void run() {
this.floatValue.set(humidity);
this.value.set(Float.toString(humidity));
}
});
}
}


Back to the Bindings
@FXML
private Label humidityLabel;
...
// HUMIDITY MONITOR
HumidityMonitor humidityMon = new HumidityMonitor(...);
humidityLabel.textProperty().bind(humidityMon.valueProperty());
humidityMonitor.start();


Start the Monitoring service
Timer timer = new Timer(true);
timer.schedule(new MonitorService(), 0, DELAY);

QUESTIONS?

Thanks!
@brunoborges

The preceding is intended to outline our general product direction. It is intended
for information purposes only, and may not be incorporated into any contract.
It is not a commitment to deliver any material, code, or functionality, and should
not be relied upon in making purchasing decisions. The development, release,
and timing of any features or functionality described for Oracle’s products
remains at the sole discretion of Oracle.

Introduction to JavaFX on Raspberry Pi

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