Jul 28

“PiMac unibody” or a new home for my touch screen

In preparation for the JavaOne 2014 Session my 7″ touch screen from Chalk-Elec finally found a new home.
I bought a 1 mm sheet of aluminium and treated it with my jig saw and a rasp and folded a triangle stand for the screen. Basically there would be room enough for e.g. a Rapsberry Pi and it also stand touching the display:





Some anti slip pads on the button side



The Sketch

PiMac Scetch

Jul 27

MQTT.fx 0.0.5 released

Just released a new version of MQTT.fx.


  • “Publish”, “Subscribe” and “Broker Status” can now be detached to be opened in a separate window: Just drag a tab title and drop it where the window should be placed. Closing of the window restores the content at the former position.
  • also I have done some UI polish

Download binaries HERE.


Jul 15

TabPaneDetacher: Make your tabs detachable

I though it would be cool to detach e.g. the pane to publish messages in MQTT.fx if needed by just dragging the tab and dropping it at the wanted position to open its content as a dedicated new window.

drag tab

The TabPaneDetacher provides an easy to use way to enable the detach capability of with any JavaFX TabPane instance just by calling:

public class TabPaneDetacherDemoController {

    private TabPane demoTabPane;
    public void initialize() {

The tab is removed from the tab pane and a new window is created containing the content of the tab, the window title is set to the tab name value. On closing that window the tab is restored at the original position:

Code can be found here in my Bitbucket repo.

Jul 10

UI logic with using JavaFX Bindings

For MQTT.fx I needed a ComboBox to enter new Topics or to choose recent topics from list.
But I want the user to enter or choose only (more or less) reasonable values otherwise the “Publish”/”Subscribe” buttons should be disabled:

ComboBox Bindings Demo 1

ComboBox Bindings Demo 2

Using the JavaFX Bindings API prevents some boilerplate code (implementing Listeners) and it is even more flexible as the result can be bound to several controls and at the end of the day its much more readable.

Contraint 1: The selection must not be empty.

  1. First create a JavaFX BooleanBinding.
  2. Then bind it to the disabledProperty of the button.

Contraint 2: Entered values must not contain only blanks (leading/trailing blanks can be trimmed later).

My approach is to

  1. add an EventFilter and to consume the event in case of only entered character is “SPACE”
  2. and if there are just blanks left when editing the value the content is cleared.
public class ComboBoxBindingsDemoController {

    private Label valueLabel;

    private Button goButton;

    private ComboBox<String> valueComboBox;

    private ObservableList<String> demoItemsList;
    private static final Pattern LEADING_BLANKS_PATTERN = Pattern.compile("^\\s*+");

    public void initialize() {

        BooleanBinding goButtonState = valueComboBox.editorProperty().get().textProperty().isEmpty()


        valueComboBox.getEditor().addEventFilter(KeyEvent.KEY_TYPED, (KeyEvent event) -> {
            Matcher matcher = LEADING_BLANKS_PATTERN.matcher(valueComboBox.getEditor().getText());
            if (" ".equals(event.getCharacter()) && valueComboBox.getEditor().getText().length() == 0) {
            else if(matcher.matches()){


    public ObservableList<String> getDemoItemsList() {
        if (demoItemsList == null) {
            demoItemsList = FXCollections.observableArrayList();
        return demoItemsList;

    public void goAction() {
        System.out.println("Value '" + valueComboBox.getValue().trim() + "'");


Complete runnable demo can be found at Bitbucket.

Jul 03

MQTT.fx 0.0.4 released

Just released new version of MQTT.fx.
Download binaries HERE.

MQTT.fx - v0.0.4

- revisited UI (return of “real” buttons)
- extended support for $SYS-topics: subscription for mosquitto or Hive MQ can be choosen (in respect to @dobermai).
- publish and subcrive/receive are now different tabs
- experimental support for http-proxy (in respect to @dimaki123).
- last choosen broker & port is restored at next app start
- updated 3rd party libs (e.g. now using features of ControlsFX 8.0.6)
MQTT.fx - v0.0.4 - broker status
MQTT.fx - v0.0.4 - subscribe
MQTT.fx - v0.0.4 - connection options
MQTT.fx - v0.0.4 - validation

- publish to topics even if not subscribed before (in respect to @_efwe_)

Configuration-format has changed, v0.0.4 might conflict with former versions.
In this case just delete (or rename) the mqttfx-config.xml.
Windows: [USER_HOME]\MQTT-FX\mqttfx-config.xml
OS X: [USER_HOME]/Library/Application Support/MQTT-FX/mqttfx-config.xml
The new configration is automatically created on next app start.

Jul 03

How to get rid of focus highlighting in JavaFX

Today I was asked if I know a way to get rid of the focus-highlighting of JavaFX controls (respectively buttons):


Most posts and tipps regarding this issue suggesting to adding:

.button:focused {
    -fx-focus-color: transparent; 

But with this style a glow like this is still left:


To get rid of this glow also often suggested to play around with -fx-background-insets additionally:

.button:focused {
    -fx-focus-color: transparent; 
    -fx-background-insets: -1.4, 0, 1, 2;

But this results in a button rendered with out an outer border:


Compared to the default button style


this is still a kind of “highlighting”:

Why is that? (And why are there actually 4 inset values ?)
(note he comment of David Grieve below)

Having a look at the JavaFX default style as defined by modena.css bares some more information:

/* A bright blue for the focus indicator of objects. Typically used as the
* first color in -fx-background-color for the "focused" pseudo-class. Also
* typically used with insets of -1.4 to provide a glowing effect.
-fx-focus-color: #f25f29;
-fx-faint-focus-color: #f25f2933;

Obviously there is not only one focus color -fx-focus-color but also -fx-faint-focus-color which is meant to create this glow-effect (that is remaining when setting -fx-focus-color:transparent;).

A closer look at the .button:focused pseudo class (in modena.css):

.button:focused {
    -fx-background-color: -fx-faint-focus-color, -fx-focus-color, -fx-inner-border, -fx-body-color; 
    -fx-background-insets: -2, -0.3, 1, 2;
    -fx-background-radius: 7, 6, 4, 3;

Playing around with some (extreme ;-)) colouring reveals the arrangement:

.button:focused {
    -fx-focus-color: red;
    -fx-faint-focus-color: green;
    -fx-inner-border: blue;
    -fx-body-color: orange;

    -fx-background-color: -fx-faint-focus-color, -fx-focus-color, -fx-inner-border, -fx-body-color; 
    -fx-background-insets: -2, -0.3, 1, 2;
    -fx-background-radius: 7, 6, 4, 3;


Getting back to the topic maybe a clent way to remove the focus hightlight is to use the default button styles also for .button:focus (same approach for other controls):

.button:focused {
    -fx-background-color: -fx-outer-border, -fx-inner-border, -fx-body-color; 
    -fx-background-insets: 0, 1, 2;
    -fx-background-radius: 5, 4, 3;
Jun 26

At your Service!

The Service class (javafx.concurrency.Service) may not only be used to keep the UI reactive on long duration tasks but can also be used to change the state of controls or keep UI in a reasonable state on short term actions.

Recall that a Service is like a reusable Task. A Task can be executed once and has to be re-instantiated to be started again. The Service class creates a new Task each time it is (re-)started (createTask() is called then).

This is the start()-method from javafx.concurrency.Service class:

public void start() {


    if (getState() != State.READY) {
        throw new IllegalStateException(
                "Can only start a Service in the READY state. Was in state " + getState());

    // Create the task
    task = createTask();

    // Wire up all the properties so they use this task

    // Advance the task to the "SCHEDULED" state

    // Start the task

Note that the properties binding of the Task (reset() is cleaning up all stuff).

In this post want to show how I’m using Services together with a JavaFX UI, like in MQTT.fx to connect or disconnect to a MQTT broker.

A simple connection pane with 5 controls:


Wanted appearance / behavior:
connectButton: only enabled if: not connected AND no service is running
disconnectButton: only enabled if: connected AND no service is running
cancelButton & progressIndicator: only visible if: any service is running
serviceMessageLabel: user feedback about the states of the services and the application





The controller has two properties and contains two services (inner classes):

StringProperty statusMessagesProperty
BooleanProperty connectedProperty


private class ConnectService extends Service<Void> {

        protected void succeeded() {

        protected void failed() {
            statusMessagesProperty().set("Connecting failed.");

        protected void cancelled() {
            statusMessagesProperty().set("Connecting cancelled.");

        protected Task<Void> createTask() {
            return new Task<Void>() {
                protected Void call() throws Exception {
                    // DEMO: un-comment to provoke "Not on FX application thread"-Exception:
                    // connectButton.setVisible(false);
                    updateMessage("Waiting for server feedback.");
                    return null;



    private class DisconnectService extends Service<Void> {

        protected void succeeded() {

        protected void cancelled() {
            statusMessagesProperty().set("Disconnecting cancelled.");

        protected Task<Void> createTask() {
            return new Task<Void>() {
                protected Void call() throws Exception {
                    updateMessage("Waiting for server feedback.");
                    return null;


The wanted UI-behavior can be accomplished just by some Bindings

BooleanBinding anyServiceRunning = connectService.runningProperty().or(disconnectService.runningProperty());

ChangeListeners are passing the messages from the services to the statusMessagesProperty:

connectService.messageProperty().addListener((ObservableValue observableValue, String oldValue, String newValue) -> {
disconnectService.messageProperty().addListener((ObservableValue observableValue, String oldValue, String newValue) -> {

Three methods to control the services:

    public void cancel() {

    public void connect() {

    public void disconnect() {

Nice & convenient:
Instead of verifying the state of the Service you can just call restart().
restart() executes:
1. cancel() (if running): cancel the executed service-task
2. reset(): clear the Service (task=null and unbind all stuff)
and then
3. start(): create new Task and bind its properties

You can get the complete code of this tutorial in my BitBucket repo:


Jun 14

MQTT.fx 0.0.3 released

Most significant change: I have added a pane to show some status values of the broker:


In v0.0.3 these $SYS topics are recognised (Tooltips are showing the descriptions):

Version: $SYS/broker/version
Build: $SYS/broker/timestamp
Uptime: $SYS/broker/uptime
Subscriptions Count: $SYS/broker/subscriptions/count
Changeset: $SYS/broker/changeset
Clients Connected: $SYS/broker/clients/active
Clients Expired: $SYS/broker/clients/expired
Clients Disconnected: $SYS/broker/clients/inactive
Clients Maximum: $SYS/broker/clients/maximum
Clients Total: $SYS/broker/clients/total
Connection: $SYS/broker/connection/#
Messages Inflight: $SYS/broker/messages/inflight
Messages Received: $SYS/broker/messages/received
Messages Sent: $SYS/broker/messages/sent
Messages Stored: $SYS/broker/messages/stored
Messages Publish Dropped: $SYS/broker/publish/messages/dropped
Messages Publish Received: $SYS/broker/publish/messages/received
Messages Publish Sent: $SYS/broker/publish/messages/sent
Messages Retained Count: $SYS/broker/retained/messages/count
Bytes Received: $SYS/broker/bytes/received
Bytes Sent: $SYS/broker/bytes/sent
Load Connections: $SYS/broker/load/connections/+
Load Bytes Received: $SYS/broker/load/bytes/received/+
Load Bytes Sent: $SYS/broker/load/bytes/sent/+
Load Messages Received: $SYS/broker/load/messages/received/+
Load Messages Sent: $SYS/broker/load/messages/sent/+
Load Publish Dropped: $SYS/broker/load/publish/dropped/+
Load Publish Received: $SYS/broker/load/publish/received/+
Load Publish Sent: $SYS/broker/load/publish/sent/+
Load Sockets Count: $SYS/broker/load/sockets/+

Download binaries:
Windows 32bit Installer
Zipped executable jar

May 21

FontAwesomeFX 8.0.7/8.0.8 released

UPDATE: In 8.0.7 I forgot to replace the TTF! So 8.0.7 still contains the 4.0.1 font. Some icons may not be displayed with 8.0.7. Have fixed this issue with fontawesomefx-8.0.8.

NavigationButtonsI have updated FontAwesomeFX and released version 8.0.7.
A few days ago the FontAwesome 4.1.0 was released with 70+ additional icons (FontAwesome now contains 439 icons).

Download Binaries
Sources @ Bitbucket

Maven Artifact:

May 16

“somehow more organic”: how to create a ‘noisy’ gradient in JavaFX

If you always wondered why some regions on your Mac, Websites or in your Smartphone-Apps look somehow more organic than a plain coloured area or even an region with a gradient, have a closer look!
Zooming into these areas shows that they are a bit “noisy”.

This effect can be created very easily with CSS in JavaFX too:
I just noticed that “-fx-background-image” is painted in front of “-fx-background-color“:


So, what is needed is a transparent “noise texture” which can be created here or here.

This texture is then used as a repeated background-image and painted in front the background-color which in JavaFX-CSS can also be a linear gradient:

-fx-background-color: linear-gradient(rgb(224,228,233) 0%, derive(rgb(224,228,233),-20%) 100%);
-fx-background-image: url("images/noise-texture.png");
-fx-background-repeat: repeat;  

I used this approach e.g in my MQTT.fx-UI: