Develop Reference

Javafx - Update progress indicator in UI from java class

The following are the changes I made in fxml
Changes in the java file , here my code :
private ProgressIndicator pi;
void handlebuildButtonAction(ActionEvent event) throws IOException, GeneralSecurityException {
if ((entServer.isSelected()==true || compasServer.isSelected()==true)) {
if(!fileList.isEmpty()){
ProgressIndicator pi = new ProgressIndicator();
pi.setProgress(10);
}
}
The progress indicator is not updated when I run the application. I'm not sure how to sync the changes to UI. Assist me on this. Thanks in advance.
output

For example: if you set 0.1 - progress will be 10%, 0.2 - 20% and so on, so when you set the progress => 1 you will always have "done".
Here, this an example with a button, when you click the button, your progress indicator will be updated(one click + 10%):
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.layout.*;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.stage.Stage;
public class Test extends Application {
private ProgressIndicator pi;
private double counter = 0;
public void start(Stage stage)
{
ProgressIndicator pi = new ProgressIndicator();
Button button = new Button("Press");
TilePane root = new TilePane();
// action event
EventHandler<ActionEvent> event = new EventHandler<ActionEvent>() {
public void handle(ActionEvent e)
{
counter += 0.1;
pi.setProgress(counter);
}
};
button.setOnAction(event);
root.getChildren().add(button);
root.getChildren().add(pi);
// create a scene
Scene scene = new Scene(root, 200, 200);
// set the scene
stage.setScene(scene);
stage.show();
}
public static void main(String args[])
{
// launch the application
launch(args);
}
}
Just change this code for your case:
EventHandler<ActionEvent> event = new EventHandler<ActionEvent>() {
public void handle(ActionEvent e)
{
if ((entServer.isSelected()==true || compasServer.isSelected()==true)) {
if (!fileList.isEmpty()) {
counter += 0.1;
pi.setProgress(counter);
}
}
}
};
Hope that helps you!

UI not updating when nodes are being removed

I'm trying to remove all the nodes from my pane sequentially 1 by 1 so I can see each line being removed.To do this I have made a new thread and used the task class and wrapped the method delWalls() in a Platform.runLater() . I then used Thread.sleep thinking it would slow the loop slow so I could see the UI updating as each line is removed However what happens is the whole UI freezes up and then after the loop is done all the nodes have disappeared? Is there a way around this ... thanks
*all nodes are lines btw
//loop calls delWalls() 1458 times to delete all 1458 nodes sequentailly
Task task = new Task<Void>() {
#Override
public Void call() {
Platform.runLater(() -> {
try {
for (int i = 0; i <= 1458 - 1; i++) {
Thread.sleep(2);
delWalls();
}
} catch (InterruptedException e) {
e.printStackTrace();
}
});
return null;
}
};
new Thread(task).start();
}
//delWalls method deletes one node each time it is called.
public void delWalls() throws InterruptedException {
pane.getChildren().remove(0);
}

As #MadProgrammer said, you need to work with Timeline to get the desired effect.
Below is a quick sample demo of how it can be done. Click "Add" to add nodes sequentially, and once all 10 nodes are added, click "remove" to remove them one by one.
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.FlowPane;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.util.Duration;
public class RemoveNodes_Demo extends Application {
#Override
public void start(Stage stage) throws Exception {
FlowPane pane = new FlowPane();
pane.setVgap(10);
pane.setHgap(10);
Button button1 = new Button("Add Nodes");
button1.setOnAction(e->{
Timeline timeline = new Timeline(new KeyFrame(Duration.millis(400), x -> {
StackPane sp = new StackPane();
sp.setMinSize(100,100);
sp.setStyle("-fx-background-color:black,red;-fx-background-insets:0,2;");
pane.getChildren().add(sp);
}));
timeline.setCycleCount(10);
timeline.play();
});
Button button2 = new Button("Remove Nodes");
button2.setOnAction(e->{
if(!pane.getChildren().isEmpty()){
int count = pane.getChildren().size();
Timeline timeline = new Timeline(new KeyFrame(Duration.millis(400), x -> {
if(!pane.getChildren().isEmpty()){
pane.getChildren().remove(0);
}
}));
timeline.setCycleCount(count);
timeline.play();
}
});
VBox root = new VBox(button1, button2,pane);
root.setSpacing(10);
Scene sc = new Scene(root, 600, 600);
stage.setScene(sc);
stage.show();
}
public static void main(String... a) {
Application.launch(a);
}
}

Check if JavaFX platform is exiting

I use a background-thread that should not stop immediately when JavaFX stops (as it does when no stage is open anymore as configured with setImplicitExit), so I do not use setDaemon for this one. But how can I check if JavaFX is shutting down? (This thread should just finish some things and stop itself)
I know I could put an setOnCloseRequest to all stages, but I'd prefer not doing that.
Runtime.getRuntime().addShutdownHook() does not work in this case as the machine does not go down as long as this thread is running).

Override Application.stop() and set a flag. Your thread will need to periodically check that flag.
SSCCE:
import java.util.concurrent.atomic.AtomicBoolean;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class ExitThreadGracefullyOnExit extends Application {
AtomicBoolean shutdownRequested = new AtomicBoolean();
#Override
public void start(Stage primaryStage) {
Label countLabel = new Label();
Thread thread = new Thread(() -> {
try {
int count = 0 ;
while (! shutdownRequested.get()) {
count++ ;
final String message = "Count = "+count ;
Platform.runLater(() -> countLabel.setText(message));
Thread.sleep(1000);
}
System.out.println("Shutdown... closing resources");
Thread.sleep(1000);
System.out.println("Almost done...");
Thread.sleep(1000);
System.out.println("Exiting thread");
} catch (InterruptedException exc) {
System.err.println("Unexpected Interruption");
}
});
VBox root = new VBox(10, countLabel);
root.setAlignment(Pos.CENTER);
thread.start();
Scene scene = new Scene(root, 350, 100);
primaryStage.setScene(scene);
primaryStage.show();
}
#Override
public void stop() {
shutdownRequested.set(true);
}
public static void main(String[] args) {
launch(args);
}
}

JavaFX - Action during event

i am trying to influence a UI-Element during an event in javaFX.
void buttonClicked(ActionEvent e) {
labelInfo.setText("restarting - might take a few seconds");
jBoss.restart();
labelInfo.setText("JBoss successfully restarted");
}
The action "jBoss.restart()" waits till the JBoss is restarted.
The problem:
the text "restarting - ..." is not displayed. The application waits till the JBoss is restarted and then it shows the Text "JBoss successfully restarted".
My thoughts:
the scene is refreshed AFTER the event is completed. So the first label-change will not happen.
How can i show a info message during an event?

The problem it's that the FX Thread has no safe operations. So I'm guessing that jBoss.restart() it's taking a lot of time. So you have to put this command in a Service. Also I recommend to you a progress indicator to show to the user you are making a long operation.
Here it is an example but I encourage you to go to Concurrency in JavaFX and take a deep look on it. Maybe there are other things that can help you.
import javafx.application.Application;
import javafx.concurrent.Service;
import javafx.concurrent.Task;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Test extends Application {
public static void main(String[] args) {
launch(args);
}
private Label labelInfo;
private Button button;
private ProgressIndicator progressIndicator;
#Override
public void start(Stage stage) throws Exception {
VBox vbox = new VBox(5);
vbox.setAlignment(Pos.CENTER);
labelInfo = new Label();
button = new Button("Restart");
button.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
buttonClicked(event);
}
});
progressIndicator = new ProgressIndicator(-1);
progressIndicator.setVisible(false);
vbox.getChildren().addAll(labelInfo, progressIndicator, button);
Scene scene = new Scene(vbox, 300, 200);
stage.setScene(scene);
stage.show();
}
void buttonClicked(ActionEvent e) {
Service<Void> service = new Service<Void>() {
#Override
protected Task<Void> createTask() {
return new Task<Void>() {
#Override
protected Void call() throws Exception {
updateMessage("restarting - might take a few seconds");
// Here the blocking operation
// jBoss.restart();
Thread.sleep(10000);
updateMessage("JBoss successfully restarted");
return null;
}
};
}
};
// Make the progress indicator visible while running
progressIndicator.visibleProperty().bind(service.runningProperty());
// Bind the message of the service to text of the label
labelInfo.textProperty().bind(service.messageProperty());
// Disable the button, to prevent more clicks during the execution of
// the service
button.disableProperty().bind(service.runningProperty());
service.start();
}
}

JavaFX: Binding Timeline's duration to a property

I have an application that has a combobox with some double values. The user can select any of the values. The application has a "TimeLine" attached to it that will print a statement on the console. The sscce is below. What should happen is that is should print the text of the option selected from the combobox. Pls advise.
package just.to.test;
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.stage.Stage;
import javafx.util.Duration;
public class TimerSample extends Application {
public static void main(String[] args) {
Application.launch(args);
}
#Override
public void start(Stage primaryStage) {
primaryStage.setTitle("Text Fonts");
Group g = new Group();
Scene scene = new Scene(g, 150, 100);
ObservableList<Double> data = FXCollections.observableArrayList();
data.add(5.0);
data.add(10.0);
data.add(15.0);
data.add(20.0);
ComboBox<Double> timeOptions = new ComboBox<Double>(data);
timeOptions.getSelectionModel().selectFirst();
g.getChildren().addAll(timeOptions);
primaryStage.setScene(scene);
primaryStage.show();
final double timerInterval = timeOptions.getSelectionModel().getSelectedItem();
KeyFrame keyFrame = new KeyFrame(Duration.seconds(timerInterval),
new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
System.out.println("This is called every "
+ timerInterval + " seconds");
}
});
Timeline timerThread = new Timeline(keyFrame);
timerThread.setCycleCount(Timeline.INDEFINITE);
timerThread.play();
}
}

You can't bind a Timeline's duration to a property because the duration of a Keyframe in a Timeline is not a property and you can only bind properties to properties.
What you need to do instead is to listen for changes in the value of the combo-box and trigger create new key frames with the new durations when the user selects a new duration. You also cannot modify the key frames of a running timeline, so you have to stop the timeline before you set the new keyframes for the timeline, then start the timeline after the new keyframes have been set.
Sample Code
import javafx.animation.*;
import javafx.application.Application;
import javafx.beans.value.*;
import javafx.collections.*;
import javafx.event.*;
import javafx.scene.*;
import javafx.scene.control.ComboBox;
import javafx.stage.Stage;
import javafx.util.Duration;
public class TimerSample extends Application {
public static void main(String[] args) {
Application.launch(args);
}
#Override
public void start(Stage stage) {
Group g = new Group();
Scene scene = new Scene(g, 150, 100);
ComboBox<Double> timerOptions = createTimerOptions(
0.5, 1.0, 1.5, 2.0
);
g.getChildren().addAll(timerOptions);
createTimer(timerOptions);
stage.setScene(scene);
stage.show();
}
private ComboBox<Double> createTimerOptions(double... options) {
ObservableList<Double> data = FXCollections.observableArrayList();
for (Double option: options) {
data.add(option);
}
return new ComboBox<Double>(data);
}
private void createTimer(ComboBox<Double> timeOptions) {
final Timeline timer = new Timeline();
timer.setCycleCount(Timeline.INDEFINITE);
timeOptions.valueProperty().addListener(new ChangeListener<Double>() {
#Override
public void changed(ObservableValue<? extends Double> observable, Double oldValue, Double newValue) {
resetTimer(timer, newValue);
}
});
timeOptions.getSelectionModel().selectFirst();
}
private void resetTimer(Timeline timer, final double timerInterval) {
KeyFrame keyFrame = new KeyFrame(
Duration.seconds(timerInterval),
new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
System.out.println(
"This is called every "
+ timerInterval
+ " seconds"
);
}
}
);
timer.stop();
timer.getKeyFrames().setAll(
keyFrame
);
timer.play();
}
}
just wondering if performance wise it is much heavier due to adding a new keyframe with every change in the combobox value.
Don't worry too much about performance in this case - this is a highly efficient operation.
There is no other solution than creating new key frames because key frames are immutable objects.
You could construct key frames up front or place them in something like a LRU cache as you lazily construct them, but in general the additional complexity involved will almost certainly not be worth it.

All animations have a rateProperty() which can be changed on a running animation!
This seems like a much cleaner solution:
private void createTimer(ComboBox<Double> timeOptions) {
Timeline timer = new Timeline(
new KeyFrame(Duration.seconds(1),
evt-> System.out.println(
"This is called every "
+ timeOptions.getValue()
+ " seconds"
));
timer.setCycleCount(Timeline.INDEFINITE);
timer.rateProperty()
.bind(new SimpleDoubleProperty(1.0)
.divide(timeOptions.valueProperty()));
timeOptions.getSelectionModel().selectFirst();
}