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1. Exkurs: JavaFX-Spinner

A Spinner in JavaFX is a UI control that allows users to select a value from a sequence by either typing it or using arrow buttons to increment/decrement the value.

1.1. Basic Usage

To create a numeric Spinner:

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Spinner;
import javafx.scene.control.SpinnerValueFactory;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class SpinnerExample extends Application {

    @Override
    public void start(Stage stage) {
        // Create a Spinner for numbers
        Spinner<Integer> spinner = new Spinner<>();

        // Set the value factory (range: 1 to 100, initial value: 50, step: 1)
        spinner.setValueFactory(new SpinnerValueFactory.IntegerSpinnerValueFactory(1, 100, 50, 1));

        // Add spinner to the scene
        VBox root = new VBox(10, spinner);
        root.setStyle("-fx-padding: 20; -fx-alignment: center;");

        Scene scene = new Scene(root, 300, 200);
        stage.setScene(scene);
        stage.setTitle("JavaFX Spinner Example");
        stage.show();
    }

    public static void main(String[] args) {
        launch();
    }
}

1.2. Spinner with Strings

A Spinner can use a list of values, such as strings:

Spinner<String> stringSpinner = new Spinner<>();
SpinnerValueFactory<String> valueFactory =
    new SpinnerValueFactory.ListSpinnerValueFactory<>(FXCollections.observableArrayList("Option 1", "Option 2", "Option 3"));

stringSpinner.setValueFactory(valueFactory);

1.3. Event Handling

You can listen to changes in the spinner’s value using a listener:

spinner.valueProperty().addListener((observable, oldValue, newValue) -> {
    System.out.println("Selected Value: " + newValue);
});

1.4. Editable Spinner

By default, a Spinner is editable. You can disable editing as follows:

spinner.setEditable(false);

1.5. Styling the Spinner

The Spinner can be styled using CSS:

.spinner {
    -fx-background-color: lightblue;
    -fx-padding: 5;
}

To apply the CSS file:

scene.getStylesheets().add("style.css");

1.6. Advanced Example: Spinner with Different Step Sizes

You can configure a Spinner with specific step sizes:

Spinner<Double> doubleSpinner = new Spinner<>();
doubleSpinner.setValueFactory(new SpinnerValueFactory.DoubleSpinnerValueFactory(0.0, 10.0, 5.0, 0.5));

1.7. Common Methods

  • getValue(): Retrieves the current value of the spinner.

  • setValue(): Sets a specific value for the spinner.

  • increment(int steps): Increases the spinner’s value by a specified number of steps.

  • decrement(int steps): Decreases the spinner’s value by a specified number of steps.

1.8. References

This content was createt with ChatGPT (Prompt: How to to use spinner in JavaFx)

2. 2025-03-25

2.1. Sockets

Erstellen des ServerSockets
var serverSocket = ServerSocketFactory
                .getDefault()
                .createServerSocket(8080);

  1. Handler für einkommende Requests (ClientSocket)

Socket clientSocket = serverSocket.accept();
handleConnect(clientSocket);

  1. Streams für Input und Output

var outputStream = clientSocket.getOutputStream();
var inputStream = clientSocket.getInputStream();