26. ComboBox

We have a ComboBox with 3 options to select a different color.

Depending on the color, we paint the circle and set the label text. We also style the text to be 16 pt.

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package ex26;

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Label;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;

public class Ex26 extends Application {

    // comboBox;

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

    @Override
    public void start(Stage primaryStage) throws Exception {
        primaryStage.setTitle("Example 26. ComboBox");
        
        ComboBox<String> comboBox = new ComboBox<>();
        comboBox.getItems().addAll(
                "Red",
                "Green",
                "Blue"
        );
        comboBox.setValue("Red");
        
        Label label = new Label("Initial Color: Red");
        Circle circle = new Circle(50, Color.RED);

        comboBox.setPromptText("Color");
        comboBox.setOnAction( e -> {
            String col = comboBox.getValue();
            label.setText("Selected Color: " + col);
            switch(col) {
                case "Red":
                    circle.setFill(Color.RED);
                    break;
                case "Green":
                    circle.setFill(Color.GREEN);
                    break;
                case "Blue":
                    circle.setFill(Color.BLUE);
                    break;
                default:
                    break;
            }
        });

        VBox layout = new VBox(50);
        layout.setPadding(new Insets(50));
        layout.getChildren().addAll(comboBox, label, circle);
        layout.setStyle("-fx-font-size: 16pt;");

        Scene scene = new Scene(layout, 400, 400);
        primaryStage.setScene(scene);
        primaryStage.show();
    }
}

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This is the output:

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