Main.java Source code

Introduction

Here is the source code for Main.java

Source

//Revised from javafx api document
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.scene.layout.GridPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.util.Callback;

public class Main extends Application {
    public static void main(String[] args) {
        Application.launch(args);
    }

    @Override
    public void start(final Stage primaryStage) {
        Group root = new Group();
        Scene scene = new Scene(root, 400, 300, Color.WHITE);
        GridPane gridpane = new GridPane();
        ComboBox<Color> cmb = new ComboBox<Color>();
        cmb.getItems().addAll(Color.RED, Color.GREEN, Color.BLUE);
        cmb.setCellFactory(new Callback<ListView<Color>, ListCell<Color>>() {
            @Override
            public ListCell<Color> call(ListView<Color> p) {
                return new ListCell<Color>() {
                    private final Rectangle rectangle;
                    {
                        setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
                        rectangle = new Rectangle(10, 10);
                    }

                    @Override
                    protected void updateItem(Color item, boolean empty) {
                        super.updateItem(item, empty);

                        if (item == null || empty) {
                            setGraphic(null);
                        } else {
                            rectangle.setFill(item);
                            setGraphic(rectangle);
                        }
                    }
                };
            }
        });

        gridpane.add(cmb, 2, 0);

        root.getChildren().add(gridpane);
        primaryStage.setScene(scene);

        primaryStage.show();
    }

}