Java tutorial
import javafx.application.Application; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.control.CheckBox; import javafx.stage.Stage; public class Main extends Application { public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) { Scene scene = new Scene(new Group()); stage.setWidth(300); stage.setHeight(150); final CheckBox cb = new CheckBox(); cb.setText("checkBox"); cb.setAllowIndeterminate(true); cb.indeterminateProperty().addListener(new ChangeListener<Boolean>() { public void changed(ObservableValue<? extends Boolean> ov, Boolean old_val, Boolean new_val) { System.out.println(cb.isSelected()); } }); ((Group) scene.getRoot()).getChildren().add(cb); stage.setScene(scene); stage.show(); } }