import javafx.application.Application;
import javafx.event.*;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

public class CalculatorTwoApp extends Application {
    TextField 			valueField, answerField;
    RadioButton[]		buttons;

    public void start(Stage primaryStage) {
        Pane  aPane = new Pane();

        // Add the value label and text field
        Label	label = new Label("Input X:");
        label.relocate(10,10);   label.setPrefSize(100, 30);
        aPane.getChildren().add(label);

        valueField = new TextField();
        valueField.relocate(80,10);   valueField.setPrefSize(140, 30);
        aPane.getChildren().add(valueField);

        // Add the "operation type" radio buttons to the window
        // and to a ButtonGroup so that one is on at a time
        label = new Label("Operation:");
        label.relocate(10,55);   label.setPrefSize(100, 30);
        aPane.getChildren().add(label);

        ToggleGroup operations = new ToggleGroup();
        buttons = new RadioButton[4];
        String[] buttonLabels = {"X + X", "X * X", "X ^ 0.5", "1 / X"};
        for (int i=0; i<4; i++) {
            buttons[i] = new RadioButton(buttonLabels[i]);
            buttons[i].relocate(80, 60 + i*20);
            buttons[i].setPrefSize(150, 20);
            aPane.getChildren().add(buttons[i]);
            buttons[i].setToggleGroup(operations);
            buttons[i].setOnAction(new EventHandler<ActionEvent>() {
                // This is the single event handler for all of the radio buttons
                public void handle(ActionEvent event) {
                    if (!valueField.getText().matches("^[-,+]?[0-9]+")) {
                        answerField.setText("INVALID INPUT");
                        return;
                    }


                    int value = Integer.parseInt(valueField.getText());

                    // Find the number of the button that was clicked
                    int buttonNumber = 0;
                    for (buttonNumber=0; buttonNumber<4; buttonNumber++) {
                        if (buttons[buttonNumber] == event.getSource())
                            break;
                    }

                    // Perform the calculation
                    double result=0;
                    switch (buttonNumber) {
                        case 0: result = value + value; break;
                        case 1: result = value * value; break;
                        case 2: result = Math.sqrt(value); break;
                        case 3: result = 1 / (double)value; break;
                    }

                    // Show the answer
                    answerField.setText("" + result);
                }
            });
        }

        // Add the answer label and text field
        label = new Label("Answer:");
        label.relocate(10,150);   label.setPrefSize(100, 30);
        aPane.getChildren().add(label);

        answerField = new TextField();
        answerField.relocate(80,150);
        answerField.setPrefSize(140, 30);
        answerField.setEditable(false);
        aPane.getChildren().add(answerField);

        primaryStage.setTitle("Calc 2");
        primaryStage.setResizable(false);
        primaryStage.setScene(new Scene(aPane, 220,180));
        primaryStage.show();
    }

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