import javafx.event.ActionEvent;
import javafx.geometry.HPos;
import javafx.geometry.Pos;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.scene.text.Font;

//************************************************************************
//  FahrenheitPane.java       Author: Lewis/Loftus
//
//  Demonstrates the use of a TextField and a GridPane.
//************************************************************************

public class FahrenheitPane extends GridPane
{
    private Label result;
    private TextField fahrenheit;

    //--------------------------------------------------------------------
    //  Sets up a GUI containing a labeled text field for converting
    //  temperatures in Fahrenheit to Celsius.
    //--------------------------------------------------------------------
    public FahrenheitPane()
    {
        Font font = new Font(18);
        
        Label inputLabel = new Label("Fahrenheit:");
        inputLabel.setFont(font);
        GridPane.setHalignment(inputLabel, HPos.RIGHT);
        
        Label outputLabel = new Label("Celsius:");
        outputLabel.setFont(font);
        GridPane.setHalignment(outputLabel, HPos.RIGHT);
        
        result = new Label("---");
        result.setFont(font);
        GridPane.setHalignment(result, HPos.CENTER);
        
        fahrenheit = new TextField();
        fahrenheit.setFont(font);
        fahrenheit.setPrefWidth(50);
        fahrenheit.setAlignment(Pos.CENTER);
        fahrenheit.setOnAction(this::processReturn);
        
        setAlignment(Pos.CENTER);
        setHgap(20);
        setVgap(10);
        setStyle("-fx-background-color: yellow");
        
        add(inputLabel, 0, 0);
        add(fahrenheit, 1, 0);
        add(outputLabel, 0, 1);
        add(result, 1, 1);
    }
    
    //--------------------------------------------------------------------
    //  Computes and displays the converted temperature when the user
    //  presses the return key while in the text field.
    //--------------------------------------------------------------------
    public void processReturn(ActionEvent event)
    {
        int fahrenheitTemp = Integer.parseInt(fahrenheit.getText());
        int celsiusTemp = (fahrenheitTemp - 32) * 5 / 9;
        result.setText(celsiusTemp + "");
    }
}