import javafx.application.Application;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.scene.Scene;
import javafx.stage.Stage;
import javafx.geometry.Insets;

/**
 * This simple program demonstrates several GUI components that are available in the
 * Java FX library.  The program shows a window containing a button, a text input
 * box, a choice box (pop-up menu), and a text area.  The text area is used for
 * a "transcript" that records interactions of the user with the other components.
 */
public class GUIDemo extends Application {

    /**
     * This main routine allows this class to be run as an application.  This is 
     * required for running Java FX programs in some versions of Java, but should
     * not be necessary in more recent versions.
     */
    public static void main(String[] args) {
        launch(args);
    }

    //-----------------------------------------------------------------------------------


    /**
     * This constructor adds several GUI components to the panel and sets
     * itself up to listen for action events from some of them.
     */
    public void start(Stage stage) {
        
        GridPane root = new GridPane();
            // I will put the transcript area in the right half of the
            // pane. The left half will be occupied by a grid of 4 rows
            // and two columns. Each row contains a component and
            // a label for that component.
        
        root.setHgap(8);
        root.setVgap(10);
        root.setPadding(new Insets(5,5,5,5));

        TextArea transcript = new TextArea();
        transcript.setEditable(false);
        transcript.setPrefRowCount(7);
        transcript.setPrefColumnCount(20);
        root.add(transcript, 2, 0, 1, 4);

        Label lab = new Label("Push Button:");
        root.add(lab, 0, 0);
        Button b = new Button("Click Me!");
        b.setOnAction( e -> transcript.appendText("Button was clicked\n\n") );
        root.add(b, 1, 0);

        lab = new Label("Checkbox:");
        root.add(lab, 0, 1);
        CheckBox c = new CheckBox("Click me!");
        c.setOnAction( e -> transcript.appendText("Checkbox was toggled\n\n") );
        root.add(c, 1, 1);

        lab = new Label("Text Field:");
        root.add(lab, 0, 2);
        TextField t = new TextField("Type here!");
        t.setPrefColumnCount(10);
        t.setOnAction( e -> transcript.appendText(
                              "Pressed return in TextField\nwith contents:  " + t.getText() + "\n\n") );
        root.add(t, 1, 2);

        lab = new Label("Pop-up Menu:");
        root.add(lab, 0, 3);
        ComboBox<String> combobox = new ComboBox<>();
        combobox.getItems().addAll("First Option", "Second Option", "Third Option", "Fourth Option");
        combobox.setValue("First Option");
        combobox.setOnAction( e -> transcript.appendText("Selected " + 
                                       combobox.getValue() + " from menu\n\n") );
        root.add(combobox, 1, 3);
        root.setStyle("-fx-border-width: 3px; -fx-border-color: darkblue");
        
        Scene scene = new Scene(root);
        stage.setScene(scene);
        stage.setTitle("GUIDemo");
        stage.show();
        stage.setResizable(false);
    }


} // end class GUIDemo