/*
   MovingBallFX.java Copyright (c) Kari Laitinen

   http://www.naturalprogramming.com/

   2014-12-10 File created.
   2014-12-27 Last modification.


   This program shows a ball that can be moved with buttons.
   The color of the ball can be adjusted with a ChoiceBox.

*/


import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.* ;
import javafx.scene.control.* ; // Label, Button, ChoiceBox

import javafx.scene.layout.* ;
import javafx.stage.Stage;
import javafx.geometry.* ; // Pos, Insets

import javafx.scene.paint.Color;

import javafx.scene.shape.Circle ;

import javafx.collections.* ; // FXCollections etc.
import javafx.beans.value.* ; // ChangeListener, ObservableValue
import javafx.beans.binding.ObjectBinding ;


public class MovingBallFX extends Application
{
   public void start( Stage stage )
   {
      Circle ball_on_screen = new Circle( 100, 100, 50, Color.RED ) ;

      ball_on_screen.setStroke( Color.BLACK ) ; // Black outline for the ball

      Button left_button = new Button( " < " ) ;
      Button up_button   = new Button( " Up " ) ;
      Button down_button = new Button( " Down " ) ;
      Button right_button = new Button( " > " ) ;


      left_button.setOnAction( ( ActionEvent event ) ->
      {
         ball_on_screen.setCenterX( ball_on_screen.getCenterX() - 3 ) ;         
      } ) ;

      up_button.setOnAction( ( ActionEvent event ) ->
      {
         ball_on_screen.setCenterY( ball_on_screen.getCenterY() - 3 ) ;         
      } ) ;

      down_button.setOnAction( ( ActionEvent event ) ->
      {
         ball_on_screen.setCenterY( ball_on_screen.getCenterY() + 3 ) ;         
      } ) ;

      right_button.setOnAction( ( ActionEvent event ) ->
      {
         ball_on_screen.setCenterX( ball_on_screen.getCenterX() + 3 ) ;         
      } ) ;


      Label ball_coordinates_label = new Label() ;

      HBox ball_coordinates_pane = new HBox() ;

      ball_coordinates_pane.getChildren().add( ball_coordinates_label ) ;
      ball_coordinates_pane.setPadding( new Insets( 10, 0, 0, 10 ) ) ;

      // Next we'll specify that whenever the ball coordinates change,
      // the text inside the Label that shows the coordinates will be
      // changed as well.

      // First we'll build a Binding object to compute the coordinates text.

      ObjectBinding<String> coordinates_text_binding = new ObjectBinding<String>()
      {

         {
             super.bind( ball_on_screen.centerXProperty(),
                         ball_on_screen.centerYProperty() ) ;
         }

         @Override
         protected String computeValue()
         {
             return "(" +  (int) ball_on_screen.getCenterX() +
                    ", " + (int) ball_on_screen.getCenterY() + ")" ;
         }
      };


      ball_coordinates_label.textProperty().bind( coordinates_text_binding ) ;

      ObservableList<String> selectable_color_names =

            FXCollections.observableArrayList(

              "Red", "Orange", "Yellow", "Green",
              "Blue", "Magenta", "Cyan", "Pink",
              "LightGray" ) ;


      ChoiceBox<String> color_selection_box = new ChoiceBox<String>();

      color_selection_box.setItems( selectable_color_names ) ;
      color_selection_box.setValue( "Red" ) ;

      Color[] selectable_colors =

            { Color.RED, Color.ORANGE, Color.YELLOW, Color.GREEN,
              Color.BLUE, Color.MAGENTA, Color.CYAN, Color.PINK,
              Color.LIGHTGRAY } ;


      color_selection_box.getSelectionModel().
                            selectedIndexProperty().addListener(

         ( observable_value, value, new_value ) ->
         {
            ball_on_screen.setFill(
                  selectable_colors[ new_value.intValue() ] ) ;
         }
         
      ) ;

      HBox operations_pane = new HBox();

      operations_pane.getChildren().addAll(
            left_button, up_button, down_button, right_button,
            color_selection_box ) ;

      operations_pane.setAlignment( Pos.CENTER ) ; // The Box is centered
      operations_pane.setSpacing( 16 ) ; // Put some space between buttons

      // With an Insets object we can specify empty space around the HBox.
      // There will be 20 pixels padding below the HBox.
      operations_pane.setPadding( new Insets( 0, 0, 20, 0 ) ) ;


      BorderPane border_pane = new BorderPane() ;


      border_pane.setTop( ball_coordinates_pane ) ;
      border_pane.setBottom( operations_pane ) ;


      StackPane stack_pane = new StackPane() ;

      // With the following statement we disble the automatic layout
      // management of the Circle object.
      ball_on_screen.setManaged( false ) ;

      stack_pane.getChildren().addAll( ball_on_screen, border_pane ) ;

      Scene scene = new Scene( stack_pane, 600, 480 ) ;

      // The ball will be positioned in the middle of the scene. 
      ball_on_screen.setCenterX( scene.getWidth() / 2 ) ;
      ball_on_screen.setCenterY( scene.getHeight() / 2 ) ;

      stage.setTitle( "MovingBallFX.java" ) ;
      stage.setScene( scene ) ;
      stage.show();
   }


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

/* NOTES:

The following links useful while developing this program:

http://docs.oracle.com/javase/8/javafx/user-interface-tutorial/choice-box.htm#BCEDJAEH

http://stackoverflow.com/questions/14134397/how-to-disable-automatic-layout-for-a-javafx-group

http://docs.oracle.com/javafx/2/ui_controls/choice-box.htm

https://docs.oracle.com/javase/8/javafx/api/javafx/scene/shape/Circle.html



// Here is another possibility to set the listener for the ChoiceBox:

      color_selection_box.getSelectionModel().
                            selectedIndexProperty().addListener(
         new ChangeListener<Number>()
         {
            public void changed( ObservableValue observable_value,
                                 Number value,
                                 Number new_value )
            {
               ball_on_screen.setFill(
                  selectable_colors[ new_value.intValue() ] ) ;
            }
         } 
      ) ;


*/