/*
   MouseDemoFX.java Copyright (c) Kari Laitinen

   http://www.naturalprogramming.com/

   2014-12-21 File created.
   2014-12-29 Last modification.


   This program demonstrates how a Java FX 8 program can react to
   mouse events. The program displays a large ellipse into the position
   where mouse cursor is moved. Inside the large ellipse it shows smaller
   ellipses when mouse buttons are pressed.
   
   This program shows how to find out which mouse button was used
   and whether the Ctrl or Shift key was pressed simulaneously with
   a mouse button.



*/


import javafx.application.Application;
import javafx.scene.input.* ; // MouseEvent, MouseButton
import javafx.scene.* ;
import javafx.stage.Stage;
import javafx.geometry.* ; // Point2D
import javafx.scene.paint.Color;
import javafx.scene.shape.Ellipse ;
import javafx.beans.property.* ; // DoubleProperty etc.

public class MouseDemoFX extends Application
{
   Group group_for_ellipses = new Group() ;

   Ellipse large_ellipse ;
   Ellipse left_small_ellipse, middle_small_ellipse, right_small_ellipse ;

   // The values of the DoubleProperty objects will be updated when
   // the position of the mouse cursor changes. Then, after these values
   // change, the positions of the ellipses will be adjusted accordingly.

   DoubleProperty event_position_x  =  new SimpleDoubleProperty() ;
   DoubleProperty event_position_y  =  new SimpleDoubleProperty() ;

   public void start( Stage stage )
   {
      stage.setTitle( "MouseDemoFX.java" ) ;

      Scene scene = new Scene( group_for_ellipses, 800, 600 ) ;

      scene.setFill( Color.LAVENDER ) ;

      // The large ellipse will be in the middle of the Scene at
      // the beginning.

      large_ellipse = new Ellipse( scene.getWidth() / 2,
                                   scene.getHeight() / 2, 80, 105 ) ;

      // The small ellipses, which represent the mouse buttons,
      // are defined without a location.

      left_small_ellipse   = new Ellipse( 16, 30 ) ;
      middle_small_ellipse = new Ellipse( 16, 30 ) ;
      right_small_ellipse  = new Ellipse( 16, 30 ) ;

      // The small ellipses are not visible when the program starts running.

      left_small_ellipse.visibleProperty().setValue( false ) ;
      middle_small_ellipse.visibleProperty().setValue( false ) ;
      right_small_ellipse.visibleProperty().setValue( false ) ;

      large_ellipse.setFill( Color.GRAY ) ;

      large_ellipse.setStroke( Color.BLACK ) ;

      left_small_ellipse.setStroke( Color.BLACK ) ;
      middle_small_ellipse.setStroke( Color.BLACK ) ;
      right_small_ellipse.setStroke( Color.BLACK ) ;


      // The following statements add listeners which specify how the
      // ellipses are re-located when the mouse cursor position changes.
      // The listeners are made with Lambda expressions.

      event_position_x.addListener(

         ( observable_value, value, new_value ) ->
         {
            large_ellipse.setCenterX( new_value.doubleValue() ) ;

            left_small_ellipse.setCenterX( new_value.doubleValue() - 40 ) ;
            middle_small_ellipse.setCenterX( new_value.doubleValue() ) ;
            right_small_ellipse.setCenterX( new_value.doubleValue() + 40 ) ;
         }
         
      ) ;

      event_position_y.addListener(

         ( observable_value, value, new_value ) ->
         {
            large_ellipse.setCenterY( new_value.doubleValue() + 75 ) ;

            left_small_ellipse.setCenterY( new_value.doubleValue() + 35 ) ;
            middle_small_ellipse.setCenterY( new_value.doubleValue() + 25 ) ;
            right_small_ellipse.setCenterY( new_value.doubleValue() + 35 ) ;
         }
         
      ) ;


      group_for_ellipses.getChildren().addAll( large_ellipse,
                                               left_small_ellipse,
                                               middle_small_ellipse,
                                               right_small_ellipse ) ;


      // The color of the Scene, i.e., the window backround, is different
      // depending on whether or not the mouse cursor is over the window.

      scene.setOnMouseEntered( ( MouseEvent event ) ->
      {
         scene.setFill( Color.LIGHTSKYBLUE ) ;
      } ) ;

      scene.setOnMouseExited( ( MouseEvent event ) ->
      {
         scene.setFill( Color.LAVENDER ) ;
      } ) ;


      scene.setOnMousePressed( ( MouseEvent event ) ->
      {
         event_position_x.setValue( event.getSceneX() ) ;
         event_position_y.setValue( event.getSceneY() ) ;

         // A small ellipse is made visible when a mouse button is pressed.
   
         if ( event.getButton()  ==  MouseButton.PRIMARY ) // Left
         {
            left_small_ellipse.visibleProperty().setValue( true ) ;
         }
         else if ( event.getButton()  ==  MouseButton.MIDDLE )
         {
            middle_small_ellipse.visibleProperty().setValue( true ) ;
         }
         else if ( event.getButton()  ==  MouseButton.SECONDARY ) // Right
         {
            right_small_ellipse.visibleProperty().setValue( true ) ;
         }
   
         //  The small ellipses will be shown with a different color
         //  if either the Ctrl or the Shift key is pressed down.

         if ( event.isControlDown() ==  true  ||
              event.isShiftDown()   ==  true )
         {
            left_small_ellipse.setFill( Color.MAGENTA ) ;
            middle_small_ellipse.setFill( Color.MAGENTA ) ;
            right_small_ellipse.setFill( Color.MAGENTA ) ;
         }
         else
         {
            left_small_ellipse.setFill( Color.YELLOW ) ;
            middle_small_ellipse.setFill( Color.YELLOW ) ;
            right_small_ellipse.setFill( Color.YELLOW ) ;
         }
      } ) ;


      //  The following statement specifies the actions when the mouse
      //  is moved without pressing its buttons.

      scene.setOnMouseMoved( ( MouseEvent event ) ->
      {
         event_position_x.setValue( event.getSceneX() ) ;
         event_position_y.setValue( event.getSceneY() ) ;
      } ) ;

      //  Dragging of the mouse means that it is moved while simultaneously
      //  pressing one or more of its buttons.

      scene.setOnMouseDragged( ( MouseEvent event ) ->
      {
         event_position_x.setValue( event.getSceneX() ) ;
         event_position_y.setValue( event.getSceneY() ) ;
      } ) ;

      scene.setOnMouseReleased( ( MouseEvent event ) ->
      {
         if ( event.getButton()  ==  MouseButton.PRIMARY ) // Left
         {
            left_small_ellipse.visibleProperty().setValue( false ) ;
         }
         else if ( event.getButton()  ==  MouseButton.MIDDLE )
         {
            middle_small_ellipse.visibleProperty().setValue( false ) ;
         }
         else if ( event.getButton()  ==  MouseButton.SECONDARY )
         {
            right_small_ellipse.visibleProperty().setValue( false ) ;
         }
      } ) ;

      stage.setScene( scene ) ;
      stage.show();
   }


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

/* NOTES:

The following links were useful when this program was developed:

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

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

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

https://docs.oracle.com/javase/8/javafx/api/javafx/beans/property/DoubleProperty.html

http://docs.oracle.com/javase/8/javafx/properties-binding-tutorial/binding.htm#JFXBD107
*/