//  MouseDemoApplication.cs  (c) Kari Laitinen

//  http://www.naturalprogramming.com/

//  2008-02-18  File created.
//  2022-12-20  Tested in Developer Command Prompt for VS 2022.

//  This program demonstrates how a C# program can react to
//  mouse events. A kind of 'mouse' is drawn to the screen
//  when the mouse is moved.

//  The program shows how to find out which mouse button
//  is used during mouse operations. In addition this program
//  checks whether the Control or Shift key is pressed down 
//  simultaneously with a mouse button.


using System ;
using System.Windows.Forms ;
using System.Drawing ;

class MouseDemoForm : Form
{
   int current_mouse_position_x  =  265 ;
   int current_mouse_position_y  =  100 ;

   bool left_mouse_button_is_down    =  false ;
   bool middle_mouse_button_is_down  =  false ;
   bool right_mouse_button_is_down   =  false ;

   bool control_key_is_down  =  false ;
   bool shift_key_is_down    =  false ;

   public MouseDemoForm()
   {
      Text = "REACTING TO MOUSE EVENTS" ;
      Size = new Size( 600, 400 ) ;    // This sets the size of the window.
   }

   //  The following method will be called automatically by the
   //  program execution system when a mouse button is pressed
   //  down. The MouseEventArgs object that is received as a parameter
   //  contains information related to the mouse event.

   protected override void OnMouseDown( MouseEventArgs mouse_data )
   {
      current_mouse_position_x = mouse_data.X ;
      current_mouse_position_y = mouse_data.Y ;

      if ( mouse_data.Button  ==  MouseButtons.Left )
      {
         left_mouse_button_is_down  =  true ;
      }
      else if ( mouse_data.Button  ==  MouseButtons.Middle )
      {
         middle_mouse_button_is_down  =  true ;
      }
      else if ( mouse_data.Button  ==  MouseButtons.Right )
      {
         right_mouse_button_is_down  =  true ;
      }

      Invalidate() ;
   }

   //  The OnMouseMove() method is called when the mouse is moved.

   protected override void OnMouseMove( MouseEventArgs mouse_data )
   {
      current_mouse_position_x = mouse_data.X ;
      current_mouse_position_y = mouse_data.Y ;

      Invalidate() ;
   }

   protected override void OnMouseUp( MouseEventArgs mouse_data )
   {
      if ( mouse_data.Button  ==  MouseButtons.Left )
      {
         left_mouse_button_is_down  =  false ;
      }
      else if ( mouse_data.Button  ==  MouseButtons.Middle )
      {
         middle_mouse_button_is_down  =  false ;
      }
      else if ( mouse_data.Button  ==  MouseButtons.Right )
      {
         right_mouse_button_is_down  =  false ;
      }

      Invalidate() ;
   }

   protected override void OnKeyDown( KeyEventArgs key_data )
   {
      if ( key_data.Control  ==  true )
      {
         control_key_is_down  =  true ;
      }

      if ( key_data.Shift  ==  true )
      {
         shift_key_is_down    =  true ;
      }

      Console.Write( " " + control_key_is_down ) ;
   }

   protected override void OnKeyUp( KeyEventArgs key_data )
   {
      if ( key_data.Control  ==  false )
      {
         control_key_is_down  =  false ;
      }

      if ( key_data.Shift  ==  false )
      {
         shift_key_is_down    =  false ;
      }

      Console.Write( " " + control_key_is_down ) ;
   }


   protected override void OnPaint( PaintEventArgs paint_data )
   {
      Graphics graphics = paint_data.Graphics ;

      //  This method draws a kind of 'mouse' to the screen.

      //  The following statement draws a body for the mouse.
      //  The mouse body is a large rectangle.

      graphics.FillRectangle( new SolidBrush( Color.Black ),
                              current_mouse_position_x - 70,
                              current_mouse_position_y - 30,
                              140, 200 ) ;

      //  The mouse buttons will be drawn with red color if either
      //  the Ctrl or the Shift key is pressed down.

      SolidBrush brush_for_mouse_buttons ;

      if ( control_key_is_down == true  ||  shift_key_is_down == true )
      {
         brush_for_mouse_buttons = new SolidBrush( Color.Red ) ;
      }
      else
      {
         brush_for_mouse_buttons = new SolidBrush( Color.Yellow ) ;
      }

      //  We'll draw only those mouse buttons that are being pressed.
      //  Small rectangles represent mouse buttons.

      if ( left_mouse_button_is_down  ==  true )
      {
         graphics.FillRectangle( brush_for_mouse_buttons,
                                 current_mouse_position_x - 50,
                                 current_mouse_position_y,
                                 30, 60 ) ;
      }


      if ( middle_mouse_button_is_down  ==  true )
      {
         graphics.FillRectangle( brush_for_mouse_buttons, 
                                 current_mouse_position_x - 15,
                                 current_mouse_position_y,
                                 30, 60 ) ;
      }


      if ( right_mouse_button_is_down  ==  true )
      {
         graphics.FillRectangle( brush_for_mouse_buttons, 
                                 current_mouse_position_x + 20,
                                 current_mouse_position_y,
                                 30, 60 ) ;
      }

   }
}


class MouseDemoApplication
{
   static void Main()
   {
      Application.Run( new MouseDemoForm() ) ;
   }
}