#  MouseDemoQt.py  (c) Kari Laitinen

#  http://www.naturalprogramming.com

#  2009-11-30  File created.
#  2010-09-22  Last modification.

#  This program demonstrates 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.


# http://www.riverbankcomputing.co.uk/static/Docs/PyQt4/html/qmouseevent.html

import sys

from PyQt4.QtCore import *
from PyQt4.QtGui import *

 
class MouseDemoWindow( QWidget ) :

   def __init__( self, parent = None ) :

      QWidget.__init__( self, parent )

      self.setGeometry( 200, 200, 680, 480 )

      self.setWindowTitle( "TESTING MOUSE BUTTONS" )

      self.current_cursor_position_x  =  340
      self.current_cursor_position_y  =  120

      self.left_mouse_button_is_down    =  False
      self.middle_mouse_button_is_down  =  False
      self.right_mouse_button_is_down   =  False

      self.control_key_is_down  =  False
      self.shift_key_is_down    =  False
      
      # As mouse tracking is set on with the following statement,
      # MouseMOVeEvents are generated also when the mouse is moved
      # without pressing its buttons.

      self.setMouseTracking( True )

      # The following statement may help to get keyboard input
      # to this window.

      self.setFocusPolicy( Qt.StrongFocus )

   def mousePressEvent( self, event ) :

      self.current_cursor_position_x = event.x()
      self.current_cursor_position_y = event.y()

      if  event.button()  ==  Qt.LeftButton  :

         self.left_mouse_button_is_down  =  True

      elif  event.button()  ==  Qt.MidButton  :

         self.middle_mouse_button_is_down  =  True

      elif  event.button()  ==  Qt.RightButton  :

         self.right_mouse_button_is_down  =  True

      self.update()



   def mouseMoveEvent( self, event ) :

      self.current_cursor_position_x = event.x()
      self.current_cursor_position_y = event.y()

      self.update()


   def mouseReleaseEvent( self, event ) :

      if  event.button()  ==  Qt.LeftButton  :

         self.left_mouse_button_is_down  =  False

      elif  event.button()  ==  Qt.MidButton  :

         self.middle_mouse_button_is_down  =  False

      elif  event.button()  ==  Qt.RightButton  :

         self.right_mouse_button_is_down  =  False

      self.update()


   def keyPressEvent( self, event ) :

      if  event.key() == Qt.Key_Control :

         self.control_key_is_down  =  True 

      elif event.key() == Qt.Key_Shift :

         self.shift_key_is_down  =  True 


   def keyReleaseEvent( self, event ) :

      if  event.key() == Qt.Key_Control :

         self.control_key_is_down  =  False 

      elif event.key() == Qt.Key_Shift :

         self.shift_key_is_down  =  False 


   def paintEvent( self, event ) :

      painter = QPainter()

      painter.begin( self )

      #  We'll change the backround by filling the entire
      #  window area with a new color
      
      painter.fillRect( QRect( 0, 0, self.width(), self.height() ),
                        QColor( 0xC8, 0xDC, 0xFF ) ) # light blueish 

      painter.setBrush( Qt.darkGray )

      #  The following statement draws a body for the mouse.
      #  The mouse body is a large ellipse.

      painter.drawEllipse( self.current_cursor_position_x - 80,
                           self.current_cursor_position_y - 30,
                           160, 210 )


      if  self.control_key_is_down  ==  True  or \
          self.shift_key_is_down    ==  True :

         painter.setBrush( Qt.magenta ) ;

      else :

         painter.setBrush( Qt.yellow ) ;


      if  self.left_mouse_button_is_down  ==  True :

         painter.drawEllipse( self.current_cursor_position_x - 55,
                              self.current_cursor_position_y + 5,
                              30, 60 )

      if  self.middle_mouse_button_is_down  ==  True :

         painter.drawEllipse( self.current_cursor_position_x - 15,
                              self.current_cursor_position_y - 5,
                              30, 60 )

      if  self.right_mouse_button_is_down  ==  True :

         painter.drawEllipse( self.current_cursor_position_x + 25,
                              self.current_cursor_position_y + 5,
                              30, 60 )

      painter.end()


#  The main program begins.

this_application = QApplication( sys.argv )

application_window = MouseDemoWindow()

application_window.show()

this_application.exec_()