#  SinglePictureQt.java  (c) Kari Laitinen

#  http://www.naturalprogramming.com/

#  2009-11-09  File created.
#  2009-11-09  Last modification.

#  This program demonstrates how a PyQt program can show
#  and scale pictures. The picture file must be in the same
#  folder where this program is located.

import sys
from PyQt4 import QtGui, QtCore

class SinglePictureWindow( QtGui.QWidget ) :

   def __init__( self, parent=None ) :

      QtGui.QWidget.__init__( self, parent )

      self.setGeometry( 100, 100, 800, 480 )
 
      self.setWindowTitle( "SINGLE PICTURE IN SEVERAL SIZES" )
      
      self.picture_to_show = QtGui.QImage(
                             "governor_arnold_schwarzenegger.jpg" )

   def paintEvent( self, event ) :

      painter = QtGui.QPainter()
      
      painter.begin( self )
      
      
      picture_width   =  self.picture_to_show.width()
      picture_height  =  self.picture_to_show.height()

      picture_position_x  =  15
      picture_position_y  =  15

      painter.drawImage( picture_position_x, picture_position_y,
                         self.picture_to_show )

      picture_position_x  =  picture_position_x  +  picture_width + 10

      #  Next we'll show a smaller version of the picture.
      #  The first parameter for the drawImage() method specifies
      #  the rectangle into which a smaller picture is drawn.
      #  The third parameter specifies that we use the whole picture
      #  which we'll squeeze into the smaller rectangle.

      painter.drawImage( QtCore.QRect( picture_position_x, picture_position_y,
                                       picture_width / 2, picture_height / 2 ),
                         self.picture_to_show,
                         QtCore.QRect( 0, 0,
                                       picture_width, picture_height ) )

      picture_position_x  =  picture_position_x  +  picture_width / 2  +  10

      #  Finally, we'll show the picture so that its width is enlarged.
      #  Here we use class QRectF in place of QRect. The letter F in
      #  the class name means that we can use floating-point values.

      painter.drawImage( QtCore.QRectF( picture_position_x, picture_position_y,
                                        picture_width * 1.5, picture_height ),
                         self.picture_to_show,
                         QtCore.QRectF( 0, 0,
                                        picture_width, picture_height ) )
      painter.end()

#  Here is the main program:

this_application = QtGui.QApplication( sys.argv )
application_window = SinglePictureWindow()
application_window.show()
this_application.exec_()