#  MenuDemoApplicationQt.py

#  http://www.naturalprogramming.com

#  2009-12-14  File received from Mikko Karjalainen.
#  2010-09-23  Many names made more informative.
#  2010-09-30  Last modification by Kari Laitinen.

#  The first PyQt version of this program was developed by 
#  Mikko Karjalainen.

#  This program represents a traditional GUI (Graphical
#  User Interface) application that provides menus
#  for the user to make selections.

#  In addition to menus, this program shows how
#    -- a QMessageBox can be activated
#    -- how to make a Python Qt application to quit itself

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

class MenuDemoWindow( QMainWindow ) :

   def __init__( self, parent = None ) :

      QMainWindow.__init__( self )

      self.setWindowTitle( "Qt GUI Application with Menus" )
      self.resize( 600, 500 )

      self.last_selected_action = "No Selections Made"
      
      self.font_in_use = QFont( "Serif", 14 )
      
      #Create actions for menu
      file_open_action = QAction( "&Open", self )
      file_open_action.setShortcut( "Ctrl+O" )
      file_open_action.setStatusTip( "&Open a file" )
      self.connect( file_open_action, SIGNAL("triggered()"),
                    self.file_open_action_selected )

      file_save_action = QAction("&Save", self)
      file_save_action.setShortcut("Ctrl+S")
      file_save_action.setStatusTip("&Save a file")
      self.connect( file_save_action, SIGNAL( "triggered()" ),
                    self.file_save_action_selected )

      exit_action = QAction( "&Quit", self )
      exit_action.setShortcut( "Ctrl+Q" )
      exit_action.setStatusTip( "Exit application" )
      self.connect( exit_action, SIGNAL( "triggered()" ), 
                    SLOT( "close()" ) )

      copy_action = QAction( "&Copy", self )
      self.connect( copy_action, SIGNAL( "triggered()" ),
                    self.copy_action_selected )
      paste_action = QAction( "&Paste", self )
      self.connect( paste_action, SIGNAL( "triggered()" ),
                    self.paste_action_selected )

      self.cyan_background_action = QAction( "&Cyan background", self )
      self.cyan_background_action.setCheckable( True )
      self.connect( self.cyan_background_action, SIGNAL( "triggered()" ),
                    self.background_color_changed )
      
      self.small_text_action = QAction( "&Small", self )
      self.small_text_action.setCheckable( True )
      self.medium_text_action = QAction( "&Medium", self )
      self.medium_text_action.setCheckable( True )
      self.large_text_action = QAction( "&Large", self )
      self.large_text_action.setCheckable( True )

      self.connect( self.small_text_action, SIGNAL("triggered()"),
                    self.text_size_changed)
      self.connect( self.medium_text_action, SIGNAL("triggered()"),
                    self.text_size_changed)
      self.connect( self.large_text_action, SIGNAL("triggered()"),
                    self.text_size_changed)

      text_size_actionGroup = QActionGroup( self )
      text_size_actionGroup.addAction( self.small_text_action )
      text_size_actionGroup.addAction( self.medium_text_action )
      text_size_actionGroup.addAction( self.large_text_action )
      text_size_actionGroup.setExclusive( True )

      text_size_menu = QMenu( "&Text size", self )

      text_size_menu.addAction( self.small_text_action )
      text_size_menu.addAction( self.medium_text_action )
      text_size_menu.addAction( self.large_text_action )
      self.medium_text_action.setChecked( True )

      about_action = QAction( "&About", self )
      self.connect( about_action, SIGNAL( "triggered()" ),
                    self.about_action_selected )

      # Create a MenuBar for this window
      menubar_of_this_window = self.menuBar()

      file_menu = menubar_of_this_window.addMenu( "&File" )
      file_menu.addAction( file_open_action )
      file_menu.addAction( file_save_action )
      file_menu.addAction( exit_action )

      edit_menu = menubar_of_this_window.addMenu( "&Edit" )
      edit_menu.addAction( copy_action )
      edit_menu.addAction( paste_action )

      settings_menu = menubar_of_this_window.addMenu( "&Settings" )
      settings_menu.addAction( self.cyan_background_action )
      settings_menu.addMenu( text_size_menu )

      help_menu = menubar_of_this_window.addMenu( "&Help" )
      help_menu.addAction( about_action )


   def file_open_action_selected( self ) :

      self.last_selected_action = "Open"
      self.update()

   def file_save_action_selected( self ) :

      self.last_selected_action = "Save"
      self.update()

   def copy_action_selected( self ) :

      self.last_selected_action = "Copy"
      self.update()

   def paste_action_selected( self ) :

      self.last_selected_action = "Paste"
      self.update()

   def about_action_selected( self ) :

      self.last_selected_action = "About"

      QMessageBox.about( self, "About this application",
                               "This is a simple GUI application" )
      self.update()

   def text_size_changed( self ) :

      if self.small_text_action.isChecked() :
         self.font_in_use.setPointSize( 10 )
         self.last_selected_action = "Small text"
      elif self.medium_text_action.isChecked() :
         self.font_in_use.setPointSize( 14 )
         self.last_selected_action = "Medium text"         
      elif self.large_text_action.isChecked() :
         self.font_in_use.setPointSize( 18 )
         self.last_selected_action = "Large text"
      
      self.update()
      
   def background_color_changed( self ) :

      self.last_selected_action = "Cyan background"         
      
      self.update()

   def paintEvent( self, event ) :
   
      painter = QPainter()

      painter.begin( self )

      if self.cyan_background_action.isChecked() :

         painter.fillRect( 0, 0, self.width(), self.height(), Qt.cyan )

      painter.setFont( self.font_in_use )

      painter.drawText( 100, 200, "Last selected action \""  +
                                  self.last_selected_action  +  "\"" )

      painter.end()

      
this_application = QApplication( sys.argv )
application_window = MenuDemoWindow()
application_window.show()
this_application.exec_()