attachment:ThreadedProcess_Demo.py of WorkingWithThreads

   1 """
   2 ThreadedProcess_Try.py
   3 
   4 Derived from "wxPython and Threads" in "Mouse vs python" by Mike Driscol
   5 @ http://www.blog.pythonlibrary.org/2010/05/22/wxpython-and-threads/
   6 
   7 Demonstration of a threaded process which sends back multiple
   8 message types using a single message name.
   9 
  10 """
  11 
  12 import time
  13 import random
  14 from threading import Thread
  15 
  16 import wx
  17  
  18 from wx.lib.pubsub import Publisher
  19 
  20 #------------------------------------------------------------------------------
  21 
  22 class MyFrame( wx.Frame ) :
  23  
  24     def __init__( self ) :
  25         
  26         wx.Frame.__init__( self, None, -1, 'Threading Tutorial', pos=(40, 40) )
  27         self.SetClientSize( (500, 500) )
  28         
  29         self.frmPanel = wx.Panel( self, wx.ID_ANY )
  30         
  31         self.btn = wx.Button( self.frmPanel, label='Start Thread' )
  32         self.btn.Bind( wx.EVT_BUTTON, self.OnButton )
  33         
  34         self.displayTxtCtrl = wx.TextCtrl( self.frmPanel, -1, 
  35                                            style=wx.TE_MULTILINE|wx.TE_READONLY )
  36         font = wx.Font( 9, wx.MODERN, wx.NORMAL, wx.NORMAL, False )
  37         self.displayTxtCtrl.SetFont( font )     #  a bigger font
  38         
  39         #-----  Lay out the two controls
  40         
  41         self.LayoutFrmPanel()
  42         
  43         #-----
  44         
  45         # Create a pubsub receiver.
  46         Publisher().subscribe( self.DisplayThreadMessages, 'update' )
  47         
  48     #end __init__
  49     
  50     #----------------------------------
  51     
  52     def LayoutFrmPanel( self ) :
  53         """ A simple and clean layout. """
  54         
  55         sizer = wx.BoxSizer( wx.VERTICAL )
  56         sizer.Add ( (0, 15) )                                       # a vertical spacer at the top
  57         sizer.Add( self.btn,            0, wx.CENTER  )             # center using its "best size"
  58         sizer.Add ( (0, 15) )                                       # spacer between controls
  59         sizer.Add( self.displayTxtCtrl, 1, wx.EXPAND|wx.CENTER )    # Expand along both axes.
  60         sizer.Add ( (0, 15) )                                       # bottom spacer
  61         
  62         self.frmPanel.SetSizer( sizer )
  63     
  64     #----------------------------------
  65     
  66     def OnButton( self, event ) :
  67         """ Creates the thread and then starts it. """
  68         
  69         self.btn.Disable()
  70         
  71         status = TestThread()               # Create and start the thread.
  72         statusMsg = 'OnButton():    status = %s\n\n' % (status)
  73         
  74         self.displayTxtCtrl.WriteText( '\nOnButton():    Thread started.\n' )
  75         self.displayTxtCtrl.WriteText( statusMsg )
  76         
  77         self.btn.Disable()
  78         
  79     #end def
  80     
  81     #----------------------------------
  82     
  83     def DisplayThreadMessages( self, msg ) :
  84         """ Receives data from thread and updates the display. """
  85 
  86         msgData = msg.data
  87         if isinstance( msgData, str ) :
  88             self.displayTxtCtrl.WriteText( 'Textual message = [ %s ]\n' % (msgData) )
  89         
  90         elif isinstance( msgData, float ) :
  91             self.displayTxtCtrl.WriteText( '\n' )   # A blank line separator.
  92             self.displayTxtCtrl.WriteText( 'Processing time was [ %s ] secs.\n' % (msgData) )
  93         
  94         elif isinstance( msgData, int ) :
  95             
  96             if (msgData == -1) :    # This flag value indicates 'Thread processing has completed'.
  97                 self.btn.Enable()   # The GUI is now ready for another thread to start.
  98                 self.displayTxtCtrl.WriteText( 'Integer ThreadCompletedFlag = [ %d ]\n' % (msgData) )
  99             
 100             else :
 101                 self.displayTxtCtrl.WriteText( 'Integer Calculation Result = [ %d ]\n' % (msgData) )
 102         #end if
 103         
 104     #end DisplayThreadMessages def
 105     
 106 #end MyFrame class
 107 
 108 #------------------------------------------------------------------------------
 109 #==============================================================================
 110 #------------------------------------------------------------------------------
 111 
 112 class TestThread( Thread ) :
 113     """Test Worker Thread Class."""
 114     
 115     def __init__( self ) :
 116         """Init Worker Thread Class."""
 117         
 118         Thread.__init__( self )
 119         self.start()            # Start this thread
 120         
 121     #end __init__
 122     
 123     #----------------------------------
 124     
 125     def run( self ) :   # Do NOT change this function's name.
 126         """ 
 127         Execute the worker thread's processing.
 128         
 129         NOTE:  This function overides the Publisher function of the same name.
 130         """
 131         
 132         wx.CallAfter( Publisher().sendMessage, 'update', 'TestThread::run():    Thread started.' )
 133         
 134         # This is the code executed in the thread.
 135         for result in range( 1, 6 ) :
 136             
 137             # Simulate a long and variable processing duration each loop.
 138             processingDuration = random.randint( 100, 1500) / 1000.0       # 0.2 to 1.5 seconds
 139             print processingDuration
 140             time.sleep( processingDuration )
 141             
 142             wx.CallAfter( self.PostResults, processingDuration )
 143             wx.CallAfter( self.PostResults, result )
 144             
 145         #end for
 146             
 147         wx.CallAfter( Publisher().sendMessage, 'update', 'TestThread::run():    Thread finished.' )
 148         wx.CallAfter( Publisher().sendMessage, 'update', -1 )
 149         
 150     #end Run def
 151     
 152     #----------------------------------
 153     
 154     def PostResults( self, result ) :
 155         """ Send time to GUI """
 156         
 157         Publisher().sendMessage( 'update', result )
 158         
 159     #end def
 160     
 161 #end TestThread class
 162 
 163 #==============================================================================
 164 
 165 if __name__ == '__main__' :
 166     
 167     app = wx.PySimpleApp( redirect=False )
 168     
 169     frame = MyFrame()
 170     frame.Show()
 171     
 172     app.MainLoop()
 173     
 174 #end if