utils/wxPython/tests/test8.py

   1 # Thread testing example. Harm van der Heijden, March 26 1999.
   2 #
   3 # Rule One in threading: make sure only one thread interacts with the
   4 # user interface. See the wxTextCtrlQueue class for an example of how
   5 # to accomplish this
   6
   7 import thread
   8 import time
   9 from   whrandom import random
  10
  11 from wxPython.wx import *
  12
  13 # Set this to zero to prevent entering the wxApp mainloop
  14 # (for testing whether threads work at all in the absense of wxWindows)
  15 use_wxpython = 1
  16
  17 # write a message to stdout every second
  18 def DoThread(mesg):
  19     while 1:
  20         sleeptime = (random() * 3) + 0.5
  21         print "Hello from %s (%1.3f)" % (mesg, sleeptime)
  22         time.sleep(sleeptime)
  23
  24 # the same, but write it to a textctrl.
  25 def DoTextCtrlThread(text, mesg):
  26     while 1:
  27         sleeptime = (random() * 3) + 0.5
  28         text.WriteText("Hello from %s (%1.3f)\n" % (mesg, sleeptime))
  29         time.sleep(sleeptime)
  30
  31 # A very simple queue for textctrls.
  32 # Nice demonstration of the power of OO programming too (at least I think so!)
  33 # WriteText puts text in the queue, rather than writing it immediately.
  34 # The main (UI) thread must call Flush to force output. (see MyFrame::OnIdle)
  35 class wxTextCtrlQueue(wxTextCtrl):
  36     def __init__(self, parent, id, value, pos, size, flags):
  37         wxTextCtrl.__init__(self,parent, id, value, pos, size, flags)
  38         self.queue = []
  39     def WriteText(self, value):
  40         self.queue.append(value)
  41     def Flush(self):
  42         queue = self.queue
  43         self.queue = []
  44         for value in queue:
  45             wxTextCtrl.WriteText(self,value)
  46
  47 # MyFrame and MyApp are very simple classes to test python threads in
  48 # wxPython.
  49 class MyFrame(wxFrame):
  50     def __init__(self):
  51         wxFrame.__init__(self, NULL, -1, "test threads", wxDefaultPosition, wxSize(300,200))
  52         self.text = wxTextCtrlQueue(self, -1, "thread output\n", wxDefaultPosition, wxDefaultSize, wxTE_MULTILINE)
  53         menu = wxMenu()
  54         menu.Append(1001, "Start thread")
  55         self.cnt = 0;
  56         menubar = wxMenuBar()
  57         menubar.Append(menu, "Action")
  58         self.SetMenuBar(menubar)
  59         EVT_MENU(self, 1001, self.StartThread)
  60     def StartThread(self, event):
  61         self.cnt = self.cnt + 1
  62         thread.start_new_thread(DoTextCtrlThread, (self.text, "thread %d" % self.cnt))
  63     def OnIdle(self, event):
  64         self.text.Flush()
  65
  66 class MyApp(wxApp):
  67     def OnInit(self):
  68         frame = MyFrame()
  69         self.SetTopWindow(frame)
  70         frame.Show(TRUE)
  71         return TRUE
  72
  73 # Start two threads that print a message every second
  74 thread.start_new_thread(DoThread, ("thread A",))
  75 thread.start_new_thread(DoThread, ("thread B",))
  76
  77 # if using wxpython, open a frame. Otherwise, just hang in while 1
  78 if use_wxpython:
  79     app = MyApp(0)
  80     app.MainLoop()
  81 else:
  82     while 1:
  83         print "main loop"
  84         time.sleep(4)
  85 print 'done!'