utils/wxPython/demo/Threads.py

   1
   2 from wxPython.wx import *
   3
   4 import thread
   5 import time
   6 from   whrandom import random
   7
   8 #----------------------------------------------------------------------
   9
  10 wxEVT_UPDATE_BARGRAPH = 25015
  11
  12 def EVT_UPDATE_BARGRAPH(win, func):
  13     win.Connect(-1, -1, wxEVT_UPDATE_BARGRAPH, func)
  14
  15
  16 class UpdateBarEvent(wxPyEvent):
  17     def __init__(self, barNum, value):
  18         wxPyEvent.__init__(self)
  19         self.SetEventType(wxEVT_UPDATE_BARGRAPH)
  20         self.barNum = barNum
  21         self.value = value
  22
  23
  24 #----------------------------------------------------------------------
  25
  26 class CalcBarThread:
  27     def __init__(self, win, barNum, val):
  28         self.win = win
  29         self.barNum = barNum
  30         self.val = val
  31
  32     def Start(self):
  33         self.keepGoing = self.running = true
  34         thread.start_new_thread(self.Run, ())
  35
  36     def Stop(self):
  37         self.keepGoing = false
  38
  39     def IsRunning(self):
  40         return self.running
  41
  42     def Run(self):
  43         while self.keepGoing:
  44             evt = UpdateBarEvent(self.barNum, int(self.val))
  45             wxPostEvent(self.win, evt)
  46             del evt
  47
  48             sleeptime = (random() * 2) + 0.5
  49             #print self.barNum, 'sleeping for', sleeptime
  50             time.sleep(sleeptime)
  51
  52             sleeptime = sleeptime * 5
  53             if int(random() * 2):
  54                 self.val = self.val + sleeptime
  55             else:
  56                 self.val = self.val - sleeptime
  57
  58             if self.val < 0: self.val = 0
  59             if self.val > 300: self.val = 300
  60
  61         self.running = false
  62
  63 #----------------------------------------------------------------------
  64
  65
  66 class GraphWindow(wxWindow):
  67     def __init__(self, parent, labels):
  68         wxWindow.__init__(self, parent, -1)
  69
  70         self.values = []
  71         for label in labels:
  72             self.values.append((label, 0))
  73
  74         self.font = wxFont(12, wxSWISS, wxNORMAL, wxBOLD)
  75         self.SetFont(self.font)
  76
  77         self.colors = [ wxRED, wxGREEN, wxBLUE, wxCYAN,
  78                         wxNamedColour("Yellow"), wxNamedColor("Navy") ]
  79
  80
  81     def SetValue(self, index, value):
  82         assert index < len(self.values)
  83         cur = self.values[index]
  84         self.values[index:index+1] = [(cur[0], value)]
  85
  86
  87     def SetFont(self, font):
  88         wxWindow.SetFont(self, font)
  89         wmax = hmax = 0
  90         for label, val in self.values:
  91             w,h = self.GetTextExtent(label)
  92             if w > wmax: wmax = w
  93             if h > hmax: hmax = h
  94         self.linePos = wmax + 10
  95         self.barHeight = hmax
  96
  97
  98     def Draw(self, dc, size):
  99         dc.SetFont(self.font)
 100         dc.SetTextForeground(wxBLUE)
 101         dc.SetBackground(wxBrush(self.GetBackgroundColour()))
 102         dc.Clear()
 103         dc.SetPen(wxPen(wxBLACK, 3, wxSOLID))
 104         dc.DrawLine(self.linePos, 0, self.linePos, size.height-10)
 105
 106         bh = ypos = self.barHeight
 107         for x in range(len(self.values)):
 108             label, val = self.values[x]
 109             dc.DrawText(label, 5, ypos)
 110
 111             if val:
 112                 color = self.colors[ x % len(self.colors) ]
 113                 dc.SetPen(wxPen(color))
 114                 dc.SetBrush(wxBrush(color))
 115                 dc.DrawRectangle(self.linePos+3, ypos, val, bh)
 116
 117             ypos = ypos + 2*bh
 118             if ypos > size.height-10:
 119                 break
 120
 121
 122     def OnPaint(self, evt):
 123         size = self.GetSize()
 124         bmp = wxEmptyBitmap(size.width, size.height)
 125         dc = wxMemoryDC()
 126         dc.SelectObject(bmp)
 127         self.Draw(dc, size)
 128
 129         wdc = wxPaintDC(self)
 130         wdc.BeginDrawing()
 131         wdc.Blit(0,0, size.width, size.height, dc, 0,0)
 132         wdc.EndDrawing()
 133
 134         dc.SelectObject(wxNullBitmap)
 135
 136
 137     def OnEraseBackground(self, evt):
 138         pass
 139
 140
 141
 142
 143 #----------------------------------------------------------------------
 144
 145 class TestFrame(wxFrame):
 146     def __init__(self, parent, log):
 147         wxFrame.__init__(self, parent, -1, "Thread Test", size=(450,300))
 148         self.log = log
 149
 150         #self.CenterOnParent()
 151
 152         panel = wxPanel(self, -1)
 153         panel.SetFont(wxFont(10, wxSWISS, wxNORMAL, wxBOLD))
 154         wxStaticText(panel, -1,
 155                      "This demo shows multiple threads interacting with this\n"
 156                      "window by sending events to it.", wxPoint(5,5))
 157         panel.Fit()
 158
 159         self.graph = GraphWindow(self, ['Zero', 'One', 'Two', 'Three', 'Four',
 160                                         'Five', 'Six', 'Seven'])
 161
 162         sizer = wxBoxSizer(wxVERTICAL)
 163         sizer.Add(panel, 0, wxEXPAND)
 164         sizer.Add(self.graph, 1, wxEXPAND)
 165
 166         self.SetSizer(sizer)
 167         self.SetAutoLayout(true)
 168
 169         #self.graph.SetValue(0, 25)
 170         #self.graph.SetValue(1, 50)
 171         #self.graph.SetValue(2, 75)
 172         #self.graph.SetValue(3, 100)
 173
 174         EVT_UPDATE_BARGRAPH(self, self.OnUpdate)
 175         self.threads = []
 176         self.threads.append(CalcBarThread(self, 0, 50))
 177         self.threads.append(CalcBarThread(self, 1, 75))
 178         self.threads.append(CalcBarThread(self, 2, 100))
 179         self.threads.append(CalcBarThread(self, 3, 150))
 180         self.threads.append(CalcBarThread(self, 4, 225))
 181         self.threads.append(CalcBarThread(self, 5, 300))
 182         self.threads.append(CalcBarThread(self, 6, 250))
 183         self.threads.append(CalcBarThread(self, 7, 175))
 184
 185         for t in self.threads:
 186             t.Start()
 187
 188
 189
 190     def OnUpdate(self, evt):
 191         self.graph.SetValue(evt.barNum, evt.value)
 192         self.graph.Refresh(false)
 193
 194
 195     def OnCloseWindow(self, evt):
 196         busy = wxBusyInfo("One moment please, waiting for threads to die...")
 197         for t in self.threads:
 198             t.Stop()
 199         running = 1
 200         while running:
 201             running = 0
 202             for t in self.threads:
 203                 running = running + t.IsRunning()
 204             time.sleep(0.1)
 205         self.Destroy()
 206
 207
 208
 209 #----------------------------------------------------------------------
 210
 211 def runTest(frame, nb, log):
 212     win = TestFrame(frame, log)
 213     frame.otherWin = win
 214     win.Show(true)
 215     return None
 216
 217 #----------------------------------------------------------------------
 218
 219
 220
 221
 222 overview = """\
 223 The main issue with multi-threaded GUI programming is the thread safty
 224 of the GUI itself.  On most platforms the GUI is not thread safe and
 225 so any cross platform GUI Toolkit and applications written with it
 226 need to take that into account.
 227
 228 The solution is to only allow interaction with the GUI from a single
 229 thread, but this often severly limits what can be done in an
 230 application and makes it difficult to use additional threads at all.
 231
 232 Since wxPython already makes extensive use of event handlers, it is a
 233 logical extension to allow events to be sent to GUI objects from
 234 alternate threads.  A function called wxPostEvent allows you to do
 235 this.  It accepts an event and an event handler (window) and instead
 236 of sending the event immediately in the current context like
 237 ProcessEvent does, it processes it later from the context of the GUI
 238 thread.
 239
 240 """