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         EVT_ERASE_BACKGROUND(self, self.OnEraseBackground)
  81         EVT_PAINT(self, self.OnPaint)
  82
  83
  84     def SetValue(self, index, value):
  85         assert index < len(self.values)
  86         cur = self.values[index]
  87         self.values[index:index+1] = [(cur[0], value)]
  88
  89
  90     def SetFont(self, font):
  91         wxWindow.SetFont(self, font)
  92         wmax = hmax = 0
  93         for label, val in self.values:
  94             w,h = self.GetTextExtent(label)
  95             if w > wmax: wmax = w
  96             if h > hmax: hmax = h
  97         self.linePos = wmax + 10
  98         self.barHeight = hmax
  99
 100
 101     def Draw(self, dc, size):
 102         dc.SetFont(self.font)
 103         dc.SetTextForeground(wxBLUE)
 104         dc.SetBackground(wxBrush(self.GetBackgroundColour()))
 105         dc.Clear()
 106         dc.SetPen(wxPen(wxBLACK, 3, wxSOLID))
 107         dc.DrawLine(self.linePos, 0, self.linePos, size.height-10)
 108
 109         bh = ypos = self.barHeight
 110         for x in range(len(self.values)):
 111             label, val = self.values[x]
 112             dc.DrawText(label, 5, ypos)
 113
 114             if val:
 115                 color = self.colors[ x % len(self.colors) ]
 116                 dc.SetPen(wxPen(color))
 117                 dc.SetBrush(wxBrush(color))
 118                 dc.DrawRectangle(self.linePos+3, ypos, val, bh)
 119
 120             ypos = ypos + 2*bh
 121             if ypos > size.height-10:
 122                 break
 123
 124
 125     def OnPaint(self, evt):
 126         size = self.GetSize()
 127         bmp = wxEmptyBitmap(size.width, size.height)
 128         dc = wxMemoryDC()
 129         dc.SelectObject(bmp)
 130         self.Draw(dc, size)
 131
 132         wdc = wxPaintDC(self)
 133         wdc.BeginDrawing()
 134         wdc.Blit(0,0, size.width, size.height, dc, 0,0)
 135         wdc.EndDrawing()
 136
 137         dc.SelectObject(wxNullBitmap)
 138
 139
 140     def OnEraseBackground(self, evt):
 141         pass
 142
 143
 144
 145
 146 #----------------------------------------------------------------------
 147
 148 class TestFrame(wxFrame):
 149     def __init__(self, parent, log):
 150         wxFrame.__init__(self, parent, -1, "Thread Test", size=(450,300))
 151         self.log = log
 152
 153         #self.CenterOnParent()
 154
 155         panel = wxPanel(self, -1)
 156         panel.SetFont(wxFont(10, wxSWISS, wxNORMAL, wxBOLD))
 157         wxStaticText(panel, -1,
 158                      "This demo shows multiple threads interacting with this\n"
 159                      "window by sending events to it.", wxPoint(5,5))
 160         panel.Fit()
 161
 162         self.graph = GraphWindow(self, ['Zero', 'One', 'Two', 'Three', 'Four',
 163                                         'Five', 'Six', 'Seven'])
 164
 165         sizer = wxBoxSizer(wxVERTICAL)
 166         sizer.Add(panel, 0, wxEXPAND)
 167         sizer.Add(self.graph, 1, wxEXPAND)
 168
 169         self.SetSizer(sizer)
 170         self.SetAutoLayout(true)
 171
 172         #self.graph.SetValue(0, 25)
 173         #self.graph.SetValue(1, 50)
 174         #self.graph.SetValue(2, 75)
 175         #self.graph.SetValue(3, 100)
 176
 177         EVT_UPDATE_BARGRAPH(self, self.OnUpdate)
 178         self.threads = []
 179         self.threads.append(CalcBarThread(self, 0, 50))
 180         self.threads.append(CalcBarThread(self, 1, 75))
 181         self.threads.append(CalcBarThread(self, 2, 100))
 182         self.threads.append(CalcBarThread(self, 3, 150))
 183         self.threads.append(CalcBarThread(self, 4, 225))
 184         self.threads.append(CalcBarThread(self, 5, 300))
 185         self.threads.append(CalcBarThread(self, 6, 250))
 186         self.threads.append(CalcBarThread(self, 7, 175))
 187
 188         for t in self.threads:
 189             t.Start()
 190
 191         EVT_CLOSE(self, self.OnCloseWindow)
 192
 193
 194     def OnUpdate(self, evt):
 195         self.graph.SetValue(evt.barNum, evt.value)
 196         self.graph.Refresh(false)
 197
 198
 199     def OnCloseWindow(self, evt):
 200         busy = wxBusyInfo("One moment please, waiting for threads to die...")
 201         for t in self.threads:
 202             t.Stop()
 203         running = 1
 204         while running:
 205             running = 0
 206             for t in self.threads:
 207                 running = running + t.IsRunning()
 208             time.sleep(0.1)
 209         self.Destroy()
 210
 211
 212
 213 #----------------------------------------------------------------------
 214
 215 def runTest(frame, nb, log):
 216     win = TestFrame(frame, log)
 217     frame.otherWin = win
 218     win.Show(true)
 219     return None
 220
 221 #----------------------------------------------------------------------
 222
 223
 224
 225
 226 overview = """\
 227 The main issue with multi-threaded GUI programming is the thread safty
 228 of the GUI itself.  On most platforms the GUI is not thread safe and
 229 so any cross platform GUI Toolkit and applications written with it
 230 need to take that into account.
 231
 232 The solution is to only allow interaction with the GUI from a single
 233 thread, but this often severly limits what can be done in an
 234 application and makes it difficult to use additional threads at all.
 235
 236 Since wxPython already makes extensive use of event handlers, it is a
 237 logical extension to allow events to be sent to GUI objects from
 238 alternate threads.  A function called wxPostEvent allows you to do
 239 this.  It accepts an event and an event handler (window) and instead
 240 of sending the event immediately in the current context like
 241 ProcessEvent does, it processes it later from the context of the GUI
 242 thread.
 243
 244 """