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
 135     def OnEraseBackground(self, evt):
 136         pass
 137
 138
 139
 140
 141 #----------------------------------------------------------------------
 142
 143 class TestFrame(wxFrame):
 144     def __init__(self, parent, log):
 145         wxFrame.__init__(self, parent, -1, "Thread Test", size=(450,300))
 146         self.log = log
 147
 148         #self.CenterOnParent()
 149
 150         panel = wxPanel(self, -1)
 151         panel.SetFont(wxFont(10, wxSWISS, wxNORMAL, wxBOLD))
 152         wxStaticText(panel, -1,
 153                      "This demo shows multiple threads interacting with this\n"
 154                      "window by sending events to it.", wxPoint(5,5))
 155         panel.Fit()
 156
 157         self.graph = GraphWindow(self, ['Zero', 'One', 'Two', 'Three', 'Four',
 158                                         'Five', 'Six', 'Seven'])
 159
 160         sizer = wxBoxSizer(wxVERTICAL)
 161         sizer.Add(panel, 0, wxEXPAND)
 162         sizer.Add(self.graph, 1, wxEXPAND)
 163
 164         self.SetSizer(sizer)
 165         self.SetAutoLayout(true)
 166
 167         #self.graph.SetValue(0, 25)
 168         #self.graph.SetValue(1, 50)
 169         #self.graph.SetValue(2, 75)
 170         #self.graph.SetValue(3, 100)
 171
 172         EVT_UPDATE_BARGRAPH(self, self.OnUpdate)
 173         self.threads = []
 174         self.threads.append(CalcBarThread(self, 0, 50))
 175         self.threads.append(CalcBarThread(self, 1, 75))
 176         self.threads.append(CalcBarThread(self, 2, 100))
 177         self.threads.append(CalcBarThread(self, 3, 150))
 178         self.threads.append(CalcBarThread(self, 4, 225))
 179         self.threads.append(CalcBarThread(self, 5, 300))
 180         self.threads.append(CalcBarThread(self, 6, 250))
 181         self.threads.append(CalcBarThread(self, 7, 175))
 182
 183         for t in self.threads:
 184             t.Start()
 185
 186
 187
 188     def OnUpdate(self, evt):
 189         self.graph.SetValue(evt.barNum, evt.value)
 190         self.graph.Refresh(false)
 191
 192
 193     def OnCloseWindow(self, evt):
 194         busy = wxBusyInfo("One moment please, waiting for threads to die...")
 195         for t in self.threads:
 196             t.Stop()
 197         running = 1
 198         while running:
 199             running = 0
 200             for t in self.threads:
 201                 running = running + t.IsRunning()
 202             time.sleep(0.1)
 203         self.Destroy()
 204
 205
 206
 207 #----------------------------------------------------------------------
 208
 209 def runTest(frame, nb, log):
 210     win = TestFrame(frame, log)
 211     frame.otherWin = win
 212     win.Show(true)
 213     return None
 214
 215 #----------------------------------------------------------------------
 216
 217
 218
 219
 220 overview = """\
 221 The main issue with multi-threaded GUI programming is the thread safty
 222 of the GUI itself.  On most platforms the GUI is not thread safe and
 223 so any cross platform GUI Toolkit and applications written with it
 224 need to take that into account.
 225
 226 The solution is to only allow interaction with the GUI from a single
 227 thread, but this often severly limits what can be done in an
 228 application and makes it difficult to use additional threads at all.
 229
 230 Since wxPython already makes extensive use of event handlers, it is a
 231 logical extension to allow events to be sent to GUI objects from
 232 alternate threads.  A function called wxPostEvent allows you to do
 233 this.  It accepts an event and an event handler (window) and instead
 234 of sending the event immediately in the current context like
 235 ProcessEvent does, it processes it later from the context of the GUI
 236 thread.
 237
 238 """