from wxPython.wx import * import thread import time from whrandom import random #---------------------------------------------------------------------- wxEVT_UPDATE_BARGRAPH = 25015 def EVT_UPDATE_BARGRAPH(win, func): win.Connect(-1, -1, wxEVT_UPDATE_BARGRAPH, func) class UpdateBarEvent(wxPyEvent): def __init__(self, barNum, value): wxPyEvent.__init__(self) self.SetEventType(wxEVT_UPDATE_BARGRAPH) self.barNum = barNum self.value = value #---------------------------------------------------------------------- class CalcBarThread: def __init__(self, win, barNum, val): self.win = win self.barNum = barNum self.val = val def Start(self): self.keepGoing = self.running = true thread.start_new_thread(self.Run, ()) def Stop(self): self.keepGoing = false def IsRunning(self): return self.running def Run(self): while self.keepGoing: evt = UpdateBarEvent(self.barNum, int(self.val)) wxPostEvent(self.win, evt) del evt sleeptime = (random() * 2) + 0.5 #print self.barNum, 'sleeping for', sleeptime time.sleep(sleeptime) sleeptime = sleeptime * 5 if int(random() * 2): self.val = self.val + sleeptime else: self.val = self.val - sleeptime if self.val < 0: self.val = 0 if self.val > 300: self.val = 300 self.running = false #---------------------------------------------------------------------- class GraphWindow(wxWindow): def __init__(self, parent, labels): wxWindow.__init__(self, parent, -1) self.values = [] for label in labels: self.values.append((label, 0)) self.font = wxFont(12, wxSWISS, wxNORMAL, wxBOLD) self.SetFont(self.font) self.colors = [ wxRED, wxGREEN, wxBLUE, wxCYAN, wxNamedColour("Yellow"), wxNamedColor("Navy") ] def SetValue(self, index, value): assert index < len(self.values) cur = self.values[index] self.values[index:index+1] = [(cur[0], value)] def SetFont(self, font): wxWindow.SetFont(self, font) wmax = hmax = 0 for label, val in self.values: w,h = self.GetTextExtent(label) if w > wmax: wmax = w if h > hmax: hmax = h self.linePos = wmax + 10 self.barHeight = hmax def Draw(self, dc, size): dc.SetFont(self.font) dc.SetTextForeground(wxBLUE) dc.SetBackground(wxBrush(self.GetBackgroundColour())) dc.Clear() dc.SetPen(wxPen(wxBLACK, 3, wxSOLID)) dc.DrawLine(self.linePos, 0, self.linePos, size.height-10) bh = ypos = self.barHeight for x in range(len(self.values)): label, val = self.values[x] dc.DrawText(label, 5, ypos) if val: color = self.colors[ x % len(self.colors) ] dc.SetPen(wxPen(color)) dc.SetBrush(wxBrush(color)) dc.DrawRectangle(self.linePos+3, ypos, val, bh) ypos = ypos + 2*bh if ypos > size.height-10: break def OnPaint(self, evt): size = self.GetSize() bmp = wxEmptyBitmap(size.width, size.height) dc = wxMemoryDC() dc.SelectObject(bmp) self.Draw(dc, size) wdc = wxPaintDC(self) wdc.BeginDrawing() wdc.Blit(0,0, size.width, size.height, dc, 0,0) wdc.EndDrawing() dc.SelectObject(wxNullBitmap) def OnEraseBackground(self, evt): pass #---------------------------------------------------------------------- class TestFrame(wxFrame): def __init__(self, parent, log): wxFrame.__init__(self, parent, -1, "Thread Test", size=(450,300)) self.log = log #self.CenterOnParent() panel = wxPanel(self, -1) panel.SetFont(wxFont(10, wxSWISS, wxNORMAL, wxBOLD)) wxStaticText(panel, -1, "This demo shows multiple threads interacting with this\n" "window by sending events to it.", wxPoint(5,5)) panel.Fit() self.graph = GraphWindow(self, ['Zero', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven']) sizer = wxBoxSizer(wxVERTICAL) sizer.Add(panel, 0, wxEXPAND) sizer.Add(self.graph, 1, wxEXPAND) self.SetSizer(sizer) self.SetAutoLayout(true) #self.graph.SetValue(0, 25) #self.graph.SetValue(1, 50) #self.graph.SetValue(2, 75) #self.graph.SetValue(3, 100) EVT_UPDATE_BARGRAPH(self, self.OnUpdate) self.threads = [] self.threads.append(CalcBarThread(self, 0, 50)) self.threads.append(CalcBarThread(self, 1, 75)) self.threads.append(CalcBarThread(self, 2, 100)) self.threads.append(CalcBarThread(self, 3, 150)) self.threads.append(CalcBarThread(self, 4, 225)) self.threads.append(CalcBarThread(self, 5, 300)) self.threads.append(CalcBarThread(self, 6, 250)) self.threads.append(CalcBarThread(self, 7, 175)) for t in self.threads: t.Start() def OnUpdate(self, evt): self.graph.SetValue(evt.barNum, evt.value) self.graph.Refresh(false) def OnCloseWindow(self, evt): busy = wxBusyInfo("One moment please, waiting for threads to die...") for t in self.threads: t.Stop() running = 1 while running: running = 0 for t in self.threads: running = running + t.IsRunning() time.sleep(0.1) self.Destroy() #---------------------------------------------------------------------- def runTest(frame, nb, log): win = TestFrame(frame, log) frame.otherWin = win win.Show(true) return None #---------------------------------------------------------------------- overview = """\ The main issue with multi-threaded GUI programming is the thread safty of the GUI itself. On most platforms the GUI is not thread safe and so any cross platform GUI Toolkit and applications written with it need to take that into account. The solution is to only allow interaction with the GUI from a single thread, but this often severly limits what can be done in an application and makes it difficult to use additional threads at all. Since wxPython already makes extensive use of event handlers, it is a logical extension to allow events to be sent to GUI objects from alternate threads. A function called wxPostEvent allows you to do this. It accepts an event and an event handler (window) and instead of sending the event immediately in the current context like ProcessEvent does, it processes it later from the context of the GUI thread. """