import random
import time
import thread
import wx
import wx.lib.newevent
#----------------------------------------------------------------------
# This creates a new Event class and a EVT binder function
(UpdateBarEvent, EVT_UPDATE_BARGRAPH) = wx.lib.newevent.NewEvent()
#----------------------------------------------------------------------
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(barNum = self.barNum, value = int(self.val))
wx.PostEvent(self.win, evt)
sleeptime = (random.random() * 2) + 0.5
time.sleep(sleeptime/4)
sleeptime = sleeptime * 5
if int(random.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(wx.Window):
def __init__(self, parent, labels):
wx.Window.__init__(self, parent, -1)
self.values = []
for label in labels:
self.values.append((label, 0))
font = wx.Font(12, wx.SWISS, wx.NORMAL, wx.BOLD)
self.SetFont(font)
self.colors = [ wx.RED, wx.GREEN, wx.BLUE, wx.CYAN,
"Yellow", "Navy" ]
self.Bind(wx.EVT_ERASE_BACKGROUND, self.OnEraseBackground)
self.Bind(wx.EVT_PAINT, self.OnPaint)
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):
wx.Window.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 GetBestHeight(self):
return 2 * (self.barHeight + 1) * len(self.values)
def Draw(self, dc, size):
dc.SetFont(self.GetFont())
dc.SetTextForeground(wx.BLUE)
dc.SetBackground(wx.Brush(self.GetBackgroundColour()))
dc.Clear()
dc.SetPen(wx.Pen(wx.BLACK, 3, wx.SOLID))
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(wx.Pen(color))
dc.SetBrush(wx.Brush(color))
dc.DrawRectangle(self.linePos+3, ypos, val, bh)
ypos = ypos + 2*bh
if ypos > size[1]-10:
break
def OnPaint(self, evt):
dc = wx.BufferedPaintDC(self)
self.Draw(dc, self.GetSize())
def OnEraseBackground(self, evt):
pass
#----------------------------------------------------------------------
class TestFrame(wx.Frame):
def __init__(self, parent, log):
wx.Frame.__init__(self, parent, -1, "Thread Test", size=(450,300))
self.log = log
#self.CenterOnParent()
panel = wx.Panel(self, -1)
panel.SetFont(wx.Font(10, wx.SWISS, wx.NORMAL, wx.BOLD))
wx.StaticText(panel, -1,
"This demo shows multiple threads interacting with this\n"
"window by sending events to it, one thread for each bar.",
(5,5))
panel.Fit()
self.graph = GraphWindow(self, ['Zero', 'One', 'Two', 'Three', 'Four',
'Five', 'Six', 'Seven'])
self.graph.SetSize((450, self.graph.GetBestHeight()))
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add(panel, 0, wx.EXPAND)
sizer.Add(self.graph, 1, wx.EXPAND)
self.SetSizer(sizer)
self.SetAutoLayout(True)
sizer.Fit(self)
self.Bind(EVT_UPDATE_BARGRAPH, 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()
self.Bind(wx.EVT_CLOSE, self.OnCloseWindow)
def OnUpdate(self, evt):
self.graph.SetValue(evt.barNum, evt.value)
self.graph.Refresh(False)
def OnCloseWindow(self, evt):
busy = wx.BusyInfo("One moment please, waiting for threads to die...")
wx.Yield()
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()
#---------------------------------------------------------------------------
class TestPanel(wx.Panel):
def __init__(self, parent, log):
self.log = log
wx.Panel.__init__(self, parent, -1)
b = wx.Button(self, -1, "Show Threads sample", (50,50))
self.Bind(wx.EVT_BUTTON, self.OnButton, b)
def OnButton(self, evt):
self.win = TestFrame(self, self.log)
self.win.Show(True)
def ShutdownDemo(self):
if hasattr(self, 'win') and self.win:
self.win.Close()
#---------------------------------------------------------------------------
def runTest(frame, nb, log):
win = TestPanel(nb, log)
return win
#----------------------------------------------------------------------
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 severely 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 wx.PostEvent 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.
"""
if __name__ == '__main__':
import sys,os
import run
run.main(['', os.path.basename(sys.argv[0])] + sys.argv[1:])
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