Posts: 2
Threads: 1
Joined: Sep 2017
new to python and wx, I wrote a simple clock program.
It works well for a while but eventually the graphics freeze.
Internally it still runs, but the graphics cease to update.
It unfreezes if I resize the frame and the print buffer releases this error message:
Error: GLib-CRITICAL **: Source ID 4759 was not found when attempting to remove it
The id keeps increasing.
My guess is that the garbage collector loses track of dc.
What did I do wrong?
xClock.py
# -*- coding: utf-8 -*-
#
import wx
import threading
import time
from datetime import datetime
#return 2 digit string from int
def fix(n):
s=repr(n)
if n<10:
s='0'+s
return s
class xClock(wx.Window):
def __init__(self,p):
super(xClock, self).__init__(p)
self.W=400
self.H=100
self.SetSize(wx.Size(self.W,self.H))
self.R=195
self.img=None
self.DRAWN=False
self.timeText=""
self.SetForegroundColour(wx.BLUE)
self.font=self.GetFont()
w,h,d,e =self.GetFullTextExtent('00:00:00')
FE=[w,h,d,e]
print ('GetFullTextExtent '+ repr(FE))
self.font.SetPointSize(70)
self.SetFont(self.font)
w,h,d,e =self.GetFullTextExtent('00:00:00')
FE=[w,h,d,e]
print ('GetFullTextExtent '+ repr(FE))
wx.EVT_PAINT(self,self.OnPaint)
wx.EVT_WINDOW_DESTROY=self.stop()
self.RUNNING=False
self.ticker=None
self.start()
def OnPaint(self, evt):
if self.img==None:
self.draw()
return False
dc=wx.PaintDC(self)
dc.BeginDrawing()
w,h=self.img.GetSize()
W,H=self.GetSize()
x=(W-w)//2
y=(H-h)//2
dc.DrawBitmap(self.img,x,y)
dc.EndDrawing()
return True
def draw(self):
if self.img==None:
self.img=wx.EmptyBitmap(self.W,self.H)
self.DRAWN=False
now=datetime.now()
h=fix(now.hour)
m=fix(now.minute)
s=fix(now.second)
t=h+":"+m+":"+s
self.timeText=t
dc = wx.MemoryDC()
dc.SelectObject(self.img)
dc.BeginDrawing()
F=self.GetFont()
dc.SetFont(F)
w,h=dc.GetTextExtent(t)
W,H=self.img.GetSize()
x0=(self.W-w)//2
y0=(self.H-h)//2
dc.SetBrush(wx.Brush(wx.WHITE, wx.SOLID))
dc.Clear()
dc.SetTextForeground(wx.BLUE)
dc.DrawText(t,x0,y0)
self.DRAWN=True
dc.EndDrawing()
self.Refresh()
def start(self):
pass
if self.ticker ==None or not self.ticker.is_alive():
self.ticker=threading.Thread(None, self.run, "Ticker")
print("start() "+self.ticker.getName())
self.ticker.start()
def stop(self):
self.RUNNING=False
time.sleep(2)
def run(self):
self.RUNNING=True
delay=1
print("RUNNING")
while self.RUNNING:
self.draw()
self.Refresh(False)
time.sleep(delay)
#T=threading.currentThread().getName() # just curious
# print(self.timeText+' '), # prove it runs when frozen
print(self.timeText)
self.RUNNING=False
__init__.py
#!/usr/bin/python
# -*- coding: utf-8 -*-
import wx
from xClock import xClock
class XCFrame(wx.Frame):
def __init__(self,parent):
super(XCFrame, self).__init__(parent)
self.SetTitle("XAOS CLOCK")
xcp=xClock(self)
sizer=wx.BoxSizer(wx.VERTICAL)
sizer.Add(xcp,1,wx.EXPAND,wx.ALL)
self.SetBackgroundColour(wx.CYAN)
self.SetSizer(sizer)
class xaosApp(wx.App):
def __init__(self):
super(xaosApp, self).__init__()
xcf=XCFrame(None)
xcf.Show()
if __name__=='__main__':
app=xaosApp()
app.MainLoop()
Posts: 11,872
Threads: 474
Joined: Sep 2016
wx.PaintDC was depreciated with the release of wxpython phoenix.
I was trying to run, but cannot in python 3.6
Since you're new to python, why not use the latest version?
Posts: 7,081
Threads: 122
Joined: Sep 2016
Oct-04-2017, 04:31 PM
(This post was last modified: Oct-04-2017, 04:31 PM by snippsat.)
There is own wx.Timer() that handles stuff like clock,
so then is no need to use threading which can freeze GUI if used wrong(interfere with GUI own main loop).
Here a analog clock example rewritten for Phoenix and Python 3.6.
See that it call wx.Timer().
import wx
import time
class Example(wx.Frame):
def __init__(self, *args, **kw):
super().__init__(*args, **kw)
self.Bind(wx.EVT_PAINT, self.OnPaint)
self.timer = wx.Timer(self)
self.Bind(wx.EVT_TIMER, self.OnTimer, self.timer)
self.timer.Start(1000)
self.Show(True)
def Draw(self, dc):
t = time.localtime(time.time())
st = time.strftime("%I:%M:%S", t)
dc.SetBackground(wx.Brush(self.GetBackgroundColour()))
dc.Clear()
dc.SetFont(wx.Font(30, wx.SWISS, wx.NORMAL, wx.NORMAL))
tw, th = dc.GetTextExtent(st)
dc.DrawText(st, 20, 20)
def OnTimer(self, evt):
dc = wx.BufferedDC(wx.ClientDC(self))
self.Draw(dc)
def OnPaint(self, evt):
dc = wx.BufferedPaintDC(self)
self.Draw(dc)
if __name__ == '__main__':
ex = wx.App()
Example(None)
ex.MainLoop()As a note Threading and GUI can be difficult,that why most GUI toolkit has own method to deal with this.
Example for wxPython: - wx.PostEvent
- wx.CallAfter
- wx.CallLater
- wx.Timer
wxPython and Threads.
Posts: 2
Threads: 1
Joined: Sep 2017
Thank-you folks, I went with the buffered paint DC and everything is smooth and solid.
Just guessing what was going wrong...
A) repainting an image every second and making a new dc probably jammed up the garbage collector ?
B) maybe the system tried to paint the image while it was being redrawn ?
Still a learning project in progress.....
###ClockProps.py
# -*- coding: utf-8 -*-
import wx
import DClockPane # may not need to import
BackgroundColor=wx.BLACK
TextColor=wx.CYAN
Draw_Frame=True #False
frame=wx.Rect(0,0,0,0)
frame_color=wx.GREEN
FontSize=100
FontFamily=wx.FONTFAMILY_DEFAULT
Show_Seconds=True
Show_Blink=False # annoyint, but could be useful as a flag
Time_sep=':'
Time_blink='.' # if Show_Blink then every half second Time_sep='.'
TimeFormat_hour=24 # might never use this, but it should be an option
# optional 'features'
Shadow_Effect=True
Shadow_color=wx.LIGHT_GREY
Shadow_x=3
Shadow_y=3 ### DClockPane
# -*- coding: utf-8 -*-
import wx
import time
import ClockProps
def fix(n):
N=repr(n)
if n<10:
N="0"+N
return N
def ts(c=':'):
b=" "
t=time.localtime()
h=fix(t[3])
m=fix(t[4])
s=fix(t[5])
return b+h+c+m+c+s+b
class DClockPane(wx.Window):
def __init__(self, p):
super(DClockPane, self).__init__(p)
font=self.GetFont()
font.SetPointSize(ClockProps.FontSize)
self.SetFont(font)
self.SetBackgroundColour(ClockProps.BackgroundColor)
w,h=self.textSize(font)
print ("text size="+ repr([w,h] ))
self.SetSize(wx.Size(w,h))
self.drawFrame=ClockProps.Draw_Frame
self.Box=None
if self.drawFrame:
ClockProps.frame=wx.Rect(0,0,w,h)
self.Box=ClockProps.frame
self.showSecs=ClockProps.Show_Seconds
self.textColor=ClockProps.TextColor
self.BLINK=ClockProps.Time_blink
self.DELAY=1000
if self.BLINK:
self.DELAY=500
self.TOCK=False
self.SHADOW=ClockProps.Shadow_Effect
self.Bind(wx.EVT_PAINT, self.OnPaint)
self.timer = wx.Timer(self)
self.Bind(wx.EVT_TIMER,self.run,self.timer )
self.timer.Start(self.DELAY)
def draw(self, dc):
dc.SetBackground(wx.Brush(self.GetBackgroundColour()))
dc.Clear()
#dc.SetFont(wx.Font(30, wx.SWISS, wx.NORMAL, wx.NORMAL))
c=':'
if self.BLINK:
self.TOCK= not self.TOCK
if self.TOCK:
c='.'
st=ts(c)
tw, th = dc.GetTextExtent(st)
w,h =self.GetSize()
x=(w-tw)/2
y=(h-th)/2
if self.drawFrame:
dc.SetPen(wx.Pen( ClockProps.frame_color ))
dc.DrawRectanglePointSize( wx.Point(x,y), self.Box.GetSize())
if self.SHADOW:
dc.SetTextForeground(ClockProps.Shadow_color)
dc.DrawText(st, x+ClockProps.Shadow_x, y+ClockProps.Shadow_y)
dc.SetTextForeground(wx.CYAN) #(wx.Brush(wx.CYAN, wx.SOLID))
dc.DrawText(st, x, y)
def run(self,e):
dc = wx.BufferedDC(wx.ClientDC(self))
self.draw(dc)
def OnPaint(self, e):
""" paint the buffer """
dc = wx.BufferedPaintDC(self)
self.draw(dc)
def textSize(self, font):
if font==None:
font=self.GetFont()
#z=font.GetSize()
dc=wx.ClientDC(self)
x,y=dc.GetTextExtent(" 88:88:88 ")
return wx.Size(x,y)#__init__.py
import wx
from DClockPane import DClockPane
class ClockFrame(wx.Frame):
def __init__(self,p):
super(ClockFrame, self).__init__(None)
self.SetTitle("Steve's Clock")
self.clock=DClockPane(self)
sizer=wx.BoxSizer(wx.VERTICAL)
sizer.Add(self.clock,1,wx.EXPAND,wx.ALL)
self.SetBackgroundColour(wx.CYAN)
self.SetSizer(sizer)
class DClock(wx.App):
def __init__(self):
super(DClock, self).__init__()
cf=ClockFrame(None)
cf.Show()
if __name__=='__main__':
app=DClock()
app.MainLoop()
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