Why does my buffered GraphicsContext application have a flickering problem?
- by Bibendum
import wx
class MainFrame(wx.Frame):
def __init__(self,parent,title):
wx.Frame.__init__(self, parent, title=title, size=(640,480))
self.mainPanel=DoubleBufferTest(self,-1)
self.Show(True)
class DoubleBufferTest(wx.Panel):
def __init__(self,parent=None,id=-1):
wx.Panel.__init__(self,parent,id,style=wx.FULL_REPAINT_ON_RESIZE)
self.SetBackgroundColour("#FFFFFF")
self.timer = wx.Timer(self)
self.timer.Start(100)
self.Bind(wx.EVT_TIMER, self.update, self.timer)
self.Bind(wx.EVT_PAINT,self.onPaint)
def onPaint(self,event):
event.Skip()
dc = wx.MemoryDC()
dc.SelectObject(wx.EmptyBitmap(640, 480))
gc = wx.GraphicsContext.Create(dc)
gc.PushState()
gc.SetBrush(wx.Brush("#CFCFCF"))
bgRect=gc.CreatePath()
bgRect.AddRectangle(0,0,640,480)
gc.FillPath(bgRect)
gc.PopState()
dc2=wx.PaintDC(self)
dc2.Blit(0,0,640,480,dc,0,0)
def update(self,event):
self.Refresh()
app = wx.App(False)
f=MainFrame(None,"Test")
app.MainLoop()
I've come up with this code to draw double buffered GraphicsContext content onto a panel, but there's a constant flickering across the window. I've tried different kinds of paths, like lines and curves but it's still there and I don't know what's causing it.
