import wx #---------------------------------------------------------------------- class TestPanel(wx.Panel): def __init__(self, parent, log): self.log = log wx.Panel.__init__(self, parent, -1) self.Bind(wx.EVT_PAINT, self.OnPaint) txt = """\ If this build of wxPython includes the new wx.GCDC class (which provides the wx.DC API on top of the new wx.GraphicsContext class) then these squares should be transparent. """ wx.StaticText(self, -1, txt, (20, 20)) def OnPaint(self, evt): pdc = wx.PaintDC(self) try: dc = wx.GCDC(pdc) except: dc = pdc rect = wx.Rect(0,0, 100, 100) for RGB, pos in [((178, 34, 34), ( 50, 90)), (( 35, 142, 35), (110, 150)), (( 0, 0, 139), (170, 90)) ]: r, g, b = RGB penclr = wx.Colour(r, g, b, wx.ALPHA_OPAQUE) brushclr = wx.Colour(r, g, b, 128) # half transparent dc.SetPen(wx.Pen(penclr)) dc.SetBrush(wx.Brush(brushclr)) rect.SetPosition(pos) dc.DrawRoundedRectangleRect(rect, 8) #---------------------------------------------------------------------- def runTest(frame, nb, log): win = TestPanel(nb, log) return win #---------------------------------------------------------------------- overview = """

Alpha Drawing

The wx.GCDC class is a class that implemented the wx.DC API using the new wx.GraphicsContext class, and so it supports anti-aliased drawing using pens and brushes, that can optionally also be drawn using an alpha transparency. (On the Mac all the DC classes are using this new implementation.) This is accomplished by enabling the wx.Colour class to have a fourth component for the alpha value, where 0 is fully transparent, and 255 is fully opaque. """ if __name__ == '__main__': import sys,os import run run.main(['', os.path.basename(sys.argv[0])] + sys.argv[1:])