wxPython/demo/AlphaDrawing.py

   1
   2 import wx
   3
   4 #----------------------------------------------------------------------
   5
   6 class TestPanel(wx.Panel):
   7     def __init__(self, parent, log):
   8         self.log = log
   9         wx.Panel.__init__(self, parent, -1)
  10         self.Bind(wx.EVT_PAINT, self.OnPaint)
  11
  12         txt = "On the Mac these squares should be transparent, if the\n" \
  13               "CoreGraphics option is turned on.  "
  14         if "wxMac" in wx.PlatformInfo:
  15             txt += "This build of wxPython\n" \
  16                    "%s have the CoreGraphics option turned on." \
  17                    % ("mac-cg" in wx.PlatformInfo and "DOES" or "DOS NOT")
  18         wx.StaticText(self, -1, txt, (20, 20))
  19
  20
  21     def OnPaint(self, evt):
  22         dc = wx.PaintDC(self)
  23         rect = wx.Rect(0,0, 100, 100)
  24         for RGB, pos in [((178,  34,  34), ( 50,  90)),
  25                          (( 35, 142,  35), (110, 150)),
  26                          ((  0,   0, 139), (170,  90))
  27                          ]:
  28             r, g, b = RGB
  29             penclr   = wx.Colour(r, g, b, wx.ALPHA_OPAQUE)
  30             brushclr = wx.Colour(r, g, b, 128)   # half transparent
  31             dc.SetPen(wx.Pen(penclr))
  32             dc.SetBrush(wx.Brush(brushclr))
  33             rect.SetPosition(pos)
  34             dc.DrawRectangleRect(rect)
  35
  36
  37 #----------------------------------------------------------------------
  38
  39 def runTest(frame, nb, log):
  40     win = TestPanel(nb, log)
  41     return win
  42
  43 #----------------------------------------------------------------------
  44
  45
  46
  47 overview = """<html><body>
  48 <h2><center>Alpha Drawing</center></h2>
  49
  50 The wx.DC on Mac now supports alpha transparent drawing using pens and
  51 brushes.  This is accomplished by enabling the wx.Colour class to have
  52 a fourth component for the alpha value, where 0 is fully transparent,
  53 and 255 is fully opaque.
  54
  55 <p>You can consider this a \"preview of coming attractions\" for the
  56 other platforms.
  57
  58 </body></html>
  59 """
  60
  61
  62
  63 if __name__ == '__main__':
  64     import sys,os
  65     import run
  66     run.main(['', os.path.basename(sys.argv[0])] + sys.argv[1:])
  67