wxPython/demo/ImageAlpha.py

   1
   2 import wx                  # This module uses the new wx namespace
   3 from Main import opj
   4
   5
   6 #----------------------------------------------------------------------
   7
   8 msg = "Some text will appear in the image's shadow..."
   9
  10 class TestPanel(wx.Panel):
  11     def __init__(self, parent, log):
  12         self.log = log
  13         wx.Panel.__init__(self, parent, -1)
  14
  15         self.Bind(wx.EVT_PAINT, self.OnPaint)
  16
  17
  18     def OnPaint(self, evt):
  19         dc = wx.PaintDC(self)
  20         dc.SetBackground(wx.Brush("WHITE"))
  21         dc.Clear()
  22
  23         dc.SetFont(wx.Font(16, wx.SWISS, wx.NORMAL, wx.BOLD, True))
  24         dc.DrawText("Bitmap alpha blending (on wxMSW and wxMac only)",
  25                     25,25)
  26
  27         bmp = wx.Bitmap(opj('bitmaps/toucan.png'))
  28         if "__WXGTK__" in wx.PlatformInfo:
  29             # try to make up for lack of alpha support a bit...
  30             img = bmp.ConvertToImage()
  31             img.ConvertAlphaToMask(220) #threshold below which alpha will be made fully transparent
  32             bmp = img.ConvertToBitmap()
  33
  34         dc.DrawBitmap(bmp, 25,100, True)
  35
  36         dc.SetFont(self.GetFont())
  37         y = 75
  38         for line in range(10):
  39             y += dc.GetCharHeight() + 5
  40             dc.DrawText(msg, 200, y)
  41         dc.DrawBitmap(bmp, 250,100, True)
  42
  43
  44
  45 #----------------------------------------------------------------------
  46
  47 def runTest(frame, nb, log):
  48     win = TestPanel(nb, log)
  49     return win
  50
  51 #----------------------------------------------------------------------
  52
  53
  54
  55 overview = """<html><body>
  56 <h2><center>Images with Alpha</center></h2>
  57
  58 wxMSW and wxMac now support alpha channels of supported image
  59 types, and will properly blend that channel when drawing a
  60 bitmap.  It is not supported yet on wxGTK, (if you would like to
  61 change that please submit a patch!)
  62
  63 <p>On wxGTK this demo turns the alpha channel into a 1-bit mask, so
  64 yes, it looks like crap.  Please help us fix it!
  65
  66 </body></html>
  67 """
  68
  69
  70
  71 if __name__ == '__main__':
  72     import sys,os
  73     import run
  74     run.main(['', os.path.basename(sys.argv[0])] + sys.argv[1:])
  75