wxPython/demo/OOR.py

   1 # 11/13/2003 - Jeff Grimmett (grimmtooth@softhome.net)
   2 #
   3 # o Updated for wx namespace
   4 #
   5
   6 import  wx
   7 import  wx.html as wxhtml
   8
   9 #----------------------------------------------------------------------
  10
  11 BTN1 = wx.NewId()
  12 BTN2 = wx.NewId()
  13
  14 class TestPanel(wx.Panel):
  15     def __init__(self, parent, log):
  16         wx.Panel.__init__(self, parent, -1)
  17         self.log = log
  18
  19         sizer = wx.BoxSizer(wx.VERTICAL)
  20         html = wxhtml.HtmlWindow(self, -1)
  21         html.SetPage(overview)
  22         sizer.Add(html, 1, wx.EXPAND|wx.ALL, 5)
  23
  24         btns = wx.BoxSizer(wx.HORIZONTAL)
  25         btns.Add((50, -1), 1, wx.EXPAND)
  26         btn1 = wx.Button(self, BTN1, "Find My Alter-ego") # don't save a ref to this one
  27         btns.Add(btn1)
  28         btns.Add((50, -1), 1, wx.EXPAND)
  29         self.btn2 = wx.Button(self, BTN2, "Find Myself")
  30         btns.Add(self.btn2)
  31         btns.Add((50, -1), 1, wx.EXPAND)
  32
  33         sizer.Add(btns, 0, wx.EXPAND|wx.ALL, 15)
  34
  35         self.SetSizer(sizer)
  36         self.SetAutoLayout(True)
  37
  38         self.sizer = sizer  # save it for testing later
  39
  40         self.Bind(wx.EVT_BUTTON, self.OnFindButton1, id=BTN1)
  41         self.Bind(wx.EVT_BUTTON, self.OnFindButton2, id=BTN2)
  42
  43
  44     def OnFindButton1(self, evt):
  45         win = self.FindWindowById(BTN1)
  46
  47         if win is None:
  48             self.log.write("***** OOPS! None returned...\n")
  49             return
  50
  51         className = win.__class__.__name__
  52
  53         if className in ["Button", "ButtonPtr"]:
  54             self.log.write("The types are the same! <grin>\n")
  55         else:
  56             self.log.write("Got %s, expected wxButton or wxButtonPtr\n" % className)
  57
  58
  59
  60     def OnFindButton2(self, evt):
  61         win = self.FindWindowById(BTN2)
  62
  63         if win is None:
  64             self.log.write("***** OOPS! None returned...\n")
  65             return
  66
  67         if win is self.btn2:
  68             self.log.write("The objects are the same! <grin>\n")
  69         else:
  70             self.log.write("The objects are NOT the same! <frown>\n")
  71
  72         win = evt.GetEventObject()
  73
  74         if win is None:
  75             self.log.write("***** OOPS! None returned...\n")
  76             return
  77
  78         if win is self.btn2:
  79             self.log.write("The objects are the same! <grin>\n")
  80         else:
  81             self.log.write("The objects are NOT the same! <frown>\n")
  82
  83         sizer = self.GetSizer()
  84
  85         if sizer is None:
  86             self.log.write("***** OOPS! None returned...\n")
  87             return
  88
  89         if sizer is self.sizer:
  90             self.log.write("The objects are the same! <grin>\n")
  91         else:
  92             self.log.write("The objects are NOT the same! <frown>\n")
  93
  94
  95 #----------------------------------------------------------------------
  96
  97 def runTest(frame, nb, log):
  98     win = TestPanel(nb, log)
  99     return win
 100
 101 #----------------------------------------------------------------------
 102
 103
 104 overview = """\
 105 <html><body>
 106 <h2>Original Object Return</h2>
 107
 108 <p>Several methods in wxWindows return pointers to base class objects,
 109 when in fact the actual object pointed to is of a derived type.  Since
 110 SWIG isn't able to tell the actual type it just creates a new Python
 111 shadow object of the base type to wrap around the base type pointer
 112 and returns it.
 113
 114 <p>In wxPython prior to 2.3.0 this could cause annoying issues.  For
 115 example if you called:
 116
 117 <pre>
 118
 119         myText = someWindow.FindWindowById(txtID)
 120 </pre>
 121
 122 expecting to get a wxTextCtrl you would actually get a wxWindow object
 123 instead.  If you then try to call SetValue on that object you'll get
 124 an exception since there is no such method.  This is the reason for
 125 the wxPyTypeCast hack that has been in wxPython for so long.
 126
 127 <p>Even with wxPyTypeCast there was the issue that the object returned
 128 was not the same one that was created in Python originally, but a new
 129 object of the same type that wraps the same C++ pointer.  If the
 130 programmer has set additional attributes of that original object they
 131 will not exist in the new object.
 132
 133 <p>For a long time now I have wanted to do away with wxPyTypeCast and
 134 also find a way to return the original Python object from methods like
 135 FindWindowById.  This project naturally divides into two phases:
 136
 137 <p><ol>
 138
 139 <li>Teach the wrapper methods how to return objects of the right type,
 140 and be able to then turn wxPyTypeCast in to a no-op.
 141
 142 <li>Be able to return the original Python shadow object if it still exists.
 143
 144 </ol>
 145
 146 <p>The first button below shows the first of these phases (<i>working</i>)
 147 and the second will show #2 (<i>working as of Python 2.3.2</i>)
 148
 149 </body></html>
 150 """
 151
 152
 153
 154
 155 if __name__ == '__main__':
 156     import sys,os
 157     import run
 158     run.main(['', os.path.basename(sys.argv[0])])
 159