wxPython/demo/XmlResourceHandler.py

   1 # 11/22/2003 - Jeff Grimmett (grimmtooth@softhome.net)
   2 #
   3 # o Updated for wx namespace
   4 # o There are issues using the wx namespace within the xrc code.
   5 #
   6 # 11/30/2003 - Jeff Grimmett (grimmtooth@softhome.net)
   7 #
   8 # o Error report: "Error: No handler found for XML node 'object',
   9 #   class 'wx.StaticText'!"; no text shows on panel.
  10 #
  11
  12 import  wx
  13 import  wx.xrc  as  xrc
  14
  15 #----------------------------------------------------------------------
  16
  17 resourceText = r'''<?xml version="1.0"?>
  18 <resource>
  19
  20 <!-- Notice that the class is NOT a standard wx class -->
  21
  22 <object class="MyBluePanel" name="MyPanel">
  23     <size>200,100</size>
  24     <object class="wx.StaticText" name="label1">
  25         <label>This blue panel is a class derived from wx.Panel,\nand is loaded by a custom XmlResourceHandler.</label>
  26         <pos>10,10</pos>
  27     </object>
  28 </object>
  29 </resource>
  30 '''
  31
  32 #----------------------------------------------------------------------
  33
  34 class MyBluePanel(wx.Panel):
  35     def __init__(self, parent, id, pos, size, style, name):
  36         wx.Panel.__init__(self, parent, id, pos, size, style, name)
  37
  38         # This is the little bit of customization that we do for this
  39         # silly example.  It could just as easily have been done in
  40         # the resource.
  41         self.SetBackgroundColour("BLUE")
  42         self.SetForegroundColour("WHITE")
  43
  44
  45 # To do it the more complex way, (see below) we need to write the
  46 # class a little differently...  This could obviously be done with a
  47 # single class, but I wanted to make separate ones to make clear what
  48 # the different requirements are.
  49 class PreMyBluePanel(wx.Panel):
  50     def __init__(self):
  51         p = wx.PrePanel()
  52         self.PostCreate(p)
  53
  54     def Create(self, parent, id, pos, size, style, name):
  55         wx.Panel.Create(self, parent, id, pos, size, style, name)
  56         self.SetBackgroundColour("BLUE")
  57         self.SetForegroundColour("WHITE")
  58
  59
  60 #----------------------------------------------------------------------
  61
  62 class MyBluePanelXmlHandler(xrc.XmlResourceHandler):
  63     def __init__(self):
  64         xrc.XmlResourceHandler.__init__(self)
  65         # Specify the styles recognized by objects of this type
  66         self.AddStyle("wx.NO_3D", wx.NO_3D);
  67         self.AddStyle("wx.TAB_TRAVERSAL", wx.TAB_TRAVERSAL);
  68         self.AddStyle("wx.WS_EX_VALIDATE_RECURSIVELY", wx.WS_EX_VALIDATE_RECURSIVELY);
  69         self.AddStyle("wx.CLIP_CHILDREN", wx.CLIP_CHILDREN);
  70         self.AddWindowStyles();
  71
  72     # This method and the next one are required for XmlResourceHandlers
  73     def CanHandle(self, node):
  74         return self.IsOfClass(node, "MyBluePanel")
  75
  76     def DoCreateResource(self):
  77         # NOTE: wxWindows can be created in either a single-phase or
  78         # in a two-phase way.  Single phase is what you normally do,
  79         # and two-phase creates the instnace first, and then later
  80         # creates the actual window when the Create method is called.
  81         # (In wxPython the first phase is done using the wxPre*
  82         # function, for example, wxPreFrame, wxPrePanel, etc.)
  83         #
  84         # wxXmlResource supports either method, a premade instance can
  85         # be created and populated by xrc using the appropriate
  86         # LoadOn* method (such as LoadOnPanel) or xrc can create the
  87         # instance too, using the Load* method.  However this makes
  88         # the handlers a bit more complex.  If you can be sure that a
  89         # particular class will never be loaded using a pre-existing
  90         # instance, then you can make the handle much simpler.  I'll
  91         # show both methods below.
  92
  93         if 1:
  94             # The simple method assumes that there is no existing
  95             # instance.  Be sure of that with an assert.
  96             assert self.GetInstance() is None
  97
  98             # Now create the object
  99             panel = MyBluePanel(self.GetParentAsWindow(),
 100                                 self.GetID(),
 101                                 self.GetPosition(),
 102                                 self.GetSize(),
 103                                 self.GetStyle("style", wx.TAB_TRAVERSAL),
 104                                 self.GetName()
 105                                 )
 106         else:
 107             # When using the more complex (but more flexible) method
 108             # the instance may already have been created, check for it
 109             panel = self.GetInstance()
 110             if panel is None:
 111                 # if not, then create the instance (but not the window)
 112                 panel = PreMyBluePanel()
 113
 114             # Now call the panel's Create method to actually create the window
 115             panel.Create(self.GetParentAsWindow(),
 116                          self.GetID(),
 117                          self.GetPosition(),
 118                          self.GetSize(),
 119                          self.GetStyle("style", wx.TAB_TRAVERSAL),
 120                          self.GetName()
 121                          )
 122
 123         # These two things should be done in either case:
 124         # Set standard window attributes
 125         self.SetupWindow(panel)
 126         # Create any child windows of this node
 127         self.CreateChildren(panel)
 128
 129         return panel
 130
 131
 132 #----------------------------------------------------------------------
 133
 134
 135 class TestPanel(wx.Panel):
 136     def __init__(self, parent, log):
 137         self.log = log
 138         wx.Panel.__init__(self, parent, -1)
 139
 140         # make the components
 141         label = wx.StaticText(self, -1, "The lower panel was built from this XML:")
 142         label.SetFont(wx.Font(12, wx.SWISS, wx.NORMAL, wx.BOLD))
 143
 144         text = wx.TextCtrl(self, -1, resourceText,
 145                           style=wx.TE_READONLY|wx.TE_MULTILINE)
 146         text.SetInsertionPoint(0)
 147
 148         line = wx.StaticLine(self, -1)
 149
 150         # Load the resource
 151         res = xrc.EmptyXmlResource()
 152         res.InsertHandler(MyBluePanelXmlHandler())
 153         res.LoadFromString(resourceText)
 154
 155         # Now create a panel from the resource data
 156         panel = res.LoadObject(self, "MyPanel", "MyBluePanel")
 157
 158         # and do the layout
 159         sizer = wx.BoxSizer(wx.VERTICAL)
 160         sizer.Add(label, 0, wx.EXPAND|wx.TOP|wx.LEFT, 5)
 161         sizer.Add(text, 1, wx.EXPAND|wx.ALL, 5)
 162         sizer.Add(line, 0, wx.EXPAND)
 163         sizer.Add(panel, 1, wx.EXPAND|wx.ALL, 5)
 164
 165         self.SetSizer(sizer)
 166         self.SetAutoLayout(True)
 167
 168
 169 #----------------------------------------------------------------------
 170
 171 def runTest(frame, nb, log):
 172     win = TestPanel(nb, log)
 173     return win
 174
 175 #----------------------------------------------------------------------
 176
 177
 178
 179 overview = """<html><body>
 180 <h2><center>wxXmlResourceHandler</center></h2>
 181
 182 Deriving a class from wxXmlResourceHandler allows you to specify your
 183 own classes in XRC resources, and your handler class will then be used
 184 to create instances of that class when the resource is loaded.
 185
 186 </body></html>
 187 """
 188
 189
 190
 191 if __name__ == '__main__':
 192     import sys,os
 193     import run
 194     run.main(['', os.path.basename(sys.argv[0])])
 195