wxPython/demo/wxXmlResourceHandler.py

   1
   2 from wxPython.wx import *
   3 from wxPython.xrc import *
   4
   5 #----------------------------------------------------------------------
   6
   7 resourceText = r'''<?xml version="1.0"?>
   8 <resource>
   9
  10 <!-- Notice that the class is NOT a standard wx class -->
  11
  12 <object class="MyBluePanel" name="MyPanel">
  13     <size>200,100</size>
  14     <object class="wxStaticText" name="lable1">
  15         <label>This blue panel is a class derived from wxPanel,\nand is loaded by a custom wxXmlResourceHandler.</label>
  16         <pos>10,10</pos>
  17     </object>
  18 </object>
  19 </resource>
  20 '''
  21
  22 #----------------------------------------------------------------------
  23
  24 class MyBluePanel(wxPanel):
  25     def __init__(self, parent, id, pos, size, style, name):
  26         wxPanel.__init__(self, parent, id, pos, size, style, name)
  27
  28         # This is the little bit of customization that we do for this
  29         # silly example.  It could just as easily have been done in
  30         # the resource.
  31         self.SetBackgroundColour("BLUE")
  32
  33
  34 # To do it the more complex way, (see below) we need to write the
  35 # class a little differently...  This could obviously be done with a
  36 # single class, but I wanted to make separate ones to make clear what
  37 # the different requirements are.
  38 class PreMyBluePanel(wxPanel):
  39     def __init__(self):
  40         p = wxPrePanel()
  41         self.this = p.this
  42
  43     def Create(self, parent, id, pos, size, style, name):
  44         wxPanel.Create(self, parent, id, pos, size, style, name)
  45         self.SetBackgroundColour("BLUE")
  46
  47 #----------------------------------------------------------------------
  48
  49 class MyBluePanelXmlHandler(wxXmlResourceHandler):
  50     def __init__(self):
  51         wxXmlResourceHandler.__init__(self)
  52         # Specify the styles recognized by objects of this type
  53         self.AddStyle("wxNO_3D", wxNO_3D);
  54         self.AddStyle("wxTAB_TRAVERSAL", wxTAB_TRAVERSAL);
  55         self.AddStyle("wxWS_EX_VALIDATE_RECURSIVELY", wxWS_EX_VALIDATE_RECURSIVELY);
  56         self.AddStyle("wxCLIP_CHILDREN", wxCLIP_CHILDREN);
  57         self.AddWindowStyles();
  58
  59     # This method and the next one are required for XmlResourceHandlers
  60     def CanHandle(self, node):
  61         return self.IsOfClass(node, "MyBluePanel")
  62
  63     def DoCreateResource(self):
  64         # NOTE: wxWindows can be created in either a single-phase or
  65         # in a two-phase way.  Single phase is what you normally do,
  66         # and two-phase creates the instnace first, and then later
  67         # creates the actual window when the Create method is called.
  68         # (In wxPython the first phase is done using the wxPre*
  69         # function, for example, wxPreFrame, wxPrePanel, etc.)
  70         #
  71         # wxXmlResource supports either method, a premade instance can
  72         # be created and populated by xrc using the appropriate
  73         # LoadOn* method (such as LoadOnPanel) or xrc can create the
  74         # instance too, using the Load* method.  However this makes
  75         # the handlers a bit more complex.  If you can be sure that a
  76         # particular class will never be loaded using a pre-existing
  77         # instance, then you can make the handle much simpler.  I'll
  78         # show both methods below.
  79
  80         if 0:
  81             # The simple method assumes that there is no existing
  82             # instance.  Be sure of that with an assert.
  83             assert self.GetInstance() is None
  84
  85             # Now create the object
  86             panel = MyBluePanel(self.GetParentAsWindow(),
  87                                 self.GetID(),
  88                                 self.GetPosition(),
  89                                 self.GetSize(),
  90                                 self.GetStyle("style", wxTAB_TRAVERSAL),
  91                                 self.GetName()
  92                                 )
  93         else:
  94             # When using the more complex (but more flexible) method
  95             # the instance may already have been created, check for it
  96             panel = self.GetInstance()
  97             if panel is None:
  98                 # if not, then create the instance (but not the window)
  99                 panel = PreMyBluePanel()
 100
 101             # Now call the panel's Create method to actually create the window
 102             panel.Create(self.GetParentAsWindow(),
 103                          self.GetID(),
 104                          self.GetPosition(),
 105                          self.GetSize(),
 106                          self.GetStyle("style", wxTAB_TRAVERSAL),
 107                          self.GetName()
 108                          )
 109
 110         # These two things should be done in either case:
 111         # Set standard window attributes
 112         self.SetupWindow(panel)
 113         # Create any child windows of this node
 114         self.CreateChildren(panel)
 115
 116         return panel
 117
 118
 119 #----------------------------------------------------------------------
 120
 121
 122 class TestPanel(wxPanel):
 123     def __init__(self, parent, log):
 124         self.log = log
 125         wxPanel.__init__(self, parent, -1)
 126
 127         # make the components
 128         label = wxStaticText(self, -1, "The lower panel was built from this XML:")
 129         label.SetFont(wxFont(12, wxSWISS, wxNORMAL, wxBOLD))
 130
 131         text = wxTextCtrl(self, -1, resourceText,
 132                           style=wxTE_READONLY|wxTE_MULTILINE)
 133         text.SetInsertionPoint(0)
 134
 135         line = wxStaticLine(self, -1)
 136
 137         # Load the resource
 138         res = wxEmptyXmlResource()
 139         res.InsertHandler(MyBluePanelXmlHandler())
 140         res.LoadFromString(resourceText)
 141
 142         # Now create a panel from the resource data
 143         panel = res.LoadObject(self, "MyPanel", "MyBluePanel")
 144
 145         # and do the layout
 146         sizer = wxBoxSizer(wxVERTICAL)
 147         sizer.Add(label, 0, wxEXPAND|wxTOP|wxLEFT, 5)
 148         sizer.Add(text, 1, wxEXPAND|wxALL, 5)
 149         sizer.Add(line, 0, wxEXPAND)
 150         sizer.Add(panel, 1, wxEXPAND|wxALL, 5)
 151
 152         self.SetSizer(sizer)
 153         self.SetAutoLayout(true)
 154
 155
 156 #----------------------------------------------------------------------
 157
 158 def runTest(frame, nb, log):
 159     win = TestPanel(nb, log)
 160     return win
 161
 162 #----------------------------------------------------------------------
 163
 164
 165
 166 overview = """<html><body>
 167 <h2><center>wxXmlResourceHandler</center></h2>
 168
 169 Deriving a class from wxXmlResourceHandler allows you to specify your
 170 own classes in XRC resources, and your handler class will then be used
 171 to create instances of that class when the resource is loaded.
 172
 173 </body></html>
 174 """
 175
 176
 177
 178 if __name__ == '__main__':
 179     import sys,os
 180     import run
 181     run.main(['', os.path.basename(sys.argv[0])])
 182