wxPython/wx/lib/wxpTag.py

   1 #----------------------------------------------------------------------
   2 # Name:        wxPython.lib.wxpTag
   3 # Purpose:     A wxHtmlTagHandler that knows how to build and place
   4 #              wxPython widgets onto web pages.
   5 #
   6 # Author:      Robin Dunn
   7 #
   8 # Created:     13-Sept-1999
   9 # RCS-ID:      $Id$
  10 # Copyright:   (c) 1999 by Total Control Software
  11 # Licence:     wxWindows license
  12 #----------------------------------------------------------------------
  13 # 12/13/2003 - Jeff Grimmett (grimmtooth@softhome.net)
  14 #
  15 # o Updated for V2.5 compatability
  16 #
  17
  18 '''
  19 wxPython.lib.wxpTag
  20
  21 This module contains a wxHtmlTagHandler that knows how to build
  22 and place wxPython widgets onto wxHtmlWindow web pages.
  23
  24 You don\'t need to use anything in this module directly, just
  25 importing it will create the tag handler and add it to any
  26 wxHtmlWinParsers created from that time forth.
  27
  28 Tags of the following form are recognised:
  29
  30     <WXP class="classname" [module="modulename"] [width="num"] [height="num"]>
  31         <PARAM name="parameterName" value="parameterValue>
  32         ...
  33     </WXP>
  34
  35 where modulename is the name of a module (possibly in package
  36 notation) to import and classname is the name of a class in that
  37 module to create an instance of.  If the module tag-attribute is not
  38 given or is an empty string, then wx is used.  The width and height
  39 attributes are expected to be integers and will be passed to the
  40 __init__ method of the class as a wxSize object named size.  However,
  41 if the width attribute ends with the percent (%) symbol then the value
  42 will be used as a percentage of the available width and the
  43 wxHtmlWindow will manage the size.
  44
  45 The name-value pairs in all the nested PARAM tags are packaged up as
  46 strings into a python dictionary and passed to the __init__ method of
  47 the class as keyword arguments.  This means that they are all
  48 accessible from the __init__ method as regular parameters, or you use
  49 the special Python **kw syntax in your __init__ method to get the
  50 dictionary directly.
  51
  52 Some parameter values are special and if they are present then they will
  53 be converted from strings to alternate datatypes.  They are:
  54
  55     id           If the value of id can be converted to an integer, it will
  56                  be.  Otherwise it is assumed to be the name of an integer
  57                  variable in the module.
  58
  59     colours      Any value of the form "#123ABC" will automatically be
  60                  converted to a wxColour object.
  61
  62     Py Types     Any value begining with "(", "[" or "{" are expected to
  63                  be a Python tuple, list, or dictionary and eval()
  64                  will be used to convert them to that type.  If the
  65                  eval() fails then the original string value will be
  66                  preserved.
  67
  68     wx Types     Any value begining with "wx" is expected to be an attempt
  69                  to create a wxPython object, such as a wxSize, etc.
  70                  The eval() will be used to try and construct the
  71                  object and if it fails then the original string value
  72                  will be used instead.
  73
  74 An example:
  75
  76     <wxp module="wx" class="Button">
  77         <param name="label" value="Click here">
  78         <param name="id" value="ID_OK">
  79     </wxp>
  80
  81 Both the begining and ending WXP tags are required.
  82
  83 In the future support will be added for another tag that can be
  84 embedded between the two begining and ending WXP tags and will
  85 facilitate calling methods of the widget to help initialize it.
  86 Additionally, support may be added to fetch the module from a web
  87 server as is done with java applets.
  88
  89 '''
  90 #----------------------------------------------------------------------
  91
  92 import  types
  93
  94 import  wx
  95 import  wx.html
  96
  97
  98 #----------------------------------------------------------------------
  99
 100 WXPTAG   = 'WXP'
 101 PARAMTAG = 'PARAM'
 102
 103 #----------------------------------------------------------------------
 104
 105 class wxpTagHandler(wx.html.HtmlWinTagHandler):
 106     def __init__(self):
 107         wx.html.HtmlWinTagHandler.__init__(self)
 108         self.ctx = None
 109
 110     def GetSupportedTags(self):
 111         return WXPTAG+','+PARAMTAG
 112
 113
 114     def HandleTag(self, tag):
 115         name = tag.GetName()
 116         if name == WXPTAG:
 117             return self.HandleWxpTag(tag)
 118         elif name == PARAMTAG:
 119             return self.HandleParamTag(tag)
 120         else:
 121             raise ValueError, 'unknown tag: ' + name
 122
 123
 124     def HandleWxpTag(self, tag):
 125         # create a new context object
 126         self.ctx = _Context()
 127
 128         # find and import the module
 129         modName = ''
 130         if tag.HasParam('MODULE'):
 131             modName = tag.GetParam('MODULE')
 132         if modName:
 133             self.ctx.classMod = _my_import(modName)
 134         else:
 135             self.ctx.classMod = wx
 136
 137         # find and verify the class
 138         if not tag.HasParam('CLASS'):
 139             raise AttributeError, "WXP tag requires a CLASS attribute"
 140
 141         className = tag.GetParam('CLASS')
 142         self.ctx.classObj = getattr(self.ctx.classMod, className)
 143         if type(self.ctx.classObj) not in [ types.ClassType, types.TypeType]:
 144             raise TypeError, "WXP tag attribute CLASS must name a class"
 145
 146         # now look for width and height
 147         width = -1
 148         height = -1
 149         if tag.HasParam('WIDTH'):
 150             width = tag.GetParam('WIDTH')
 151             if width[-1] == '%':
 152                 self.ctx.floatWidth = int(width[:-1], 0)
 153                 width = self.ctx.floatWidth
 154             else:
 155                 width = int(width)
 156         if tag.HasParam('HEIGHT'):
 157             height = int(tag.GetParam('HEIGHT'))
 158         self.ctx.kwargs['size'] = wx.Size(width, height)
 159
 160         # parse up to the closing tag, and gather any nested Param tags.
 161         self.ParseInner(tag)
 162
 163         # create the object
 164         parent = self.GetParser().GetWindow()
 165         if parent:
 166             obj = apply(self.ctx.classObj,
 167                         (parent,),
 168                         self.ctx.kwargs)
 169             obj.Show(True)
 170
 171             # add it to the HtmlWindow
 172             self.GetParser().GetContainer().InsertCell(
 173                 wx.html.HtmlWidgetCell(obj, self.ctx.floatWidth))
 174             self.ctx = None
 175
 176         return True
 177
 178
 179     def HandleParamTag(self, tag):
 180         if not tag.HasParam('NAME'):
 181             return False
 182
 183         name = tag.GetParam('NAME')
 184         value = ""
 185         if tag.HasParam('VALUE'):
 186             value = tag.GetParam('VALUE')
 187
 188         # check for a param named 'id'
 189         if name == 'id':
 190             theID = -1
 191             try:
 192                 theID = int(value)
 193             except ValueError:
 194                 theID = getattr(self.ctx.classMod, value)
 195             value = theID
 196
 197
 198         # check for something that should be evaluated
 199         elif value and value[0] in '[{(' or value[:2] == 'wx':
 200             saveVal = value
 201             try:
 202                 value = eval(value, self.ctx.classMod.__dict__)
 203             except:
 204                 value = saveVal
 205
 206         # convert to wx.Colour
 207         elif value and value[0] == '#':
 208             try:
 209                 red   = int('0x'+value[1:3], 16)
 210                 green = int('0x'+value[3:5], 16)
 211                 blue  = int('0x'+value[5:], 16)
 212                 value = wx.Color(red, green, blue)
 213             except:
 214                 pass
 215
 216         if self.ctx:
 217           self.ctx.kwargs[str(name)] = value
 218         return False
 219
 220
 221 #----------------------------------------------------------------------
 222 # just a place to hold some values
 223 class _Context:
 224     def __init__(self):
 225         self.kwargs = {}
 226         self.width = -1
 227         self.height = -1
 228         self.classMod = None
 229         self.classObj = None
 230         self.floatWidth = 0
 231
 232
 233 #----------------------------------------------------------------------
 234 # Function to assist with importing packages
 235 def _my_import(name):
 236     mod = __import__(name)
 237     components = name.split('.')
 238     for comp in components[1:]:
 239         mod = getattr(mod, comp)
 240     return mod
 241
 242
 243 #----------------------------------------------------------------------
 244 # Function to parse a param string (of the form 'item=value item2="value etc"'
 245 # and creates a dictionary
 246 def _param2dict(param):
 247     i = 0; j = 0; s = len(param); d = {}
 248     while 1:
 249         while i<s and param[i] == " " : i = i+1
 250         if i>=s: break
 251         j = i
 252         while j<s and param[j] != "=": j=j+1
 253         if j+1>=s:
 254             break
 255         word = param[i:j]
 256         i=j+1
 257         if (param[i] == '"'):
 258             j=i+1
 259             while j<s and param[j] != '"' : j=j+1
 260             if j == s: break
 261             val = param[i+1:j]
 262         elif (param[i] != " "):
 263             j=i+1
 264             while j<s and param[j] != " " : j=j+1
 265             val = param[i:j]
 266         else:
 267             val = ""
 268         i=j+1
 269         d[word] = val
 270     return d
 271
 272 #----------------------------------------------------------------------
 273
 274
 275
 276 wx.html.HtmlWinParser_AddTagHandler(wxpTagHandler)