docs/tech/tn0014.txt

   1                       XRC resources format specification
   2                       ==================================
   3
   4                          !!!!! NOT YET FINISHED !!!!!
   5
   6 0. Introduction
   7 ===============
   8
   9 This note describes the file format used for storing XRC resources that are
  10 used by wxXmlResource class. It is probably only useful for those implementing
  11 dialog editors with XRC support.
  12
  13 If you only want to use the resources, you can choose from a number of editors:
  14   a) wxDesigner (http://www.roebling.de)
  15   b) XRCed (wxPython/tools)
  16   c) wxWorkshop (http://wxworkshop.sf.net)
  17   b) wxrcedit (contrib/utils/wxrcedit)
  18
  19 The XRC format is based on XML 1.0 (please consult W3C's specification). There
  20 is no DTD available since it is not possible to fully describe the format with
  21 the limited expressive power of DTDs.
  22
  23
  24 Note: see also http://ldaptool.sourceforge.net/XRCGuide/XRCGuideSingle/
  25
  26
  27
  28 1. Terminology
  29 ==============
  30
  31 The usual XML terminology applies. In particular, we shall use the terms
  32 NODE, PROPERTY and VALUE in the XML sense:
  33
  34     <node property1="value1" property2="value2">...</node>
  35
  36 The term ATTRIBUTE is specific to XRC and refers to a subnode
  37 of an <object> or <object_ref> node that is itself not <object> or <object_ref>.
  38 In the example below, <pos>, <label> and <style> are attributes, while neither
  39 <resource> nor either of <object>s is:
  40
  41     <?xml version="1.0" encoding="utf-8">
  42     <resource xmlns="http://www.wxwidgets.org/wxxrc" version="2.5.3.0">
  43         <object class="wxPanel">
  44             <style>wxSUNKEN_BORDER</style>             <!-- attr -->
  45             <object class="wxStaticText">
  46                 <label>A label</label>                 <!-- attr -->
  47                 <pos>10,10</pos>                       <!-- attr -->
  48             </object>
  49         </object>
  50     </resource>
  51
  52 ATTRIBUTE VALUE is the content of all text elements within attribute tag. In the
  53 above example, "wxSUNKEN_BORDER", "A label" and "10,10" are attribute values.
  54 ATTRIBUTE TYPE defines what attribute values are valid for given attribute (you
  55 can think of it as attribute value syntax definition).
  56
  57
  58
  59 2. Elementary description
  60 =========================
  61
  62 XRC resource file is a well-formed XML 1.0 document. All elements of XRC file
  63 are from the http://www.wxwidgets.org/wxxrc namespace.
  64
  65 The root node of XRC document must be <resource>. The <resource> node has
  66 optional "version" property. Default version  (in absence of the version
  67 property) is "0.0.0.0". The version consists of four integers separated by
  68 periods. Version of XRC format changes only if there was an incompatible
  69 change introduced (i.e. either the library cannot understand old resource
  70 files or older versions of the library wouldn't understand the new format).
  71 The first three integers are major, minor and release number of the wxWidgets
  72 release when the change was introduced, the last one is revision number and
  73 is 0 for the first incompatible change in given wxWidgets release, 1 for
  74 the second etc.
  75
  76 Differences between versions are described within this document in paragraphs
  77 entitled "Version Note".
  78
  79 The <resource> node contains namespace declaration, too:
  80
  81     <resource xmlns="http://www.wxwidgets.org/wxxrc" version="2.5.3.0">
  82
  83 The <resource> node is only allowed to have <object> and <object_ref>
  84 subnodes, all of which must have the "name" property.
  85
  86 The <object> node represents a single object (GUI element) and it usually maps
  87 directly to a wxWidgets class instance. It three properties: "name", "class"
  88 and "subclass". "class" must always be present, it tells XRC what wxWidgets
  89 object should be created in this place. The other two are optional.  "name" is
  90 ID used to identify the object. It is the value passed to the XRCID() macro and
  91 is also used to construct wxWindow's id and name attributes and must be unique
  92 among all children of the neareset container object (wxDialog, wxFrame,
  93 wxPanel, wxNotebook) upside from the object in XML nodes hiearchy (two distinct
  94 containers may contain objects with same "name", though). "subclass" is
  95 optional name of class whose constructor will be called instead of the
  96 constructor for "class". Subclass must be available in the program that loads
  97 the resource, must be derived from "class" and must be registered within
  98 wxWidgets' RTTI system.
  99
 100 Example:
 101
 102     <object name="MyList1" class="wxListCtrl" subclass="MyListCtrlClass">
 103         ...
 104     </object>
 105
 106 <object> node may have arbitrary child nodes. What child nodes and their
 107 semantics are class-dependent and are defined later in this document. The user
 108 is allowed to register new object handlers within XRC and extend it to accept
 109 new <object> classes (and therefore different <object>'s child nodes).
 110
 111 <object_ref> node is identical to <object>, except that it does _not_ have
 112 "class" property and has additonal required property "ref". It's concept is
 113 similar to Unix symlinks: value of the "ref" property is equal to the value of
 114 "name" property of some existing node (called referred node) in the resources
 115 (not neccessary top-level).  Referred node's "class" property and all subnodes
 116 are copied in place of the referee <object_ref> node which is then processed as
 117 regular <object> node. If the <object_ref> node itself has child nodes, then
 118 these nodes _override_ any nodes from the referred node.
 119
 120 Example:
 121
 122     <object name="foo" class="wxTextCtrl">
 123         <value>hello</value>
 124         <size>100,-1d</size>
 125     </object>
 126     <object_ref name="bar" ref="foo">
 127         <value>bar</value>               <!-- override! -->
 128     </object_ref>
 129
 130 is identical to:
 131
 132     <object name="foo" class="wxTextCtrl">
 133         <value>hello</value>
 134         <size>100,-1d</size>
 135     </object>
 136     <object name="bar" class="wxTextCtrl">
 137         <value>bar</value>
 138         <size>100,-1d</size>
 139     </object>
 140
 141
 142
 143 3. Common attribute types
 144 =========================
 145
 146 There are several attribute types (see section 1. Terminology) that are common
 147 to many attributes of different classes:
 148
 149 String
 150 ------
 151 Any text. Some characters have special interpretation and are translated
 152 by XRC parser according to this table:
 153     "_"    -> "&"  ('&' is used to underline e.g. menu items in wxWidgets)
 154     "__"   -> "_"
 155     "\n"   -> line break (C character '\n')
 156     "\r"   -> carriage return (C character '\r')
 157     "\t"   -> tabelator (C character '\t')
 158     "\\"   -> "\"
 159               (introduced in version 2.5.3.0, not done in earlier versions)
 160
 161 Version Note:
 162     '$' was used instead of '_' prior to version 2.3.0.1.
 163
 164
 165 I18nString
 166 ----------
 167 Like String, but the value is translated to native language using wxLocale
 168 at runtime (unless it was disabled by not passing wxXRC_USE_LOCALE flag to
 169 wxXmlResource constructor). Used for strings that are "visible" in the GUI.
 170
 171
 172 UnsignedInteger
 173 ---------------
 174 This is obvious. Only digits 0-9 may be present and there must be at least
 175 one digit.
 176
 177
 178 Integer
 179 -------
 180 Like UnsignedInteger but may be prefixed with '-' (ints less than zero).
 181
 182
 183 Position
 184 --------
 185 Specifies (window's) position in 2D space. Syntax is <integer>,<integer>[d]
 186 where <integer> is valid value of Integer type.
 187
 188
 189 Size
 190 ----
 191 Syntax is same as Position's syntax, but the values are interpreted as window
 192 size (wxSize type) and not position (wxPosition type).
 193
 194
 195 Style[wxSomeClass]
 196 ------------------
 197 List of style flags that can be passed to wxSomeClass' constructor. Flags are
 198 written in same way as in C++ code (e.g. "wxSUNKEN_BORDER",
 199 "wxHW_SCROLLBAR_NEVER") and are delimined with any combination of whitespaces
 200 and '|'. Possible flags are class-dependent and are not described in this
 201 technote. Please refer to wxWidgets manual for all styles that given class can
 202 accept; if XRC does not accept a flag listed in wxWidgets documentation, it is
 203 a bug.
 204
 205
 206 Bitmap
 207 ------
 208 Attribute value is interpreted as filename (either absolute or relative to
 209 the location of XRC resource file). In addition, attribute node may have
 210 "stock_id" and "stock_client" properties. Their values may be any of wxArtID (or
 211 wxArtClient respectively) values as used by wxArtProvider (because the user may
 212 define own constants, efectively any string is legal here). Examples are
 213 "wxART_FILE_OPEN" (id) or "wxART_MENU" (client).
 214
 215 Any of "stock_id" or "stock_client" properties or the filename may be omitted.
 216 XRC determines the bitmap to use according to this algorithm:
 217   1. If there is non-empty "stock_id" property, query wxArtProvider for the
 218      bitmap (if there is no "stock_client", use default one, which is usually
 219      wxART_OTHER; exceptions are noted in class-specific sections below). If
 220      the query fails, continue to 2.
 221   2. Load the bitmap from the file in attribute value.
 222
 223
 224 Boolean
 225 -------
 226 Boolean value, either "0" (false) or "1" (true).
 227
 228
 229
 230 4. Supported classes
 231 ====================
 232
 233 Attributes are listed in tables in the following format:
 234 attribute name             attribute type          default value, if any
 235                            [(optional remarks....................
 236                            ...................................)]
 237
 238 wxBitmap
 239 --------
 240 This is a special case, because it does not create a wxWindow instance but
 241 creates wxBitmap instead. Another exceptional thing is that it does not have
 242 any attributes. Instead, the node itself is interpreted as if it were attribute
 243 of type Bitmap.
 244
 245 Example: <object class="wxBitmap">bitmaps/foo.gif</object>
 246
 247
 248 wxIcon
 249 ------
 250 Identical to wxBitmap class, except that it creates wxIcon instead of wxBitmap.
 251
 252
 253 wxButton
 254 --------
 255 position                   Position                -1,-1
 256 size                       Size                    -1,-1
 257 style                      Style[wxButton]
 258
 259 label                      I18nString
 260 default                    Boolean                 false
 261                            (Is the button default button?)
 262
 263
 264 wxCalendarCtrl
 265 --------------
 266 position                   Position                -1,-1
 267 size                       Size                    -1,-1
 268 style                      Style[wxCalendarCtrl]
 269
 270
 271 wxCheckBox
 272 ----------
 273 position                   Position                -1,-1
 274 size                       Size                    -1,-1
 275 style                      Style[wxCheckBox]
 276 checked                    Boolean                 false
 277
 278
 279 wxCheckList
 280 -----------
 281 position                   Position                -1,-1
 282 size                       Size                    -1,-1
 283 style                      Style[wxCheckList]
 284 content                    (see below)             (empty)
 285
 286 Optional "content" attribute does not have attribute value. Instead,
 287 arbitrary number of <item> nodes may be rooted under it (the control
 288 is filled with strings contained in these nodes). Each <item>
 289 node must contain I18nString value and may have "checked" property
 290 with possible values "0" or "1" indicating the the item is initially
 291 checked.
 292
 293 Example:
 294 <object class="wxCheckList">
 295     <content>
 296       <item>One</item>
 297       <item checked="1">Two</item>
 298       <item checked="1">Three</item>
 299       <item>Four</item>
 300     </content>
 301 </object>
 302
 303
 304 wxScrolledWindow
 305 ----------------
 306 position                   Position                -1,-1
 307 size                       Size                    -1,-1
 308 style                      Style[wxScrolledWindow] wxHSCROLL | wxVSCROLL
 309
 310
 311 wxSplitterWindow
 312 ----------------
 313 position                   Position                -1,-1
 314 size                       Size                    -1,-1
 315 style                      Style[wxSplitterWindow] wxSP_3D
 316 sashpos                    Integer                 0
 317                            (Initial sash position)
 318 minsize                    Integer                 -1
 319                            (Minimal panel size)
 320 orientation                "horizontal"|"vertical" horizontal
 321
 322 wxSplitterWindow must have at least one and at most two children objects.
 323 If there's only one child object, it is passed to wxSplitterWindow::Initialize
 324 and the splitter is created unsplitted. If there are two children, the
 325 splitter is created splitted, either horizontally or vertically depending
 326 on the value of "orientation" attribute.
 327
 328 wxStatusBar
 329 -----------
 330 fields                     Integer number of fields
 331 widths                     Width1, Width2, Width3, ...
 332
 333 wxToolBar
 334 ---------
 335 position                   Position                -1,-1
 336 size                       Size                    -1,-1
 337 style                      Style[wxToolBar]        wxNO_BORDER|wxTB_HORIZONTAL
 338 bitmapsize                 Size                    -1,-1
 339                            (Size of contained bitmaps)
 340 margins                    Size                    -1,-1
 341 packing                    Integer                 -1
 342 separation                 Integer                 -1
 343
 344 wxToolBar node may have children <object> and <object_ref> nodes. Their class
 345 may be either "tool", "separator" or any wxWidgets class derived from
 346 wxControl. "tool" and "separator" are special pseudo-classes that may only
 347 appear within wxToolBar node. Their attributes are as follows:
 348
 349     separator
 350     ---------
 351     (doesn't have any attributes)
 352
 353     tool
 354     ----
 355     bitmap                 Bitmap
 356     bitmap2                Bitmap                  wxNullBitmap
 357     toggle                 Boolean                 0
 358     radio                  Boolean                 0
 359     label                  I18nString              ""
 360     tooltip                I18nString              ""
 361     longhelp               I18nString              ""
 362     position               Position                -1,-1
 363
 364     Constraints:
 365       At most one of "toggle" and "radio" attributes may be 1.
 366       Attribute "position" may not appear if "label" or "radio" attributes
 367       are used or if parent wxToolBar's style contains wxTB_TEXT.
 368
 369     Note:
 370       Use of "position" attribute is strongly discouraged, it is deprecated
 371       usage of wxToolBar and it is not supported by MSW and GTK
 372       implementations.
 373
 374 Children objects are added to the toolbar using AddTool for "tool" class,
 375 AddSeparator for "separator" and AddControl for other classes.
 376
 377
 378
 379 5. More features
 380 ================
 381
 382 FIXME -- "platform" property handling
 383
 384
 385 === EOF ===
 386
 387 Version: $Id$