TableOfContents()

Introduction

This page is meant to be the end-all/be-all for all information relating to using XRC files, both in C++ and in wxPython. If you have come to this page expecting pure Python or pure C++, you will be heavily disappointed. Both languages are given full attention here.

As of right now, there is very little here. This is meant to simply be a placeholder page to get things started. More will be forthcoming as quickly as possible.

XRC Editors

Using XRC with wxPython

Using XRC with wxPython

Opening XRC Files

Embedding XRC Files In Code

Using wxrc

Using pywxrc

["pywxrc"]

Subclassing Controls

Custom Controls

Using XRC with C++

Using XRC with C++

Opening XRC Files

Embedding XRC Files In Code

Using wxrc

Using pywxrc

This is, unfortunately, not possible at this time.

Subclassing Controls

Custom Controls

File: tn0014.txt - Annotated

This is the file which defines XRC. This section provides the full text of the file, cross-references within it, and annotates with extra comments. For now, this is version 1.22, taken from http://cvs.wxwidgets.org/viewcvs.cgi/wxWidgets/docs/tech/tn0014.txt

XRC resources format specification

!!!!! NOT YET FINISHED !!!!!

1. Introduction

• This note describes the file format used for storing XRC resources that are used by wxXmlResource class. It is probably only useful for those implementing dialog editors with XRC support. If you only want to use the resources, you can choose from a number of editors:

  • wxDesigner (http://www.roebling.de)

  • XRCed (wxPython/tools)

  • DialogBlocks (wxPython/tools)

  and others listed on the Resources section of the wxWidgets web site.

  The XRC format is based on XML 1.0 (please consult W3C's specification). There is no DTD available since it is not possible to fully describe the format with the limited expressive power of DTDs. Note: see also http://ldaptool.sourceforge.net/XRCGuide/XRCGuideSingle/

1. Terminology

• The usual XML terminology applies. In particular, we shall use the terms NODE, PROPERTY and VALUE in the XML sense:  <node property1="value1" property2="value2">...</node> 

  The term ATTRIBUTE is specific to XRC and refers to a subnode of an  <object>  or  <object_ref>  node that is itself not  <object>  or  <object_ref> . In the example below,  <pos> ,  <label>  and  <style>  are attributes, while neither  <resource>  nor either of  <object> s is:

  •         <?xml version="1.0" encoding="utf-8">
            <resource xmlns="http://www.wxwidgets.org/wxxrc" version="2.5.3.0">
                <object class="wxPanel">
                    <style>wxSUNKEN_BORDER</style>             <!-- attr -->
                    <object class="wxStaticText">
                        <label>A label</label>                 <!-- attr -->
                        <pos>10,10</pos>                       <!-- attr -->
                    </object>
                </object>
            </resource>

  ATTRIBUTE VALUE is the content of all text elements within attribute tag. In the above example, "wxSUNKEN_BORDER", "A label" and "10,10" are attribute values. ATTRIBUTE TYPE defines what attribute values are valid for given attribute (you can think of it as attribute value syntax definition).

1. Elementary description

• XRC resource file is a well-formed XML 1.0 document. All elements of XRC file are from the http://www.wxwidgets.org/wxxrc namespace.

  The root node of XRC document must be  <resource>  The  <resource>  node has optional "version" property. Default version (in absence of the version property) is "0.0.0.0". The version consists of four integers separated by periods. Version of XRC format changes only if there was an incompatible change introduced (i.e. either the library cannot understand old resource files or older versions of the library wouldn't understand the new format). The first three integers are major, minor and release number of the wxWidgets release when the change was introduced, the last one is revision number and is 0 for the first incompatible change in given wxWidgets release, 1 for the second etc. Differences between versions are described within this document in paragraphs entitled "Version Note".

  The  <resource>  node contains namespace declaration, too:

  •         <resource xmlns="http://www.wxwidgets.org/wxxrc" version="2.5.3.0">

  The  <resource>  node is only allowed to have  <object>  and  <object_ref>  subnodes, all of which must have the "name" property. The  <object>  node represents a single object (GUI element) and it usually maps directly to a wxWidgets class instance. It has the properties: "name", "class" and "subclass". "class" must always be present, it tells XRC what wxWidgets object should be created in this place. The other two are optional. "name" is ID used to identify the object. It is the value passed to the XRCID() macro and is also used to construct wxWindow's id and name attributes and must be unique among all children of the nearest container object (wxDialog, wxFrame, wxPanel, wxNotebook) upside from the object in XML nodes hierarchy (two distinct containers may contain objects with same "name", though). "subclass" is optional name of class whose constructor will be called instead of the constructor for "class". Subclass must be available in the program that loads the resource, must be derived from "class" and must be registered within wxWidgets' RTTI system. Finally, an optional "insert_at" property may be present. Currently only the values "begin" and "end" are supported, meaning to insert the object in the beginning of the parent node objects list or to append it at the end (which is the default if this property is absent). Example:

  •         <object name="MyList1" class="wxListCtrl" subclass="MyListCtrlClass">
                ...
            </object>

   <object>  node may have arbitrary child nodes. What child nodes and their semantics are class-dependent and are defined later in this document. The user is allowed to register new object handlers within XRC and extend it to accept new  <object>  classes (and therefore different  <object> s child nodes).  <object_ref>  node is identical to  <object>  except that it does _not_ have "class" property and has additional required property "ref". Its concept is similar to Unix symlinks: value of the "ref" property is equal to the value of "name" property of some existing node (called referred node) in the resources (not necessary top-level). Referred node's "class" property and all subnodes are copied in place of the referee  <object_ref>  node which is then processed as regular  <object>  node. If the  <object_ref>  node itself has child nodes, then these nodes _override_ any nodes from the referred node. Example:

  •         <object name="foo" class="wxTextCtrl">
                <value>hello</value>
                <size>100,-1d</size>
            </object>
            <object_ref name="bar" ref="foo">
                <value>bar</value>               <!-- override! -->
            </object_ref>

  is identical to:

  •         <object name="foo" class="wxTextCtrl">
                <value>hello</value>
                <size>100,-1d</size>
            </object>
            <object name="bar" class="wxTextCtrl">
                <value>bar</value>
                <size>100,-1d</size>
            </object>

 1. Common attribute types
    ----
    There are several attribute types (see section 1. Terminology) that are common
    to many attributes of different classes:
    String
    ------
    Any text. Some characters have special interpretation and are translated
    by XRC parser according to this table:
        "_"    -> "&"  ('&' is used to underline e.g. menu items in wxWidgets)
        "__"   -> "_"
        "\n"   -> line break (C character '\n')
        "\r"   -> carriage return (C character '\r')
        "\t"   -> tab (C character '\t')
        "\\"   -> "\"
                  (introduced in version 2.5.3.0, not done in earlier versions)
    Version Note:
        '$' was used instead of '_' prior to version 2.3.0.1.
    I18nString
    ----------
    Like String, but the value is translated to native language using wxLocale
    at runtime (unless it was disabled by not passing wxXRC_USE_LOCALE flag to
    wxXmlResource constructor). Used for strings that are "visible" in the GUI.
    UnsignedInteger
    ---------------
    This is obvious. Only digits 0-9 may be present and there must be at least
    one digit.
    Integer
    -------
    Like UnsignedInteger but may be prefixed with '-' (ints less than zero).
    Position
    --------
    Specifies (window's) position in 2D space. Syntax is <integer>,<integer>[d]
    where <integer> is valid value of Integer type.
    Size
    ----
    Syntax is same as Position's syntax, but the values are interpreted as window
    size (wxSize type) and not position (wxPosition type).
    Style[wxSomeClass]
    ------------------
    List of style flags that can be passed to wxSomeClass' constructor. Flags are
    written in same way as in C++ code (e.g. "wxSUNKEN_BORDER",
    "wxHW_SCROLLBAR_NEVER") and are delimited with any combination of whitespaces
    and '|'. Possible flags are class-dependent and are not described in this
    technote. Please refer to wxWidgets manual for all styles that given class can
    accept; if XRC does not accept a flag listed in wxWidgets documentation, it is
    a bug.
    Bitmap
    ------
    Attribute value is interpreted as filename (either absolute or relative to
    the location of XRC resource file). In addition, attribute node may have
    "stock_id" and "stock_client" properties. Their values may be any of wxArtID (or
    wxArtClient respectively) values as used by wxArtProvider (because the user may
    define own constants, effectively any string is legal here). Examples are
    "wxART_FILE_OPEN" (id) or "wxART_MENU" (client).
    Any of "stock_id" or "stock_client" properties or the filename may be omitted.
    XRC determines the bitmap to use according to this algorithm:
      1. If there is non-empty "stock_id" property, query wxArtProvider for the
         bitmap (if there is no "stock_client", use default one, which is usually
         wxART_OTHER; exceptions are noted in class-specific sections below). If
         the query fails, continue to 2.
      2. Load the bitmap from the file in attribute value.
    Boolean
    -------
    Boolean value, either "0" (false) or "1" (true).
    Font
    ----
    Font value. A font can be described either in terms of its elementary
    properties, or it can be derived from one of system fonts. The font node
    may contain following subnodes (the table lists subnode name on the left and
    variable type as per the definitions above on the right side):
    size            UnsignedInteger
    style           normal | italic | slant
    weight          normal | bold | light
    family          roman | script | decorative | swiss | modern | teletype
    underlined      Boolean
    face            comma-separated list of faces
    encoding        charset of the font (meaningless in Unicode build), as string
    sysfont         symbolic name of system standard font
                    (one of wxSYS_*_FONT constants)
    relativesize    Float, font size relative to choosen system font's size;
                    can only be used when 'sysfont' is used and when 'size' is not
                    used
    All of them are optional, if they are missing, wxFont default is used.
    Examples:
        <font>
            <face>arial,helvetica</face>
            <size>12</size>
        </font>
        <font>
            <sysfont>wxSYS_DEFAULT_GUI_FONT</sysfont>
            <weight>bold</weight>
            <relativesize>1.5</relativesize>
        </font>
    Colour
    ------
    A colour value is either explicit RGB value in the standard #rrggbb format
    where rr, gg and bb are hexadecimal case-insensitive values in the 00..FF
    range, or a symbolic name. Symbolic names are wxSYS_COLOUR_* constants defined
    by wxWidgets, written as strings.
    Example:
        <bg>wxSYS_COLOUR_SCROLLBAR</bg>
        <fg>#FF0000</fg>
 1. Supported classes
    ----
    Attributes are listed in tables in the following format:
    attribute name             attribute type          default value, if any
                               [(optional remarks....................
                               ...................................)]
    wxBitmap
    --------
    This is a special case, because it does not create a wxWindow instance but
    creates wxBitmap instead. Another exceptional thing is that it does not have
    any attributes. Instead, the node itself is interpreted as if it were attribute
    of type Bitmap.
    Example: <object class="wxBitmap">bitmaps/foo.gif</object>
    wxIcon
    ------
    Identical to wxBitmap class, except that it creates wxIcon instead of wxBitmap.
    wxButton
    --------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxButton]
    label                      I18nString
    default                    Boolean                 false
                               (Is the button default button?)
    wxCalendarCtrl
    --------------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxCalendarCtrl]
    wxCheckBox
    ----------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxCheckBox]
    checked                    Boolean                 false
    wxCheckList
    -----------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxCheckList]
    content                    (see below)             (empty)
    Optional "content" attribute does not have attribute value. Instead,
    arbitrary number of <item> nodes may be rooted under it (the control
    is filled with strings contained in these nodes). Each <item>
    node must contain I18nString value and may have "checked" property
    with possible values "0" or "1" indicating the the item is initially
    checked.
    Example:
    <object class="wxCheckList">
        <content>
          <item>One</item>
          <item checked="1">Two</item>
          <item checked="1">Three</item>
          <item>Four</item>
        </content>
    </object>
    wxDatePickerCtrl
    ----------------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxDatePickerCtrl]
    wxDialog
    --------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxDialog]         wxDEFAULT_DIALOG_STYLE
    title                      I18nString              ""
    icon                       Bitmap                  (empty)
    centered                   Boolean                 false
    wxDialog may have children objects.
    wxFrame
    --------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxDialog]         wxDEFAULT_FRAME_STYLE
    title                      I18nString              ""
    icon                       Bitmap                  (empty)
    centered                   Boolean                 false
    wxFrame may have children objects. There can be at most one wxToolBar,
    wxMenuBar and wxStatusBar children; objects of these types are automatically
    set as frame's tool-, menu- and statusbar respectively.
    wxMDIParentFrame
    ----------------
    Supports same attributes and children nodes as wxFrame. Additionally, children
    may be of the wxMDIChildFrame type.
    wxMDIChildFrame
    ---------------
    Supports same attributes and children nodes as wxFrame.
    wxScrolledWindow
    ----------------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxScrolledWindow] wxHSCROLL | wxVSCROLL
    wxScolledWindow may have children objects.
    wxSplitterWindow
    ----------------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxSplitterWindow] wxSP_3D
    sashpos                    Integer                 0
                               (Initial sash position)
    minsize                    Integer                 -1
                               (Minimal panel size)
    orientation                "horizontal"|"vertical" horizontal
    wxSplitterWindow must have at least one and at most two children objects.
    If there's only one child object, it is passed to wxSplitterWindow::Initialize
    and the splitter is created unsplit. If there are two children, the
    splitter is created split, either horizontally or vertically depending
    on the value of "orientation" attribute.
    wxStatusBar
    -----------
    fields                     Integer number of fields
    widths                     Width1, Width2, Width3, ...
    wxToolBar
    ---------
    pos                        Position                -1,-1
    size                       Size                    -1,-1
    style                      Style[wxToolBar]        wxNO_BORDER|wxTB_HORIZONTAL
    bitmapsize                 Size                    -1,-1
                               (Size of contained bitmaps)
    margins                    Size                    -1,-1
    packing                    Integer                 -1
    separation                 Integer                 -1
    bg                         Background colour       None
    dontattachtoframe          Boolean                 False
    wxToolBar node may have children <object> and <object_ref> nodes. Their class
    may be either "tool", "separator" or any wxWidgets class derived from
    wxControl. "tool" and "separator" are special pseudo-classes that may only
    appear within wxToolBar node. Their attributes are as follows:
        separator
        ---------
        (doesn't have any attributes)
        tool
        ----
        bitmap                 Bitmap
        bitmap2                Bitmap                  wxNullBitmap
        toggle                 Boolean                 0
        radio                  Boolean                 0
        disabled               Boolean                 0
        label                  I18nString              ""
        tooltip                I18nString              ""
        longhelp               I18nString              ""
        pos                    Position                -1,-1
        Constraints:
          At most one of "toggle" and "radio" attributes may be 1.
          Attribute "pos" may not appear if "label" or "radio" attributes
          are used or if parent wxToolBar's style contains wxTB_TEXT.
        Note:
          Use of "pos" attribute is strongly discouraged, it is deprecated
          usage of wxToolBar and it is not supported by MSW and GTK
          implementations.
    Children objects are added to the toolbar using AddTool for "tool" class,
    AddSeparator for "separator" and AddControl for other classes.
 1. More features
    ----
    FIXME -- "platform" property handling

• = Page Comments =

  This section is dedicated to User Comments. See TheRules for why this section exists, and why it is down here.