!!!!! NOT YET FINISHED !!!!!
0. 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
is no DTD available since it is not possible to fully describe the format with
the limited expressive power of DTDs.
+
+
1. Terminology
---------------
+==============
The usual XML terminology applies. In particular, we shall use the terms
-"node", "property" and "value" in the XML sense:
+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 property-less subnode
-of an <object> or <object_ref> node. In the example bellow, <pos>, <label> and
-<style> are attributes, while neither <resource> nor either of <object>s is:
+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 bellow, <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.wxwindows.org/wxxrc" version="2.3.0.1">
<object class="wxPanel">
- <style>wxSUNKEN_BORDER</style>
+ <style>wxSUNKEN_BORDER</style> <!-- attr -->
<object class="wxStaticText">
- <label>A label</label>
- <pos>10,10</pos>
+ <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).
+
+
+
2. Elementary description
--------------------------
+=========================
-XRC resource file is a well-formed XML 1.0 document. All elements of XRC file are
-from the http://www.wxwindows.org/wxxrc namespace.
+XRC resource file is a well-formed XML 1.0 document. All elements of XRC file
+are from the http://www.wxwindows.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
the second etc.
Differences between versions are described within this document in paragraphs
-entitled "Version Note".
+entitled "Version Note".
The <resource> node contains namespace declaration, too:
The <resource> node is only allowed to have <object> and <object_ref>
subnodes, all of which must have the "name" property.
-<object> - TODO (name, class, subclass)
+The <object> node represents a single object (GUI element) and it usually maps
+directly to a wxWindows class instance. It three properties: "name", "class"
+and "subclass". "class" must always be present, it tells XRC what wxWindows
+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 neareset container object (wxDialog, wxFrame,
+wxPanel, wxNotebook) upside from the object in XML nodes hiearchy (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
+wxWindows' RTTI system.
+
+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 additonal required property "ref". It's 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 neccessary 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>
+
+
+
+3. 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 wxWindows)
+ "__" -> "_"
+ "\n" -> line break (C character '\n')
+ "\r" -> carriage return (C character '\r')
+ "\t" -> tabelator (C character '\t')
+
+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 delimined with any combination of whitespaces
+and '|'. Possible flags are class-dependent and are not described in this
+technote. Please refer to wxWindows manual for all styles that given class can
+accept; if XRC does not accept a flag listed in wxWindows 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, efectively any string is legal here). Examples are
+"wxART_FILE_OPEN" (id) or "wxART_MENU" (client).
-<object_ref> - TODO (name, ref, subclass)
+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 bellow). If
+ the query fails, continue to 2.
+ 2. Load the bitmap from the file in attribute value.
-3. Common attributes
---------------------
+Boolean
+-------
+Boolean value, either "0" (false) or "1" (true).
+
-TODO
4. 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
+--------
+position Position -1,-1
+size Size -1,-1
+style Style[wxButton]
+
+label I18nString
+default Boolean false
+ (Is the button default button?)
+
+
+wxCalendarCtrl
+--------------
+position Position -1,-1
+size Size -1,-1
+style Style[wxCalendarCtrl]
+
+
+wxCheckBox
+----------
+position Position -1,-1
+size Size -1,-1
+style Style[wxCheckBox]
+checked Boolean false
+
+
+wxCheckList
+-----------
+position Position -1,-1
+size Size -1,-1
+style Style[wxCheckList]
+content (see bellow) (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>
+
+
+wxScrolledWindow
+----------------
+position Position -1,-1
+size Size -1,-1
+style Style[wxScrolledWindow] wxHSCROLL | wxVSCROLL
+
+
+wxSplitterWindow
+----------------
+position 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 unsplitted. If there are two children, the
+splitter is created splitted, either horizontally or vertically depending
+on the value of "orientation" attribute.
+
+
+wxToolBar
+---------
+position 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
+
+wxToolBar node may have children <object> and <object_ref> nodes. Their class
+may be either "tool", "separator" or any wxWindows 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
+ label I18nString ""
+ tooltip I18nString ""
+ longhelp I18nString ""
+ position Position -1,-1
+
+ Constraints:
+ At most one of "toggle" and "radio" attributes may be 1.
+ Attribute "position" may not appear if "label" or "radio" attributes
+ are used or if parent wxToolBar's style contains wxTB_TEXT.
+
+ Note:
+ Use of "position" 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.
+
+
+
+5. More features
+================
+
+FIXME -- "platform" property handling
-TODO
=== EOF ===