XRC resources format specification ================================== !!!!! 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 dialog editors with XRC support. If you only want to use the resources, you can choose from a number of editors: a) wxDesigner (http://www.roebling.de) b) XRCed (wxPython/tools) c) 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: ... The term ATTRIBUTE is specific to XRC and refers to a subnode of an or node that is itself not or . In the example below, , 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.wxwidgets.org/wxxrc namespace. The root node of XRC document must be . The 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 node contains namespace declaration, too: The node is only allowed to have and subnodes, all of which must have the "name" property. The 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: ... 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 classes (and therefore different 's child nodes). node is identical to , 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 node which is then processed as regular node. If the node itself has child nodes, then these nodes _override_ any nodes from the referred node. Example: hello 100,-1d bar is identical to: hello 100,-1d bar 100,-1d 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 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 ,[d] where 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: arial,helvetica 12 wxSYS_DEFAULT_GUI_FONT bold 1.5 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: wxSYS_COLOUR_SCROLLBAR #FF0000 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: bitmaps/foo.gif 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 nodes may be rooted under it (the control is filled with strings contained in these nodes). Each node must contain I18nString value and may have "checked" property with possible values "0" or "1" indicating the the item is initially checked. Example: One Two Three Four 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. wxRadioBox ---------- This control may have "dimension" (major dimension) and (initial) "selection" Integer subelements and a composite "content" element similar to wxCheckList. The only difference is that the "item" subelements can have an optional "tooltip=I18nString" attribute to specify the per-item tooltip. 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 and 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. 5. More features ================ FIXME -- "platform" property handling === EOF === Version: $Id$