XdkWrl: FontStyle Class Reference

6.22 FontStyle

6.22.1 Introduction

The FontStyle node defines the size, family, and style used for Text nodes, as well as the direction of the text strings and any language-specific rendering techniques used for non-English text. See 6.47, Text, for a description of the Text node.

The size field specifies the nominal height, in the local coordinate system of the Text node, of glyphs rendered and determines the spacing of adjacent lines of text. Values of the size field shall be greater than zero.

The spacing field determines the line spacing between adjacent lines of text. The distance between the baseline of each line of text is (spacing × size) in the appropriate direction (depending on other fields described below). The effects of the size and spacing field are depicted in Figure 6.7 (spacing greater than 1.0). Values of the spacing field shall be non-negative.

Figure 6.7 -- Text size and spacing fields

6.22.2 Font family and style

Font attributes are defined with the family and style fields. The browser shall map the specified font attributes to an appropriate available font as described below.

The family field contains a case-sensitive MFString value that specifies a sequence of font family names in preference order. The browser shall search the MFString value for the first font family name matching a supported font family. If none of the string values matches a supported font family, the default font family "SERIF" shall be used. All browsers shall support at least "SERIF" (the default) for a serif font such as Times Roman; "SANS" for a sans-serif font such as Helvetica; and "TYPEWRITER" for a fixed-pitch font such as Courier. An empty family value is identical to ["SERIF"].

The style field specifies a case-sensitive SFString value that may be "PLAIN" (the default) for default plain type; "BOLD" for boldface type; "ITALIC" for italic type; or "BOLDITALIC" for bold and italic type. An empty style value ("") is identical to "PLAIN".

6.22.3 Direction and justification

The horizontal, leftToRight, and topToBottom fields indicate the direction of the text. The horizontal field indicates whether the text advances horizontally in its major direction (horizontal = TRUE, the default) or vertically in its major direction (horizontal = FALSE). The leftToRight and topToBottom fields indicate direction of text advance in the major (characters within a single string) and minor (successive strings) axes of layout. Which field is used for the major direction and which is used for the minor direction is determined by the horizontal field.

For horizontal text (horizontal = TRUE), characters on each line of text advance in the positive X direction if leftToRight is TRUE or in the negative X direction if leftToRight is FALSE. Characters are advanced according to their natural advance width. Each line of characters is advanced in the negative Y direction if topToBottom is TRUE or in the positive Y direction if topToBottom is FALSE. Lines are advanced by the amount of size × spacing.

For vertical text (horizontal = FALSE), characters on each line of text advance in the negative Y direction if topToBottom is TRUE or in the positive Y direction if topToBottom is FALSE. Characters are advanced according to their natural advance height. Each line of characters is advanced in the positive X direction if leftToRight is TRUE or in the negative X direction if leftToRight is FALSE. Lines are advanced by the amount of size × spacing.

The justify field determines alignment of the above text layout relative to the origin of the object coordinate system. The justify field is an MFString which can contain 2 values. The first value specifies alignment along the major axis and the second value specifies alignment along the minor axis, as determined by the horizontal field. An empty justify value ("") is equivalent to the default value. If the second string, minor alignment, is not specified, minor alignment defaults to the value "FIRST". Thus, justify values of "", "BEGIN", and ["BEGIN" "FIRST"] are equivalent.

The major alignment is along the X-axis when horizontal is TRUE and along the Y-axis when horizontal is FALSE. The minor alignment is along the Y-axis when horizontal is TRUE and along the X-axis when horizontal is FALSE. The possible values for each enumerant of the justify field are "FIRST", "BEGIN", "MIDDLE", and "END". For major alignment, each line of text is positioned individually according to the major alignment enumerant. For minor alignment, the block of text representing all lines together is positioned according to the minor alignment enumerant. Tables 6.2-6.5 describe the behaviour in terms of which portion of the text is at the origin

Table 6.2 -- Major Alignment, horizontal= TRUE

justify Enumerant	leftToRight = TRUE	leftToRight = FALSE
FIRST	Left edge of each line	Right edge of each line
BEGIN	Left edge of each line	Right edge of each line
MIDDLE	Centred about X-axis	Centred about X-axis
END	Right edge of each line	Left edge of each line

Table 6.3 -- Major Alignment, horizontal = FALSE

justify Enumerant	topToBottom = TRUE	topToBottom = FALSE
FIRST	Top edge of each line	Bottom edge of each line
BEGIN	Top edge of each line	Bottom edge of each line
MIDDLE	Centred about Y-axis	Centre about Y-axis
END	Bottom edge of each line	Top edge of each line

Table 6.4 -- Minor Alignment, horizontal = TRUE

justify Enumerant	topToBottom = TRUE	topToBottom = FALSE
FIRST	Baseline of first line	Baseline of first line
BEGIN	Top edge of first line	Bottom edge of first line
MIDDLE	Centred about Y-axis	Centred about Y-axis
END	Bottom edge of last line	Top edge of last line

Table 6.5 -- Minor Alignment, horizontal = FALSE

justify Enumerant	leftToRight = TRUE	leftToRight = FALSE
FIRST	Left edge of first line	Right edge of first line
BEGIN	Left edge of first line	Right edge of first line
MIDDLE	Centred about X-axis	Centred about X-axis
END	Right edge of last line	Left edge of last line

The default minor alignment is "FIRST". This is a special case of minor alignment when horizontal is TRUE. Text starts at the baseline at the Y-axis. In all other cases, "FIRST" is identical to "BEGIN". In Tables 6.6 and 6.7, each colour-coded cross-hair indicates where the X-axis and Y-axis shall be in relation to the text. Figure 6.8 describes the symbols used in Tables 6.6 and 6.7.

Figure 6.8 -- Key for Tables 6.6 and 6.7

Table 6.6 -- horizontal = TRUE

Table 6.7 -- horizontal = FALSE

6.22.4 Language

The language field specifies the context of the language for the text string. Due to the multilingual nature of the ISO/IEC 10646-1:1993, the language field is needed to provide a proper language attribute of the text string. The format is based on RFC 1766: language[_territory] 2.[1766]. The value for the language tag is based on ISO 639:1988 (e.g., 'zh' for Chinese, 'jp' for Japanese, and 'sc' for Swedish.) The territory tag is based on ISO 3166:1993 country codes (e.g., 'TW' for Taiwan and 'CN' for China for the 'zh' Chinese language tag). If the language field is empty (""), local language bindings are used.

See 2, Normative references, for more information on RFC 1766 (2.[1766]), ISO/IEC 10646:1993 (2.[UTF8]), ISO/IEC 639:1998 (2.[I639]), and ISO 3166:1993 (2.[I3166]).

Constructor & Destructor Documentation

FontStyle ( const char * name = "" )

Construct a node with all its fields set to default value, which is equivalent to the code below:

  horizontal = true;
  
  language = string("");
  leftToRight = true;
  size = 1;
  spacing = 1;
  style = string("PLAIN");
  topToBottom = true;

Member Function Documentation

wrl::Node * duplicate ( std::map< const Node *, Node * > & ) const [virtual]

Implements Node.

wrl::Node * duplicate ( ) const [virtual]

Returns a deep copy of this node, that is a fully independant node with all children (if any) also copied. This is mainly useful for instanciating protos.

Implements Node.

wrl::Node::EventInHandle eventIn ( const unsigned int i ) [virtual]

Return a handle on the i th event in of the node or a "unknown" typed handle if there is no such node. emarks This class has no eventIn. This function is useful, with nbEventsIn() if you want to traverse all events in of a Node.

Implements Node.

wrl::Node::EventInHandle eventIn ( const std::string & n ) [virtual]

Return a handle on the event in named n of the node or a "unknown" typed handle if there is no such event. Valid names are:

Implements Node.

wrl::Node::EventOutHandle eventOut ( const unsigned int i ) [virtual]

Return a handle on the i th event out of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields: This function is useful, with nbEventsOut() if you want to traverse all events in of a Node.

Implements Node.

wrl::Node::EventOutHandle eventOut ( const std::string & n ) [virtual]

Return a handle on the event out named n of the node or a "unknown" typed handle if there is no such event. Valid names are:

Implements Node.

wrl::Node::FieldHandle field ( const unsigned int n ) [virtual]

Return a handle on the i th field of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields:

0 : family
1 : horizontal
2 : justify
3 : language
4 : leftToRight
5 : size
6 : spacing
7 : style
8 : topToBottom This function is useful, with nbFields() if you want to traverse all fields of a Node.

Implements Node.

wrl::Node::FieldHandle field ( const std::string & n ) [virtual]

Return a handle on the field named n of the node or a "unknown" typed handle if there is no such field. Valid names are:

family
horizontal
justify
language
leftToRight
size
spacing
style
topToBottom

Implements Node.

bool isSetToDefaultValue ( const unsigned int i ) const [virtual]

Implements Node.

unsigned int nbEventsIn ( ) const [inline, virtual]

Returns the number of events in for this node type.

Implements Node.

unsigned int nbEventsOut ( ) const [inline, virtual]

Returns the number of events out for this node type.

Implements Node.

unsigned int nbFields ( ) const [inline, virtual]

Returns the number of fields (exposed or not) for this node type.

Implements Node.

const char * typeName ( ) const [inline, virtual]

Returns "FontStyle". Useful for printing.

Implements Node.


Public Member Functions
	FontStyle (const char *name="")
virtual	~FontStyle ()
virtual unsigned int	nbFields () const
virtual FieldHandle	field (const std::string &n)
virtual FieldHandle	field (const unsigned int i)
virtual bool	isSetToDefaultValue (const unsigned int i) const
virtual unsigned int	nbEventsIn () const
virtual EventInHandle	eventIn (const std::string &n)
virtual EventInHandle	eventIn (const unsigned int i)
virtual unsigned int	nbEventsOut () const
virtual EventOutHandle	eventOut (const std::string &n)
virtual EventOutHandle	eventOut (const unsigned int i)
const char *	typeName () const
virtual Node *	duplicate () const
virtual Node *	duplicate (std::map< const Node , Node > &) const
Public Attributes
Fields
A property or attribute of a node. Each node type has a fixed set of fields. Fields may contain various kinds of data and one or many values. Each field has a default value.
MFString	family
SFBool	horizontal
MFString	justify
SFString	language
SFBool	leftToRight
SFFloat	size
SFFloat	spacing
SFString	style
SFBool	topToBottom

FontStyle Class Reference
[Standard Node Types]

Public Member Functions

Public Attributes

Detailed Description

6.22 FontStyle

6.22.1 Introduction

Figure 6.7 -- Text size and spacing fields

6.22.2 Font family and style

6.22.3 Direction and justification

Table 6.2 -- Major Alignment, horizontal= TRUE

Table 6.3 -- Major Alignment, horizontal = FALSE

Table 6.4 -- Minor Alignment, horizontal = TRUE

Table 6.5 -- Minor Alignment, horizontal = FALSE

Figure 6.8 -- Key for Tables 6.6 and 6.7

Table 6.6 -- horizontal = TRUE

Table 6.7 -- horizontal = FALSE

6.22.4 Language

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

FontStyle Class Reference [Standard Node Types]

Public Member Functions

Public Attributes

Detailed Description

6.22 FontStyle

6.22.1 Introduction

Figure 6.7 -- Text size and spacing fields

6.22.2 Font family and style

6.22.3 Direction and justification

Table 6.2 -- Major Alignment, horizontal= TRUE

Table 6.3 -- Major Alignment, horizontal = FALSE

Table 6.4 -- Minor Alignment, horizontal = TRUE

Table 6.5 -- Minor Alignment, horizontal = FALSE

Figure 6.8 -- Key for Tables 6.6 and 6.7Table 6.6 -- horizontal = TRUE

Table 6.7 -- horizontal = FALSE

6.22.4 Language

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

FontStyle Class Reference
[Standard Node Types]

Figure 6.8 -- Key for Tables 6.6 and 6.7

Table 6.6 -- horizontal = TRUE