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Markup

Markup — Simple markup language for text with attributes

Functions

gboolean pango_parse_markup ()
GMarkupParseContext * pango_markup_parser_new ()
gboolean pango_markup_parser_finish ()

Description

Frequently, you want to display some text to the user with attributes applied to part of the text (for example, you might want bold or italicized words). With the base Pango interfaces, you could create a PangoAttrList and apply it to the text; the problem is that you'd need to apply attributes to some numeric range of characters, for example "characters 12-17." This is broken from an internationalization standpoint; once the text is translated, the word you wanted to italicize could be in a different position.

The solution is to include the text attributes in the string to be translated. Pango provides this feature with a small markup language. You can parse a marked-up string into the string text plus a PangoAttrList using either of pango_parse_markup() or pango_markup_parser_new().

A simple example of a marked-up string might be:

1
 
<span foreground="blue" size="x-large">Blue text</span> is <i>cool</i>!

Pango uses GMarkup to parse this language, which means that XML features such as numeric character entities such as &amp;#169; for © can be used too.

The root tag of a marked-up document is <markup>, but pango_parse_markup() allows you to omit this tag, so you will most likely never need to use it. The most general markup tag is <span>, then there are some convenience tags.

Span attributes

<span> has the following attributes:

  • font_desc: A font description string, such as "Sans Italic 12". See pango_font_description_from_string() for a description of the format of the string representation . Note that any other span attributes will override this description. So if you have "Sans Italic" and also a style="normal" attribute, you will get Sans normal, not italic.

  • font_family: A font family name

  • font_size, size: Font size in 1024ths of a point, or one of the absolute sizes xx-small, x-small, small, medium, large, x-large, xx-large, or one of the relative sizes smaller or larger. If you want to specify a absolute size, it's usually easier to take advantage of the ability to specify a partial font description using font; you can use font='12.5' rather than size='12800'.

  • font_style: One of normal, oblique, italic

  • font_weight: One of ultralight, light, normal, bold, ultrabold, heavy, or a numeric weight

  • font_variant: One of normal or smallcaps

  • font_stretch, stretch: One of ultracondensed, extracondensed, condensed, semicondensed, normal, semiexpanded, expanded, extraexpanded, ultraexpanded

  • font_features: A comma-separated list of OpenType font feature settings, in the same syntax as accepted by CSS. E.g: font_features='dlig=1, -kern, afrc on'

  • foreground, fgcolor: An RGB color specification such as #00FF00 or a color name such as red. Since 1.38, an RGBA color specification such as #00FF007F will be interpreted as specifying both a foreground color and foreground alpha.

  • background, bgcolor: An RGB color specification such as #00FF00 or a color name such as red. Since 1.38, an RGBA color specification such as #00FF007F will be interpreted as specifying both a background color and background alpha.

  • alpha, fgalpha: An alpha value for the foreground color, either a plain integer between 1 and 65536 or a percentage value like 50%.

  • background_alpha, bgalpha: An alpha value for the background color, either a plain integer between 1 and 65536 or a percentage value like 50%.

  • underline: One of none, single, double, low, error, single-line, double-line or error-line.

  • underline_color: The color of underlines; an RGB color specification such as #00FF00 or a color name such as red

  • overline: One of none or single

  • overline_color: The color of overlines; an RGB color specification such as #00FF00 or a color name such as red

  • rise: Vertical displacement, in Pango units. Can be negative for subscript, positive for superscript.

  • strikethrough true or false whether to strike through the text

  • strikethrough_color: The color of strikethrough lines; an RGB color specification such as #00FF00 or a color name such as red

  • fallback: true or false whether to enable fallback. If disabled, then characters will only be used from the closest matching font on the system. No fallback will be done to other fonts on the system that might contain the characters in the text. Fallback is enabled by default. Most applications should not disable fallback.

  • allow_breaks: true or false whether to allow line breaks or not. If not allowed, the range will be kept in a single run as far as possible. Breaks are allowed by default.

  • insert_hyphens: true or false` whether to insert hyphens when breaking lines in the middle of a word. Hyphens are inserted by default.

  • show: A value determining how invisible characters are treated. Possible values are spaces, line-breaks, ignorables or combinations, such as spaces|line-breaks.

  • lang: A language code, indicating the text language

  • letter_spacing: Inter-letter spacing in 1024ths of a point.

  • gravity: One of south, east, north, west, auto.

  • gravity_hint: One of natural, strong, line.

Convenience tags

The following convenience tags are provided:

  • <b>: Bold

  • <big>: Makes font relatively larger, equivalent to <span size="larger">

  • <i>: Italic

  • <s>: Strikethrough

  • <sub>: Subscript

  • <sup>: Superscript

  • <small>: Makes font relatively smaller, equivalent to <span size="smaller">

  • <tt>: Monospace

  • <u>: Underline

Functions

pango_parse_markup ()

gboolean
pango_parse_markup (const char *markup_text,
                    int length,
                    gunichar accel_marker,
                    PangoAttrList **attr_list,
                    char **text,
                    gunichar *accel_char,
                    GError **error);

Parses marked-up text (see

markup format) to create

a plain-text string and an attribute list.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, accel_marker might be an ampersand or underscore. All characters marked as an accelerator will receive a PANGO_UNDERLINE_LOW attribute, and the first character so marked will be returned in accel_char . Two accel_marker characters following each other produce a single literal accel_marker character.

To parse a stream of pango markup incrementally, use pango_markup_parser_new().

If any error happens, none of the output arguments are touched except for error .

Parameters

markup_text

markup to parse (see markup format)

  

length

length of markup_text , or -1 if nul-terminated

  

accel_marker

character that precedes an accelerator, or 0 for none

  

attr_list

address of return location for a PangoAttrList, or NULL.

[out][allow-none]

text

address of return location for text with tags stripped, or NULL.

[out][allow-none]

accel_char

address of return location for accelerator char, or NULL.

[out][allow-none]

error

address of return location for errors, or NULL

  

Returns

FALSE if error is set, otherwise TRUE

pango_markup_parser_new ()

GMarkupParseContext *
pango_markup_parser_new (gunichar accel_marker);

Parses marked-up text (see

markup format) to create

a plain-text string and an attribute list.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, accel_marker might be an ampersand or underscore. All characters marked as an accelerator will receive a PANGO_UNDERLINE_LOW attribute, and the first character so marked will be returned in accel_char , when calling finish(). Two accel_marker characters following each other produce a single literal accel_marker character.

To feed markup to the parser, use g_markup_parse_context_parse() on the returned GMarkupParseContext. When done with feeding markup to the parser, use pango_markup_parser_finish() to get the data out of it, and then use g_markup_parse_context_free() to free it.

This function is designed for applications that read pango markup from streams. To simply parse a string containing pango markup, the simpler pango_parse_markup() API is recommended instead.

Parameters

accel_marker

character that precedes an accelerator, or 0 for none

  

Returns

a GMarkupParseContext that should be destroyed with g_markup_parse_context_free().

[transfer none]

Since: 1.31.0

pango_markup_parser_finish ()

gboolean
pango_markup_parser_finish (GMarkupParseContext *context,
                            PangoAttrList **attr_list,
                            char **text,
                            gunichar *accel_char,
                            GError **error);

After feeding a pango markup parser some data with g_markup_parse_context_parse(), use this function to get the list of pango attributes and text out of the markup. This function will not free context , use g_markup_parse_context_free() to do so.

Parameters

context

A valid parse context that was returned from pango_markup_parser_new()

  

attr_list

address of return location for a PangoAttrList, or NULL.

[out][allow-none]

text

address of return location for text with tags stripped, or NULL.

[out][allow-none]

accel_char

address of return location for accelerator char, or NULL.

[out][allow-none]

error

address of return location for errors, or NULL

  

Returns

FALSE if error is set, otherwise TRUE

Since: 1.31.0

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