Creates a new font description structure with all fields unset.
Determines if the style attributes of new_match
are a closer match
for desc
than those of old_match
are, or if old_match
is %NULL,
determines if new_match
is a match at all.
Approximate matching is done for weight and style; other style attributes must match exactly. Style attributes are all attributes other than family and size-related attributes. Approximate matching for style considers %PANGO_STYLE_OBLIQUE and %PANGO_STYLE_ITALIC as matches, but not as good a match as when the styles are equal.
Note that old_match
must match desc
.
a PangoFontDescription
, or %NULL
a PangoFontDescription
Make a copy of a PangoFontDescription
.
Make a copy of a PangoFontDescription
, but don't duplicate
allocated fields.
This is like [methodPango
.FontDescription.copy], but only a shallow
copy is made of the family name and other allocated fields. The result
can only be used until desc
is modified or freed. This is meant
to be used when the copy is only needed temporarily.
Compares two font descriptions for equality.
Two font descriptions are considered equal if the fonts they describe are provably identical. This means that their masks do not have to match, as long as other fields are all the same. (Two font descriptions may result in identical fonts being loaded, but still compare %FALSE.)
another PangoFontDescription
Frees a font description.
Gets the family name field of a font description.
See [methodPango
.FontDescription.set_family].
Determines which fields in a font description have been set.
Gets the size field of a font description.
See [methodPango
.FontDescription.set_size].
Determines whether the size of the font is in points (not absolute) or device units (absolute).
See [methodPango
.FontDescription.set_size]
and [methodPango
.FontDescription.set_absolute_size].
Gets the stretch field of a font description.
See [methodPango
.FontDescription.set_stretch].
Gets the variations field of a font description.
See [methodPango
.FontDescription.set_variations].
Gets the weight field of a font description.
See [methodPango
.FontDescription.set_weight].
Computes a hash of a PangoFontDescription
structure.
This is suitable to be used, for example, as an argument
to g_hash_table_new(). The hash value is independent of desc->
mask.
Merges the fields that are set in desc_to_merge
into the fields in
desc
.
If replace_existing
is %FALSE, only fields in desc
that
are not already set are affected. If %TRUE, then fields that are
already set will be replaced as well.
If desc_to_merge
is %NULL, this function performs nothing.
the PangoFontDescription
to merge from, or %NULL
if %TRUE, replace fields in desc
with the corresponding values from desc_to_merge,
even if they are already exist.
Merges the fields that are set in desc_to_merge
into the fields in
desc,
without copying allocated fields.
This is like [methodPango
.FontDescription.merge], but only a shallow copy
is made of the family name and other allocated fields. desc
can only
be used until desc_to_merge
is modified or freed. This is meant to
be used when the merged font description is only needed temporarily.
the PangoFontDescription
to merge from
if %TRUE, replace fields in desc
with the corresponding values from desc_to_merge,
even if they are already exist.
Sets the size field of a font description, in device units.
This is mutually exclusive with [methodPango
.FontDescription.set_size]
which sets the font size in points.
the new size, in Pango units. There are %PANGO_SCALE Pango units in one device unit. For an output backend where a device unit is a pixel, a size
value of 10 * PANGO_SCALE gives a 10 pixel font.
Sets the family name field of a font description.
The family
name represents a family of related font styles, and will
resolve to a particular PangoFontFamily
. In some uses of
PangoFontDescription
, it is also possible to use a comma
separated list of family names for this field.
a string representing the family name.
Sets the family name field of a font description, without copying the string.
This is like [methodPango
.FontDescription.set_family], except that no
copy of family
is made. The caller must make sure that the
string passed in stays around until desc
has been freed or the
name is set again. This function can be used if family
is a static
string such as a C string literal, or if desc
is only needed temporarily.
a string representing the family name
Sets the gravity field of a font description.
The gravity field
specifies how the glyphs should be rotated. If gravity
is
%PANGO_GRAVITY_AUTO, this actually unsets the gravity mask on
the font description.
This function is seldom useful to the user. Gravity should normally
be set on a PangoContext
.
Sets the size field of a font description in fractional points.
This is mutually exclusive with
[methodPango
.FontDescription.set_absolute_size].
the size of the font in points, scaled by %PANGO_SCALE. (That is, a size
value of 10 * PANGO_SCALE is a 10 point font. The conversion factor between points and device units depends on system configuration and the output device. For screen display, a logical DPI of 96 is common, in which case a 10 point font corresponds to a 10 * (96 / 72) = 13.3 pixel font. Use [methodPango
.FontDescription.set_absolute_size] if you need a particular size in device units.
Sets the stretch field of a font description.
The [enumPango
.Stretch] field specifies how narrow or
wide the font should be.
the stretch for the font description
Sets the style field of a PangoFontDescription
.
The [enumPango
.Style] enumeration describes whether the font is
slanted and the manner in which it is slanted; it can be either
%PANGO_STYLE_NORMAL, %PANGO_STYLE_ITALIC, or %PANGO_STYLE_OBLIQUE.
Most fonts will either have a italic style or an oblique style, but not both, and font matching in Pango will match italic specifications with oblique fonts and vice-versa if an exact match is not found.
Sets the variations field of a font description.
OpenType font variations allow to select a font instance by specifying values for a number of axes, such as width or weight.
The format of the variations string is
AXIS1=VALUE,AXIS2=VALUE...
with each AXIS a 4 character tag that identifies a font axis, and each VALUE a floating point number. Unknown axes are ignored, and values are clamped to their allowed range.
Pango does not currently have a way to find supported axes of a font. Both harfbuzz and freetype have API for this. See for example hb_ot_var_get_axis_infos.
a string representing the variations
Sets the variations field of a font description.
This is like [methodPango
.FontDescription.set_variations], except
that no copy of variations
is made. The caller must make sure that
the string passed in stays around until desc
has been freed
or the name is set again. This function can be used if
variations
is a static string such as a C string literal,
or if desc
is only needed temporarily.
a string representing the variations
Sets the weight field of a font description.
The weight field
specifies how bold or light the font should be. In addition
to the values of the [enumPango
.Weight] enumeration, other
intermediate numeric values are possible.
the weight for the font description.
Creates a filename representation of a font description.
The filename is identical to the result from calling
[methodPango
.FontDescription.to_string], but with underscores
instead of characters that are untypical in filenames, and in
lower case only.
Creates a string representation of a font description.
See [funcPango
.FontDescription.from_string] for a description
of the format of the string representation. The family list in
the string description will only have a terminating comma if
the last word of the list is a valid style option.
Unsets some of the fields in a PangoFontDescription
.
The unset fields will get back to their default values.
bitmask of fields in the desc
to unset.
Creates a new font description from a string representation.
The string must have the form
"\[FAMILY-LIST] \[STYLE-OPTIONS] \[SIZE] \[VARIATIONS]",
where FAMILY-LIST is a comma-separated list of families optionally terminated by a comma, STYLE_OPTIONS is a whitespace-separated list of words where each word describes one of style, variant, weight, stretch, or gravity, and SIZE is a decimal number (size in points) or optionally followed by the unit modifier "px" for absolute size. VARIATIONS is a comma-separated list of font variation specifications of the form "`axis=`value" (the = sign is optional).
The following words are understood as styles: "Normal", "Roman", "Oblique", "Italic".
The following words are understood as variants: "Small-Caps", "All-Small-Caps", "Petite-Caps", "All-Petite-Caps", "Unicase", "Title-Caps".
The following words are understood as weights: "Thin", "Ultra-Light", "Extra-Light", "Light", "Semi-Light", "Demi-Light", "Book", "Regular", "Medium", "Semi-Bold", "Demi-Bold", "Bold", "Ultra-Bold", "Extra-Bold", "Heavy", "Black", "Ultra-Black", "Extra-Black".
The following words are understood as stretch values: "Ultra-Condensed", "Extra-Condensed", "Condensed", "Semi-Condensed", "Semi-Expanded", "Expanded", "Extra-Expanded", "Ultra-Expanded".
The following words are understood as gravity values: "Not-Rotated", "South", "Upside-Down", "North", "Rotated-Left", "East", "Rotated-Right", "West".
Any one of the options may be absent. If FAMILY-LIST is absent, then the family_name field of the resulting font description will be initialized to %NULL. If STYLE-OPTIONS is missing, then all style options will be set to the default values. If SIZE is missing, the size in the resulting font description will be set to 0.
A typical example:
"Cantarell Italic Light 15 \`wght=`200"
string representation of a font description.
Creates a new font description structure with all fields unset.
A
PangoFontDescription
describes a font in an implementation-independent manner.PangoFontDescription
structures are used both to list what fonts are available on the system and also for specifying the characteristics of a font to load.