The Pango.Font.Pango_Font structure is used to represent a font in a rendering-system-independent matter. To create an implementation of a Pango.Font.Pango_Font, the rendering-system specific code should allocate a larger structure that contains a nested Pango.Font.Pango_Font, fill in the <structfield>klass</structfield> member of the nested Pango.Font.Pango_Font with a pointer to a appropriate Pango_Font_Class, then call pango_font_init on the structure.
The Pango.Font.Pango_Font structure contains one member which the implementation fills in.
function Better_Match
(Self : Pango_Font_Description;
Old_Match : Pango_Font_Description;
New_Match : Pango_Font_Description) return Boolean
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 Pango.Font.Pango_Font_Description, or null
a Pango.Font.Pango_Font_Description
True if New_Match is a better match
function Copy
(Self : Pango_Font_Description) return Pango_Font_Description
Make a copy of a Pango.Font.Pango_Font_Description.
the newly allocated Pango.Font.Pango_Font_Description, which should be freed with pango_font_description_free, or null if Desc was null.
function Copy_Static
(Self : Pango_Font_Description) return Pango_Font_Description
Like Pango.Font.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.
the newly allocated Pango.Font.Pango_Font_Description, which should be freed with pango_font_description_free, or null if Desc was null.
package Desc_Properties is new Generic_Internal_Boxed_Property
(Pango_Font_Description, Get_Type, To_Address);
function Describe
(Font : not null access Pango_Font_Record'Class)
return Pango_Font_Description
Returns a description of the font, with font size set in points. Use Pango.Font.Describe_With_Absolute_Size if you want the font size in device units.
a newly-allocated Pango.Font.Pango_Font_Description object.
function Describe_With_Absolute_Size
(Font : not null access Pango_Font_Record'Class)
return Pango_Font_Description
Returns a description of the font, with absolute font size set (in device units). Use Pango.Font.Describe if you want the font size in points. Since: gtk+ 1.14
a newly-allocated Pango.Font.Pango_Font_Description object.
function Equal
(Self : Pango_Font_Description;
Desc2 : Pango_Font_Description) return Boolean
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 Pango.Font.Pango_Font_Description
True if the two font descriptions are identical, False otherwise.
function Font_Get_Type return Glib.GType
procedure Free (Desc : in out Pango_Font_Description)
Deallocate the given font description.
function From_String (Str : UTF8_String) return Pango_Font_Description
Creates a new font description from a string representation in 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". 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.
a new Pango.Font.Pango_Font_Description.
procedure Gdk_New (Self : out Pango_Font_Description)
Creates a new font description structure with all fields unset.
function Get_Coverage
(Font : not null access Pango_Font_Record;
Language : Pango.Language.Pango_Language)
return Pango.Coverage.Pango_Coverage
Computes the coverage map for a given font and language tag.
the language tag
a newly-allocated Pango.Coverage.Pango_Coverage object. Has transfer-ownership='full'.
function Get_Face
(Font : not null access Pango_Font_Record)
return Pango.Font_Face.Pango_Font_Face
Gets the Pango.Font_Face.Pango_Font_Face to which Font belongs. Since: gtk+ 1.46
the Pango.Font_Face.Pango_Font_Face. Has transfer-ownership='none'.
function Get_Family (Self : Pango_Font_Description) return UTF8_String
Gets the family name field of a font description. See Pango.Font.Set_Family.
the family name field for the font description, or null if not previously set. This has the same life-time as the font description itself and should not be freed.
function Get_Font_Map
(Font : access Pango_Font_Record'Class)
return Pango.Font_Map.Pango_Font_Map
Gets the font map for which the font was created. Note that the font maintains a <firstterm>weak</firstterm> reference to the font map, so if all references to font map are dropped, the font map will be finalized even if there are fonts created with the font map that are still alive. In that case this function will return null. It is the responsibility of the user to ensure that the font map is kept alive. In most uses this is not an issue as a Pango.Context.Pango_Context holds a reference to the font map. Since: gtk+ 1.10
the Pango.Font_Map.Pango_Font_Map for the font, or null if Font is null. Has transfer-ownership='none'.
procedure Get_Glyph_Extents
(Font : access Pango_Font_Record'Class;
Glyph : Pango_Glyph;
Ink_Rect : out Pango_Rectangle;
Logical_Rect : out Pango_Rectangle)
Gets the logical and ink extents of a glyph within a font. The coordinate system for each rectangle has its origin at the base line and horizontal origin of the character with increasing coordinates extending to the right and down. The macros PANGO_ASCENT, PANGO_DESCENT, PANGO_LBEARING, and PANGO_RBEARING can be used to convert from the extents rectangle to more traditional font metrics. The units of the rectangles are in 1/PANGO_SCALE of a device unit. If Font is null, this function gracefully sets some sane values in the output variables and returns.
the glyph index
rectangle used to store the extents of the glyph as drawn or null to indicate that the result is not needed.
rectangle used to store the logical extents of the glyph or null to indicate that the result is not needed.
function Get_Gravity
(Self : Pango_Font_Description) return Pango.Enums.Gravity
Gets the gravity field of a font description. See Pango.Font.Set_Gravity. Since: gtk+ 1.16
the gravity field for the font description. Use Pango.Font.Get_Set_Fields to find out if the field was explicitly set or not.
function Get_Metrics
(Font : access Pango_Font_Record'Class;
Language : Pango.Language.Pango_Language := Pango.Language.Null_Pango_Language)
return Pango.Font_Metrics.Pango_Font_Metrics
Gets overall metric information for a font. Since the metrics may be substantially different for different scripts, a language tag can be provided to indicate that the metrics should be retrieved that correspond to the script(s) used by that language. If Font is null, this function gracefully sets some sane values in the output variables and returns.
language tag used to determine which script to get the metrics for, or null to indicate to get the metrics for the entire font.
a Pango.Font_Metrics.Pango_Font_Metrics object. The caller must call Pango.Font_Metrics.Unref when finished using the object. Has transfer-ownership='full'.
function Get_Set_Fields
(Self : Pango_Font_Description) return Pango.Enums.Font_Mask
Determines which fields in a font description have been set.
a bitmask with bits set corresponding to the fields in Desc that have been set.
function Get_Size (Self : Pango_Font_Description) return Glib.Gint
Gets the size field of a font description. See Pango.Font.Set_Size.
the size field for the font description in points or device units. You must call Pango.Font.Get_Size_Is_Absolute to find out which is the case. Returns 0 if the size field has not previously been set or it has been set to 0 explicitly. Use Pango.Font.Get_Set_Fields to find out if the field was explicitly set or not.
function Get_Size_Is_Absolute
(Self : Pango_Font_Description) return Boolean
Determines whether the size of the font is in points (not absolute) or device units (absolute). See Pango.Font.Set_Size and Pango.Font.Set_Absolute_Size. Since: gtk+ 1.8
whether the size for the font description is in points or device units. Use Pango.Font.Get_Set_Fields to find out if the size field of the font description was explicitly set or not.
function Get_Stretch
(Self : Pango_Font_Description) return Pango.Enums.Stretch
Gets the stretch field of a font description. See Pango.Font.Set_Stretch.
the stretch field for the font description. Use Pango.Font.Get_Set_Fields to find out if the field was explicitly set or not.
function Get_Style
(Self : Pango_Font_Description) return Pango.Enums.Style
Gets the style field of a Pango.Font.Pango_Font_Description. See Pango.Font.Set_Style.
the style field for the font description. Use Pango.Font.Get_Set_Fields to find out if the field was explicitly set or not.
function Get_Style_As_String
(Self : Pango_Font_Description) return String
Return the font's style as a string (e.g: 'Oblique').
function Get_Type return Glib.GType
function Get_Variant
(Self : Pango_Font_Description) return Pango.Enums.Variant
Gets the variant field of a Pango.Font.Pango_Font_Description. See Pango.Font.Set_Variant.
the variant field for the font description. Use Pango.Font.Get_Set_Fields to find out if the field was explicitly set or not.
function Get_Variations
(Self : Pango_Font_Description) return UTF8_String
Gets the variations field of a font description. See Pango.Font.Set_Variations. Since: gtk+ 1.42
the varitions field for the font description, or null if not previously set. This has the same life-time as the font description itself and should not be freed.
function Get_Weight
(Self : Pango_Font_Description) return Pango.Enums.Weight
Gets the weight field of a font description. See Pango.Font.Set_Weight.
the weight field for the font description. Use Pango.Font.Get_Set_Fields to find out if the field was explicitly set or not.
function Get_Weight_As_String
(Self : Pango_Font_Description) return String
Return the font's style as a string (e.g: 'Oblique').
function Has_Char
(Font : not null access Pango_Font_Record;
Wc : Gunichar) return Boolean
Returns whether the font provides a glyph for this character. Returns True if Font can render Wc Since: gtk+ 1.44
a Unicode character
function Hash (Self : Pango_Font_Description) return Guint
Computes a hash of a Pango.Font.Pango_Font_Description structure suitable to be used, for example, as an argument to g_hash_table_new. The hash value is independent of Desc->mask.
the hash value.
procedure Merge
(Self : Pango_Font_Description;
Desc_To_Merge : Pango_Font_Description;
Replace_Existing : Boolean)
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 Pango.Font.Pango_Font_Description 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.
procedure Merge_Static
(Self : Pango_Font_Description;
Desc_To_Merge : Pango_Font_Description;
Replace_Existing : Boolean)
Like Pango.Font.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 Pango.Font.Pango_Font_Description to merge from
if True, replace fields in Desc with the corresponding values from Desc_To_Merge, even if they are already exist.
type Pango_Font is access all Pango_Font_Record'Class;
type Pango_Font_Description is new Glib.C_Proxy;
function Pango_Font_Description_New return Pango_Font_Description
Creates a new font description structure with all fields unset.
type Pango_Font_Record is new GObject_Record with null record;
type Property_Font_Description is new Desc_Properties.Property;
procedure Set_Absolute_Size
(Self : Pango_Font_Description;
Size : Gdouble)
Sets the size field of a font description, in device units. This is mutually exclusive with Pango.Font.Set_Size which sets the font size in points. Since: gtk+ 1.8
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.
procedure Set_Family
(Self : Pango_Font_Description;
Family : UTF8_String)
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 Pango.Font_Family.Pango_Font_Family. In some uses of Pango.Font.Pango_Font_Description, it is also possible to use a comma separated list of family names for this field.
a string representing the family name.
procedure Set_Family_Static
(Self : Pango_Font_Description;
Family : UTF8_String)
Like Pango.Font.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.
procedure Set_Gravity
(Self : Pango_Font_Description;
Gravity : Pango.Enums.Gravity)
Sets the gravity field of a font description. The gravity field specifies how the glyphs should be rotated. If Gravity is Pango.Enums.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 Pango.Context.Pango_Context. Since: gtk+ 1.16
the gravity for the font description.
procedure Set_Size (Self : Pango_Font_Description; Size : Glib.Gint)
Sets the size field of a font description in fractional points. This is mutually exclusive with Pango.Font.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 Pango.Font.Set_Absolute_Size if you need a particular size in device units.
procedure Set_Stretch
(Self : Pango_Font_Description;
Stretch : Pango.Enums.Stretch)
Sets the stretch field of a font description. The stretch field specifies how narrow or wide the font should be.
the stretch for the font description
procedure Set_Style
(Self : Pango_Font_Description;
Style : Pango.Enums.Style)
Sets the style field of a Pango.Font.Pango_Font_Description. The Pango.Enums.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.
the style for the font description
procedure Set_Variant
(Self : Pango_Font_Description;
Variant : Pango.Enums.Variant)
Sets the variant field of a font description. The Pango.Enums.Variant can either be Pango.Enums.Pango_Variant_Normal or Pango.Enums.Pango_Variant_Small_Caps.
the variant type for the font description.
procedure Set_Variations
(Self : Pango_Font_Description;
Variations : UTF8_String)
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 or freetype have API for this. Since: gtk+ 1.42
a string representing the variations
procedure Set_Variations_Static
(Self : Pango_Font_Description;
Variations : UTF8_String)
Like Pango.Font.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. Since: gtk+ 1.42
a string representing the variations
procedure Set_Weight
(Self : Pango_Font_Description;
Weight : Pango.Enums.Weight)
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 Pango.Enums.Weight enumeration, other intermediate numeric values are possible.
the weight for the font description.
function To_Address
(F : Pango_Font_Description; Add : System.Address) return System.Address
function To_Filename (Self : Pango_Font_Description) return UTF8_String
Creates a filename representation of a font description. The filename is identical to the result from calling Pango.Font.To_String, but with underscores instead of characters that are untypical in filenames, and in lower case only.
a new string that must be freed with g_free.
function To_Font_Description
(Family_Name : String := "";
Style : Pango.Enums.Style := Pango.Enums.Pango_Style_Normal;
Variant : Pango.Enums.Variant := Pango.Enums.Pango_Variant_Normal;
Weight : Pango.Enums.Weight := Pango.Enums.Pango_Weight_Normal;
Stretch : Pango.Enums.Stretch := Pango.Enums.Pango_Stretch_Normal;
Size : Gint := 0) return Pango_Font_Description
Create a new font decription from the given parameters.
function To_String (Self : Pango_Font_Description) return UTF8_String
Creates a string representation of a font description. See Pango.Font.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.
a new string that must be freed with g_free.
procedure Unset_Fields
(Self : Pango_Font_Description;
To_Unset : Pango.Enums.Font_Mask)
Unsets some of the fields in a Pango.Font.Pango_Font_Description. The unset fields will get back to their default values.
bitmask of fields in the Desc to unset.