Class: Pango::Font

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Direct Known Subclasses

PangoFc::Font

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.descriptions_free(descs, n_descs) ⇒ nil

Frees an array of font descriptions.

Parameters:

  • descs (Array<Pango::FontDescription>) —

    a pointer to an array of PangoFontDescription, may be nil

  • n_descs (Integer) —

    number of font descriptions in descs

Returns:

  • (nil)

.deserialize(context, bytes) ⇒ Pango::Font

Loads data previously created via [methodPango.Font.serialize].

For a discussion of the supported format, see that function.

Note: to verify that the returned font is identical to the one that was serialized, you can compare bytes to the result of serializing the font again.

Parameters:

  • context (Pango::Context) —

    a PangoContext

  • bytes (GLib::Bytes) —

    the bytes containing the data

Returns:

Instance Method Details

#describe ⇒ Pango::FontDescription

Returns a description of the font, with font size set in points.

Use [methodPango.Font.describe_with_absolute_size] if you want the font size in device units.

Returns:

#describe_with_absolute_size ⇒ Pango::FontDescription

Returns a description of the font, with absolute font size set in device units.

Use [methodPango.Font.describe] if you want the font size in points.

Returns:

#face ⇒ Pango::FontFace

Gets the PangoFontFace to which font belongs.

Returns:

#font_map ⇒ Pango::FontMap

Gets the font map for which the font was created.

Note that the font maintains a weak 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 nil.

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 PangoContext holds a reference to the font map.

Returns:

#get_coverage(language) ⇒ Pango::Coverage

Computes the coverage map for a given font and language tag.

Parameters:

Returns:

#get_features(features, len, num_features) ⇒ nil

Obtain the OpenType features that are provided by the font.

These are passed to the rendering system, together with features that have been explicitly set via attributes.

Note that this does not include OpenType features which the rendering system enables by default.

Parameters:

  • features (Array<HarfBuzz::feature_t>) —

    Array to features in

  • len (Integer) —

    the length of features

  • num_features (Integer) —

    the number of used items in features

Returns:

  • (nil)

#get_glyph_extents(glyph, ink_rect, logical_rect) ⇒ nil

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 nil, this function gracefully sets some sane values in the output variables and returns.

Parameters:

  • glyph (Pango::Glyph) —

    the glyph index

  • ink_rect (Pango::Rectangle) —

    rectangle used to store the extents of the glyph as drawn

  • logical_rect (Pango::Rectangle) —

    rectangle used to store the logical extents of the glyph

Returns:

  • (nil)

#get_metrics(language) ⇒ Pango::FontMetrics

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 nil, this function gracefully sets some sane values in the output variables and returns.

Parameters:

  • language (Pango::Language) —

    language tag used to determine which script to get the metrics for, or nil to indicate to get the metrics for the entire font.

Returns:

  • (Pango::FontMetrics) —

    a PangoFontMetrics object. The caller must call [methodPango.FontMetrics.unref] when finished using the object.

#has_char(wc) ⇒ Boolean

Returns whether the font provides a glyph for this character.

Parameters:

  • wc (String) —

    a Unicode character

Returns:

  • (Boolean) —

    TRUE if font can render wc

#hb_font ⇒ HarfBuzz::font_t

Get a hb_font_t object backing this font.

Note that the objects returned by this function are cached and immutable. If you need to make changes to the hb_font_t, use hb_font_create_sub_font().

Returns:

  • (HarfBuzz::font_t) —

    the hb_font_t object backing the font

#languages ⇒ Array<Pango::Language>

Returns the languages that are supported by font.

If the font backend does not provide this information, nil is returned. For the fontconfig backend, this corresponds to the FC_LANG member of the FcPattern.

The returned array is only valid as long as the font and its fontmap are valid.

Returns:

#serialize ⇒ GLib::Bytes

Serializes the font in a way that can be uniquely identified.

There are no guarantees about the format of the output across different versions of Pango.

The intended use of this function is testing, benchmarking and debugging. The format is not meant as a permanent storage format.

To recreate a font from its serialized form, use [funcPango.Font.deserialize].

Returns:

  • (GLib::Bytes) —

    a GBytes containing the serialized form of font