Pango.Context¶

Subclasses:: None

Methods¶

Inherited:: GObject.Object (37)
Structs:: GObject.ObjectClass (5)

class	`new` ()
	`changed` ()
	`get_base_dir` ()
	`get_base_gravity` ()
	`get_font_description` ()
	`get_font_map` ()
	`get_gravity` ()
	`get_gravity_hint` ()
	`get_language` ()
	`get_matrix` ()
	`get_metrics` (desc, language)
	`get_round_glyph_positions` ()
	`get_serial` ()
	`list_families` ()
	`load_font` (desc)
	`load_fontset` (desc, language)
	`set_base_dir` (direction)
	`set_base_gravity` (gravity)
	`set_font_description` (desc)
	`set_font_map` (font_map)
	`set_gravity_hint` (hint)
	`set_language` (language)
	`set_matrix` (matrix)
	`set_round_glyph_positions` (round_positions)

Virtual Methods¶

Inherited:: GObject.Object (7)

Properties¶

None

Signals¶

Inherited:: GObject.Object (1)

Fields¶

Inherited:: GObject.Object (1)

Class Details¶

class Pango.Context(**kwargs)¶

Bases:: GObject.Object
Abstract:: No
Structure:: Pango.ContextClass

A PangoContext stores global information used to control the itemization process.

The information stored by PangoContext includes the fontmap used to look up fonts, and default values such as the default language, default gravity, or default font.

To obtain a PangoContext, use [method`Pango`.FontMap.create_context].

classmethod new()[source]¶

Returns:: the newly allocated PangoContext, which should be freed with GObject.Object.unref().
Return type:: Pango.Context

Creates a new PangoContext initialized to default values.

This function is not particularly useful as it should always be followed by a [method`Pango`.Context.set_font_map] call, and the function [method`Pango`.FontMap.create_context] does these two steps together and hence users are recommended to use that.

If you are using Pango as part of a higher-level system, that system may have it’s own way of create a PangoContext. For instance, the GTK toolkit has, among others, gtk_widget_get_pango_context(). Use those instead.

changed()[source]¶

Forces a change in the context, which will cause any PangoLayout using this context to re-layout.

This function is only useful when implementing a new backend for Pango, something applications won’t do. Backends should call this function if they have attached extra data to the context and such data is changed.

New in version 1.32.4.

get_base_dir()[source]¶

Returns:: the base direction for the context.
Return type:: Pango.Direction

Retrieves the base direction for the context.

See [method`Pango`.Context.set_base_dir].

get_base_gravity()[source]¶

Returns:: the base gravity for the context.
Return type:: Pango.Gravity

Retrieves the base gravity for the context.

See [method`Pango`.Context.set_base_gravity].

New in version 1.16.

get_font_description()[source]¶

Returns:: a pointer to the context’s default font description. This value must not be modified or freed.
Return type:: Pango.FontDescription or None

Retrieve the default font description for the context.

get_font_map()[source]¶

Returns:: the font map for the. PangoContext This value is owned by Pango and should not be unreferenced.
Return type:: Pango.FontMap or None

Gets the PangoFontMap used to look up fonts for this context.

New in version 1.6.

get_gravity()[source]¶

Returns:: the resolved gravity for the context.
Return type:: Pango.Gravity

Retrieves the gravity for the context.

This is similar to [method`Pango`.Context.get_base_gravity], except for when the base gravity is Pango.Gravity.AUTO for which [func`Pango`.Gravity.get_for_matrix] is used to return the gravity from the current context matrix.

New in version 1.16.

get_gravity_hint()[source]¶

Returns:: the gravity hint for the context.
Return type:: Pango.GravityHint

Retrieves the gravity hint for the context.

See [method`Pango`.Context.set_gravity_hint] for details.

New in version 1.16.

get_language()[source]¶

Returns:: the global language tag.
Return type:: Pango.Language

Retrieves the global language tag for the context.

get_matrix()[source]¶

Returns:: the matrix, or None if no matrix has been set (which is the same as the identity matrix). The returned matrix is owned by Pango and must not be modified or freed.
Return type:: Pango.Matrix or None

Gets the transformation matrix that will be applied when rendering with this context.

See [method`Pango`.Context.set_matrix].

New in version 1.6.

get_metrics(desc, language)[source]¶

Parameters:

desc (Pango.FontDescription or None) – a PangoFontDescription structure. None means that the font description from the context will be used.
language (Pango.Language or None) – language tag used to determine which script to get the metrics for. None means that the language tag from the context will be used. If no language tag is set on the context, metrics for the default language (as determined by [func`Pango`.Language.get_default] will be returned.

Returns:

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

Return type:

Pango.FontMetrics

Get overall metric information for a particular font description.

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.

The PangoFontDescription is interpreted in the same way as by [func`itemize`], and the family name may be a comma separated list of names. If characters from multiple of these families would be used to render the string, then the returned fonts would be a composite of the metrics for the fonts loaded for the individual families.

get_round_glyph_positions()[source]¶

Return type:: bool

Returns whether font rendering with this context should round glyph positions and widths.

New in version 1.44.

get_serial()[source]¶

Returns:: The current serial number of self.
Return type:: int

Returns the current serial number of self.

The serial number is initialized to an small number larger than zero when a new context is created and is increased whenever the context is changed using any of the setter functions, or the PangoFontMap it uses to find fonts has changed. The serial may wrap, but will never have the value 0. Since it can wrap, never compare it with “less than”, always use “not equals”.

This can be used to automatically detect changes to a PangoContext, and is only useful when implementing objects that need update when their PangoContext changes, like PangoLayout.

New in version 1.32.4.

list_families()[source]¶

Returns:: location to store a pointer to an array of PangoFontFamily. This array should be freed with GLib.free().
Return type:: families: [Pango.FontFamily]

List all families for a context.

load_font(desc)[source]¶

Parameters:: desc (Pango.FontDescription) – a PangoFontDescription describing the font to load
Returns:: the newly allocated PangoFont that was loaded, or None if no font matched.
Return type:: Pango.Font or None

Loads the font in one of the fontmaps in the context that is the closest match for desc.

load_fontset(desc, language)[source]¶

Parameters:

desc (Pango.FontDescription) – a PangoFontDescription describing the fonts to load
language (Pango.Language) – a PangoLanguage the fonts will be used for

Returns:

the newly allocated PangoFontset loaded, or None if no font matched.

Return type:

Pango.Fontset or None

Load a set of fonts in the context that can be used to render a font matching desc.

set_base_dir(direction)[source]¶

Parameters:: direction (Pango.Direction) – the new base direction

Sets the base direction for the context.

The base direction is used in applying the Unicode bidirectional algorithm; if the direction is Pango.Direction.LTR or Pango.Direction.RTL, then the value will be used as the paragraph direction in the Unicode bidirectional algorithm. A value of Pango.Direction.WEAK_LTR or Pango.Direction.WEAK_RTL is used only for paragraphs that do not contain any strong characters themselves.

set_base_gravity(gravity)[source]¶

Parameters:: gravity (Pango.Gravity) – the new base gravity

Sets the base gravity for the context.

The base gravity is used in laying vertical text out.

New in version 1.16.

set_font_description(desc)[source]¶

Parameters:: desc (Pango.FontDescription or None) – the new pango font description

Set the default font description for the context

set_font_map(font_map)[source]¶

Parameters:: font_map (Pango.FontMap or None) – the PangoFontMap to set.

Sets the font map to be searched when fonts are looked-up in this context.

This is only for internal use by Pango backends, a PangoContext obtained via one of the recommended methods should already have a suitable font map.

set_gravity_hint(hint)[source]¶

Parameters:: hint (Pango.GravityHint) – the new gravity hint

Sets the gravity hint for the context.

The gravity hint is used in laying vertical text out, and is only relevant if gravity of the context as returned by [method`Pango`.Context.get_gravity] is set to Pango.Gravity.EAST or Pango.Gravity.WEST.

New in version 1.16.

set_language(language)[source]¶

Parameters:: language (Pango.Language or None) – the new language tag.

Sets the global language tag for the context.

The default language for the locale of the running process can be found using [func`Pango`.Language.get_default].

set_matrix(matrix)[source]¶

Parameters:: matrix (Pango.Matrix or None) – a PangoMatrix, or None to unset any existing matrix. (No matrix set is the same as setting the identity matrix.)

Sets the transformation matrix that will be applied when rendering with this context.

Note that reported metrics are in the user space coordinates before the application of the matrix, not device-space coordinates after the application of the matrix. So, they don’t scale with the matrix, though they may change slightly for different matrices, depending on how the text is fit to the pixel grid.

New in version 1.6.

set_round_glyph_positions(round_positions)[source]¶

Parameters:: round_positions (bool) – whether to round glyph positions

Sets whether font rendering with this context should round glyph positions and widths to integral positions, in device units.

This is useful when the renderer can’t handle subpixel positioning of glyphs.

The default value is to round glyph positions, to remain compatible with previous Pango behavior.

New in version 1.44.