class: Context

[17:7] extends: object

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].

Members

• handleObj
• lib
• retainedCallbacks
• signalHandlerNames
• signalSetterHandlers

Methods

• 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.

• toNativeHandle (Source)

  Normalizes a constructor argument into a raw pointer carrier. Accepts a raw NativeHandle, a raw NativeBuffer returned from fn.call(...), another generated wrapper exposing handle(), or null. Returns null when the argument carries no pointer.

  • @p Source is the raw handle, raw buffer, wrapper, or null.
  • @r A raw pointer carrier or null when no pointer is present.

• getLib ()

  Returns the opened native library for this generated wrapper.

  • @r The opened native library.

• handle ()

  Returns the wrapped NativeHandle.

  • @r The wrapped NativeHandle.

• isNull ()

  Returns true when the wrapped handle is null.

  • @r A bool.

• describe ()

  Returns a small string for debugging generated wrappers.

  • @r A string.

• asObject ()

  Wraps this handle as Object.

  • @r A Object object.

• changed ()

  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.

  • @r None.

• get_base_dir ()

  Retrieves the base direction for the context. See [method@Pango.Context.set_base_dir].

• get_base_gravity ()

  Retrieves the base gravity for the context. See [method@Pango.Context.set_base_gravity].

• get_font_description ()

  Retrieve the default font description for the context.

• get_font_map ()

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

• get_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.

• get_gravity_hint ()

  Retrieves the gravity hint for the context. See [method@Pango.Context.set_gravity_hint] for details.

• get_language ()

  Retrieves the global language tag for the context.

• get_matrix ()

  Gets the transformation matrix that will be applied when rendering with this context. See [method@Pango.Context.set_matrix].

• get_metrics (object desc, object language)

  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.

  • @p desc is a PangoFontDescription structure. %NULL means that the font description from the context will be used..
  • @p language is language tag used to determine which script to get the metrics for. %NULL 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..

• get_round_glyph_positions ()

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

• get_serial ()

  Returns the current serial number of @context. 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.

• load_font (object desc)

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

  • @p desc is a PangoFontDescription describing the font to load.

• load_fontset (object desc, object language)

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

  • @p desc is a PangoFontDescription describing the fonts to load.
  • @p language is a PangoLanguage the fonts will be used for.

• set_base_dir (string 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.

  • @p direction is the new base direction.
  • @r None.

• set_base_gravity (string gravity)

  Sets the base gravity for the context. The base gravity is used in laying vertical text out.

  • @p gravity is the new base gravity.
  • @r None.

• set_font_description (object desc)

  Set the default font description for the context

  • @p desc is the new pango font description.
  • @r None.

• set_font_map (object font_map)

  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.

  • @p font_map is the PangoFontMap to set..
  • @r None.

• set_gravity_hint (string 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.

  • @p hint is the new gravity hint.
  • @r None.

• set_language (object language)

  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].

  • @p language is the new language tag..
  • @r None.

• set_matrix (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.

  • @p matrix is a PangoMatrix, or %NULL to unset any existing matrix. (No matrix set is the same as setting the identity matrix.).
  • @r None.

• set_round_glyph_positions (bool round_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.

  • @p round_positions is whether to round glyph positions.
  • @r None.