fonts.c

GTK+-2.0源码之pango-1.15.6.tar.gz

      metrics->strikethrough_thickness = PANGO_SCALE;

      return metrics;
    }

  return PANGO_FONT_GET_CLASS (font)->get_metrics (font, language);
}

/**
 * pango_font_get_font_map:
 * @font: a #PangoFont
 *
 * Gets the font map for which the font was created.
 *
 * Return value: the #PangoFontMap for the font
 *
 * Since: 1.10
 **/
PangoFontMap *
pango_font_get_font_map (PangoFont *font)
{
  if (G_UNLIKELY (!font))
    {

      if (!_pango_warning_history.get_font_map)
	{
	  _pango_warning_history.get_font_map = TRUE;
	  g_warning (bad_font_warning, "pango_font_get_font_map");
	}
      return NULL;
    }

  if (PANGO_FONT_GET_CLASS (font)->get_font_map)
    return PANGO_FONT_GET_CLASS (font)->get_font_map (font);
  else
    return NULL;
}

GType
pango_font_metrics_get_type (void)
{
  static GType our_type = 0;

  if (our_type == 0)
    our_type = g_boxed_type_register_static (I_("PangoFontMetrics"),
					     (GBoxedCopyFunc)pango_font_metrics_ref,
					     (GBoxedFreeFunc)pango_font_metrics_unref);

  return our_type;
}


/**
 * pango_font_metrics_new:
 *
 * Creates a new #PangoFontMetrics structure. This is only for
 * internal use by Pango backends and there is no public way
 * to set the fields of the structure.
 *
 * Return value: a newly-created #PangoFontMetrics structure
 *   with a reference count of 1.
 **/
PangoFontMetrics *
pango_font_metrics_new (void)
{
  PangoFontMetrics *metrics = g_slice_new0 (PangoFontMetrics);
  metrics->ref_count = 1;

  return metrics;
}

/**
 * pango_font_metrics_ref:
 * @metrics: a #PangoFontMetrics structure
 *
 * Increase the reference count of a font metrics structure by one.
 *
 * Return value: @metrics
 **/
PangoFontMetrics *
pango_font_metrics_ref (PangoFontMetrics *metrics)
{
  if (!metrics)
    return NULL;

  metrics->ref_count++;

  return metrics;
}

/**
 * pango_font_metrics_unref:
 * @metrics: a #PangoFontMetrics structure
 *
 * Decrease the reference count of a font metrics structure by one. If
 * the result is zero, frees the structure and any associated
 * memory.
 **/
void
pango_font_metrics_unref (PangoFontMetrics *metrics)
{
  if (!metrics)
    return;
  g_return_if_fail (metrics->ref_count > 0 );

  metrics->ref_count--;

  if (metrics->ref_count == 0)
    g_slice_free (PangoFontMetrics, metrics);
}

/**
 * pango_font_metrics_get_ascent:
 * @metrics: a #PangoFontMetrics structure
 *
 * Gets the ascent from a font metrics structure. The ascent is
 * the distance from the baseline to the logical top of a line
 * of text. (The logical top may be above or below the top of the
 * actual drawn ink. It is necessary to lay out the text to figure
 * where the ink will be.)
 *
 * Return value: the ascent, in Pango units. (1 point == %PANGO_SCALE Pango units.)
 **/
int
pango_font_metrics_get_ascent (PangoFontMetrics *metrics)
{
  g_return_val_if_fail (metrics != NULL, 0);

  return metrics->ascent;
}

/**
 * pango_font_metrics_get_descent:
 * @metrics: a #PangoFontMetrics structure
 *
 * Gets the descent from a font metrics structure. The descent is
 * the distance from the baseline to the logical bottom of a line
 * of text. (The logical bottom may be above or below the bottom of the
 * actual drawn ink. It is necessary to lay out the text to figure
 * where the ink will be.)
 *
 * Return value: the descent, in Pango units. (1 point == %PANGO_SCALE Pango units.)
 **/
int
pango_font_metrics_get_descent (PangoFontMetrics *metrics)
{
  g_return_val_if_fail (metrics != NULL, 0);

  return metrics->descent;
}

/**
 * pango_font_metrics_get_approximate_char_width:
 * @metrics: a #PangoFontMetrics structure
 *
 * Gets the approximate character width for a font metrics structure.
 * This is merely a representative value useful, for example, for
 * determining the initial size for a window. Actual characters in
 * text will be wider and narrower than this.
 *
 * Return value: the character width, in Pango units. (1 point == %PANGO_SCALE Pango units.)
 **/
int
pango_font_metrics_get_approximate_char_width (PangoFontMetrics *metrics)
{
  g_return_val_if_fail (metrics != NULL, 0);

  return metrics->approximate_char_width;
}

/**
 * pango_font_metrics_get_approximate_digit_width:
 * @metrics: a #PangoFontMetrics structure
 *
 * Gets the approximate digit width for a font metrics structure.
 * This is merely a representative value useful, for example, for
 * determining the initial size for a window. Actual digits in
 * text can be wider or narrower than this, though this value
 * is generally somewhat more accurate than the result of
 * pango_font_metrics_get_approximate_char_width() for digits.
 *
 * Return value: the digit width, in Pango units. (1 point == %PANGO_SCALE Pango units.)
 **/
int
pango_font_metrics_get_approximate_digit_width (PangoFontMetrics *metrics)
{
  g_return_val_if_fail (metrics != NULL, 0);

  return metrics->approximate_digit_width;
}

/**
 * pango_font_metrics_get_underline_position:
 * @metrics: a #PangoFontMetrics structure
 *
 * Gets the suggested position to draw the underline.
 * The value returned is the distance <emphasis>above</emphasis> the
 * baseline of the top of the underline. Since most fonts have
 * underline positions beneath the baseline, this value is typically
 * negative.
 *
 * Return value: the suggested underline position, in Pango units.
 *
 * Since: 1.6
 **/
int
pango_font_metrics_get_underline_position (PangoFontMetrics *metrics)
{
  g_return_val_if_fail (metrics != NULL, 0);

  return metrics->underline_position;
}

/**
 * pango_font_metrics_get_underline_thickness:
 * @metrics: a #PangoFontMetrics structure
 *
 * Gets the suggested thickness to draw for the underline.
 *
 * Return value: the suggested underline thickness, in Pango units.
 *
 * Since: 1.6
 **/
int
pango_font_metrics_get_underline_thickness (PangoFontMetrics *metrics)
{
  g_return_val_if_fail (metrics != NULL, 0);

  return metrics->underline_thickness;
}

/**
 * pango_font_metrics_get_strikethrough_position:
 * @metrics: a #PangoFontMetrics structure
 *
 * Gets the suggested position to draw the strikethrough.
 * The value returned is the distance <emphasis>above</emphasis> the
 * baseline of the top of the strikethrough.
 *
 * Return value: the suggested strikethrough position, in Pango units.
 *
 * Since: 1.6
 **/
int
pango_font_metrics_get_strikethrough_position (PangoFontMetrics *metrics)
{
  g_return_val_if_fail (metrics != NULL, 0);

  return metrics->strikethrough_position;
}

/**
 * pango_font_metrics_get_strikethrough_thickness:
 * @metrics: a #PangoFontMetrics structure
 *
 * Gets the suggested thickness to draw for the strikethrough.
 *
 * Return value: the suggested strikethrough thickness, in Pango units.
 *
 * Since: 1.6
 **/
int
pango_font_metrics_get_strikethrough_thickness (PangoFontMetrics *metrics)
{
  g_return_val_if_fail (metrics != NULL, 0);

  return metrics->strikethrough_thickness;
}

/*
 * PangoFontFamily
 */

G_DEFINE_TYPE (PangoFontFamily, pango_font_family, G_TYPE_OBJECT)

static void
pango_font_family_class_init (PangoFontFamilyClass *class)
{
}

static void
pango_font_family_init (PangoFontFamily *family)
{
}

/**
 * pango_font_family_get_name:
 * @family: a #PangoFontFamily
 *
 * Gets the name of the family. The name is unique among all
 * fonts for the font backend and can be used in a #PangoFontDescription
 * to specify that a face from this family is desired.
 *
 * Return value: the name of the family. This string is owned
 *   by the family object and must not be modified or freed.
 **/
G_CONST_RETURN char *
pango_font_family_get_name (PangoFontFamily  *family)
{
  g_return_val_if_fail (PANGO_IS_FONT_FAMILY (family), NULL);

  return PANGO_FONT_FAMILY_GET_CLASS (family)->get_name (family);
}

/**
 * pango_font_family_list_faces:
 * @family: a #PangoFontFamily
 * @faces: location to store an array of pointers to #PangoFontFace
 *   objects, or %NULL. This array should be freed with g_free()
 *   when it is no longer needed.
 * @n_faces: location to store number of elements in @faces.
 *
 * Lists the different font faces that make up @family. The faces
 * in a family share a common design, but differ in slant, weight,
 * width and other aspects.
 **/
void
pango_font_family_list_faces (PangoFontFamily  *family,
			      PangoFontFace  ***faces,
			      int              *n_faces)
{
  g_return_if_fail (PANGO_IS_FONT_FAMILY (family));

  PANGO_FONT_FAMILY_GET_CLASS (family)->list_faces (family, faces, n_faces);
}

/**
 * pango_font_family_is_monospace:
 * @family: a #PangoFontFamily
 *
 * A monospace font is a font designed for text display where the the
 * characters form a regular grid. For Western languages this would
 * mean that the advance width of all characters are the same, but
 * this categorization also includes Asian fonts which include
 * double-width characters: characters that occupy two grid cells.
 * g_unichar_iswide() returns a result that indicates whether a
 * character is typically double-width in a monospace font.
 *
 * The best way to find out the grid-cell size is to call
 * pango_font_metrics_get_approximate_digit_width(), since the results
 * of pango_font_metrics_get_approximate_char_width() may be affected
 * by double-width characters.
 *
 * Return value: %TRUE if the family is monospace.
 *
 * Since: 1.4
 **/
gboolean
pango_font_family_is_monospace (PangoFontFamily  *family)
{
  g_return_val_if_fail (PANGO_IS_FONT_FAMILY (family), FALSE);

  if (PANGO_FONT_FAMILY_GET_CLASS (family)->is_monospace)
    return PANGO_FONT_FAMILY_GET_CLASS (family)->is_monospace (family);
  else
    return FALSE;
}

/*
 * PangoFontFace
 */

G_DEFINE_TYPE (PangoFontFace, pango_font_face, G_TYPE_OBJECT)

static void
pango_font_face_class_init (PangoFontFaceClass *class)
{
}

static void
pango_font_face_init (PangoFontFace *face)
{
}

/**
 * pango_font_face_describe:
 * @face: a #PangoFontFace
 *
 * Returns the family, style, variant, weight and stretch of
 * a #PangoFontFace. The size field of the resulting font description
 * will be unset.
 *
 * Return value: a newly-created #PangoFontDescription structure
 *  holding the description of the face. Use pango_font_description_free()
 *  to free the result.
 **/
PangoFontDescription *
pango_font_face_describe (PangoFontFace *face)
{
  g_return_val_if_fail (PANGO_IS_FONT_FACE (face), NULL);

  return PANGO_FONT_FACE_GET_CLASS (face)->describe (face);
}

/**
 * pango_font_face_get_face_name:
 * @face: a #PangoFontFace.
 *
 * Gets a name representing the style of this face among the
 * different faces in the #PangoFontFamily for the face. This
 * name is unique among all faces in the family and is suitable
 * for displaying to users.
 *
 * Return value: the face name for the face. This string is
 *   owned by the face object and must not be modified or freed.
 **/
G_CONST_RETURN char *
pango_font_face_get_face_name (PangoFontFace *face)
{
  g_return_val_if_fail (PANGO_IS_FONT_FACE (face), NULL);

  return PANGO_FONT_FACE_GET_CLASS (face)->get_face_name (face);
}

/**
 * pango_font_face_list_sizes:
 * @face: a #PangoFontFace.
 * @sizes: location to store a pointer to an array of int. This array
 *         should be freed with g_free().
 * @n_sizes: location to store the number of elements in @sizes
 *
 * List the available sizes for a font. This is only applicable to bitmap
 * fonts. For scalable fonts, stores %NULL at the location pointed to by
 * @sizes and 0 at the location pointed to by @n_sizes. The sizes returned
 * are in Pango units and are sorted in ascending order.
 *
 * Since: 1.4
 **/
void
pango_font_face_list_sizes (PangoFontFace  *face,
			    int           **sizes,
			    int            *n_sizes)
{
  g_return_if_fail (PANGO_IS_FONT_FACE (face));
  g_return_if_fail (sizes == NULL || n_sizes != NULL);

  if (n_sizes == NULL)
    return;

  if (PANGO_FONT_FACE_GET_CLASS (face)->list_sizes != NULL)
    PANGO_FONT_FACE_GET_CLASS (face)->list_sizes (face, sizes, n_sizes);
  else
    {
      if (sizes != NULL)
	*sizes = NULL;
      *n_sizes = 0;
    }
}