pangox.c

GTK+-2.0源码之pango-1.15.6.tar.gz

			  PangoLanguage *language,
			  guint32        ch)
{
  PangoMap *shape_map = NULL;
  PangoScript script;

  shape_map = pango_x_get_shaper_map (language);
  script = pango_script_for_unichar (ch);
  return (PangoEngineShape *)pango_map_get_engine (shape_map, script);
}

/* Utility functions */

static XCharStruct *
pango_x_get_per_char (PangoFont         *font,
		      PangoXSubfontInfo *subfont,
		      guint16            char_index)
{
  XFontStruct *fs;

  int index;
  int byte1;
  int byte2;

  fs = pango_x_get_font_struct (font, subfont);
  if (!fs)
    return NULL;

  if (subfont->is_1byte)
    {
      index = (int)char_index - fs->min_char_or_byte2;
      if (index < 0 || index >= subfont->range_byte2)
	return NULL;
    }
  else
    {
      byte1 = (int)(char_index / 256) - fs->min_byte1;
      if (byte1 < 0 || byte1 >= subfont->range_byte1)
	return NULL;

      byte2 = (int)(char_index % 256) - fs->min_char_or_byte2;
      if (byte2 < 0 || byte2 >= subfont->range_byte2)
	return NULL;

      index = byte1 * subfont->range_byte2 + byte2;
    }

  if (fs->per_char)
    return &fs->per_char[index];
  else
    return &fs->min_bounds;
}

static gboolean
pango_x_find_glyph (PangoFont *font,
		    PangoGlyph glyph,
		    PangoXSubfontInfo **subfont_return,
		    XCharStruct **charstruct_return)
{
  PangoXSubfontInfo *subfont;
  XCharStruct *cs;

  guint16 char_index = PANGO_X_GLYPH_INDEX (glyph);
  guint16 subfont_index = PANGO_X_GLYPH_SUBFONT (glyph);

  subfont = pango_x_find_subfont (font, subfont_index);
  if (!subfont)
    return FALSE;

  cs = pango_x_get_per_char (font, subfont, char_index);

  if (cs && (cs->lbearing != cs->rbearing || cs->width != 0))
    {
      if (subfont_return)
	*subfont_return = subfont;

      if (charstruct_return)
	*charstruct_return = cs;

      return TRUE;
    }
  else
    return FALSE;
}

/**
 * pango_x_get_unknown_glyph:
 * @font: a #PangoFont.
 *
 * Returns the index of a glyph suitable for drawing unknown characters;
 * you should generally use PANGO_GET_UNKNOWN_GLYPH() instead,
 * since that may return a glyph that provides a better representation
 * of a particular char. (E.g., by showing hex digits, or a glyph
 * representative of a certain Unicode range.)
 *
 * Return value: a glyph index into @font.
 **/
PangoGlyph
pango_x_get_unknown_glyph (PangoFont *font)
{
  return PANGO_GET_UNKNOWN_GLYPH (0);
}

/**
 * pango_x_render_layout_line:
 * @display:   the X display.
 * @drawable:  the drawable on which to draw.
 * @gc:        GC to use for uncolored drawing.
 * @line:      a #PangoLayoutLine.
 * @x:         the x position of start of string (in pixels).
 * @y:         the y position of baseline (in pixels).
 *
 * Renders a #PangoLayoutLine onto an X drawable.
 */
void
pango_x_render_layout_line (Display          *display,
			    Drawable          drawable,
			    GC                gc,
			    PangoLayoutLine  *line,
			    int               x,
			    int               y)
{
  GSList *tmp_list = line->runs;
  PangoRectangle overall_rect;
  PangoRectangle logical_rect;
  PangoRectangle ink_rect;
  PangoContext *context = pango_layout_get_context (line->layout);
  PangoXContextInfo *info =
    g_object_get_qdata (G_OBJECT (context),
			g_quark_from_static_string ("pango-x-info"));

  int x_off = 0;

  pango_layout_line_get_extents (line,NULL, &overall_rect);

  while (tmp_list)
    {
      PangoUnderline uline = PANGO_UNDERLINE_NONE;
      PangoLayoutRun *run = tmp_list->data;
      PangoAttrColor fg_color, bg_color;
      gboolean fg_set, bg_set;
      GC fg_gc;

      tmp_list = tmp_list->next;

      pango_x_get_item_properties (run->item, &uline, &fg_color, &fg_set, &bg_color, &bg_set);

      if (fg_set && info->get_gc_func)
	fg_gc = info->get_gc_func (context, &fg_color.color, gc);
      else
	fg_gc = gc;

      if (uline == PANGO_UNDERLINE_NONE)
	pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
				    NULL, &logical_rect);
      else
	pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
				    &ink_rect, &logical_rect);

      if (bg_set && info->get_gc_func)
	{
	  GC bg_gc = info->get_gc_func (context, &bg_color.color, gc);

	  XFillRectangle (display, drawable, bg_gc,
			  x + (x_off + logical_rect.x) / PANGO_SCALE,
			  y + overall_rect.y / PANGO_SCALE,
			  logical_rect.width / PANGO_SCALE,
			  overall_rect.height / PANGO_SCALE);

	  if (info->free_gc_func)
	    info->free_gc_func (context, bg_gc);
	}

      pango_x_render (display, drawable, fg_gc, run->item->analysis.font, run->glyphs,
		      x + x_off / PANGO_SCALE, y);

      switch (uline)
	{
	case PANGO_UNDERLINE_NONE:
	  break;
	case PANGO_UNDERLINE_DOUBLE:
	  XDrawLine (display, drawable, fg_gc,
		     x + (x_off + ink_rect.x) / PANGO_SCALE - 1, y + 4,
		     x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE, y + 4);
	  /* Fall through */
	case PANGO_UNDERLINE_SINGLE:
	  XDrawLine (display, drawable, fg_gc,
		     x + (x_off + ink_rect.x) / PANGO_SCALE - 1, y + 2,
		     x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE, y + 2);
	  break;
	case PANGO_UNDERLINE_ERROR:
	  {
	    int point_x;
	    int counter = 0;
	    int end_x = x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE;

	    for (point_x = x + PANGO_PIXELS (x_off + ink_rect.x) - 1;
		 point_x <= end_x;
		 point_x += 2)
	      {
		if (counter)
		  XDrawLine (display, drawable, gc,
			     point_x, y + 2, MIN (point_x + 1, end_x), y + 2);
		else
		  XDrawLine (display, drawable, gc,
			     point_x, y + 3, MIN (point_x + 1, end_x), y + 3);

		counter = (counter + 1) % 2;
	      }
	  }
	  break;
	case PANGO_UNDERLINE_LOW:
	  XDrawLine (display, drawable, fg_gc,
		     x + (x_off + ink_rect.x) / PANGO_SCALE - 1, y + (ink_rect.y + ink_rect.height) / PANGO_SCALE + 2,
		     x + (x_off + ink_rect.x + ink_rect.width) / PANGO_SCALE, y + (ink_rect.y + ink_rect.height) / PANGO_SCALE + 2);
	  break;
	}

      if (fg_set && info->get_gc_func && info->free_gc_func)
	info->free_gc_func (context, fg_gc);

      x_off += logical_rect.width;
    }
}

/**
 * pango_x_render_layout:
 * @display:   the X display.
 * @drawable:  the drawable on which to draw.
 * @gc:        GC to use for uncolored drawing.
 * @layout:    a #PangoLayout.
 * @x:         the x position of the left of the layout (in pixels).
 * @y:         the y position of the top of the layout (in pixels).
 *
 * Renders a #PangoLayout onto an X drawable.
 */
void
pango_x_render_layout (Display         *display,
		       Drawable         drawable,
		       GC               gc,
		       PangoLayout     *layout,
		       int              x,
		       int              y)
{
  PangoLayoutIter *iter;

  g_return_if_fail (display != NULL);
  g_return_if_fail (PANGO_IS_LAYOUT (layout));

  iter = pango_layout_get_iter (layout);

  do
    {
      PangoRectangle   logical_rect;
      PangoLayoutLine *line;
      int              baseline;

      line = pango_layout_iter_get_line_readonly (iter);

      pango_layout_iter_get_line_extents (iter, NULL, &logical_rect);
      baseline = pango_layout_iter_get_baseline (iter);

      pango_x_render_layout_line (display, drawable, gc,
				  line,
				  x + PANGO_PIXELS (logical_rect.x),
				  y + PANGO_PIXELS (baseline));
    }
  while (pango_layout_iter_next_line (iter));

  pango_layout_iter_free (iter);
}

/* This utility function is duplicated here and in pango-layout.c; should it be
 * public? Trouble is - what is the appropriate set of properties?
 */
static void
pango_x_get_item_properties (PangoItem      *item,
			     PangoUnderline *uline,
			     PangoAttrColor *fg_color,
			     gboolean       *fg_set,
			     PangoAttrColor *bg_color,
			     gboolean       *bg_set)
{
  GSList *tmp_list = item->analysis.extra_attrs;

  if (fg_set)
    *fg_set = FALSE;

  if (bg_set)
    *bg_set = FALSE;

  while (tmp_list)
    {
      PangoAttribute *attr = tmp_list->data;

      switch (attr->klass->type)
	{
	case PANGO_ATTR_UNDERLINE:
	  if (uline)
	    *uline = ((PangoAttrInt *)attr)->value;
	  break;

	case PANGO_ATTR_FOREGROUND:
	  if (fg_color)
	    *fg_color = *((PangoAttrColor *)attr);
	  if (fg_set)
	    *fg_set = TRUE;

	  break;

	case PANGO_ATTR_BACKGROUND:
	  if (bg_color)
	    *bg_color = *((PangoAttrColor *)attr);
	  if (bg_set)
	    *bg_set = TRUE;

	  break;

	default:
	  break;
	}
      tmp_list = tmp_list->next;
    }
}

/**
 * pango_x_apply_ligatures:
 * @font: unused
 * @subfont: unused
 * @glyphs: unused
 * @n_glyphs: unused
 * @clusters: unused
 *
 * Previously did subfont-specific ligation. Now a no-op.
 *
 * Return value: %FALSE, always.
 */
gboolean
pango_x_apply_ligatures (PangoFont     *font,
			 PangoXSubfont  subfont_id,
			 gunichar     **glyphs,
			 int           *n_glyphs,
			 int           **clusters)
{
  return FALSE;
}

/**
 * pango_x_find_first_subfont:
 * @font: A #PangoFont.
 * @rfont: A pointer to a #PangoXSubfont.
 * @charsets: An array of charsets.
 * @n_charsets: The number of charsets in @charsets.
 *
 * Looks for subfonts with the @charset charset,
 * in @font, and puts the first one in *@rfont.
 *
 * Return value: %TRUE if *@rfont now contains a font.
 */
gboolean
pango_x_find_first_subfont (PangoFont      *font,
			    char          **charsets,
			    int             n_charsets,
			    PangoXSubfont  *rfont)
{
  int n_subfonts;
  gboolean result = FALSE;
  PangoXSubfont *subfonts;
  int *subfont_charsets;

  g_return_val_if_fail (font, 0);
  g_return_val_if_fail (charsets, 0);
  g_return_val_if_fail (rfont, 0);

  n_subfonts = pango_x_list_subfonts (font, charsets, n_charsets,
				      &subfonts, &subfont_charsets);

  if (n_subfonts > 0)
    {
      *rfont = subfonts[0];
      result = TRUE;
    }

  g_free (subfonts);
  g_free (subfont_charsets);
  return result;
}

/**
 * pango_x_fallback_shape:
 * @font: A #PangoFont.
 * @glyphs: A pointer to a #PangoGlyphString.
 * @text: UTF-8 string.
 * @n_chars: Number of UTF-8 seqs in @text.
 *
 * This is a simple fallback shaper, that can be used
 * if no subfont that supports a given script is found.
 * For every character in @text, it puts the unknown glyph.
 */
void
pango_x_fallback_shape (PangoFont        *font,
			PangoGlyphString *glyphs,
			const char       *text,
			int               n_chars)
{
  PangoGlyph unknown_glyph = pango_x_get_unknown_glyph (font);
  PangoRectangle logical_rect;
  const char *p;
  int i;

  g_return_if_fail (font);
  g_return_if_fail (glyphs);
  g_return_if_fail (text);
  g_return_if_fail (n_chars >= 0);

  pango_font_get_glyph_extents (font, unknown_glyph, NULL, &logical_rect);
  pango_glyph_string_set_size (glyphs, n_chars);
  p = text;
  for (i = 0; i < n_chars; i++)
    {
      glyphs->glyphs[i].glyph = unknown_glyph;

      glyphs->glyphs[i].geometry.x_offset = 0;
      glyphs->glyphs[i].geometry.y_offset = 0;
      glyphs->glyphs[i].geometry.width = logical_rect.width;

      glyphs->log_clusters[i] = p - text;

      p = g_utf8_next_char (p);
    }
}

/**
 * pango_x_font_get_unknown_glyph:
 * @font: a #PangoFont.
 * @wc: the Unicode character for which a glyph is needed.
 *
 * Returns the index of a glyph suitable for drawing @wc as an
 * unknown character.
 *
 * Use PANGO_GET_UNKNOWN_GLYPH() instead.
 *
 * Return value: a glyph index into @font.
 */
PangoGlyph
pango_x_font_get_unknown_glyph (PangoFont *font,
				gunichar   wc)
{
  return PANGO_GET_UNKNOWN_GLYPH (wc);
}