pango-context.c

linux

      state->free_attr_iter = TRUE;
    }
  else
    {
      state->attr_iter = NULL;
      state->free_attr_iter = FALSE;
    }

  if (state->attr_iter)
    {
      state->font_desc = NULL;
      state->lang = NULL;

      advance_attr_iterator_to (state->attr_iter, start_index);
      update_attr_iterator (state);
    }
  else
    {
      state->font_desc = pango_font_description_copy_static (desc ? desc : state->context->font_desc);
      state->lang = state->context->language;
      state->extra_attrs = NULL;
      state->copy_extra_attrs = FALSE;

      state->attr_end = state->end;
      state->enable_fallback = TRUE;
    }

  /* Initialize the script iterator
   */
  state->script_iter = pango_script_iter_new (text + start_index, length);
  pango_script_iter_get_range (state->script_iter, NULL,
			       &state->script_end, &state->script);

  update_end (state);

  if (pango_font_description_get_set_fields (state->font_desc) & PANGO_FONT_MASK_GRAVITY)
    state->font_desc_gravity = pango_font_description_get_gravity (state->font_desc);
  else
    state->font_desc_gravity = PANGO_GRAVITY_AUTO;

  state->gravity = PANGO_GRAVITY_AUTO;
  state->centered_baseline = PANGO_GRAVITY_IS_VERTICAL (state->context->resolved_gravity);
  state->gravity_hint = state->context->gravity_hint;
  state->resolved_gravity = PANGO_GRAVITY_AUTO;
  state->derived_lang = NULL;
  state->lang_engine = NULL;
  state->current_fonts = NULL;
  state->cache = NULL;
  state->exact_engines = NULL;
  state->fallback_engines = NULL;
  state->base_font = NULL;

  state->changed = EMBEDDING_CHANGED | SCRIPT_CHANGED | LANG_CHANGED | FONT_CHANGED;
}

static gboolean
itemize_state_next (ItemizeState *state)
{
  if (state->run_end == state->end)
    return FALSE;

  state->changed = 0;

  state->run_start = state->run_end;

  if (state->run_end == state->embedding_end)
    {
      update_embedding_end (state);
    }

  if (state->run_end == state->attr_end)
    {
      pango_attr_iterator_next (state->attr_iter);
      update_attr_iterator (state);
    }

  if (state->run_end == state->script_end)
    {
      pango_script_iter_next (state->script_iter);
      pango_script_iter_get_range (state->script_iter, NULL,
				   &state->script_end, &state->script);
      state->changed |= SCRIPT_CHANGED;
    }

  update_end (state);

  return TRUE;
}

static GSList *
copy_attr_slist (GSList *attr_slist)
{
  GSList *new_list = NULL;
  GSList *l;

  for (l = attr_slist; l; l = l->next)
    new_list = g_slist_prepend (new_list, pango_attribute_copy (l->data));

  return g_slist_reverse (new_list);
}

static void
itemize_state_fill_shaper (ItemizeState     *state,
			   PangoEngineShape *shape_engine,
			   PangoFont        *font)
{
  GList *l;

  for (l = state->result; l; l = l->next)
    {
      PangoItem *item = l->data;
      if (item->analysis.shape_engine)
	break;
      if (font)
	item->analysis.font = g_object_ref (font);
      else
	item->analysis.font = NULL;
      item->analysis.shape_engine = shape_engine;
    }
}

static void
itemize_state_add_character (ItemizeState     *state,
			     PangoEngineShape *shape_engine,
			     PangoFont        *font,
			     gboolean          force_break,
			     const char       *pos)
{
  if (state->item)
    {
      if (!state->item->analysis.shape_engine && shape_engine)
	{
	  itemize_state_fill_shaper (state, shape_engine, font);
	}
      else if (state->item->analysis.shape_engine && !shape_engine)
	{
	  font = state->item->analysis.font;
	  shape_engine = state->item->analysis.shape_engine;
	}

      if (!force_break &&
	  state->item->analysis.lang_engine == state->lang_engine &&
	  state->item->analysis.shape_engine == shape_engine &&
	  state->item->analysis.font == font)
	{
	  state->item->num_chars++;
	  return;
	}

      state->item->length = (pos - state->text) - state->item->offset;
    }

  state->item = pango_item_new ();
  state->item->offset = pos - state->text;
  state->item->length = 0;
  state->item->num_chars = 1;
  state->item->analysis.shape_engine = shape_engine;
  state->item->analysis.lang_engine = state->lang_engine;

  if (font)
    g_object_ref (font);
  state->item->analysis.font = font;

  state->item->analysis.level = state->embedding;
  state->item->analysis.gravity = state->resolved_gravity;

  /* The level vs. gravity dance:
   *	- If gravity is SOUTH, leave level untouched.
   *	- If gravity is NORTH, step level one up, to
   *	  not get mirrored upside-down text.
   *	- If gravity is EAST, step up to an even level, as
   *	  it's a clockwise-rotated layout, so the rotated
   *	  top is unrotated left.
   *	- If gravity is WEST, step up to an odd level, as
   *	  it's a counter-clockwise-rotated layout, so the rotated
   *	  top is unrotated right.
   *
   * A similar dance is performed in pango-layout.c:
   * line_set_resolved_dir().  Keep in synch.
   */
  switch (state->item->analysis.gravity)
    {
      case PANGO_GRAVITY_SOUTH:
      default:
	break;
      case PANGO_GRAVITY_NORTH:
	state->item->analysis.level++;
	break;
      case PANGO_GRAVITY_EAST:
	state->item->analysis.level += 1;
	state->item->analysis.level &= ~1;
	break;
      case PANGO_GRAVITY_WEST:
	state->item->analysis.level |= 1;
	break;
    }

  state->item->analysis.flags = state->centered_baseline ? PANGO_ANALYSIS_FLAG_CENTERED_BASELINE : 0;

  state->item->analysis.script = state->script;
  state->item->analysis.language = state->derived_lang;

  if (state->copy_extra_attrs)
    {
      state->item->analysis.extra_attrs = copy_attr_slist (state->extra_attrs);
    }
  else
    {
      state->item->analysis.extra_attrs = state->extra_attrs;
      state->copy_extra_attrs = TRUE;
    }

  state->result = g_list_prepend (state->result, state->item);
}

static void
get_engines (PangoContext  *context,
	     PangoLanguage *lang,
	     PangoScript    script,
	     GSList       **exact_engines,
	     GSList       **fallback_engines)
{
  const char *engine_type = pango_font_map_get_shape_engine_type (context->font_map);
  PangoMap *shaper_map = pango_find_map (lang,
					 g_quark_from_string (PANGO_ENGINE_TYPE_SHAPE),
					 g_quark_from_string (engine_type));
  pango_map_get_engines (shaper_map, script,
			 exact_engines, fallback_engines);
}

typedef struct {
  PangoLanguage *lang;
  gunichar wc;
  GSList *engines;
  PangoEngineShape *shape_engine;
  PangoFont *font;
} GetShaperFontInfo;

static gboolean
get_shaper_and_font_foreach (PangoFontset *fontset,
			     PangoFont    *font,
			     gpointer      data)
{
  GetShaperFontInfo *info = data;
  GSList *l;

  for (l = info->engines; l; l = l->next)
    {
      PangoEngineShape *engine = l->data;
      PangoCoverageLevel level;

      level = _pango_engine_shape_covers (engine, font,
					  info->lang, info->wc);
      if (level != PANGO_COVERAGE_NONE)
	{
	  info->shape_engine = engine;
	  info->font = g_object_ref (font);
	  return TRUE;
	}
    }

  return FALSE;
}

static PangoFont *
get_base_font (ItemizeState *state)
{
  if (!state->base_font)
    state->base_font = pango_font_map_load_font (state->context->font_map,
						 state->context,
						 state->font_desc);
  return state->base_font;
}

static gboolean
get_shaper_and_font (ItemizeState      *state,
		     gunichar           wc,
		     PangoEngineShape **shape_engine,
		     PangoFont        **font)
{
  GetShaperFontInfo info;

  /* We'd need a separate cache when fallback is disabled, but since lookup
   * with fallback disabled is faster anyways, we just skip caching */
  if (state->enable_fallback && shaper_font_cache_get (state->cache, wc, shape_engine, font))
    return *shape_engine != NULL;

  if (!state->exact_engines && !state->fallback_engines)
    {
      /* Always use a basic shaper for vertical layout (ie, east/west gravity)
       * as we do not support vertical shaping as of now.
       */
      PangoScript script;

      if (PANGO_GRAVITY_IS_VERTICAL (state->resolved_gravity))
	script = PANGO_SCRIPT_COMMON;
      else
	script = state->script;

      get_engines (state->context, state->derived_lang, script,
		   &state->exact_engines, &state->fallback_engines);
    }

  info.lang = state->derived_lang;
  info.wc = wc;
  info.shape_engine = NULL;
  info.font = NULL;

  info.engines = state->exact_engines;
  if (state->enable_fallback)
    pango_fontset_foreach (state->current_fonts, get_shaper_and_font_foreach, &info);
  else
    get_shaper_and_font_foreach (NULL, get_base_font (state), &info);

  if (info.shape_engine)
    {
      *shape_engine = info.shape_engine;
      *font = info.font;

      /* skip caching if fallback disabled (see above) */
      if (state->enable_fallback)
	shaper_font_cache_insert (state->cache, wc, *shape_engine, *font);

      return TRUE;
    }

  info.engines = state->fallback_engines;
  if (state->enable_fallback)
    pango_fontset_foreach (state->current_fonts, get_shaper_and_font_foreach, &info);
  else
    get_shaper_and_font_foreach (NULL, get_base_font (state), &info);

  *shape_engine = info.shape_engine;
  *font = info.font;

  /* skip caching if fallback disabled (see above) */
  if (state->enable_fallback)
    shaper_font_cache_insert (state->cache, wc, *shape_engine, *font);

  return *shape_engine != NULL;
}

static void
itemize_state_reset_shape_engines (ItemizeState *state)
{
  g_slist_free (state->exact_engines);
  state->exact_engines = NULL;
  g_slist_free (state->fallback_engines);
  state->fallback_engines = NULL;
}

static PangoLanguage *
compute_derived_language (PangoLanguage *lang,
			  PangoScript    script)
{
  PangoLanguage *derived_lang;

  /* Make sure the language tag is consistent with the derived
   * script. There is no point in marking up a section of
   * Arabic text with the "en" language tag.
   */
  if (lang && pango_language_includes_script (lang, script))
    derived_lang = lang;
  else
    {
      derived_lang = pango_script_get_sample_language (script);
      /* If we don't find a sample language for the script, we
       * use a language tag that shouldn't actually be used
       * anywhere. This keeps fontconfig (for the PangoFc*
       * backend) from using the language tag to affect the
       * sort order. I don't have a reference for 'xx' being
       * safe here, though Keith Packard claims it is.
       */
      if (!derived_lang)
	derived_lang = pango_language_from_string ("xx");
    }

  return derived_lang;
}

static PangoMap *
get_lang_map (PangoLanguage *lang)
{
  static guint engine_type_id = 0;
  static guint render_type_id = 0;

  if (engine_type_id == 0)
    {
      engine_type_id = g_quark_from_static_string (PANGO_ENGINE_TYPE_LANG);
      render_type_id = g_quark_from_static_string (PANGO_RENDER_TYPE_NONE);
    }

  return pango_find_map (lang, engine_type_id, render_type_id);
}

static void
itemize_state_update_for_new_run (ItemizeState *state)
{
  /* This block should be moved to update_attr_iterator, but I'm too lazy to
   * do it right now */
  if (state->changed & (FONT_CHANGED | SCRIPT_CHANGED))
    {
      PangoGravity old_gravity = state->resolved_gravity;

      if (state->font_desc_gravity != PANGO_GRAVITY_AUTO)
	{
	  state->resolved_gravity = state->font_desc_gravity;
	}
      else
	{
	  PangoGravity gravity = state->gravity;