pango-context.c

linux

}

/**
 * pango_context_get_base_dir:
 * @context: a #PangoContext
 *
 * Retrieves the base direction for the context. See
 * pango_context_set_base_dir().
 *
 * Return value: the base direction for the context.
 **/
PangoDirection
pango_context_get_base_dir (PangoContext *context)
{
  g_return_val_if_fail (context != NULL, PANGO_DIRECTION_LTR);

  return context->base_dir;
}

/**
 * pango_context_set_base_gravity:
 * @context: a #PangoContext
 * @gravity: the new base gravity
 *
 * Sets the base gravity for the context.
 *
 * The base gravity is used in laying vertical text out.
 *
 * Since: 1.16
 **/
void
pango_context_set_base_gravity (PangoContext  *context,
				PangoGravity gravity)
{
  g_return_if_fail (context != NULL);

  context->base_gravity = gravity;

  update_resolved_gravity (context);
}

/**
 * pango_context_get_base_gravity:
 * @context: a #PangoContext
 *
 * Retrieves the base gravity for the context. See
 * pango_context_set_base_gravity().
 *
 * Return value: the base gravity for the context.
 *
 * Since: 1.16
 **/
PangoGravity
pango_context_get_base_gravity (PangoContext *context)
{
  g_return_val_if_fail (context != NULL, PANGO_GRAVITY_SOUTH);

  return context->base_gravity;
}

/**
 * pango_context_get_gravity:
 * @context: a #PangoContext
 *
 * Retrieves the gravity for the context. This is similar to
 * pango_context_get_base_gravity(), except for when the base gravity
 * is %PANGO_GRAVITY_AUTO for which pango_gravity_get_for_matrix() is used
 * to return the gravity from the current context matrix.
 *
 * Return value: the resolved gravity for the context.
 *
 * Since: 1.16
 **/
PangoGravity
pango_context_get_gravity (PangoContext *context)
{
  g_return_val_if_fail (context != NULL, PANGO_GRAVITY_SOUTH);

  return context->resolved_gravity;
}

/**
 * pango_context_set_gravity_hint:
 * @context: a #PangoContext
 * @hint: 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 pango_context_get_gravity()
 * is set %PANGO_GRAVITY_EAST or %PANGO_GRAVITY_WEST.
 *
 * Since: 1.16
 **/
void
pango_context_set_gravity_hint (PangoContext    *context,
				PangoGravityHint hint)
{
  g_return_if_fail (context != NULL);

  context->gravity_hint = hint;
}

/**
 * pango_context_get_gravity_hint:
 * @context: a #PangoContext
 *
 * Retrieves the gravity hint for the context. See
 * pango_context_set_gravity_hint() for details.
 *
 * Return value: the gravity hint for the context.
 *
 * Since: 1.16
 **/
PangoGravityHint
pango_context_get_gravity_hint (PangoContext *context)
{
  g_return_val_if_fail (context != NULL, PANGO_GRAVITY_HINT_NATURAL);

  return context->gravity_hint;
}

/**********************************************************************/

static gboolean
advance_attr_iterator_to (PangoAttrIterator *iterator,
			  int                start_index)
{
  int start_range, end_range;

  pango_attr_iterator_range (iterator, &start_range, &end_range);

  while (start_index >= end_range)
    {
      if (!pango_attr_iterator_next (iterator))
	return FALSE;
      pango_attr_iterator_range (iterator, &start_range, &end_range);
    }

  if (start_range > start_index)
    g_warning ("In pango_itemize(), the cached iterator passed in "
	       "had already moved beyond the start_index");

  return TRUE;
}

/***************************************************************************
 * We cache the results of character,fontset => font,shaper in a hash table
 ***************************************************************************/

typedef struct {
  GHashTable *hash;
} ShaperFontCache;

typedef struct {
  PangoEngineShape *shape_engine;
  PangoFont *font;
} ShaperFontElement;

static void
shaper_font_cache_destroy (ShaperFontCache *cache)
{
  g_hash_table_destroy (cache->hash);
  g_slice_free (ShaperFontCache, cache);
}

static void
shaper_font_element_destroy (ShaperFontElement *element)
{
  if (element->font)
    g_object_unref (element->font);
  g_slice_free (ShaperFontElement, element);
}

static ShaperFontCache *
get_shaper_font_cache (PangoFontset *fontset)
{
  ShaperFontCache *cache;

  static GQuark cache_quark = 0;
  if (!cache_quark)
    cache_quark = g_quark_from_static_string ("pango-shaper-font-cache");

  cache = g_object_get_qdata (G_OBJECT (fontset), cache_quark);
  if (!cache)
    {
      cache = g_slice_new (ShaperFontCache);
      cache->hash = g_hash_table_new_full (g_direct_hash, NULL,
					   NULL, (GDestroyNotify)shaper_font_element_destroy);

      g_object_set_qdata_full (G_OBJECT (fontset), cache_quark,
			       cache, (GDestroyNotify)shaper_font_cache_destroy);
    }

  return cache;
}

static gboolean
shaper_font_cache_get (ShaperFontCache   *cache,
		       gunichar           wc,
		       PangoEngineShape **shape_engine,
		       PangoFont        **font)
{
  ShaperFontElement *element;

  element = g_hash_table_lookup (cache->hash, GUINT_TO_POINTER (wc));
  if (element)
    {
      *shape_engine = element->shape_engine;
      *font = element->font;

      return TRUE;
    }
  else
    return FALSE;
}

static void
shaper_font_cache_insert (ShaperFontCache   *cache,
			  gunichar           wc,
			  PangoEngineShape  *shape_engine,
			  PangoFont         *font)
{
  ShaperFontElement *element = g_slice_new (ShaperFontElement);
  element->shape_engine = shape_engine;
  element->font = font;

  g_hash_table_insert (cache->hash, GUINT_TO_POINTER (wc), element);
}

/**********************************************************************/

typedef enum {
  EMBEDDING_CHANGED    = 1 << 0,
  SCRIPT_CHANGED       = 1 << 1,
  LANG_CHANGED         = 1 << 2,
  FONT_CHANGED         = 1 << 3,
  DERIVED_LANG_CHANGED = 1 << 4
} ChangedFlags;

typedef struct _ItemizeState ItemizeState;

struct _ItemizeState
{
  PangoContext *context;
  const char *text;
  const char *end;

  const char *run_start;
  const char *run_end;

  GList *result;
  PangoItem *item;

  guint8 *embedding_levels;
  int embedding_end_offset;
  const char *embedding_end;
  guint8 embedding;

  PangoGravity gravity;
  PangoGravityHint gravity_hint;
  PangoGravity resolved_gravity;
  PangoGravity font_desc_gravity;
  gboolean centered_baseline;

  PangoAttrIterator *attr_iter;
  gboolean free_attr_iter;
  const char *attr_end;
  PangoFontDescription *font_desc;
  PangoLanguage *lang;
  GSList *extra_attrs;
  gboolean copy_extra_attrs;

  ChangedFlags changed;

  PangoScriptIter *script_iter;
  const char *script_end;
  PangoScript script;

  PangoLanguage *derived_lang;
  PangoEngineLang *lang_engine;

  PangoFontset *current_fonts;
  ShaperFontCache *cache;
  PangoFont *base_font;
  gboolean enable_fallback;

  GSList *exact_engines;
  GSList *fallback_engines;
};

static void
update_embedding_end (ItemizeState *state)
{
  state->embedding = state->embedding_levels[state->embedding_end_offset];
  while (state->embedding_end < state->end &&
	 state->embedding_levels[state->embedding_end_offset] == state->embedding)
    {
      state->embedding_end_offset++;
      state->embedding_end = g_utf8_next_char (state->embedding_end);
    }

  state->changed |= EMBEDDING_CHANGED;
}

static PangoAttribute *
find_attribute (GSList        *attr_list,
		PangoAttrType  type)
{
  GSList *node;

  for (node = attr_list; node; node = node->next)
    if (((PangoAttribute *) node->data)->klass->type == type)
      return (PangoAttribute *) node->data;

  return NULL;
}

static void
update_attr_iterator (ItemizeState *state)
{
  PangoLanguage *old_lang;
  PangoAttribute *attr;
  int end_index;

  pango_attr_iterator_range (state->attr_iter, NULL, &end_index);
  if (end_index < state->end - state->text)
    state->attr_end = state->text + end_index;
  else
    state->attr_end = state->end;

  old_lang = state->lang;
  if (state->font_desc)
    pango_font_description_free (state->font_desc);
  state->font_desc = pango_font_description_copy_static (state->context->font_desc);
  pango_attr_iterator_get_font (state->attr_iter, state->font_desc,
				&state->lang, &state->extra_attrs);
  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->copy_extra_attrs = FALSE;

  if (!state->lang)
    state->lang = state->context->language;

  attr = find_attribute (state->extra_attrs, PANGO_ATTR_FALLBACK);
  state->enable_fallback = (attr == NULL || ((PangoAttrInt *)attr)->value);

  attr = find_attribute (state->extra_attrs, PANGO_ATTR_GRAVITY);
  state->gravity = attr == NULL ? PANGO_GRAVITY_AUTO : ((PangoAttrInt *)attr)->value;

  attr = find_attribute (state->extra_attrs, PANGO_ATTR_GRAVITY_HINT);
  state->gravity_hint = attr == NULL ? state->context->gravity_hint : ((PangoAttrInt *)attr)->value;

  state->changed |= FONT_CHANGED;
  if (state->lang != old_lang)
    state->changed |= LANG_CHANGED;
}

static void
update_end (ItemizeState *state)
{
  state->run_end = state->embedding_end;
  if (state->attr_end < state->run_end)
    state->run_end = state->attr_end;
  if (state->script_end < state->run_end)
    state->run_end = state->script_end;
}

static void
itemize_state_init (ItemizeState      *state,
		    PangoContext      *context,
		    const char        *text,
		    PangoDirection     base_dir,
		    int                start_index,
		    int                length,
		    PangoAttrList     *attrs,
		    PangoAttrIterator *cached_iter,
		    const PangoFontDescription *desc)
{

  state->context = context;
  state->text = text;
  state->end = text + start_index + length;

  state->result = NULL;
  state->item = NULL;

  state->run_start = text + start_index;

  /* First, apply the bidirectional algorithm to break
   * the text into directional runs.
   */
  state->embedding_levels = pango_log2vis_get_embedding_levels (text + start_index, length, &base_dir);

  state->embedding_end_offset = 0;
  state->embedding_end = text + start_index;
  update_embedding_end (state);

  /* Initialize the attribute iterator
   */
  if (cached_iter)
    {
      state->attr_iter = cached_iter;
      state->free_attr_iter = FALSE;
    }
  else if (attrs)
    {
      state->attr_iter = pango_attr_list_get_iterator (attrs);