Rename PangoLayoutRun to PangoGlyphItem (with a typedef for compat), add

Sun Nov 17 23:28:26 2002  Owen Taylor  <otaylor@redhat.com>

        * pango/pango-glyph-item.[ch] pango/pango-layout.h:
        Rename PangoLayoutRun to PangoGlyphItem (with a
        typedef for compat), add pango_glyph_item_split(),
        pango_glyph_item_apply_attrs().

        * pango/pango-attributes.[ch]: Add
        pango_attr_list_filter(), pango_attr_iterator_get_attrs().

        * pango/pango-layout.c: Remove attributes that don't
        affect shaping before shaping, shape and then add
        them back. Fixes the infamous "underscores break
        arabic shaping" bug (#83058)

        * pango/pango-item.h: Remove an extraneous include.

        * pango/pango-layout.c (imposed_shape): Fix bytes/chars
        problem for glyph->log_clusters.

        * pango/pango-layout.c (cluster_end_index)
        * pango/pango-layout.c (pango_layout_iter_next_cluster): Fix
        confusion between global indices and run-relative indices.

        * docs/tmpl/glyphs.sgml: Improve docs for log_clusters.

        * docs/*: Document new API and PangoOTRuleset

1 files changed, 208 insertions, 0 deletions

diff --git a/pango/pango-glyph-item.c b/pango/pango-glyph-item.c
new file mode 100644
index 00000000..0ea520ac
--- /dev/null
+++ b/pango/pango-glyph-item.c
@@ -0,0 +1,208 @@
+/* -*- mode: C; c-file-style: "gnu" -*- */
+/* Pango
+ * pango-glyph-item.c: Pair of PangoItem and a glyph string
+ *
+ * Copyright (C) 2002 Red Hat Software
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <string.h>
+
+#include "pango-glyph-item.h"
+
+/**
+ * pango_glyph_item_split:
+ * @orig: a #PangoItem
+ * @text: text to which positions in @orig apply.
+ * @split_index: byte index of position to split item, relative to the start of the item
+ * 
+ * Modifies @orig to cover only the text after @split_index, and
+ * returns a new item that covers the text before @split_index that
+ * used to be in @orig. You can think of @split_index as the length of
+ * the returned item. @split_index may not be 0, and it may not be
+ * greater than or equal to the length of @orig (that is, there must
+ * be at least one byte assigned to each item, you can't create a
+ * zero-length item).
+ *
+ * This function is similar in function to pango_item_split() (and uses
+ * it internally)
+ * 
+ * Return value: new item representing text before @split_index
+ **/
+PangoGlyphItem *
+pango_glyph_item_split (PangoGlyphItem *orig,
+			const char     *text,
+			int             split_index)
+{
+  PangoGlyphItem *new;
+  int i;
+  int num_glyphs;
+  int num_remaining;
+  int split_offset;
+  gboolean ltr = (orig->item->analysis.level % 2) == 0;
+
+  g_return_val_if_fail (orig != NULL, NULL);
+  g_return_val_if_fail (orig->item->length > 0, NULL);
+  g_return_val_if_fail (split_index > 0, NULL);
+  g_return_val_if_fail (split_index < orig->item->length, NULL);
+
+  if (ltr)
+    {
+      for (i = 0; i < orig->glyphs->num_glyphs; i++)
+	{
+	  if (orig->glyphs->log_clusters[i] >= split_index)
+	    break;
+	}
+
+      if (i == orig->glyphs->num_glyphs) /* No splitting necessary */
+	return NULL;
+
+      split_index = orig->glyphs->log_clusters[i];
+      num_glyphs = i;
+    }
+  else
+    {
+      for (i = orig->glyphs->num_glyphs - 1; i >= 0; i--)
+	{
+	  if (orig->glyphs->log_clusters[i] >= split_index)
+	    break;
+	}
+
+      if (i < 0) /* No splitting necessary */
+	return NULL;
+
+      split_index = orig->glyphs->log_clusters[i];
+      num_glyphs = orig->glyphs->num_glyphs - 1 - i;
+    }
+
+  num_remaining = orig->glyphs->num_glyphs - num_glyphs;
+
+  new = g_new (PangoGlyphItem, 1);
+  split_offset = g_utf8_pointer_to_offset (text + orig->item->offset,
+					   text + orig->item->offset + split_index);
+  new->item = pango_item_split (orig->item, split_index, split_offset);
+
+  new->glyphs = pango_glyph_string_new ();
+  pango_glyph_string_set_size (new->glyphs, num_glyphs);
+
+  if (ltr)
+    {
+      memcpy (new->glyphs->glyphs, orig->glyphs->glyphs, num_glyphs * sizeof (PangoGlyphInfo));
+      memcpy (new->glyphs->log_clusters, orig->glyphs->log_clusters, num_glyphs * sizeof (int));
+      
+      memmove (orig->glyphs->glyphs, orig->glyphs->glyphs + num_glyphs,
+	       num_remaining * sizeof (PangoGlyphInfo));
+      for (i = num_glyphs; i < orig->glyphs->num_glyphs; i++)
+	orig->glyphs->log_clusters[i - num_glyphs] = orig->glyphs->log_clusters[i] - split_index;
+    }
+  else
+    {
+      memcpy (new->glyphs->glyphs, orig->glyphs->glyphs + num_remaining, num_glyphs * sizeof (PangoGlyphInfo));
+      memcpy (new->glyphs->log_clusters, orig->glyphs->log_clusters + num_remaining, num_glyphs * sizeof (int));
+
+      for (i = 0; i < num_remaining; i++)
+	orig->glyphs->log_clusters[i] = orig->glyphs->log_clusters[i] - split_index;
+    }
+
+  pango_glyph_string_set_size (orig->glyphs, orig->glyphs->num_glyphs - num_glyphs);
+
+  return new;
+}
+
+static void
+append_attrs (PangoGlyphItem *glyph_item,
+	      GSList         *attrs)
+{
+  glyph_item->item->analysis.extra_attrs =
+    g_slist_concat (glyph_item->item->analysis.extra_attrs, attrs);
+}
+
+/**
+ * pango_glyph_item_apply_attrs:
+ * @glyph_item: a shaped item 
+ * @text: text that @list applies to
+ * @list: a #PangoAttrList
+ *   
+ * Splits a shaped item (PangoGlyphItem) into multiple items based
+ * on an attribute list. The idea is that if you have attributes
+ * that don't affect shaping, such as color or underline, to avoid
+ * affecting shaping, you filter them out (pango_attr_list_filter()),
+ * apply the shaping process and then reapply them to the result using
+ * this function.
+ *
+ * This function takes ownership of @glyph_item; it will be reused
+ * as one of the elements in the list.
+ * 
+ * Return value: a list of glyph items resulting from splitting
+ *   @glyph_item. Free the elements using pango_glyph_item_free(),
+ *   the list using g_slist_free().
+ **/
+GSList *
+pango_glyph_item_apply_attrs (PangoGlyphItem   *glyph_item,
+			      const char       *text,
+			      PangoAttrList    *list)
+{
+  PangoAttrIterator *iter = pango_attr_list_get_iterator (list);
+  PangoGlyphItem *new;
+  GSList *result = NULL;
+  int start;
+  int end;
+
+  gboolean ltr = (glyph_item->item->analysis.level % 2) == 0;
+
+  while (TRUE)
+    {
+      pango_attr_iterator_range (iter, &start, &end);
+
+      if (start > glyph_item->item->offset)
+	{
+	  if (start >= glyph_item->item->offset + glyph_item->item->length)
+	    break;
+
+	  new = pango_glyph_item_split (glyph_item, text,
+					start - glyph_item->item->offset);
+	  
+	  result = g_slist_prepend (result, new);
+	}
+
+      if (end > glyph_item->item->offset)
+	{
+	  if (end >= glyph_item->item->offset + glyph_item->item->length)
+	    {
+	      append_attrs (glyph_item, pango_attr_iterator_get_attrs (iter));
+	      break;
+	    }
+
+	  new = pango_glyph_item_split (glyph_item, text,
+					end - glyph_item->item->offset);
+
+	  append_attrs (new, pango_attr_iterator_get_attrs (iter));
+
+	  result = g_slist_prepend (result, new);
+	}
+
+      if (!pango_attr_iterator_next (iter))
+	  break;
+    }
+
+  result = g_slist_prepend (result, glyph_item);
+
+  if (ltr)
+    result = g_slist_reverse (result);
+  
+  return result;
+}