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authorOwen Taylor <otaylor@src.gnome.org>2000-01-13 04:12:07 +0000
committerOwen Taylor <otaylor@src.gnome.org>2000-01-13 04:12:07 +0000
commit282fb5fc9f9d01c4d933a6eb6bee6ae9f0d512c7 (patch)
tree0b19c69692a2fe52a1b33d5e27c97b26a64417e3 /pango/reorder-items.c
parent66ae87f9fc45f5f564acf5014e9bd1341d052958 (diff)
downloadpango-282fb5fc9f9d01c4d933a6eb6bee6ae9f0d512c7.tar.gz
Initial revision
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diff --git a/pango/reorder-items.c b/pango/reorder-items.c
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+/* Pango
+ * reorder-items.c:
+ *
+ * Copyright (C) 1999 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 <pango.h>
+
+static GList *reorder_items_recurse (GList *items, int n_items);
+
+/**
+ * pango_reorder_items:
+ * @logical_items: a GList of #PangoItem in logical order.
+ *
+ * From a list of items in logical order and the associated
+ * directional levels, produce a list in visual order.
+ * The original list is unmodified.
+ *
+ * Returns a GList of PangoItem structures in visual order.
+ */
+GList *
+pango_reorder_items (GList *logical_items)
+{
+ return reorder_items_recurse (logical_items, g_list_length (logical_items));
+}
+
+static GList *
+reorder_items_recurse (GList *items, int n_items)
+{
+ GList *tmp_list, *level_start_node;
+ int i, level_start_i;
+ int min_level = G_MAXINT;
+ GList *result = NULL;
+
+ if (n_items == 0)
+ return NULL;
+
+ tmp_list = items;
+ for (i=0; i<n_items; i++)
+ {
+ PangoItem *item = tmp_list->data;
+
+ min_level = MIN (min_level, item->analysis.level);
+
+ tmp_list = tmp_list->next;
+ }
+
+ level_start_i = 0;
+ level_start_node = items;
+ tmp_list = items;
+ for (i=0; i<n_items; i++)
+ {
+ PangoItem *item = tmp_list->data;
+
+ if (item->analysis.level == min_level)
+ {
+ if (min_level % 2)
+ {
+ if (i > level_start_i)
+ result = g_list_concat (reorder_items_recurse (level_start_node, i - level_start_i), result);
+ result = g_list_prepend (result, item);
+ }
+ else
+ {
+ if (i > level_start_i)
+ result = g_list_concat (result, reorder_items_recurse (level_start_node, i - level_start_i));
+ result = g_list_append (result, item);
+ }
+
+ level_start_i = i + 1;
+ level_start_node = tmp_list->next;
+ }
+
+ tmp_list = tmp_list->next;
+ }
+
+ if (min_level % 2)
+ {
+ if (i > level_start_i)
+ result = g_list_concat (reorder_items_recurse (level_start_node, i - level_start_i), result);
+ }
+ else
+ {
+ if (i > level_start_i)
+ result = g_list_concat (result, reorder_items_recurse (level_start_node, i - level_start_i));
+ }
+
+ return result;
+}