Make PangoEngine{,Lang,Shape} GObjects, and use a GTypeModule-based

Sat Aug  2 23:19:16 2003  Owen Taylor  <otaylor@redhat.com>

        * pango/pango-engine.[ch] modules/*/*-{fc,win32,x}.c
        pango/modules.c pango/break.c pango/pango-context.c
        pango/pango-layout.c pango/pango-modules.h
        pango/querymodules.c pango/shape.c: Make
        PangoEngine{,Lang,Shape} GObjects, and use a
        GTypeModule-based module-loading system closely based
        on the one used for GtkIMContext and GtkThemeEngine.

        * pango/pango-impl-utils.h: OK, I'm tired of typing
        in get_type() functions.

        * pango/pango-script.[ch] pango/pango-script-table.h
        tests/testscript.c tools/gen-script-table.pl: Add port
        of script-range code from ICU in preparation for future
        use. (#91542)

        * tools/gen-script-for-lang.c: Utility program to determine
        the script for each fontconfig .orth file.

        * docs/tmpl/{scripts.sgml,pango-engine-lang.sgml,
        pango-engine-shape.sgml} docs/pango-sections.txt docs/pango-docs.sgml:
        Redo to go along with the above changes.

        * configure.in: chmod +x tests/runtests.sh

1 files changed, 343 insertions, 0 deletions

diff --git a/pango/pango-script.c b/pango/pango-script.c
new file mode 100644
index 00000000..39a95641
--- /dev/null
+++ b/pango/pango-script.c
@@ -0,0 +1,343 @@
+/* -*- mode: C; c-file-style: "gnu" -*- */
+/* Pango
+ * pango-script.c: Script tag handling
+ *
+ * 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.
+ *
+ * Implementation of pango_script_iter is derived from ICU:
+ *
+ *  icu/sources/common/usc_impl.c
+ *
+ **********************************************************************
+ *   Copyright (C) 1999-2002, International Business Machines
+ *   Corporation and others.  All Rights Reserved.
+ **********************************************************************
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, and/or sell copies of the Software, and to permit persons
+ * to whom the Software is furnished to do so, provided that the above
+ * copyright notice(s) and this permission notice appear in all copies of
+ * the Software and that both the above copyright notice(s) and this
+ * permission notice appear in supporting documentation.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+ * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
+ * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
+ * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
+ * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ * 
+ * Except as contained in this notice, the name of a copyright holder
+ * shall not be used in advertising or otherwise to promote the sale, use
+ * or other dealings in this Software without prior written authorization
+ * of the copyright holder.
+ */
+#include <string.h>
+
+#include "pango-script.h"
+#include "pango-script-table.h"
+
+#define PAREN_STACK_DEPTH 128
+
+typedef struct _ParenStackEntry ParenStackEntry;
+
+struct _ParenStackEntry
+{
+  int pair_index;
+  PangoScript script_code;
+};
+
+struct _PangoScriptIter
+{
+  const gchar *text_start;
+  const gchar *text_end;
+
+  const gchar *script_start;
+  const gchar *script_end;
+  PangoScript script_code;
+
+  ParenStackEntry paren_stack[PAREN_STACK_DEPTH];
+  int paren_sp;
+};
+
+/**
+ * pango_script_for_unichar:
+ * @ch: a unicode characters
+ * 
+ * Looks up the #PangoScript for a particular character (as defined by
+ * Unicode Technical report #24). No check is made for @ch being
+ * valid unicode character; if you pass in invalid character, the
+ * result is undefined.
+ * 
+ * Return value: the #PangoScript for the character.
+ **/
+PangoScript
+pango_script_for_unichar (gunichar ch)
+{
+  int lower = 0;
+  int upper = G_N_ELEMENTS (pango_script_table) - 1;
+
+  while (lower <= upper)
+    {
+      int mid = (lower + upper) / 2;
+      if (ch < pango_script_table[mid].start)
+	upper = mid - 1;
+      else if (ch >= pango_script_table[mid].start + pango_script_table[mid].chars)
+	lower = mid + 1;
+      else
+	return pango_script_table[mid].script;
+    }
+  
+  return PANGO_SCRIPT_COMMON;
+}
+
+/**********************************************************************/
+
+/**
+ * pango_script_iter_new:
+ * @text: a UTF-8 string
+ * @length: length of @text, or -1 if @text is NUL-terminated.
+ * 
+ * Create a new #PangoScriptIter, used to break a string of
+ * Unicode into runs by text. No copy is made of @text, so
+ * the caller needs to make sure it remains valid until
+ * the iterator is freed with pango_script_iter_free ().x
+ * 
+ * Return value: the newly created script iterator, initialized
+ *  to point at the first range in the text. If the string is
+ *  empty, it will point at an empty range.
+ **/
+PangoScriptIter *
+pango_script_iter_new (const char *text,
+		       int         length)
+{
+  PangoScriptIter *iter = g_new (PangoScriptIter, 1);
+
+  iter->text_start = text;
+  if (length >= 0)
+    iter->text_end = text + length;
+  else
+    iter->text_end = text + strlen (text);
+
+  iter->script_start = text;
+  iter->script_end = text;
+  iter->script_code = PANGO_SCRIPT_COMMON;
+  
+  iter->paren_sp = -1;
+
+  pango_script_iter_next (iter);
+
+  return iter;
+}
+
+/**
+ * pango_script_iter_free:
+ * @iter: a #PangoScriptIter
+ * 
+ * Frees a #PangoScriptIter created with pango_script_iter_new().
+ **/
+void
+pango_script_iter_free (PangoScriptIter *iter)
+{
+  g_free (iter);
+}
+
+/**
+ * pango_script_iter_get_range:
+ * @iter: a #PangoScriptIter
+ * @start: location to store start position of the range, or %NULL
+ * @end: location to store end position of the range, or %NULL
+ * @script: location to store script for range, or %NULL
+ * 
+ * Gets information about the range to which @iter currently points.
+ * The range is the is the set of locations p where *start <= p < *end.
+ * (That is, it doesn't include the character stored at *end)
+ **/
+void
+pango_script_iter_get_range (PangoScriptIter      *iter,
+			     G_CONST_RETURN char **start,
+			     G_CONST_RETURN char **end,
+			     PangoScript          *script)
+{
+  if (start)
+    *start = iter->script_start;
+  if (end)
+    *end = iter->script_end;
+  if (script)
+    *script = iter->script_code;
+}
+
+static const gunichar paired_chars[] = {
+  0x0028, 0x0029, /* ascii paired punctuation */
+  0x003c, 0x003e,
+  0x005b, 0x005d,
+  0x007b, 0x007d,
+  0x00ab, 0x00bb, /* guillemets */
+  0x2018, 0x2019, /* general punctuation */
+  0x201c, 0x201d,
+  0x2039, 0x203a,
+  0x3008, 0x3009, /* chinese paired punctuation */
+  0x300a, 0x300b,
+  0x300c, 0x300d,
+  0x300e, 0x300f,
+  0x3010, 0x3011,
+  0x3014, 0x3015,
+  0x3016, 0x3017,
+  0x3018, 0x3019,
+  0x301a, 0x301b
+};
+
+int
+get_pair_index (gunichar ch)
+{
+  int lower = 0;
+  int upper = G_N_ELEMENTS (paired_chars) - 1;
+
+  while (lower <= upper)
+    {
+      int mid = (lower + upper) / 2;
+      
+      if (ch < paired_chars[mid])
+	upper = mid - 1;
+      else if (ch > paired_chars[mid])
+	lower = mid + 1;
+      else
+	return mid;
+    }
+
+  return -1;
+}
+
+#define REAL_SCRIPT(script) \
+  ((script) > PANGO_SCRIPT_INHERITED)
+
+#define SAME_SCRIPT(script1, script2) \
+  (!REAL_SCRIPT (script1) || !REAL_SCRIPT (script2) || (script1) == (script2))
+
+#define IS_OPEN(pair_index) (((pair_index) & 1) == 0)
+
+/**
+ * pango_script_iter_next:
+ * @iter: a #PangoScriptIter
+ * 
+ * Advances a #PangoScriptIter to the next range. If the iter
+ * is already at the end, it is left unchanged and %FALSE
+ * is returned.
+ * 
+ * Return value: %TRUE if the iter was succesfully advanced.
+ **/
+gboolean
+pango_script_iter_next (PangoScriptIter *iter)
+{
+  int start_sp;
+  
+  if (iter->script_end == iter->text_end)
+    return FALSE;
+
+  start_sp = iter->paren_sp;
+  iter->script_code = PANGO_SCRIPT_COMMON;
+  iter->script_start = iter->script_end;
+  
+  for (; iter->script_end < iter->text_end; iter->script_end = g_utf8_next_char (iter->script_end))
+    {
+      gunichar ch = g_utf8_get_char (iter->script_end);
+      PangoScript sc;
+      int pair_index;
+
+      sc = pango_script_for_unichar (ch);
+      pair_index = get_pair_index (ch);
+
+      /*
+       * Paired character handling:
+       *
+       * if it's an open character, push it onto the stack.
+       * if it's a close character, find the matching open on the
+       * stack, and use that script code. Any non-matching open
+       * characters above it on the stack will be poped.
+       */
+      if (pair_index >= 0)
+	{
+	  if (IS_OPEN (pair_index))
+	    {
+	      /*
+	       * If the paren stack is full, empty it. This
+	       * means that deeply nested paired punctuation
+	       * characters will be ignored, but that's an unusual
+	       * case, and it's better to ignore them than to
+	       * write off the end of the stack...
+	       */
+	      if (++iter->paren_sp >= PAREN_STACK_DEPTH)
+		iter->paren_sp = 0;
+
+	      iter->paren_stack[iter->paren_sp].pair_index = pair_index;
+	      iter->paren_stack[iter->paren_sp].script_code = iter->script_code;
+	    }
+	  else if (iter->paren_sp >= 0)
+	    {
+	      int pi = pair_index & ~1;
+
+	      while (iter->paren_sp >= 0 && iter->paren_stack[iter->paren_sp].pair_index != pi)
+		iter->paren_sp--;
+
+	      if (iter->paren_sp < start_sp)
+		start_sp = iter->paren_sp;
+
+	      if (iter->paren_sp >= 0)
+		sc = iter->paren_stack[iter->paren_sp].script_code;
+	    }
+	}
+
+      if (SAME_SCRIPT (iter->script_code, sc))
+	{
+	  if (!REAL_SCRIPT (iter->script_code) && REAL_SCRIPT (sc))
+	    {
+	      iter->script_code = sc;
+
+	      /*
+	       * now that we have a final script code, fix any open
+	       * characters we pushed before we knew the script code.
+	       */
+	      while (start_sp < iter->paren_sp)
+		iter->paren_stack[++start_sp].script_code = iter->script_code;
+	    }
+
+	  /*
+	   * if this character is a close paired character,
+	   * pop it from the stack
+	   */
+	  if (pair_index >= 0 && !IS_OPEN (pair_index) != 0 && iter->paren_sp >= 0)
+	    {
+	      iter->paren_sp--;
+	      start_sp--;
+            }
+	}
+      else
+	{
+	  /* Different script, we're done */
+	  break;
+	}
+    }
+
+  return TRUE;
+}