From: handa <handa>
Date: Mon, 5 Jan 2009 15:29:15 +0000 (+0000)
Subject: *** empty log message ***
X-Git-Url: http://git.chise.org/gitweb/?a=commitdiff_plain;h=4b35a76d029d447f0b0ebcee26ea42316773662d;p=m17n%2Fm17n-lib-cs.git

*** empty log message ***
---

diff --git a/MText.cs b/MText.cs
index 477d7e6..cd9b9db 100644
--- a/MText.cs
+++ b/MText.cs
@@ -48,6 +48,7 @@ namespace M17N.Core
     private MTextPlist plist;
 
     private static UTF8Encoding utf8 = new UTF8Encoding ();
+    private static UTF32Encoding utf32 = new UTF8Encoding ();
 
     public MText ()
     {
@@ -58,24 +59,84 @@ namespace M17N.Core
 
     public MText (byte[] str)
     {
-      cache_pos = cache_idx = 0;
-      plist = null;          
       sb = new StringBuilder (utf8.GetString (str));
     }
 
     public MText (String str)
     {
-      cache_pos = cache_idx = 0;
-      plist = null;          
       sb = new StringBuilder (str);
     }
 
+    private static int inc_idx (int i)
+    {
+      return ((sb[i] >= 0xD800 && sb[i] < 0xDC00)
+	      ? i + 2 : i + 1);
+    }
+
+    private static int dec_idx (int i)
+    {
+      return ((sb[i - 1] >= 0xDC00 && sb[i - 1] < 0xE000)
+	      ? i - 2 : i - 1);
+    }
+
+    private static int pos_to_idx (int pos)
+    {
+      int p, i;
+      bool forward;
+
+      if (pos < cache_pos)
+	{
+	  if (cache_pos == cache_idx)
+	    return cache_idx;
+	  if (pos < cache_pos - pos)
+	    {
+	      p = i = 0;
+	      forward = true;
+	    }
+	  else
+	    {
+	      p = cache_pos; i = cache_idx;
+	      forward = false;
+	    }
+	}
+      else
+	{
+	  if (nchars - cache_pos == sb.Length - cache_idx)
+	    return (cache_idx + pos - cache_pos);
+	  if (pos - cache_pos < nchars - pos)
+	    {
+	      p = char_pos; i = char_idx;
+	      forward = true;
+	    }
+	  else
+	    {
+	      p = nchars; i = sb.Length;
+	      forward = false;
+	    }
+	}
+      if (forward)
+	for (; p < pos; i = inc_idx (i), p++);
+      else
+	for (; p > pos; i = dec_idx (i), p--);
+      cache_pos = p;
+      cache_idx = i;
+      return i;
+    }
+
     public int this[int i]
     {
-      set { this.sb[i] = (char) value; }
+      set {
+	if (i != cache_pos)
+	  i = pos_to_idx (i);
+	if (value < 0x10000)
+	  this.sb[i] = (char) value;
+	else
+	  {
+	    
+	  }
+      }
       get { return this.sb[i]; }
     }
-  }
 
   public class MTextProperty
   {