diff --git a/scim-wnn/src/Makefile.am b/scim-wnn/src/Makefile.am
index 150de1a..41688df 100644
--- a/scim-wnn/src/Makefile.am
+++ b/scim-wnn/src/Makefile.am
@@ -25,12 +25,13 @@
 			  -DSCIM_WNN_ICON_FILE=\"@SCIM_ICONDIR@/scim-wnn.png\"
 
 noinst_HEADERS = scim_wnn_imengine.h wnnproto.h romkan.h romkan_table.h \
-	wnnconversion.h scim_wnn_def.h
+		wnnconversion.h scim_wnn_def.h preeditor.h
 
 moduledir		= @SCIM_MODULEDIR@/IMEngine
 module_LTLIBRARIES	= wnn.la
 
-wnn_la_SOURCES = scim_wnn_imengine.cpp romkan.cpp wnnconversion.cpp
+wnn_la_SOURCES = scim_wnn_imengine.cpp romkan.cpp wnnconversion.cpp \
+	preeditor.cpp
 
 wnn_la_CFLAGS		= @SCIM_CFLAGS@ @SCIM_DEBUG_FLAGS@
 wnn_la_CXXFLAGS		= @SCIM_CFLAGS@ @SCIM_DEBUG_FLAGS@
diff --git a/scim-wnn/src/preeditor.cpp b/scim-wnn/src/preeditor.cpp
new file mode 100644
index 0000000..88dfa37
--- /dev/null
+++ b/scim-wnn/src/preeditor.cpp
@@ -0,0 +1,191 @@
+/***************************************************************************
+ *   Copyright (C) 2004 by TAM(Teppei Tamra)                               *
+ *   tam-t@par.odn.ne.jp                                                   *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ ***************************************************************************/
+#include "preeditor.h"
+
+PreEditor::PreEditor()
+{
+    iconvert.set_encoding ("EUC-JP");
+}
+
+
+PreEditor::~PreEditor()
+{
+}
+
+WideString PreEditor::text = WideString();
+int PreEditor::pos = 0;
+IConvert PreEditor::iconvert;
+
+/*!
+    \fn PreEditor::getPos()
+ */
+int PreEditor::getPos()
+{
+    return(pos);
+}
+
+
+/*!
+    \fn PreEditor::getTextLength()
+ */
+int PreEditor::getTextLength()
+{
+    return(text.length());
+}
+
+
+/*!
+    \fn PreEditor::setPos(int p)
+ */
+void PreEditor::setPos(int p)
+{
+    if (p < 0) p = 0;
+    else if (p > getTextLength()) p = getTextLength();
+    pos = p;
+}
+
+
+/*!
+    \fn PreEditor::clear()
+ */
+void PreEditor::clear()
+{
+    text.clear();
+}
+
+
+/*!
+    \fn PreEditor::insert(char k)
+ */
+WideString PreEditor::insert(char k)
+{
+    if (k == 0) return(text);
+    String s;
+    s = k;
+    text = text.substr(0,pos) + utf8_mbstowcs(s) + text.substr(pos);
+    pos ++;
+    return(getText());
+}
+
+
+
+
+/*!
+    \fn PreEditor::reset()
+ */
+void PreEditor::reset()
+{
+    clear();
+    pos = 0;
+}
+
+
+/*!
+    \fn PreEditor::getText(bool hosei)
+ */
+WideString PreEditor::getText(bool hosei)
+{
+    return(text);
+}
+
+
+/*!
+    \fn PreEditor::backspace()
+ */
+void PreEditor::backspace()
+{
+    if (getPos() == 0) return;
+    text = text.substr(0,pos - 1) + text.substr(pos);
+    setPos(pos - 1);
+}
+
+
+
+/*!
+    \fn PreEditor::del()
+ */
+void PreEditor::del()
+{
+    if (getPos() == getTextLength()) return;
+    text = text.substr(0,pos) + text.substr(pos + 1);
+}
+
+
+/*!
+    \fn PreEditor::convHiraKata(WideString &t)
+ */
+void PreEditor::convHiraKata(WideString &t)
+{
+    WideString start_c,end_c,conv_c;
+    iconvert.convert(start_c,String("��"));
+    iconvert.convert(end_c,String("��"));
+    iconvert.convert(conv_c,String("��"));
+    for(unsigned int i = 0;i < t.size();i ++) {
+        if ((t[i] >= start_c[0]) && (t[i] <= end_c[0]))
+            t[i] = t[i] - start_c[0] + conv_c[0];
+    }
+    return;
+}
+
+
+/*!
+    \fn PreEditor::convKataHira(WideString &t)
+ */
+void PreEditor::convKataHira(WideString &t)
+{
+    WideString start_c,end_c,conv_c;
+    iconvert.convert(start_c,String("��"));
+    iconvert.convert(end_c,String("��"));
+    iconvert.convert(conv_c,String("��"));
+    for(unsigned int i = 0;i < t.size();i ++) {
+        if ((t[i] >= start_c[0]) && (t[i] <= end_c[0]))
+            t[i] = t[i] - start_c[0] + conv_c[0];
+    }
+    return;
+
+}
+
+
+/*!
+    \fn PreEditor::hiraKata()
+ */
+void PreEditor::hiraKata()
+{
+    convHiraKata(text);
+}
+
+
+/*!
+    \fn PreEditor::kataHira()
+ */
+void PreEditor::kataHira()
+{
+    convKataHira(text);
+}
+
+
+/*!
+    \fn PreEditor::keyEventHook(const KeyEvent &key)
+ */
+bool PreEditor::keyEventHook(const KeyEvent &key)
+{
+    return(false);
+}
+
diff --git a/scim-wnn/src/preeditor.h b/scim-wnn/src/preeditor.h
new file mode 100644
index 0000000..7b7de62
--- /dev/null
+++ b/scim-wnn/src/preeditor.h
@@ -0,0 +1,61 @@
+/***************************************************************************
+ *   Copyright (C) 2004 by TAM(Teppei Tamra)                               *
+ *   tam-t@par.odn.ne.jp                                                   *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ ***************************************************************************/
+#ifndef PREEDITOR_H
+#define PREEDITOR_H
+
+#define Uses_SCIM_ICONV
+#include <scim.h>
+#include <scim_iconv.h>
+#include <scim_event.h>
+
+using namespace std;
+using namespace scim;
+
+/**
+@author TAM(Teppei Tamra)
+*/
+class PreEditor{
+public:
+    PreEditor();
+
+    ~PreEditor();
+    virtual void clear();
+    virtual WideString insert(char k);
+    int getPos();
+    virtual void setPos(int p);
+    int getTextLength();
+    virtual void reset();
+    WideString getText(bool hosei = false);
+    virtual void backspace();
+    virtual void del();
+    virtual void hiraKata();
+    virtual void kataHira();
+    virtual bool keyEventHook(const KeyEvent &key);
+    static void convHiraKata(WideString &t);
+    static void convKataHira(WideString &t);
+
+protected:
+    static WideString text;
+    static int pos;
+    static IConvert iconvert;
+
+};
+
+#endif
diff --git a/scim-wnn/src/romkan.cpp b/scim-wnn/src/romkan.cpp
index e2aaa69..8b3aa7f 100644
--- a/scim-wnn/src/romkan.cpp
+++ b/scim-wnn/src/romkan.cpp
@@ -32,23 +32,6 @@
 }
 
 
-/*!
-    \fn Romkan::getPos()
- */
-int Romkan::getPos()
-{
-    return(pos);
-}
-
-
-/*!
-    \fn Romkan::getTextLength()
- */
-int Romkan::getTextLength()
-{
-    return(text.length());
-}
-
 
 /*!
     \fn Romkan::setPos(int p)
@@ -196,40 +179,6 @@
 }
 
 
-/*!
-    \fn Romkan::convHiraKata(WideString &t)
- */
-void Romkan::convHiraKata(WideString &t)
-{
-    WideString start_c,end_c,conv_c;
-    iconvert.convert(start_c,String("��"));
-    iconvert.convert(end_c,String("��"));
-    iconvert.convert(conv_c,String("��"));
-    for(unsigned int i = 0;i < t.size();i ++) {
-        if ((t[i] >= start_c[0]) && (t[i] <= end_c[0]))
-            t[i] = t[i] - start_c[0] + conv_c[0];
-    }
-    return;
-}
-
-
-/*!
-    \fn Romkan::convKataHira(WideString &t)
- */
-void Romkan::convKataHira(WideString &t)
-{
-    WideString start_c,end_c,conv_c;
-    iconvert.convert(start_c,String("��"));
-    iconvert.convert(end_c,String("��"));
-    iconvert.convert(conv_c,String("��"));
-    for(unsigned int i = 0;i < t.size();i ++) {
-        if ((t[i] >= start_c[0]) && (t[i] <= end_c[0]))
-            t[i] = t[i] - start_c[0] + conv_c[0];
-    }
-    return;
-
-}
-
 
 /*!
     \fn Romkan::hiraKata()
diff --git a/scim-wnn/src/romkan.h b/scim-wnn/src/romkan.h
index ca3d54e..ba970c0 100644
--- a/scim-wnn/src/romkan.h
+++ b/scim-wnn/src/romkan.h
@@ -25,6 +25,7 @@
 #include <scim.h>
 #include <scim_iconv.h>
 #include <scim_event.h>
+#include "preeditor.h"
 
 using namespace std;
 using namespace scim;
@@ -32,32 +33,27 @@
 /**
 @author TAM(Teppei Tamra)
 */
-class Romkan{
+class Romkan : public PreEditor {
 public:
     Romkan();
 
     ~Romkan();
-    void clear();
-    WideString insert(char k);
-    WideString eval();
-    int getPos();
-    void setPos(int p);
-    int getTextLength();
-    void reset();
-    WideString getText(bool hosei = false);
-    void backspace();
-    void del();
-    void convHiraKata(WideString &t);
-    void convKataHira(WideString &t);
-    void hiraKata();
-    void kataHira();
-    bool keyEventHook(const KeyEvent &key);
+    virtual void clear();
+    virtual WideString insert(char k);
+    virtual void setPos(int p);
+    virtual void reset();
+    virtual WideString getText(bool hosei = false);
+    virtual void backspace();
+    virtual void del();
+    virtual void hiraKata();
+    virtual void kataHira();
+    virtual bool keyEventHook(const KeyEvent &key);
 
 protected:
-    WideString text;
+    WideString eval();
+
+protected:
     String buf;
-    int pos;
-    IConvert iconvert;
 };
 
 #endif
diff --git a/scim-wnn/src/scim_wnn_imengine.cpp b/scim-wnn/src/scim_wnn_imengine.cpp
index 7a6a3a0..548b31a 100644
--- a/scim-wnn/src/scim_wnn_imengine.cpp
+++ b/scim-wnn/src/scim_wnn_imengine.cpp
@@ -182,11 +182,13 @@
 {
     m_iconv.set_encoding ("EUC-JP");
     m_connected = false;
+    m_preeditor = new Romkan;
     init();
 }
 
 WnnInstance::~ WnnInstance()
 {
+    delete m_preeditor;
 }
 
 
@@ -276,68 +278,68 @@
  */
 bool WnnInstance::process_preedit_key_event(const KeyEvent &key)
 {
-    if (m_rk.keyEventHook(key)) {
+    if (m_preeditor->keyEventHook(key)) {
         show_preedit_string();
-        update_preedit_string(m_rk.getText());
-        update_preedit_caret(m_rk.getPos());
+        update_preedit_string(m_preeditor->getText());
+        update_preedit_caret(m_preeditor->getPos());
         return(true);
     } else
-    if (m_rk.getTextLength()) {
+    if (m_preeditor->getTextLength()) {
         if (k_conversion_start.comp(key)) {
-            startConversion(m_rk.getText(true));
+            startConversion(m_preeditor->getText(true));
             alp_count ++;
             return(true);
         } else
         if (k_commit.comp(key)) {
-            commit_string(m_rk.getText(true));
-            m_rk.reset();
+            commit_string(m_preeditor->getText(true));
+            m_preeditor->reset();
             hide_preedit_string();
             return(true);
         } else
         if (k_forward.comp(key) || k_backward.comp(key)) {
-            k_backward.comp(key) ? m_rk.setPos(m_rk.getPos() - 1) : m_rk.setPos(m_rk.getPos() + 1);
-            update_preedit_string(m_rk.getText());
-            update_preedit_caret(m_rk.getPos());
+            k_backward.comp(key) ? m_preeditor->setPos(m_preeditor->getPos() - 1) : m_preeditor->setPos(m_preeditor->getPos() + 1);
+            update_preedit_string(m_preeditor->getText());
+            update_preedit_caret(m_preeditor->getPos());
             return(true);
         } else
         if (k_backspace.comp(key)) {
-            m_rk.backspace();
-            update_preedit_string(m_rk.getText());
-            update_preedit_caret(m_rk.getPos());
+            m_preeditor->backspace();
+            update_preedit_string(m_preeditor->getText());
+            update_preedit_caret(m_preeditor->getPos());
             return(true);
         } else
         if (k_delete.comp(key)) {
-            m_rk.del();
-            update_preedit_string(m_rk.getText());
-            update_preedit_caret(m_rk.getPos());
+            m_preeditor->del();
+            update_preedit_string(m_preeditor->getText());
+            update_preedit_caret(m_preeditor->getPos());
             return(true);
         } else
         if (k_cancel.comp(key)) {
-            m_rk.reset();
+            m_preeditor->reset();
             hide_preedit_string();
             return(true);
         } else
         if (k_convert_hiragana.comp(key)) {
-            m_rk.kataHira();
-            update_preedit_string(m_rk.getText());
-            update_preedit_caret(m_rk.getPos());
+            m_preeditor->kataHira();
+            update_preedit_string(m_preeditor->getText());
+            update_preedit_caret(m_preeditor->getPos());
             return(true);
         } else
         if (k_convert_katakana.comp(key)) {
-            m_rk.hiraKata();
-            update_preedit_string(m_rk.getText());
-            update_preedit_caret(m_rk.getPos());
+            m_preeditor->hiraKata();
+            update_preedit_string(m_preeditor->getText());
+            update_preedit_caret(m_preeditor->getPos());
             return(true);
         }
     }
     if (isprint(key.code)) {
         if (key.mask & (SCIM_KEY_AltMask | SCIM_KEY_ControlMask)) return(false);
         // �Хåե������λ��ι�Ƭ���ڡ�����ľ�����ϡ�
-        if ((key.code == SCIM_KEY_space) && (!m_rk.getTextLength())) return(false);
+        if ((key.code == SCIM_KEY_space) && (!m_preeditor->getTextLength())) return(false);
         show_preedit_string();
         SCIM_DEBUG_IMENGINE(1) << key.get_key_string() << "\n";
-        update_preedit_string(m_rk.insert(key.get_ascii_code()));
-        update_preedit_caret(m_rk.getPos());
+        update_preedit_string(m_preeditor->insert(key.get_ascii_code()));
+        update_preedit_caret(m_preeditor->getPos());
         return(true);
     }
     return(false);
@@ -370,7 +372,7 @@
     if (k_commit.comp(key)) {
         commit_string(wnn.getText());
         wnn.updateFrequency();
-        m_rk.reset();
+        m_preeditor->reset();
         wnn.reset();
         m_conversion = false;
         hide_preedit_string();
@@ -383,8 +385,8 @@
     if (k_cancel.comp(key) || k_backspace.comp(key)) {
         wnn.reset();
         m_conversion = false;
-        update_preedit_string(m_rk.getText());
-        update_preedit_caret(m_rk.getPos());
+        update_preedit_string(m_preeditor->getText());
+        update_preedit_caret(m_preeditor->getPos());
         hide_lookup_table();
         hide_aux_string();
         m_lookup = false;
@@ -441,7 +443,7 @@
     } else
     if (k_convert_hiragana.comp(key) || k_convert_katakana.comp(key)) {
         WideString res = m_convList.Yomi;
-        k_convert_hiragana.comp(key) ? m_rk.convKataHira(res) : m_rk.convHiraKata(res);
+        k_convert_hiragana.comp(key) ? m_preeditor->convKataHira(res) : m_preeditor->convHiraKata(res);
         for(unsigned int i = 0;i < m_convList.count;i ++) {
             if (res == m_convList.kouho[i]) {
                 m_convList.pos = i;
@@ -485,7 +487,7 @@
 
         commit_string(wnn.getText());
         wnn.updateFrequency();
-        m_rk.reset();
+        m_preeditor->reset();
         wnn.reset();
         m_conversion = false;
         hide_preedit_string();
@@ -503,7 +505,7 @@
 
 void WnnInstance::move_preedit_caret (unsigned int pos)
 {
-    //if (!m_conversion) m_rk.setPos(pos);
+    //if (!m_conversion) m_preeditor->setPos(pos);
     //update_preedit_caret(pos);
 }
 
@@ -565,7 +567,7 @@
     hide_aux_string();
     hide_preedit_string ();
     wnn.reset();
-    m_rk.reset();
+    m_preeditor->reset();
 }
 
 void WnnInstance::focus_in ()
@@ -577,7 +579,7 @@
     if (m_conversion) {
         commit_string(wnn.getText());
         wnn.updateFrequency();
-        m_rk.reset();
+        m_preeditor->reset();
         wnn.reset();
         m_conversion = false;
         hide_preedit_string();
@@ -585,9 +587,9 @@
         hide_aux_string();
         m_lookup = false;
         alp_count = 0;
-    } else if (m_rk.getTextLength()) {
-        commit_string(m_rk.getText(true));
-        m_rk.reset();
+    } else if (m_preeditor->getTextLength()) {
+        commit_string(m_preeditor->getText(true));
+        m_preeditor->reset();
         hide_preedit_string();
     }
 }
diff --git a/scim-wnn/src/scim_wnn_imengine.h b/scim-wnn/src/scim_wnn_imengine.h
index d323287..aa175ba 100644
--- a/scim-wnn/src/scim_wnn_imengine.h
+++ b/scim-wnn/src/scim_wnn_imengine.h
@@ -80,7 +80,7 @@
 
 protected:
     CommonLookupTable m_lookup_table;
-    Romkan m_rk;
+    PreEditor *m_preeditor;
     WnnConversion wnn;
     bool m_conversion;
     bool m_lookup;