diff --git a/BUILD.gn b/BUILD.gn
index 8a96f21..916ba25 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -930,7 +930,6 @@
       "xfa/fee/fx_wordbreak/fx_wordbreak_impl.cpp",
       "xfa/fee/fx_wordbreak/fx_wordbreak_impl.h",
       "xfa/fee/fx_wordbreak/fx_wordbreakdata.cpp",
-      "xfa/fee/ifde_txtedtbuf.h",
       "xfa/fee/ifde_txtedtengine.h",
       "xfa/fee/ifde_txtedtpage.h",
       "xfa/fgas/crt/fgas_algorithm.cpp",
diff --git a/xfa.gyp b/xfa.gyp
index 25b0646..aeef051 100644
--- a/xfa.gyp
+++ b/xfa.gyp
@@ -87,7 +87,6 @@
         "xfa/fee/fx_wordbreak/fx_wordbreakdata.cpp",
         "xfa/fee/fx_wordbreak/fx_wordbreak_impl.cpp",
         "xfa/fee/fx_wordbreak/fx_wordbreak_impl.h",
-        "xfa/fee/ifde_txtedtbuf.h",
         "xfa/fee/ifde_txtedtengine.h",
         "xfa/fee/ifde_txtedtpage.h",
         "xfa/fgas/crt/fgas_algorithm.cpp",
diff --git a/xfa/fee/fde_txtedtbuf.cpp b/xfa/fee/fde_txtedtbuf.cpp
index 4464a0f..988ca4a 100644
--- a/xfa/fee/fde_txtedtbuf.cpp
+++ b/xfa/fee/fde_txtedtbuf.cpp
@@ -8,9 +8,14 @@
 
 #include <algorithm>
 
-#include "xfa/fee/ifde_txtedtbuf.h"
 #include "xfa/fee/ifde_txtedtengine.h"
 
+namespace {
+
+const int kDefaultChunkSize = 1024;
+
+}  // namespace
+
 #define FDE_DEFCHUNKCOUNT 2
 #define FDE_TXTEDT_FORMATBLOCK_BGN 0xFFF9
 #define FDE_TXTEDT_FORMATBLOCK_END 0xFFFB
@@ -34,7 +39,7 @@
       return FALSE;
     }
     ASSERT(m_nCurChunk < m_pBuf->m_Chunks.GetSize());
-    CFDE_TxtEdtBuf::FDE_LPCHUNKHEADER lpChunk = NULL;
+    CFDE_TxtEdtBuf::FDE_CHUNKHEADER* lpChunk = nullptr;
     if (m_nCurIndex > 0) {
       m_nCurIndex--;
     } else {
@@ -55,14 +60,14 @@
       return FALSE;
     }
     ASSERT(m_nCurChunk < m_pBuf->m_Chunks.GetSize());
-    CFDE_TxtEdtBuf::FDE_LPCHUNKHEADER lpChunk = m_pBuf->m_Chunks[m_nCurChunk];
+    CFDE_TxtEdtBuf::FDE_CHUNKHEADER* lpChunk = m_pBuf->m_Chunks[m_nCurChunk];
     if (lpChunk->nUsed != (m_nCurIndex + 1)) {
       m_nCurIndex++;
     } else {
       int32_t nEnd = m_pBuf->m_Chunks.GetSize() - 1;
       while (m_nCurChunk < nEnd) {
         m_nCurChunk++;
-        CFDE_TxtEdtBuf::FDE_LPCHUNKHEADER lpChunkTemp =
+        CFDE_TxtEdtBuf::FDE_CHUNKHEADER* lpChunkTemp =
             m_pBuf->m_Chunks[m_nCurChunk];
         if (lpChunkTemp->nUsed > 0) {
           m_nCurIndex = 0;
@@ -103,8 +108,9 @@
   pIter->m_Alias = m_Alias;
   return pIter;
 }
-CFDE_TxtEdtBuf::CFDE_TxtEdtBuf(int32_t nDefChunkSize)
-    : m_nChunkSize(nDefChunkSize),
+
+CFDE_TxtEdtBuf::CFDE_TxtEdtBuf()
+    : m_nChunkSize(kDefaultChunkSize),
       m_nTotal(0),
       m_bChanged(FALSE),
       m_pAllocator(NULL) {
@@ -138,8 +144,9 @@
       ((nTextLength - 1) / m_nChunkSize + 1) - m_Chunks.GetSize();
   int32_t i = 0;
   for (i = 0; i < nNeedCount; i++) {
-    FDE_LPCHUNKHEADER lpChunk = (FDE_LPCHUNKHEADER)m_pAllocator->Alloc(
-        sizeof(FDE_CHUNKHEADER) + (m_nChunkSize - 1) * sizeof(FX_WCHAR));
+    FDE_CHUNKHEADER* lpChunk =
+        static_cast<FDE_CHUNKHEADER*>(m_pAllocator->Alloc(
+            sizeof(FDE_CHUNKHEADER) + (m_nChunkSize - 1) * sizeof(FX_WCHAR)));
     lpChunk->nUsed = 0;
     m_Chunks.Add(lpChunk);
   }
@@ -151,7 +158,7 @@
     if (nLeave < nCopyedLength) {
       nCopyedLength = nLeave;
     }
-    FDE_LPCHUNKHEADER lpChunk = m_Chunks[i];
+    FDE_CHUNKHEADER* lpChunk = m_Chunks[i];
     FXSYS_memcpy(lpChunk->wChars, lpSrcBuf, nCopyedLength * sizeof(FX_WCHAR));
     nLeave -= nCopyedLength;
     lpSrcBuf += nCopyedLength;
@@ -165,7 +172,7 @@
 }
 FX_WCHAR CFDE_TxtEdtBuf::GetCharByIndex(int32_t nIndex) const {
   ASSERT(nIndex >= 0 && nIndex < GetTextLength());
-  FDE_LPCHUNKHEADER pChunkHeader = NULL;
+  FDE_CHUNKHEADER* pChunkHeader = nullptr;
   int32_t nTotal = 0;
   int32_t nCount = m_Chunks.GetSize();
   int32_t i = 0;
@@ -188,7 +195,7 @@
   int32_t nCount = m_Chunks.GetSize();
   FX_WCHAR* lpDstBuf = wsText.GetBuffer(nLength);
   int32_t nChunkIndex = cp.nChunkIndex;
-  FDE_LPCHUNKHEADER lpChunkHeader = m_Chunks[nChunkIndex];
+  FDE_CHUNKHEADER* lpChunkHeader = m_Chunks[nChunkIndex];
   int32_t nCopyLength = lpChunkHeader->nUsed - cp.nCharIndex;
   FX_WCHAR* lpSrcBuf = lpChunkHeader->wChars + cp.nCharIndex;
   while (nLeave > 0) {
@@ -216,9 +223,10 @@
   Index2CP(nPos, cp);
   int32_t nLengthTemp = nLength;
   if (cp.nCharIndex != 0) {
-    FDE_LPCHUNKHEADER lpNewChunk = (FDE_LPCHUNKHEADER)m_pAllocator->Alloc(
-        sizeof(FDE_CHUNKHEADER) + (m_nChunkSize - 1) * sizeof(FX_WCHAR));
-    FDE_LPCHUNKHEADER lpChunk = m_Chunks[cp.nChunkIndex];
+    FDE_CHUNKHEADER* lpNewChunk =
+        static_cast<FDE_CHUNKHEADER*>(m_pAllocator->Alloc(
+            sizeof(FDE_CHUNKHEADER) + (m_nChunkSize - 1) * sizeof(FX_WCHAR)));
+    FDE_CHUNKHEADER* lpChunk = m_Chunks[cp.nChunkIndex];
     int32_t nCopy = lpChunk->nUsed - cp.nCharIndex;
     FXSYS_memcpy(lpNewChunk->wChars, lpChunk->wChars + cp.nCharIndex,
                  nCopy * sizeof(FX_WCHAR));
@@ -229,7 +237,7 @@
     cp.nCharIndex = 0;
   }
   if (cp.nChunkIndex != 0) {
-    FDE_LPCHUNKHEADER lpChunk = m_Chunks[cp.nChunkIndex - 1];
+    FDE_CHUNKHEADER* lpChunk = m_Chunks[cp.nChunkIndex - 1];
     if (lpChunk->nUsed != m_nChunkSize) {
       cp.nChunkIndex--;
       int32_t nFree = m_nChunkSize - lpChunk->nUsed;
@@ -243,8 +251,9 @@
     }
   }
   while (nLengthTemp > 0) {
-    FDE_LPCHUNKHEADER lpChunk = (FDE_LPCHUNKHEADER)m_pAllocator->Alloc(
-        sizeof(FDE_CHUNKHEADER) + (m_nChunkSize - 1) * sizeof(FX_WCHAR));
+    FDE_CHUNKHEADER* lpChunk =
+        static_cast<FDE_CHUNKHEADER*>(m_pAllocator->Alloc(
+            sizeof(FDE_CHUNKHEADER) + (m_nChunkSize - 1) * sizeof(FX_WCHAR)));
     ASSERT(lpChunk);
     int32_t nCopy = std::min(nLengthTemp, m_nChunkSize);
     FXSYS_memcpy(lpChunk->wChars, lpText, nCopy * sizeof(FX_WCHAR));
@@ -262,7 +271,7 @@
   FDE_CHUNKPLACE cpEnd;
   Index2CP(nIndex + nLength - 1, cpEnd);
   m_nTotal -= nLength;
-  FDE_LPCHUNKHEADER lpChunk = m_Chunks[cpEnd.nChunkIndex];
+  FDE_CHUNKHEADER* lpChunk = m_Chunks[cpEnd.nChunkIndex];
   int32_t nFirstPart = cpEnd.nCharIndex + 1;
   int32_t nMovePart = lpChunk->nUsed - nFirstPart;
   if (nMovePart != 0) {
@@ -316,7 +325,7 @@
   }
   int32_t i = 0;
   for (; i < nCount; i++) {
-    FDE_LPCHUNKHEADER lpChunk = m_Chunks[i];
+    FDE_CHUNKHEADER* lpChunk = m_Chunks[i];
     if (lpChunk->nUsed == 0) {
       m_pAllocator->Free(lpChunk);
       m_Chunks.RemoveAt(i);
@@ -324,11 +333,11 @@
       --nCount;
     }
   }
-  if (pPause != NULL && pPause->NeedToPauseNow()) {
+  if (pPause && pPause->NeedToPauseNow())
     return FALSE;
-  }
-  FDE_LPCHUNKHEADER lpPreChunk = m_Chunks[0];
-  FDE_LPCHUNKHEADER lpCurChunk = NULL;
+
+  FDE_CHUNKHEADER* lpPreChunk = m_Chunks[0];
+  FDE_CHUNKHEADER* lpCurChunk = nullptr;
   for (i = 1; i < nCount; i++) {
     lpCurChunk = m_Chunks[i];
     if (lpPreChunk->nUsed + lpCurChunk->nUsed <= m_nChunkSize) {
@@ -364,8 +373,8 @@
   m_pAllocator =
       FX_CreateAllocator(FX_ALLOCTYPE_Fixed, nDefChunkCount, nChunkLength);
   ASSERT(m_pAllocator);
-  FDE_LPCHUNKHEADER lpChunkHeader =
-      (FDE_LPCHUNKHEADER)m_pAllocator->Alloc(nChunkLength);
+  FDE_CHUNKHEADER* lpChunkHeader =
+      static_cast<FDE_CHUNKHEADER*>(m_pAllocator->Alloc(nChunkLength));
   ASSERT(lpChunkHeader);
   lpChunkHeader->nUsed = 0;
   m_Chunks.Add(lpChunkHeader);
diff --git a/xfa/fee/fde_txtedtbuf.h b/xfa/fee/fde_txtedtbuf.h
index 102217d..5d7de45 100644
--- a/xfa/fee/fde_txtedtbuf.h
+++ b/xfa/fee/fde_txtedtbuf.h
@@ -7,7 +7,6 @@
 #ifndef XFA_FEE_FDE_TXTEDTBUF_H_
 #define XFA_FEE_FDE_TXTEDTBUF_H_
 
-#include "xfa/fee/ifde_txtedtbuf.h"
 #include "xfa/fee/ifde_txtedtengine.h"
 #include "xfa/fgas/crt/fgas_memory.h"
 
@@ -36,47 +35,43 @@
   int32_t m_nIndex;
   FX_WCHAR m_Alias;
 };
-class CFDE_TxtEdtBuf : public IFDE_TxtEdtBuf {
+class CFDE_TxtEdtBuf {
+ public:
+  CFDE_TxtEdtBuf();
+
+  void Release();
+  FX_BOOL SetChunkSize(int32_t nChunkSize);
+  int32_t GetChunkSize() const;
+  int32_t GetTextLength() const;
+  void SetText(const CFX_WideString& wsText);
+  void GetText(CFX_WideString& wsText) const;
+  FX_WCHAR GetCharByIndex(int32_t nIndex) const;
+  void GetRange(CFX_WideString& wsText,
+                int32_t nBegin,
+                int32_t nCount = -1) const;
+
+  void Insert(int32_t nPos, const FX_WCHAR* lpText, int32_t nLength = 1);
+  void Delete(int32_t nIndex, int32_t nLength = 1);
+  void Clear(FX_BOOL bRelease = TRUE);
+
+  FX_BOOL Optimize(IFX_Pause* pPause = nullptr);
+
+ protected:
+  ~CFDE_TxtEdtBuf();
+
+ private:
   friend class CFDE_TxtEdtBufIter;
-  struct _FDE_CHUNKHEADER {
+
+  struct FDE_CHUNKHEADER {
     int32_t nUsed;
     FX_WCHAR wChars[1];
   };
-  typedef _FDE_CHUNKHEADER FDE_CHUNKHEADER;
-  typedef _FDE_CHUNKHEADER* FDE_LPCHUNKHEADER;
-  struct _FDE_CHUNKPLACE {
+
+  struct FDE_CHUNKPLACE {
     int32_t nChunkIndex;
     int32_t nCharIndex;
   };
-  typedef _FDE_CHUNKPLACE FDE_CHUNKPLACE;
-  typedef _FDE_CHUNKPLACE* FDE_LPCHUNKPLACE;
 
- public:
-  CFDE_TxtEdtBuf(int32_t nDefChunkSize = FDE_DEFCHUNKLENGTH);
-
-  virtual void Release();
-  virtual FX_BOOL SetChunkSize(int32_t nChunkSize);
-  virtual int32_t GetChunkSize() const;
-  virtual int32_t GetTextLength() const;
-  virtual void SetText(const CFX_WideString& wsText);
-  virtual void GetText(CFX_WideString& wsText) const;
-  virtual FX_WCHAR GetCharByIndex(int32_t nIndex) const;
-  virtual void GetRange(CFX_WideString& wsText,
-                        int32_t nBegine,
-                        int32_t nCount = -1) const;
-
-  virtual void Insert(int32_t nPos,
-                      const FX_WCHAR* lpText,
-                      int32_t nLength = 1);
-  virtual void Delete(int32_t nIndex, int32_t nLength = 1);
-  virtual void Clear(FX_BOOL bRelease = TRUE);
-
-  virtual FX_BOOL Optimize(IFX_Pause* pPause = NULL);
-
- protected:
-  virtual ~CFDE_TxtEdtBuf();
-
- private:
   void ResetChunkBuffer(int32_t nDefChunkCount, int32_t nChunkSize);
   int32_t CP2Index(const FDE_CHUNKPLACE& cp) const;
   void Index2CP(int32_t nIndex, FDE_CHUNKPLACE& cp) const;
diff --git a/xfa/fee/fde_txtedtengine.cpp b/xfa/fee/fde_txtedtengine.cpp
index 1dc03dc..812817f 100644
--- a/xfa/fee/fde_txtedtengine.cpp
+++ b/xfa/fee/fde_txtedtengine.cpp
@@ -9,11 +9,10 @@
 #include <algorithm>
 
 #include "xfa/fde/tto/fde_textout.h"
-#include "xfa/fee/fde_txtedtbuf.h"
 #include "xfa/fee/fde_txtedtparag.h"
-#include "xfa/fee/ifde_txtedtbuf.h"
 #include "xfa/fee/ifde_txtedtengine.h"
 #include "xfa/fee/ifde_txtedtpage.h"
+#include "xfa/fwl/basewidget/fwl_editimp.h"
 
 #define FDE_PAGEWIDTH_MAX 0xFFFF
 #define FDE_TXTPLATESIZE (1024 * 12)
@@ -21,9 +20,6 @@
 #define FDE_TXTEDT_DORECORD_INS 0
 #define FDE_TXTEDT_DORECORD_DEL 1
 
-IFDE_TxtEdtEngine* IFDE_TxtEdtEngine::Create() {
-  return new CFDE_TxtEdtEngine();
-}
 CFDE_TxtEdtEngine::CFDE_TxtEdtEngine()
     : m_pTextBreak(nullptr),
       m_nPageLineCount(20),
@@ -71,7 +67,7 @@
   m_bAutoLineEnd = (m_Param.nLineEnd == FDE_TXTEDIT_LINEEND_Auto);
   UpdateTxtBreak();
 }
-const FDE_TXTEDTPARAMS* CFDE_TxtEdtEngine::GetEditParams() const {
+FDE_TXTEDTPARAMS* CFDE_TxtEdtEngine::GetEditParams() {
   return &m_Param;
 }
 int32_t CFDE_TxtEdtEngine::CountPages() const {
@@ -329,7 +325,7 @@
     int32_t nTotalLength = GetTextBufLength();
     int32_t nCount = m_SelRangePtrArr.GetSize();
     for (int32_t i = 0; i < nCount; i++) {
-      FDE_LPTXTEDTSELRANGE lpSelRange = m_SelRangePtrArr.GetAt(i);
+      FDE_TXTEDTSELRANGE* lpSelRange = m_SelRangePtrArr.GetAt(i);
       nTotalLength -= lpSelRange->nCount;
     }
     int32_t nExpectLength = nTotalLength + nLength;
@@ -538,7 +534,7 @@
 }
 
 void CFDE_TxtEdtEngine::RemoveSelRange(int32_t nStart, int32_t nCount) {
-  FDE_LPTXTEDTSELRANGE lpTemp = NULL;
+  FDE_TXTEDTSELRANGE* lpTemp = nullptr;
   int32_t nRangeCount = m_SelRangePtrArr.GetSize();
   int32_t i = 0;
   for (i = 0; i < nRangeCount; i++) {
@@ -557,17 +553,17 @@
   }
   int32_t nSize = m_SelRangePtrArr.GetSize();
   if (nSize <= 0) {
-    FDE_LPTXTEDTSELRANGE lpSelRange = new FDE_TXTEDTSELRANGE;
+    FDE_TXTEDTSELRANGE* lpSelRange = new FDE_TXTEDTSELRANGE;
     lpSelRange->nStart = nStart;
     lpSelRange->nCount = nCount;
     m_SelRangePtrArr.Add(lpSelRange);
     m_Param.pEventSink->On_SelChanged(this);
     return;
   }
-  FDE_LPTXTEDTSELRANGE lpTemp = NULL;
+  FDE_TXTEDTSELRANGE* lpTemp = nullptr;
   lpTemp = m_SelRangePtrArr[nSize - 1];
   if (nStart >= lpTemp->nStart + lpTemp->nCount) {
-    FDE_LPTXTEDTSELRANGE lpSelRange = new FDE_TXTEDTSELRANGE;
+    FDE_TXTEDTSELRANGE* lpSelRange = new FDE_TXTEDTSELRANGE;
     lpSelRange->nStart = nStart;
     lpSelRange->nCount = nCount;
     m_SelRangePtrArr.Add(lpSelRange);
@@ -602,7 +598,7 @@
     }
   }
   if (nRangeCnt == 0) {
-    FDE_LPTXTEDTSELRANGE lpSelRange = new FDE_TXTEDTSELRANGE;
+    FDE_TXTEDTSELRANGE* lpSelRange = new FDE_TXTEDTSELRANGE;
     lpSelRange->nStart = nStart;
     lpSelRange->nCount = nCount;
     m_SelRangePtrArr.InsertAt(nRangeBgn, lpSelRange);
@@ -683,7 +679,7 @@
   for (; m_nLayoutPos < nCount; m_nLayoutPos++) {
     pParag = m_ParagPtrArray[m_nLayoutPos];
     pParag->CalcLines();
-    nLineCount += pParag->m_nLineCount;
+    nLineCount += pParag->GetLineCount();
     if ((pPause != NULL) && (nLineCount > m_nPageLineCount) &&
         pPause->NeedToPauseNow()) {
       m_nLineCount += nLineCount;
@@ -709,8 +705,8 @@
 FX_BOOL CFDE_TxtEdtEngine::Optimize(IFX_Pause* pPause) {
   return m_pTxtBuf->Optimize(pPause);
 }
-IFDE_TxtEdtBuf* CFDE_TxtEdtEngine::GetTextBuf() const {
-  return (IFDE_TxtEdtBuf*)m_pTxtBuf;
+CFDE_TxtEdtBuf* CFDE_TxtEdtEngine::GetTextBuf() const {
+  return m_pTxtBuf;
 }
 int32_t CFDE_TxtEdtEngine::GetTextBufLength() const {
   return m_pTxtBuf->GetTextLength() - 1;
@@ -727,7 +723,7 @@
 int32_t CFDE_TxtEdtEngine::CountParags() const {
   return m_ParagPtrArray.GetSize();
 }
-IFDE_TxtEdtParag* CFDE_TxtEdtEngine::GetParag(int32_t nParagIndex) const {
+CFDE_TxtEdtParag* CFDE_TxtEdtEngine::GetParag(int32_t nParagIndex) const {
   return m_ParagPtrArray[nParagIndex];
 }
 IFX_CharIter* CFDE_TxtEdtEngine::CreateCharIter() {
@@ -746,12 +742,12 @@
   int32_t i = nStartParag;
   for (; i < nCount; i++) {
     pParag = m_ParagPtrArray[i];
-    nLineTotal += pParag->m_nLineCount;
+    nLineTotal += pParag->GetLineCount();
     if (nLineTotal > nLineIndex) {
       break;
     }
   }
-  nStartLine = nLineTotal - pParag->m_nLineCount;
+  nStartLine = nLineTotal - pParag->GetLineCount();
   return i;
 }
 void CFDE_TxtEdtEngine::GetPreDeleteText(CFX_WideString& wsText,
@@ -812,14 +808,14 @@
   m_Param.pEventSink->On_PageUnload(this, m_nCaretPage, 0);
   int32_t nParagCount = m_ParagPtrArray.GetSize();
   int32_t i = 0;
-  for (i = ParagPos.nParagIndex + 1; i < nParagCount; i++) {
-    m_ParagPtrArray[i]->m_nCharStart += nLength;
-  }
+  for (i = ParagPos.nParagIndex + 1; i < nParagCount; i++)
+    m_ParagPtrArray[i]->IncrementStartIndex(nLength);
+
   CFDE_TxtEdtParag* pParag = m_ParagPtrArray[ParagPos.nParagIndex];
-  int32_t nReserveLineCount = pParag->m_nLineCount;
-  int32_t nReserveCharStart = pParag->m_nCharStart;
+  int32_t nReserveLineCount = pParag->GetLineCount();
+  int32_t nReserveCharStart = pParag->GetStartIndex();
   int32_t nLeavePart = ParagPos.nCharIndex;
-  int32_t nCutPart = pParag->m_nCharCount - ParagPos.nCharIndex;
+  int32_t nCutPart = pParag->GetTextLength() - ParagPos.nCharIndex;
   int32_t nTextStart = 0;
   FX_WCHAR wCurChar = L' ';
   const FX_WCHAR* lpPos = lpText;
@@ -829,30 +825,30 @@
     wCurChar = *lpPos;
     if (wCurChar == m_wLineEnd) {
       if (bFirst) {
-        pParag->m_nCharCount = nLeavePart + (i - nTextStart + 1);
-        pParag->m_nLineCount = -1;
-        nReserveCharStart += pParag->m_nCharCount;
+        pParag->SetTextLength(nLeavePart + (i - nTextStart + 1));
+        pParag->SetLineCount(-1);
+        nReserveCharStart += pParag->GetTextLength();
         bFirst = FALSE;
       } else {
         pParag = new CFDE_TxtEdtParag(this);
-        pParag->m_nLineCount = -1;
-        pParag->m_nCharCount = i - nTextStart + 1;
-        pParag->m_nCharStart = nReserveCharStart;
+        pParag->SetLineCount(-1);
+        pParag->SetTextLength(i - nTextStart + 1);
+        pParag->SetStartIndex(nReserveCharStart);
         m_ParagPtrArray.InsertAt(++nParagIndex, pParag);
-        nReserveCharStart += pParag->m_nCharCount;
+        nReserveCharStart += pParag->GetTextLength();
       }
       nTextStart = i + 1;
     }
   }
   if (bFirst) {
-    pParag->m_nCharCount += nLength;
-    pParag->m_nLineCount = -1;
+    pParag->IncrementTextLength(nLength);
+    pParag->SetLineCount(-1);
     bFirst = FALSE;
   } else {
     pParag = new CFDE_TxtEdtParag(this);
-    pParag->m_nLineCount = -1;
-    pParag->m_nCharCount = nLength - nTextStart + nCutPart;
-    pParag->m_nCharStart = nReserveCharStart;
+    pParag->SetLineCount(-1);
+    pParag->SetTextLength(nLength - nTextStart + nCutPart);
+    pParag->SetStartIndex(nReserveCharStart);
     m_ParagPtrArray.InsertAt(++nParagIndex, pParag);
   }
   m_pTxtBuf->Insert(nStart, lpText, nLength);
@@ -860,7 +856,7 @@
   for (i = ParagPos.nParagIndex; i <= nParagIndex; i++) {
     pParag = m_ParagPtrArray[i];
     pParag->CalcLines();
-    nTotalLineCount += pParag->m_nLineCount;
+    nTotalLineCount += pParag->GetLineCount();
   }
   m_nLineCount += nTotalLineCount - nReserveLineCount;
   m_Param.pEventSink->On_PageLoad(this, m_nCaretPage, 0);
@@ -879,7 +875,7 @@
   TextPos2ParagPos(nEnd, ParagPosEnd);
   CFDE_TxtEdtParag* pParag = m_ParagPtrArray[ParagPosEnd.nParagIndex];
   FX_BOOL bLastParag = FALSE;
-  if (ParagPosEnd.nCharIndex == pParag->m_nCharCount - 1) {
+  if (ParagPosEnd.nCharIndex == pParag->GetTextLength() - 1) {
     if (ParagPosEnd.nParagIndex < m_ParagPtrArray.GetSize() - 1) {
       ParagPosEnd.nParagIndex++;
     } else {
@@ -892,8 +888,8 @@
   for (i = ParagPosBgn.nParagIndex; i <= ParagPosEnd.nParagIndex; i++) {
     CFDE_TxtEdtParag* pParag = m_ParagPtrArray[i];
     pParag->CalcLines();
-    nTotalLineCount += pParag->m_nLineCount;
-    nTotalCharCount += pParag->m_nCharCount;
+    nTotalLineCount += pParag->GetLineCount();
+    nTotalCharCount += pParag->GetTextLength();
   }
   m_pTxtBuf->Delete(nStart, nCount);
   int32_t nNextParagIndex = (ParagPosBgn.nCharIndex == 0 && bLastParag)
@@ -905,14 +901,14 @@
   }
   if (!(bLastParag && ParagPosBgn.nCharIndex == 0)) {
     pParag = m_ParagPtrArray[ParagPosBgn.nParagIndex];
-    pParag->m_nCharCount = nTotalCharCount - nCount;
+    pParag->SetTextLength(nTotalCharCount - nCount);
     pParag->CalcLines();
-    nTotalLineCount -= pParag->m_nLineCount;
+    nTotalLineCount -= pParag->GetTextLength();
   }
   int32_t nParagCount = m_ParagPtrArray.GetSize();
-  for (i = nNextParagIndex; i < nParagCount; i++) {
-    m_ParagPtrArray[i]->m_nCharStart -= nCount;
-  }
+  for (i = nNextParagIndex; i < nParagCount; i++)
+    m_ParagPtrArray[i]->DecrementStartIndex(nCount);
+
   m_nLineCount -= nTotalLineCount;
   UpdatePages();
   int32_t nPageCount = CountPages();
@@ -964,9 +960,9 @@
     nIndex = pIter->GetAt();
     if (wChar == m_wLineEnd) {
       CFDE_TxtEdtParag* pParag = new CFDE_TxtEdtParag(this);
-      pParag->m_nCharStart = nParagStart;
-      pParag->m_nCharCount = nIndex - nParagStart + 1;
-      pParag->m_nLineCount = -1;
+      pParag->SetStartIndex(nParagStart);
+      pParag->SetTextLength(nIndex - nParagStart + 1);
+      pParag->SetLineCount(-1);
       m_ParagPtrArray.Add(pParag);
       nParagStart = nIndex + 1;
     }
@@ -1002,22 +998,22 @@
   int32_t i = 0;
   for (i = 0; i < nCount; i++) {
     pParag = m_ParagPtrArray[i];
-    if (pParag->m_nLineCount == -1) {
+    if (pParag->GetLineCount() == -1)
       pParag->CalcLines();
-    }
-    nLineCount += pParag->m_nLineCount;
+
+    nLineCount += pParag->GetLineCount();
   }
   m_nLineCount = nLineCount;
 }
 void CFDE_TxtEdtEngine::UpdatePages() {
-  if (m_nLineCount == 0) {
+  if (m_nLineCount == 0)
     return;
-  }
+
   int32_t nPageCount = (m_nLineCount - 1) / (m_nPageLineCount) + 1;
   int32_t nSize = m_PagePtrArray.GetSize();
-  if (nSize == nPageCount) {
+  if (nSize == nPageCount)
     return;
-  }
+
   if (nSize > nPageCount) {
     IFDE_TxtEdtPage* pPage = NULL;
     int32_t i = 0;
@@ -1028,7 +1024,6 @@
       }
       m_PagePtrArray.RemoveAt(i);
     }
-    m_Param.pEventSink->On_PageCountChanged(this);
     return;
   }
   if (nSize < nPageCount) {
@@ -1038,7 +1033,6 @@
       pPage = IFDE_TxtEdtPage::Create(this, i);
       m_PagePtrArray.Add(pPage);
     }
-    m_Param.pEventSink->On_PageCountChanged(this);
     return;
   }
 }
@@ -1244,25 +1238,24 @@
   int32_t i = 0;
   for (i = 0; i < nParagCount; i++) {
     pParag = m_ParagPtrArray[i];
-    if (pParag->m_nCharStart <= nIndex &&
-        nIndex < (pParag->m_nCharStart + pParag->m_nCharCount)) {
+    if (pParag->GetStartIndex() <= nIndex &&
+        nIndex < (pParag->GetStartIndex() + pParag->GetTextLength())) {
       break;
     }
-    nLineCount += pParag->m_nLineCount;
+    nLineCount += pParag->GetLineCount();
   }
   pParag->LoadParag();
   int32_t nLineStart = -1;
   int32_t nLineCharCount = -1;
-  for (i = 0; i < pParag->m_nLineCount; i++) {
+  for (i = 0; i < pParag->GetLineCount(); i++) {
     pParag->GetLineRange(i, nLineStart, nLineCharCount);
     if (nLineStart <= nIndex && nIndex < (nLineStart + nLineCharCount)) {
       break;
     }
   }
-  ASSERT(i < pParag->m_nLineCount);
+  ASSERT(i < pParag->GetLineCount());
   nLineCount += (i + 1);
   m_nCaretPage = (nLineCount - 1) / m_nPageLineCount + 1 - 1;
-  m_Param.pEventSink->On_PageChange(this, m_nCaretPage);
   pParag->UnloadParag();
   return m_nCaretPage;
 }
@@ -1276,9 +1269,9 @@
   while (nEnd > nBgn) {
     nMid = (nBgn + nEnd) / 2;
     CFDE_TxtEdtParag* pParag = m_ParagPtrArray[nMid];
-    if (nIndex < pParag->m_nCharStart) {
+    if (nIndex < pParag->GetStartIndex()) {
       nEnd = nMid - 1;
-    } else if (nIndex >= (pParag->m_nCharStart + pParag->m_nCharCount)) {
+    } else if (nIndex >= (pParag->GetStartIndex() + pParag->GetTextLength())) {
       nBgn = nMid + 1;
     } else {
       break;
@@ -1287,11 +1280,11 @@
   if (nBgn == nEnd) {
     nMid = nBgn;
   }
-  ASSERT(nIndex >= m_ParagPtrArray[nMid]->m_nCharStart &&
-         (nIndex < m_ParagPtrArray[nMid]->m_nCharStart +
-                       m_ParagPtrArray[nMid]->m_nCharCount));
+  ASSERT(nIndex >= m_ParagPtrArray[nMid]->GetStartIndex() &&
+         (nIndex < m_ParagPtrArray[nMid]->GetStartIndex() +
+                       m_ParagPtrArray[nMid]->GetTextLength()));
   ParagPos.nParagIndex = nMid;
-  ParagPos.nCharIndex = nIndex - m_ParagPtrArray[nMid]->m_nCharStart;
+  ParagPos.nCharIndex = nIndex - m_ParagPtrArray[nMid]->GetStartIndex();
 }
 int32_t CFDE_TxtEdtEngine::MoveForward(FX_BOOL& bBefore) {
   if (m_nCaret == m_pTxtBuf->GetTextLength() - 1) {
@@ -1343,7 +1336,6 @@
       } else {
         m_nCaretPage--;
       }
-      m_Param.pEventSink->On_PageChange(this, m_nCaretPage);
       ptCaret.x -= rtContent.left;
       IFDE_TxtEdtPage* pCurPage = GetPage(m_nCaretPage);
       ptCaret.x += pCurPage->GetContentsBox().right();
@@ -1357,7 +1349,6 @@
       }
       ptCaret.y -= rtContent.top;
       m_nCaretPage--;
-      m_Param.pEventSink->On_PageChange(this, m_nCaretPage);
       IFDE_TxtEdtPage* pCurPage = GetPage(m_nCaretPage);
       ptCaret.y += pCurPage->GetContentsBox().bottom();
     }
@@ -1387,7 +1378,6 @@
       } else {
         m_nCaretPage++;
       }
-      m_Param.pEventSink->On_PageChange(this, m_nCaretPage);
       ptCaret.x -= rtContent.right();
       IFDE_TxtEdtPage* pCurPage = GetPage(m_nCaretPage);
       ptCaret.x += pCurPage->GetContentsBox().left;
@@ -1401,7 +1391,6 @@
       }
       ptCaret.y -= rtContent.bottom();
       m_nCaretPage++;
-      m_Param.pEventSink->On_PageChange(this, m_nCaretPage);
       IFDE_TxtEdtPage* pCurPage = GetPage(m_nCaretPage);
       ptCaret.y += pCurPage->GetContentsBox().top;
     }
@@ -1414,7 +1403,7 @@
   TextPos2ParagPos(nIndex, ParagPos);
   CFDE_TxtEdtParag* pParag = m_ParagPtrArray[ParagPos.nParagIndex];
   pParag->LoadParag();
-  int32_t nLineCount = pParag->m_nLineCount;
+  int32_t nLineCount = pParag->GetLineCount();
   int32_t i = 0;
   int32_t nStart = 0;
   int32_t nCount = 0;
@@ -1434,7 +1423,7 @@
   TextPos2ParagPos(nIndex, ParagPos);
   CFDE_TxtEdtParag* pParag = m_ParagPtrArray[ParagPos.nParagIndex];
   pParag->LoadParag();
-  int32_t nLineCount = pParag->m_nLineCount;
+  int32_t nLineCount = pParag->GetLineCount();
   int32_t i = 0;
   int32_t nStart = 0;
   int32_t nCount = 0;
@@ -1469,7 +1458,7 @@
   FDE_TXTEDTPARAGPOS ParagPos;
   TextPos2ParagPos(nIndex, ParagPos);
   CFDE_TxtEdtParag* pParag = m_ParagPtrArray[ParagPos.nParagIndex];
-  UpdateCaretRect(pParag->m_nCharStart, TRUE);
+  UpdateCaretRect(pParag->GetStartIndex(), TRUE);
   return TRUE;
 }
 FX_BOOL CFDE_TxtEdtEngine::MoveParagEnd() {
@@ -1477,7 +1466,7 @@
   FDE_TXTEDTPARAGPOS ParagPos;
   TextPos2ParagPos(nIndex, ParagPos);
   CFDE_TxtEdtParag* pParag = m_ParagPtrArray[ParagPos.nParagIndex];
-  nIndex = pParag->m_nCharStart + pParag->m_nCharCount - 1;
+  nIndex = pParag->GetStartIndex() + pParag->GetTextLength() - 1;
   FX_WCHAR wChar = m_pTxtBuf->GetCharByIndex(nIndex);
   if (wChar == L'\n' && nIndex > 0) {
     nIndex--;
diff --git a/xfa/fee/fde_txtedtengine.h b/xfa/fee/fde_txtedtengine.h
index b122969..4671bf5 100644
--- a/xfa/fee/fde_txtedtengine.h
+++ b/xfa/fee/fde_txtedtengine.h
@@ -8,7 +8,7 @@
 #define XFA_FEE_FDE_TXTEDTENGINE_H_
 
 #include "core/fxcrt/include/fx_string.h"
-#include "xfa/fee/ifde_txtedtbuf.h"
+#include "xfa/fee/fde_txtedtbuf.h"
 #include "xfa/fee/ifde_txtedtengine.h"
 #include "xfa/fgas/layout/fgas_textbreak.h"
 
@@ -28,83 +28,64 @@
   virtual void Serialize(CFX_ByteString& bsDoRecord) const = 0;
 };
 
-class CFDE_TxtEdtEngine : public IFDE_TxtEdtEngine {
-  friend class CFDE_TxtEdtDoRecord_Insert;
-  friend class CFDE_TxtEdtDoRecord_DeleteRange;
-  friend class CFDE_TxtEdtPage;
-  struct _FDE_TXTEDTSELRANGE {
-    int32_t nStart;
-    int32_t nCount;
-  };
-  typedef _FDE_TXTEDTSELRANGE FDE_TXTEDTSELRANGE;
-  typedef _FDE_TXTEDTSELRANGE* FDE_LPTXTEDTSELRANGE;
-  struct _FDE_TXTEDTPARAGPOS {
-    int32_t nParagIndex;
-    int32_t nCharIndex;
-  };
-  typedef _FDE_TXTEDTPARAGPOS FDE_TXTEDTPARAGPOS;
-  typedef _FDE_TXTEDTPARAGPOS* FDE_LPTXTEDTPARAGPOS;
-
+class CFDE_TxtEdtEngine {
  public:
   CFDE_TxtEdtEngine();
-  virtual void Release();
 
-  virtual void SetEditParams(const FDE_TXTEDTPARAMS& params);
-  virtual const FDE_TXTEDTPARAMS* GetEditParams() const;
+  void Release();
 
-  virtual int32_t CountPages() const;
-  virtual IFDE_TxtEdtPage* GetPage(int32_t nIndex);
+  void SetEditParams(const FDE_TXTEDTPARAMS& params);
+  FDE_TXTEDTPARAMS* GetEditParams();
 
-  virtual FX_BOOL SetBufChunkSize(int32_t nChunkSize);
-  virtual void SetTextByStream(IFX_Stream* pStream);
-  virtual void SetText(const CFX_WideString& wsText);
-  virtual int32_t GetTextLength() const;
-  virtual void GetText(CFX_WideString& wsText,
-                       int32_t nStart,
-                       int32_t nCount = -1);
-  virtual void ClearText();
+  int32_t CountPages() const;
+  IFDE_TxtEdtPage* GetPage(int32_t nIndex);
 
-  virtual int32_t GetCaretRect(CFX_RectF& rtCaret) const;
-  virtual int32_t GetCaretPos() const;
-  virtual int32_t SetCaretPos(int32_t nIndex, FX_BOOL bBefore);
-  virtual int32_t MoveCaretPos(FDE_TXTEDTMOVECARET eMoveCaret,
-                               FX_BOOL bShift = FALSE,
-                               FX_BOOL bCtrl = FALSE);
-  virtual void Lock();
-  virtual void Unlock();
-  virtual FX_BOOL IsLocked() const;
+  FX_BOOL SetBufChunkSize(int32_t nChunkSize);
+  void SetTextByStream(IFX_Stream* pStream);
+  void SetText(const CFX_WideString& wsText);
+  int32_t GetTextLength() const;
+  void GetText(CFX_WideString& wsText, int32_t nStart, int32_t nCount = -1);
+  void ClearText();
 
-  virtual int32_t Insert(int32_t nStart,
-                         const FX_WCHAR* lpText,
-                         int32_t nLength);
-  virtual int32_t Delete(int32_t nStart, FX_BOOL bBackspace = FALSE);
-  virtual int32_t DeleteRange(int32_t nStart, int32_t nCount = -1);
-  virtual int32_t Replace(int32_t nStart,
-                          int32_t nLength,
-                          const CFX_WideString& wsReplace);
+  int32_t GetCaretRect(CFX_RectF& rtCaret) const;
+  int32_t GetCaretPos() const;
+  int32_t SetCaretPos(int32_t nIndex, FX_BOOL bBefore);
+  int32_t MoveCaretPos(FDE_TXTEDTMOVECARET eMoveCaret,
+                       FX_BOOL bShift = FALSE,
+                       FX_BOOL bCtrl = FALSE);
+  void Lock();
+  void Unlock();
+  FX_BOOL IsLocked() const;
 
-  virtual void SetLimit(int32_t nLimit);
-  virtual void SetAliasChar(FX_WCHAR wcAlias);
+  int32_t Insert(int32_t nStart, const FX_WCHAR* lpText, int32_t nLength);
+  int32_t Delete(int32_t nStart, FX_BOOL bBackspace = FALSE);
+  int32_t DeleteRange(int32_t nStart, int32_t nCount = -1);
+  int32_t Replace(int32_t nStart,
+                  int32_t nLength,
+                  const CFX_WideString& wsReplace);
+
+  void SetLimit(int32_t nLimit);
+  void SetAliasChar(FX_WCHAR wcAlias);
 
   void RemoveSelRange(int32_t nStart, int32_t nCount = -1);
 
-  virtual void AddSelRange(int32_t nStart, int32_t nCount = -1);
-  virtual int32_t CountSelRanges();
-  virtual int32_t GetSelRange(int32_t nIndex, int32_t& nStart);
-  virtual void ClearSelection();
+  void AddSelRange(int32_t nStart, int32_t nCount = -1);
+  int32_t CountSelRanges();
+  int32_t GetSelRange(int32_t nIndex, int32_t& nStart);
+  void ClearSelection();
 
-  virtual FX_BOOL Redo(const CFX_ByteStringC& bsRedo);
-  virtual FX_BOOL Undo(const CFX_ByteStringC& bsUndo);
+  FX_BOOL Redo(const CFX_ByteStringC& bsRedo);
+  FX_BOOL Undo(const CFX_ByteStringC& bsUndo);
 
-  virtual int32_t StartLayout();
-  virtual int32_t DoLayout(IFX_Pause* pPause);
-  virtual void EndLayout();
+  int32_t StartLayout();
+  int32_t DoLayout(IFX_Pause* pPause);
+  void EndLayout();
 
-  virtual FX_BOOL Optimize(IFX_Pause* pPause = NULL);
-  virtual int32_t CountParags() const;
-  virtual IFDE_TxtEdtParag* GetParag(int32_t nParagIndex) const;
-  virtual IFX_CharIter* CreateCharIter();
-  IFDE_TxtEdtBuf* GetTextBuf() const;
+  FX_BOOL Optimize(IFX_Pause* pPause = NULL);
+  int32_t CountParags() const;
+  CFDE_TxtEdtParag* GetParag(int32_t nParagIndex) const;
+  IFX_CharIter* CreateCharIter();
+  CFDE_TxtEdtBuf* GetTextBuf() const;
   int32_t GetTextBufLength() const;
   CFX_TxtBreak* GetTextBreak() const;
   int32_t GetLineCount() const;
@@ -117,9 +98,23 @@
   FX_WCHAR GetAliasChar() const { return m_wcAliasChar; }
 
  protected:
-  virtual ~CFDE_TxtEdtEngine();
+  ~CFDE_TxtEdtEngine();
 
  private:
+  friend class CFDE_TxtEdtDoRecord_Insert;
+  friend class CFDE_TxtEdtDoRecord_DeleteRange;
+  friend class CFDE_TxtEdtPage;
+
+  struct FDE_TXTEDTSELRANGE {
+    int32_t nStart;
+    int32_t nCount;
+  };
+
+  struct FDE_TXTEDTPARAGPOS {
+    int32_t nParagIndex;
+    int32_t nCharIndex;
+  };
+
   void Inner_Insert(int32_t nStart, const FX_WCHAR* lpText, int32_t nLength);
   void GetPreDeleteText(CFX_WideString& wsText,
                         int32_t nIndex,
@@ -173,12 +168,12 @@
   FX_BOOL IsSelect();
   void DeleteSelect();
 
-  IFDE_TxtEdtBuf* m_pTxtBuf;
+  CFDE_TxtEdtBuf* m_pTxtBuf;
   CFX_TxtBreak* m_pTextBreak;
   FDE_TXTEDTPARAMS m_Param;
   CFX_ArrayTemplate<IFDE_TxtEdtPage*> m_PagePtrArray;
   CFX_ArrayTemplate<CFDE_TxtEdtParag*> m_ParagPtrArray;
-  CFX_ArrayTemplate<FDE_LPTXTEDTSELRANGE> m_SelRangePtrArr;
+  CFX_ArrayTemplate<FDE_TXTEDTSELRANGE*> m_SelRangePtrArr;
   int32_t m_nPageLineCount;
   int32_t m_nLineCount;
   int32_t m_nAnchorPos;
diff --git a/xfa/fee/fde_txtedtpage.cpp b/xfa/fee/fde_txtedtpage.cpp
index c50f66e..d46e1a1 100644
--- a/xfa/fee/fde_txtedtpage.cpp
+++ b/xfa/fee/fde_txtedtpage.cpp
@@ -12,13 +12,12 @@
 #include "xfa/fee/fde_txtedtengine.h"
 #include "xfa/fee/fde_txtedtparag.h"
 #include "xfa/fee/fx_wordbreak/fx_wordbreak.h"
-#include "xfa/fee/ifde_txtedtbuf.h"
 #include "xfa/fee/ifde_txtedtengine.h"
 #include "xfa/fee/ifde_txtedtpage.h"
 
 #define FDE_TXTEDT_TOLERANCE 0.1f
 
-IFDE_TxtEdtPage* IFDE_TxtEdtPage::Create(IFDE_TxtEdtEngine* pEngine,
+IFDE_TxtEdtPage* IFDE_TxtEdtPage::Create(CFDE_TxtEdtEngine* pEngine,
                                          int32_t nIndex) {
   return (IFDE_TxtEdtPage*)new CFDE_TxtEdtPage(pEngine, nIndex);
 }
@@ -122,7 +121,7 @@
   tr.wLineBreakChar = pTextParams->wLineBreakChar;
   return pEngine->GetTextBreak()->GetCharRects(&tr, rtArray, bBBox);
 }
-CFDE_TxtEdtPage::CFDE_TxtEdtPage(IFDE_TxtEdtEngine* pEngine, int32_t nPageIndex)
+CFDE_TxtEdtPage::CFDE_TxtEdtPage(CFDE_TxtEdtEngine* pEngine, int32_t nPageIndex)
     : m_pIter(nullptr),
       m_pTextSet(nullptr),
       m_pBgnParag(nullptr),
@@ -151,8 +150,8 @@
 void CFDE_TxtEdtPage::Release() {
   delete this;
 }
-IFDE_TxtEdtEngine* CFDE_TxtEdtPage::GetEngine() const {
-  return (IFDE_TxtEdtEngine*)m_pEditEngine;
+CFDE_TxtEdtEngine* CFDE_TxtEdtPage::GetEngine() const {
+  return m_pEditEngine;
 }
 FDE_VISUALOBJTYPE CFDE_TxtEdtPage::GetType() {
   return FDE_VISUALOBJ_Text;
@@ -349,7 +348,7 @@
   if (m_nRefCount < 0) {
     return -1;
   }
-  IFDE_TxtEdtBuf* pBuf = m_pEditEngine->GetTextBuf();
+  CFDE_TxtEdtBuf* pBuf = m_pEditEngine->GetTextBuf();
   FX_BOOL bBefore;
   int32_t nIndex = GetCharIndex(fPoint, bBefore);
   if (nIndex == m_pEditEngine->GetTextBufLength()) {
@@ -375,7 +374,7 @@
     m_nRefCount++;
     return m_nRefCount;
   }
-  IFDE_TxtEdtBuf* pBuf = m_pEditEngine->GetTextBuf();
+  CFDE_TxtEdtBuf* pBuf = m_pEditEngine->GetTextBuf();
   const FDE_TXTEDTPARAMS* pParams = m_pEditEngine->GetEditParams();
   if (m_pIter != NULL) {
     m_pIter->Release();
diff --git a/xfa/fee/fde_txtedtpage.h b/xfa/fee/fde_txtedtpage.h
index 13a444f..8ac104c 100644
--- a/xfa/fee/fde_txtedtpage.h
+++ b/xfa/fee/fde_txtedtpage.h
@@ -97,11 +97,11 @@
 
 class CFDE_TxtEdtPage : public IFDE_TxtEdtPage {
  public:
-  CFDE_TxtEdtPage(IFDE_TxtEdtEngine* pEngine, int32_t nLineIndex);
+  CFDE_TxtEdtPage(CFDE_TxtEdtEngine* pEngine, int32_t nLineIndex);
 
   // IFDE_TxtEditPage:
   void Release() override;
-  IFDE_TxtEdtEngine* GetEngine() const override;
+  CFDE_TxtEdtEngine* GetEngine() const override;
   int32_t GetCharRect(int32_t nIndex,
                       CFX_RectF& rect,
                       FX_BOOL bBBox = FALSE) const override;
diff --git a/xfa/fee/fde_txtedtparag.cpp b/xfa/fee/fde_txtedtparag.cpp
index 0aae327..f49f431 100644
--- a/xfa/fee/fde_txtedtparag.cpp
+++ b/xfa/fee/fde_txtedtparag.cpp
@@ -9,7 +9,6 @@
 #include "xfa/fee/fde_txtedtbuf.h"
 #include "xfa/fee/fde_txtedtengine.h"
 #include "xfa/fee/fx_wordbreak/fx_wordbreak.h"
-#include "xfa/fee/ifde_txtedtbuf.h"
 #include "xfa/fee/ifde_txtedtengine.h"
 #include "xfa/fgas/layout/fgas_textbreak.h"
 
@@ -32,7 +31,7 @@
     return;
   }
   CFX_TxtBreak* pTxtBreak = m_pEngine->GetTextBreak();
-  IFDE_TxtEdtBuf* pTxtBuf = m_pEngine->GetTextBuf();
+  CFDE_TxtEdtBuf* pTxtBuf = m_pEngine->GetTextBuf();
   const FDE_TXTEDTPARAMS* pParam = m_pEngine->GetEditParams();
   FX_WCHAR wcAlias = 0;
   if (pParam->dwMode & FDE_TEXTEDITMODE_Password) {
@@ -102,7 +101,7 @@
 }
 void CFDE_TxtEdtParag::CalcLines() {
   CFX_TxtBreak* pTxtBreak = m_pEngine->GetTextBreak();
-  IFDE_TxtEdtBuf* pTxtBuf = m_pEngine->GetTextBuf();
+  CFDE_TxtEdtBuf* pTxtBuf = m_pEngine->GetTextBuf();
   IFX_CharIter* pIter = new CFDE_TxtEdtBufIter((CFDE_TxtEdtBuf*)pTxtBuf);
   int32_t nCount = 0;
   uint32_t dwBreakStatus = FX_TXTBREAK_None;
diff --git a/xfa/fee/fde_txtedtparag.h b/xfa/fee/fde_txtedtparag.h
index 39921d5..24ecbc7 100644
--- a/xfa/fee/fde_txtedtparag.h
+++ b/xfa/fee/fde_txtedtparag.h
@@ -7,29 +7,35 @@
 #ifndef XFA_FEE_FDE_TXTEDTPARAG_H_
 #define XFA_FEE_FDE_TXTEDTPARAG_H_
 
-#include "xfa/fee/ifde_txtedtengine.h"
+#include <stdint.h>
 
 class CFDE_TxtEdtEngine;
 
-class CFDE_TxtEdtParag : public IFDE_TxtEdtParag {
+class CFDE_TxtEdtParag {
  public:
   explicit CFDE_TxtEdtParag(CFDE_TxtEdtEngine* pEngine);
   ~CFDE_TxtEdtParag();
 
-  virtual int32_t GetTextLength() const { return m_nCharCount; }
-  virtual int32_t GetStartIndex() const { return m_nCharStart; }
-  virtual int32_t CountLines() const { return m_nLineCount; }
-  virtual void GetLineRange(int32_t nLineIndex,
-                            int32_t& nStart,
-                            int32_t& nCount) const;
+  int32_t GetTextLength() const { return m_nCharCount; }
+  int32_t GetStartIndex() const { return m_nCharStart; }
+  int32_t GetLineCount() const { return m_nLineCount; }
+
+  void SetTextLength(int32_t len) { m_nCharCount = len; }
+  void IncrementTextLength(int32_t len) { m_nCharCount += len; }
+  void SetStartIndex(int32_t idx) { m_nCharStart = idx; }
+  void IncrementStartIndex(int32_t val) { m_nCharStart += val; }
+  void DecrementStartIndex(int32_t val) { m_nCharStart -= val; }
+  void SetLineCount(int32_t count) { m_nLineCount = count; }
+
+  void GetLineRange(int32_t nLineIndex, int32_t& nStart, int32_t& nCount) const;
   void LoadParag();
   void UnloadParag();
   void CalcLines();
+
+ private:
   int32_t m_nCharStart;
   int32_t m_nCharCount;
   int32_t m_nLineCount;
-
- private:
   void* m_lpData;
   CFDE_TxtEdtEngine* m_pEngine;
 };
diff --git a/xfa/fee/ifde_txtedtbuf.h b/xfa/fee/ifde_txtedtbuf.h
deleted file mode 100644
index db744b1..0000000
--- a/xfa/fee/ifde_txtedtbuf.h
+++ /dev/null
@@ -1,39 +0,0 @@
-// Copyright 2014 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#ifndef XFA_FEE_IFDE_TXTEDTBUF_H_
-#define XFA_FEE_IFDE_TXTEDTBUF_H_
-
-#include "core/fxcrt/include/fx_basic.h"
-
-#define FDE_DEFCHUNKLENGTH (1024)
-
-class IFDE_TxtEdtBuf {
- public:
-  virtual ~IFDE_TxtEdtBuf() {}
-  virtual void Release() = 0;
-
-  virtual FX_BOOL SetChunkSize(int32_t nChunkSize) = 0;
-  virtual int32_t GetChunkSize() const = 0;
-  virtual int32_t GetTextLength() const = 0;
-  virtual void SetText(const CFX_WideString& wsText) = 0;
-  virtual void GetText(CFX_WideString& wsText) const = 0;
-  virtual FX_WCHAR GetCharByIndex(int32_t nIndex) const = 0;
-  virtual void GetRange(CFX_WideString& wsText,
-                        int32_t nBegin,
-                        int32_t nCount = -1) const = 0;
-
-  virtual void Insert(int32_t nPos,
-                      const FX_WCHAR* lpText,
-                      int32_t nLength = 1) = 0;
-  virtual void Delete(int32_t nIndex, int32_t nLength = 1) = 0;
-
-  virtual void Clear(FX_BOOL bRelease = TRUE) = 0;
-
-  virtual FX_BOOL Optimize(IFX_Pause* pPause = NULL) = 0;
-};
-
-#endif  // XFA_FEE_IFDE_TXTEDTBUF_H_
diff --git a/xfa/fee/ifde_txtedtengine.h b/xfa/fee/ifde_txtedtengine.h
index e03a53e..1855f6f 100644
--- a/xfa/fee/ifde_txtedtengine.h
+++ b/xfa/fee/ifde_txtedtengine.h
@@ -10,10 +10,9 @@
 #include "core/fxge/include/fx_dib.h"
 #include "xfa/fgas/font/fgas_font.h"
 
+class CFDE_TxtEdtEngine;
+class CFWL_EditImp;
 class IFDE_TxtEdtPage;
-class IFDE_TxtEdtEngine;
-class IFDE_TxtEdtEventSink;
-class IFDE_TxtEdtParag;
 
 typedef struct FDE_HTXTEDTFIND_ { void* pData; } * FDE_HTXTEDTFIND;
 
@@ -62,6 +61,7 @@
   MC_Home,
   MC_End,
 };
+
 enum FDE_TXTEDT_MODIFY_RET {
   FDE_TXTEDT_MODIFY_RET_F_Tab = -6,
   FDE_TXTEDT_MODIFY_RET_F_Locked = -5,
@@ -75,21 +75,23 @@
   FDE_TXTEDT_MODIFY_RET_S_Empty = 3,
   FDE_TXTEDT_MODIFY_RET_T_Tab = 4,
 };
+
 enum FDE_TXTEDIT_LINEEND {
   FDE_TXTEDIT_LINEEND_Auto,
   FDE_TXTEDIT_LINEEND_CRLF,
   FDE_TXTEDIT_LINEEND_CR,
   FDE_TXTEDIT_LINEEND_LF,
 };
-struct _FDE_TXTEDTPARAMS {
-  _FDE_TXTEDTPARAMS()
+
+struct FDE_TXTEDTPARAMS {
+  FDE_TXTEDTPARAMS()
       : fPlateWidth(0),
         fPlateHeight(0),
         nLineCount(0),
         dwLayoutStyles(0),
         dwAlignment(0),
         dwMode(0),
-        pFont(NULL),
+        pFont(nullptr),
         fFontSize(10.0f),
         dwFontColor(0xff000000),
         fLineSpace(10.0f),
@@ -101,7 +103,8 @@
         nLineEnd(0),
         nHorzScale(100),
         fCharSpace(0),
-        pEventSink(NULL) {}
+        pEventSink(nullptr) {}
+
   FX_FLOAT fPlateWidth;
   FX_FLOAT fPlateHeight;
   int32_t nLineCount;
@@ -120,56 +123,22 @@
   int32_t nLineEnd;
   int32_t nHorzScale;
   FX_FLOAT fCharSpace;
-  IFDE_TxtEdtEventSink* pEventSink;
+  CFWL_EditImp* pEventSink;
 };
-typedef _FDE_TXTEDTPARAMS FDE_TXTEDTPARAMS;
-typedef _FDE_TXTEDTPARAMS* FDE_LPTXTEDTPARAMS;
+
 enum FDE_TXTEDT_TEXTCHANGE_TYPE {
   FDE_TXTEDT_TEXTCHANGE_TYPE_Insert = 0,
   FDE_TXTEDT_TEXTCHANGE_TYPE_Delete,
   FDE_TXTEDT_TEXTCHANGE_TYPE_Replace,
 };
-struct _FDE_TXTEDT_TEXTCHANGE_INFO {
+
+struct FDE_TXTEDT_TEXTCHANGE_INFO {
   int32_t nChangeType;
   CFX_WideString wsInsert;
   CFX_WideString wsDelete;
   CFX_WideString wsPrevText;
 };
-typedef _FDE_TXTEDT_TEXTCHANGE_INFO FDE_TXTEDT_TEXTCHANGE_INFO;
-typedef _FDE_TXTEDT_TEXTCHANGE_INFO* FDE_LPTXTEDT_TEXTCHANGE_INFO;
-class IFDE_TxtEdtEventSink {
- public:
-  virtual ~IFDE_TxtEdtEventSink() {}
-  virtual void On_CaretChanged(IFDE_TxtEdtEngine* pEdit,
-                               int32_t nPage,
-                               FX_BOOL bVisible = TRUE) = 0;
-  virtual void On_TextChanged(IFDE_TxtEdtEngine* pEdit,
-                              FDE_TXTEDT_TEXTCHANGE_INFO& ChangeInfo) = 0;
-  virtual void On_PageCountChanged(IFDE_TxtEdtEngine* pEdit) = 0;
-  virtual void On_SelChanged(IFDE_TxtEdtEngine* pEdit) = 0;
-  virtual FX_BOOL On_PageLoad(IFDE_TxtEdtEngine* pEdit,
-                              int32_t nPageIndex,
-                              int32_t nPurpose) = 0;
-  virtual FX_BOOL On_PageUnload(IFDE_TxtEdtEngine* pEdit,
-                                int32_t nPageIndex,
-                                int32_t nPurpose) = 0;
-  virtual FX_BOOL On_PageChange(IFDE_TxtEdtEngine* pEdit,
-                                int32_t nPageIndex) = 0;
-  virtual void On_AddDoRecord(IFDE_TxtEdtEngine* pEdit,
-                              const CFX_ByteStringC& bsDoRecord) = 0;
-  virtual FX_BOOL On_ValidateField(IFDE_TxtEdtEngine* pEdit,
-                                   int32_t nBlockIndex,
-                                   int32_t nFieldIndex,
-                                   const CFX_WideString& wsFieldText,
-                                   int32_t nCharIndex) = 0;
-  virtual FX_BOOL On_ValidateBlock(IFDE_TxtEdtEngine* pEdit,
-                                   int32_t nBlockIndex) = 0;
-  virtual FX_BOOL On_GetBlockFormatText(IFDE_TxtEdtEngine* pEdit,
-                                        int32_t nBlockIndex,
-                                        CFX_WideString& wsBlockText) = 0;
-  virtual FX_BOOL On_Validate(IFDE_TxtEdtEngine* pEdit,
-                              CFX_WideString& wsText) = 0;
-};
+
 class IFX_CharIter {
  public:
   virtual ~IFX_CharIter() {}
@@ -181,73 +150,5 @@
   virtual FX_BOOL IsEOF(FX_BOOL bTail = TRUE) const = 0;
   virtual IFX_CharIter* Clone() = 0;
 };
-class IFDE_TxtEdtEngine {
- public:
-  static IFDE_TxtEdtEngine* Create();
-
-  virtual ~IFDE_TxtEdtEngine() {}
-  virtual void Release() = 0;
-  virtual void SetEditParams(const FDE_TXTEDTPARAMS& params) = 0;
-  virtual const FDE_TXTEDTPARAMS* GetEditParams() const = 0;
-
-  virtual int32_t CountPages() const = 0;
-  virtual IFDE_TxtEdtPage* GetPage(int32_t nIndex) = 0;
-  virtual FX_BOOL SetBufChunkSize(int32_t nChunkSize) = 0;
-  virtual void SetTextByStream(IFX_Stream* pStream) = 0;
-  virtual void SetText(const CFX_WideString& wsText) = 0;
-  virtual int32_t GetTextLength() const = 0;
-  virtual void GetText(CFX_WideString& wsText,
-                       int32_t nStart,
-                       int32_t nCount = -1) = 0;
-  virtual void ClearText() = 0;
-
-  virtual int32_t GetCaretRect(CFX_RectF& rtCaret) const = 0;
-  virtual int32_t GetCaretPos() const = 0;
-  virtual int32_t SetCaretPos(int32_t nIndex, FX_BOOL bBefore = TRUE) = 0;
-  virtual int32_t MoveCaretPos(FDE_TXTEDTMOVECARET eMoveCaret,
-                               FX_BOOL bShift = FALSE,
-                               FX_BOOL bCtrl = FALSE) = 0;
-
-  virtual void Lock() = 0;
-  virtual void Unlock() = 0;
-  virtual FX_BOOL IsLocked() const = 0;
-
-  virtual int32_t Insert(int32_t nStart,
-                         const FX_WCHAR* lpText,
-                         int32_t nLength) = 0;
-  virtual int32_t Delete(int32_t nStart, FX_BOOL bBackspace = FALSE) = 0;
-  virtual int32_t DeleteRange(int32_t nStart, int32_t nCount = -1) = 0;
-  virtual int32_t Replace(int32_t nStart,
-                          int32_t nLength,
-                          const CFX_WideString& wsReplace) = 0;
-  virtual void SetLimit(int32_t nLimit) = 0;
-  virtual void SetAliasChar(FX_WCHAR wAlias) = 0;
-  virtual void AddSelRange(int32_t nStart, int32_t nCount = -1) = 0;
-  virtual int32_t CountSelRanges() = 0;
-  virtual int32_t GetSelRange(int32_t nIndex, int32_t& nStart) = 0;
-  virtual void ClearSelection() = 0;
-
-  virtual FX_BOOL Redo(const CFX_ByteStringC& bsRedo) = 0;
-  virtual FX_BOOL Undo(const CFX_ByteStringC& bsUndo) = 0;
-
-  virtual int32_t StartLayout() = 0;
-  virtual int32_t DoLayout(IFX_Pause* pPause) = 0;
-  virtual void EndLayout() = 0;
-
-  virtual FX_BOOL Optimize(IFX_Pause* pPause = NULL) = 0;
-  virtual int32_t CountParags() const = 0;
-  virtual IFDE_TxtEdtParag* GetParag(int32_t nParagIndex) const = 0;
-  virtual IFX_CharIter* CreateCharIter() = 0;
-};
-class IFDE_TxtEdtParag {
- public:
-  virtual ~IFDE_TxtEdtParag() {}
-  virtual int32_t GetTextLength() const = 0;
-  virtual int32_t GetStartIndex() const = 0;
-  virtual int32_t CountLines() const = 0;
-  virtual void GetLineRange(int32_t nLineIndex,
-                            int32_t& nStart,
-                            int32_t& nCount) const = 0;
-};
 
 #endif  // XFA_FEE_IFDE_TXTEDTENGINE_H_
diff --git a/xfa/fee/ifde_txtedtpage.h b/xfa/fee/ifde_txtedtpage.h
index 0945688..695b442 100644
--- a/xfa/fee/ifde_txtedtpage.h
+++ b/xfa/fee/ifde_txtedtpage.h
@@ -11,14 +11,15 @@
 #include "xfa/fde/fde_visualset.h"
 #include "xfa/fgas/layout/fgas_textbreak.h"
 
-class IFDE_TxtEdtEngine;
+class CFDE_TxtEdtEngine;
+
 class IFDE_TxtEdtPage : public IFDE_CanvasSet, public IFX_TxtAccess {
  public:
-  static IFDE_TxtEdtPage* Create(IFDE_TxtEdtEngine* pEngine, int32_t nIndex);
+  static IFDE_TxtEdtPage* Create(CFDE_TxtEdtEngine* pEngine, int32_t nIndex);
 
   virtual void Release() = 0;
 
-  virtual IFDE_TxtEdtEngine* GetEngine() const = 0;
+  virtual CFDE_TxtEdtEngine* GetEngine() const = 0;
   virtual int32_t GetCharRect(int32_t nIndex,
                               CFX_RectF& rect,
                               FX_BOOL bBBox = FALSE) const = 0;
diff --git a/xfa/fwl/basewidget/fwl_comboboximp.cpp b/xfa/fwl/basewidget/fwl_comboboximp.cpp
index 60794da4..55f0910 100644
--- a/xfa/fwl/basewidget/fwl_comboboximp.cpp
+++ b/xfa/fwl/basewidget/fwl_comboboximp.cpp
@@ -7,6 +7,7 @@
 #include "xfa/fwl/basewidget/fwl_comboboximp.h"
 
 #include "xfa/fde/tto/fde_textout.h"
+#include "xfa/fee/fde_txtedtengine.h"
 #include "xfa/fwl/basewidget/fwl_editimp.h"
 #include "xfa/fwl/basewidget/fwl_formproxyimp.h"
 #include "xfa/fwl/basewidget/fwl_listboximp.h"
diff --git a/xfa/fwl/basewidget/fwl_editimp.cpp b/xfa/fwl/basewidget/fwl_editimp.cpp
index 17aef3b..29fab8b 100644
--- a/xfa/fwl/basewidget/fwl_editimp.cpp
+++ b/xfa/fwl/basewidget/fwl_editimp.cpp
@@ -11,6 +11,7 @@
 
 #include "xfa/fde/fde_gedevice.h"
 #include "xfa/fde/fde_render.h"
+#include "xfa/fee/fde_txtedtengine.h"
 #include "xfa/fee/ifde_txtedtpage.h"
 #include "xfa/fwl/basewidget/fwl_caretimp.h"
 #include "xfa/fwl/basewidget/fwl_comboboximp.h"
@@ -755,8 +756,7 @@
 FWL_ERR CFWL_EditImp::SetTabWidth(FX_FLOAT fTabWidth, FX_BOOL bEquidistant) {
   if (!m_pEdtEngine)
     return FWL_ERR_Succeeded;
-  FDE_LPTXTEDTPARAMS pParams =
-      (FDE_LPTXTEDTPARAMS)m_pEdtEngine->GetEditParams();
+  FDE_TXTEDTPARAMS* pParams = m_pEdtEngine->GetEditParams();
   pParams->fTabWidth = fTabWidth;
   pParams->bTabEquidistant = bEquidistant;
   return FWL_ERR_Succeeded;
@@ -771,7 +771,7 @@
   m_bSetRange = TRUE;
   return FWL_ERR_Succeeded;
 }
-void CFWL_EditImp::On_CaretChanged(IFDE_TxtEdtEngine* pEdit,
+void CFWL_EditImp::On_CaretChanged(CFDE_TxtEdtEngine* pEdit,
                                    int32_t nPage,
                                    FX_BOOL bVisible) {
   if (m_rtEngine.IsEmpty()) {
@@ -799,7 +799,7 @@
     Repaint(&rtInvalid);
   }
 }
-void CFWL_EditImp::On_TextChanged(IFDE_TxtEdtEngine* pEdit,
+void CFWL_EditImp::On_TextChanged(CFDE_TxtEdtEngine* pEdit,
                                   FDE_TXTEDT_TEXTCHANGE_INFO& ChangeInfo) {
   uint32_t dwStyleEx = m_pProperties->m_dwStyleExes;
   if (dwStyleEx & FWL_STYLEEXT_EDT_VAlignMask) {
@@ -864,25 +864,25 @@
   LayoutScrollBar();
   Repaint(&rtTemp);
 }
-void CFWL_EditImp::On_SelChanged(IFDE_TxtEdtEngine* pEdit) {
+void CFWL_EditImp::On_SelChanged(CFDE_TxtEdtEngine* pEdit) {
   CFX_RectF rtTemp;
   GetClientRect(rtTemp);
   Repaint(&rtTemp);
 }
-FX_BOOL CFWL_EditImp::On_PageLoad(IFDE_TxtEdtEngine* pEdit,
+FX_BOOL CFWL_EditImp::On_PageLoad(CFDE_TxtEdtEngine* pEdit,
                                   int32_t nPageIndex,
                                   int32_t nPurpose) {
-  IFDE_TxtEdtEngine* pEdtEngine = m_pEdtEngine;
+  CFDE_TxtEdtEngine* pEdtEngine = m_pEdtEngine;
   IFDE_TxtEdtPage* pPage = pEdtEngine->GetPage(nPageIndex);
   if (!pPage)
     return FALSE;
   pPage->LoadPage(nullptr, nullptr);
   return TRUE;
 }
-FX_BOOL CFWL_EditImp::On_PageUnload(IFDE_TxtEdtEngine* pEdit,
+FX_BOOL CFWL_EditImp::On_PageUnload(CFDE_TxtEdtEngine* pEdit,
                                     int32_t nPageIndex,
                                     int32_t nPurpose) {
-  IFDE_TxtEdtEngine* pEdtEngine = m_pEdtEngine;
+  CFDE_TxtEdtEngine* pEdtEngine = m_pEdtEngine;
   IFDE_TxtEdtPage* pPage = pEdtEngine->GetPage(nPageIndex);
   if (!pPage)
     return FALSE;
@@ -890,28 +890,12 @@
   return TRUE;
 }
 
-void CFWL_EditImp::On_AddDoRecord(IFDE_TxtEdtEngine* pEdit,
+void CFWL_EditImp::On_AddDoRecord(CFDE_TxtEdtEngine* pEdit,
                                   const CFX_ByteStringC& bsDoRecord) {
   AddDoRecord(bsDoRecord);
 }
 
-FX_BOOL CFWL_EditImp::On_ValidateField(IFDE_TxtEdtEngine* pEdit,
-                                       int32_t nBlockIndex,
-                                       int32_t nFieldIndex,
-                                       const CFX_WideString& wsFieldText,
-                                       int32_t nCharIndex) {
-  return TRUE;
-}
-FX_BOOL CFWL_EditImp::On_ValidateBlock(IFDE_TxtEdtEngine* pEdit,
-                                       int32_t nBlockIndex) {
-  return TRUE;
-}
-FX_BOOL CFWL_EditImp::On_GetBlockFormatText(IFDE_TxtEdtEngine* pEdit,
-                                            int32_t nBlockIndex,
-                                            CFX_WideString& wsBlockText) {
-  return FALSE;
-}
-FX_BOOL CFWL_EditImp::On_Validate(IFDE_TxtEdtEngine* pEdit,
+FX_BOOL CFWL_EditImp::On_Validate(CFDE_TxtEdtEngine* pEdit,
                                   CFX_WideString& wsText) {
   IFWL_Widget* pDst = GetOuter();
   if (!pDst) {
@@ -1607,11 +1591,10 @@
   pScrollBar->Initialize();
   (bVert ? &m_pVertScrollBar : &m_pHorzScrollBar)->reset(pScrollBar);
 }
+
 void CFWL_EditImp::InitEngine() {
-  if (m_pEdtEngine) {
-    return;
-  }
-  m_pEdtEngine = IFDE_TxtEdtEngine::Create();
+  if (!m_pEdtEngine)
+    m_pEdtEngine = new CFDE_TxtEdtEngine;
 }
 
 FX_BOOL FWL_ShowCaret(IFWL_Widget* pWidget,
diff --git a/xfa/fwl/basewidget/fwl_editimp.h b/xfa/fwl/basewidget/fwl_editimp.h
index f8fb1aa..226a0e8 100644
--- a/xfa/fwl/basewidget/fwl_editimp.h
+++ b/xfa/fwl/basewidget/fwl_editimp.h
@@ -24,7 +24,7 @@
 class CFWL_EditImp;
 class CFWL_EditImpDelegate;
 
-class CFWL_EditImp : public CFWL_WidgetImp, public IFDE_TxtEdtEventSink {
+class CFWL_EditImp : public CFWL_WidgetImp {
  public:
   CFWL_EditImp(const CFWL_WidgetImpProperties& properties, IFWL_Widget* pOuter);
   ~CFWL_EditImp() override;
@@ -79,38 +79,24 @@
   virtual FWL_ERR SetTabWidth(FX_FLOAT fTabWidth, FX_BOOL bEquidistant);
   virtual FWL_ERR SetOuter(IFWL_Widget* pOuter);
   virtual FWL_ERR SetNumberRange(int32_t iMin, int32_t iMax);
-  void On_CaretChanged(IFDE_TxtEdtEngine* pEdit,
-                       int32_t nPage,
-                       FX_BOOL bVisible = true) override;
-  void On_TextChanged(IFDE_TxtEdtEngine* pEdit,
-                      FDE_TXTEDT_TEXTCHANGE_INFO& ChangeInfo) override;
-  void On_PageCountChanged(IFDE_TxtEdtEngine* pEdit) override {}
-  void On_SelChanged(IFDE_TxtEdtEngine* pEdit) override;
-  FX_BOOL On_PageLoad(IFDE_TxtEdtEngine* pEdit,
-                      int32_t nPageIndex,
-                      int32_t nPurpose) override;
-  FX_BOOL On_PageUnload(IFDE_TxtEdtEngine* pEdit,
-                        int32_t nPageIndex,
-                        int32_t nPurpose) override;
-  FX_BOOL On_PageChange(IFDE_TxtEdtEngine* pEdit, int32_t nPageIndex) override {
-    return TRUE;
-  }
-  void On_AddDoRecord(IFDE_TxtEdtEngine* pEdit,
-                      const CFX_ByteStringC& bsDoRecord) override;
-  FX_BOOL On_ValidateField(IFDE_TxtEdtEngine* pEdit,
-                           int32_t nBlockIndex,
-                           int32_t nFieldIndex,
-                           const CFX_WideString& wsFieldText,
-                           int32_t nCharIndex) override;
-  FX_BOOL On_ValidateBlock(IFDE_TxtEdtEngine* pEdit,
-                           int32_t nBlockIndex) override;
-  FX_BOOL On_GetBlockFormatText(IFDE_TxtEdtEngine* pEdit,
-                                int32_t nBlockIndex,
-                                CFX_WideString& wsBlockText) override;
-  FX_BOOL On_Validate(IFDE_TxtEdtEngine* pEdit,
-                      CFX_WideString& wsText) override;
   virtual FWL_ERR SetBackgroundColor(uint32_t color);
   virtual FWL_ERR SetFont(const CFX_WideString& wsFont, FX_FLOAT fSize);
+
+  void On_CaretChanged(CFDE_TxtEdtEngine* pEdit,
+                       int32_t nPage,
+                       FX_BOOL bVisible = true);
+  void On_TextChanged(CFDE_TxtEdtEngine* pEdit,
+                      FDE_TXTEDT_TEXTCHANGE_INFO& ChangeInfo);
+  void On_SelChanged(CFDE_TxtEdtEngine* pEdit);
+  FX_BOOL On_PageLoad(CFDE_TxtEdtEngine* pEdit,
+                      int32_t nPageIndex,
+                      int32_t nPurpose);
+  FX_BOOL On_PageUnload(CFDE_TxtEdtEngine* pEdit,
+                        int32_t nPageIndex,
+                        int32_t nPurpose);
+  void On_AddDoRecord(CFDE_TxtEdtEngine* pEdit,
+                      const CFX_ByteStringC& bsDoRecord);
+  FX_BOOL On_Validate(CFDE_TxtEdtEngine* pEdit, CFX_WideString& wsText);
   void SetScrollOffset(FX_FLOAT fScrollOffset);
   FX_BOOL GetSuggestWords(CFX_PointF pointf,
                           std::vector<CFX_ByteString>& sSuggest);
@@ -160,7 +146,7 @@
   FX_FLOAT m_fVAlignOffset;
   FX_FLOAT m_fScrollOffsetX;
   FX_FLOAT m_fScrollOffsetY;
-  IFDE_TxtEdtEngine* m_pEdtEngine;
+  CFDE_TxtEdtEngine* m_pEdtEngine;
   FX_BOOL m_bLButtonDown;
   int32_t m_nSelStart;
   int32_t m_nLimit;