diff --git a/fpdfsdk/include/fsdk_annothandler.h b/fpdfsdk/include/fsdk_annothandler.h
index 5edb504..369a080 100644
--- a/fpdfsdk/include/fsdk_annothandler.h
+++ b/fpdfsdk/include/fsdk_annothandler.h
@@ -21,86 +21,188 @@
 class CPDF_Point;
 class CPDF_Rect;
 
-class CPDFSDK_AnnotHandler {
+class IPDFSDK_AnnotHandler {
  public:
-  explicit CPDFSDK_AnnotHandler(CPDFDoc_Environment* pApp)
-      : m_pApp(pApp), m_pFormFiller(nullptr) {}
+  virtual ~IPDFSDK_AnnotHandler() {}
 
-  ~CPDFSDK_AnnotHandler() {}
+  virtual CFX_ByteString GetType() = 0;
 
-  CFX_ByteString GetType() { return CFX_ByteString("Widget"); }
-  CFX_ByteString GetName() { return CFX_ByteString("WidgetHandler"); }
-  FX_BOOL CanAnswer(CPDFSDK_Annot* pAnnot);
-  CPDFSDK_Annot* NewAnnot(CPDF_Annot* pAnnot, CPDFSDK_PageView* pPage);
-  void ReleaseAnnot(CPDFSDK_Annot* pAnnot);
-  void DeleteAnnot(CPDFSDK_Annot* pAnnot) {}
-  CPDF_Rect GetViewBBox(CPDFSDK_PageView* pPageView, CPDFSDK_Annot* pAnnot);
+  virtual CFX_ByteString GetName() = 0;
+
+  virtual FX_BOOL CanAnswer(CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual CPDFSDK_Annot* NewAnnot(CPDF_Annot* pAnnot,
+                                  CPDFSDK_PageView* pPage) = 0;
+
+  virtual void ReleaseAnnot(CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual void DeleteAnnot(CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual CPDF_Rect GetViewBBox(CPDFSDK_PageView* pPageView,
+                                CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual FX_BOOL HitTest(CPDFSDK_PageView* pPageView,
+                          CPDFSDK_Annot* pAnnot,
+                          const CPDF_Point& point) = 0;
+
+  virtual void OnDraw(CPDFSDK_PageView* pPageView,
+                      CPDFSDK_Annot* pAnnot,
+                      CFX_RenderDevice* pDevice,
+                      CPDF_Matrix* pUser2Device,
+                      FX_DWORD dwFlags) = 0;
+
+  virtual void OnDrawSleep(CPDFSDK_PageView* pPageView,
+                           CPDFSDK_Annot* pAnnot,
+                           CFX_RenderDevice* pDevice,
+                           CPDF_Matrix* pUser2Device,
+                           const CPDF_Rect& rcWindow,
+                           FX_DWORD dwFlags) = 0;
+
+  virtual void OnCreate(CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual void OnLoad(CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual void OnDelete(CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual void OnRelease(CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual void OnMouseEnter(CPDFSDK_PageView* pPageView,
+                            CPDFSDK_Annot* pAnnot,
+                            FX_DWORD nFlag) = 0;
+  virtual void OnMouseExit(CPDFSDK_PageView* pPageView,
+                           CPDFSDK_Annot* pAnnot,
+                           FX_DWORD nFlag) = 0;
+
+  virtual FX_BOOL OnLButtonDown(CPDFSDK_PageView* pPageView,
+                                CPDFSDK_Annot* pAnnot,
+                                FX_DWORD nFlags,
+                                const CPDF_Point& point) = 0;
+  virtual FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
+                              CPDFSDK_Annot* pAnnot,
+                              FX_DWORD nFlags,
+                              const CPDF_Point& point) = 0;
+  virtual FX_BOOL OnLButtonDblClk(CPDFSDK_PageView* pPageView,
+                                  CPDFSDK_Annot* pAnnot,
+                                  FX_DWORD nFlags,
+                                  const CPDF_Point& point) = 0;
+  virtual FX_BOOL OnMouseMove(CPDFSDK_PageView* pPageView,
+                              CPDFSDK_Annot* pAnnot,
+                              FX_DWORD nFlags,
+                              const CPDF_Point& point) = 0;
+  virtual FX_BOOL OnMouseWheel(CPDFSDK_PageView* pPageView,
+                               CPDFSDK_Annot* pAnnot,
+                               FX_DWORD nFlags,
+                               short zDelta,
+                               const CPDF_Point& point) = 0;
+  virtual FX_BOOL OnRButtonDown(CPDFSDK_PageView* pPageView,
+                                CPDFSDK_Annot* pAnnot,
+                                FX_DWORD nFlags,
+                                const CPDF_Point& point) = 0;
+  virtual FX_BOOL OnRButtonUp(CPDFSDK_PageView* pPageView,
+                              CPDFSDK_Annot* pAnnot,
+                              FX_DWORD nFlags,
+                              const CPDF_Point& point) = 0;
+  virtual FX_BOOL OnRButtonDblClk(CPDFSDK_PageView* pPageView,
+                                  CPDFSDK_Annot* pAnnot,
+                                  FX_DWORD nFlags,
+                                  const CPDF_Point& point) = 0;
+  // by wjm.
+  virtual FX_BOOL OnChar(CPDFSDK_Annot* pAnnot,
+                         FX_DWORD nChar,
+                         FX_DWORD nFlags) = 0;
+  virtual FX_BOOL OnKeyDown(CPDFSDK_Annot* pAnnot, int nKeyCode, int nFlag) = 0;
+  virtual FX_BOOL OnKeyUp(CPDFSDK_Annot* pAnnot, int nKeyCode, int nFlag) = 0;
+
+  virtual void OnDeSelected(CPDFSDK_Annot* pAnnot) = 0;
+  virtual void OnSelected(CPDFSDK_Annot* pAnnot) = 0;
+
+  virtual FX_BOOL OnSetFocus(CPDFSDK_Annot* pAnnot, FX_DWORD nFlag) = 0;
+  virtual FX_BOOL OnKillFocus(CPDFSDK_Annot* pAnnot, FX_DWORD nFlag) = 0;
+};
+
+class CPDFSDK_BFAnnotHandler : public IPDFSDK_AnnotHandler {
+ public:
+  CPDFSDK_BFAnnotHandler(CPDFDoc_Environment* pApp)
+      : m_pApp(pApp), m_pFormFiller(NULL) {}
+  ~CPDFSDK_BFAnnotHandler() override {}
+
+  // IPDFSDK_AnnotHandler
+  CFX_ByteString GetType() override { return CFX_ByteString("Widget"); }
+  CFX_ByteString GetName() override { return CFX_ByteString("WidgetHandler"); }
+  FX_BOOL CanAnswer(CPDFSDK_Annot* pAnnot) override;
+  CPDFSDK_Annot* NewAnnot(CPDF_Annot* pAnnot, CPDFSDK_PageView* pPage) override;
+  void ReleaseAnnot(CPDFSDK_Annot* pAnnot) override;
+  void DeleteAnnot(CPDFSDK_Annot* pAnnot) override {}
+  CPDF_Rect GetViewBBox(CPDFSDK_PageView* pPageView,
+                        CPDFSDK_Annot* pAnnot) override;
   FX_BOOL HitTest(CPDFSDK_PageView* pPageView,
                   CPDFSDK_Annot* pAnnot,
-                  const CPDF_Point& point);
+                  const CPDF_Point& point) override;
   void OnDraw(CPDFSDK_PageView* pPageView,
               CPDFSDK_Annot* pAnnot,
               CFX_RenderDevice* pDevice,
               CPDF_Matrix* pUser2Device,
-              FX_DWORD dwFlags);
+              FX_DWORD dwFlags) override;
   void OnDrawSleep(CPDFSDK_PageView* pPageView,
                    CPDFSDK_Annot* pAnnot,
                    CFX_RenderDevice* pDevice,
                    CPDF_Matrix* pUser2Device,
                    const CPDF_Rect& rcWindow,
-                   FX_DWORD dwFlags) {}
-  void OnCreate(CPDFSDK_Annot* pAnnot);
-  void OnLoad(CPDFSDK_Annot* pAnnot);
-  void OnDelete(CPDFSDK_Annot* pAnnot) {}
-  void OnRelease(CPDFSDK_Annot* pAnnot) {}
+                   FX_DWORD dwFlags) override {}
+  void OnCreate(CPDFSDK_Annot* pAnnot) override;
+  void OnLoad(CPDFSDK_Annot* pAnnot) override;
+  void OnDelete(CPDFSDK_Annot* pAnnot) override {}
+  void OnRelease(CPDFSDK_Annot* pAnnot) override {}
   void OnMouseEnter(CPDFSDK_PageView* pPageView,
                     CPDFSDK_Annot* pAnnot,
-                    FX_DWORD nFlag);
+                    FX_DWORD nFlag) override;
   void OnMouseExit(CPDFSDK_PageView* pPageView,
                    CPDFSDK_Annot* pAnnot,
-                   FX_DWORD nFlag);
+                   FX_DWORD nFlag) override;
   FX_BOOL OnLButtonDown(CPDFSDK_PageView* pPageView,
                         CPDFSDK_Annot* pAnnot,
                         FX_DWORD nFlags,
-                        const CPDF_Point& point);
+                        const CPDF_Point& point) override;
   FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
                       CPDFSDK_Annot* pAnnot,
                       FX_DWORD nFlags,
-                      const CPDF_Point& point);
+                      const CPDF_Point& point) override;
   FX_BOOL OnLButtonDblClk(CPDFSDK_PageView* pPageView,
                           CPDFSDK_Annot* pAnnot,
                           FX_DWORD nFlags,
-                          const CPDF_Point& point);
+                          const CPDF_Point& point) override;
   FX_BOOL OnMouseMove(CPDFSDK_PageView* pPageView,
                       CPDFSDK_Annot* pAnnot,
                       FX_DWORD nFlags,
-                      const CPDF_Point& point);
+                      const CPDF_Point& point) override;
   FX_BOOL OnMouseWheel(CPDFSDK_PageView* pPageView,
                        CPDFSDK_Annot* pAnnot,
                        FX_DWORD nFlags,
                        short zDelta,
-                       const CPDF_Point& point);
+                       const CPDF_Point& point) override;
   FX_BOOL OnRButtonDown(CPDFSDK_PageView* pPageView,
                         CPDFSDK_Annot* pAnnot,
                         FX_DWORD nFlags,
-                        const CPDF_Point& point);
+                        const CPDF_Point& point) override;
   FX_BOOL OnRButtonUp(CPDFSDK_PageView* pPageView,
                       CPDFSDK_Annot* pAnnot,
                       FX_DWORD nFlags,
-                      const CPDF_Point& point);
+                      const CPDF_Point& point) override;
   FX_BOOL OnRButtonDblClk(CPDFSDK_PageView* pPageView,
                           CPDFSDK_Annot* pAnnot,
                           FX_DWORD nFlags,
-                          const CPDF_Point& point) {
+                          const CPDF_Point& point) override {
     return FALSE;
   }
-  FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_DWORD nChar, FX_DWORD nFlags);
-  FX_BOOL OnKeyDown(CPDFSDK_Annot* pAnnot, int nKeyCode, int nFlag);
-  FX_BOOL OnKeyUp(CPDFSDK_Annot* pAnnot, int nKeyCode, int nFlag);
-  void OnDeSelected(CPDFSDK_Annot* pAnnot) {}
-  void OnSelected(CPDFSDK_Annot* pAnnot) {}
-  FX_BOOL OnSetFocus(CPDFSDK_Annot* pAnnot, FX_DWORD nFlag);
-  FX_BOOL OnKillFocus(CPDFSDK_Annot* pAnnot, FX_DWORD nFlag);
+  FX_BOOL OnChar(CPDFSDK_Annot* pAnnot,
+                 FX_DWORD nChar,
+                 FX_DWORD nFlags) override;
+  FX_BOOL OnKeyDown(CPDFSDK_Annot* pAnnot, int nKeyCode, int nFlag) override;
+  FX_BOOL OnKeyUp(CPDFSDK_Annot* pAnnot, int nKeyCode, int nFlag) override;
+  void OnDeSelected(CPDFSDK_Annot* pAnnot) override {}
+  void OnSelected(CPDFSDK_Annot* pAnnot) override {}
+  FX_BOOL OnSetFocus(CPDFSDK_Annot* pAnnot, FX_DWORD nFlag) override;
+  FX_BOOL OnKillFocus(CPDFSDK_Annot* pAnnot, FX_DWORD nFlag) override;
 
   void SetFormFiller(CFFL_IFormFiller* pFiller) { m_pFormFiller = pFiller; }
   CFFL_IFormFiller* GetFormFiller() { return m_pFormFiller; }
@@ -110,16 +212,16 @@
   CFFL_IFormFiller* m_pFormFiller;
 };
 
-using CBA_AnnotHandlerArray = CFX_ArrayTemplate<CPDFSDK_AnnotHandler*>;
-
+#define CBA_AnnotHandlerArray CFX_ArrayTemplate<IPDFSDK_AnnotHandler*>
 class CPDFSDK_AnnotHandlerMgr {
  public:
   // Destroy the handler
   explicit CPDFSDK_AnnotHandlerMgr(CPDFDoc_Environment* pApp);
   virtual ~CPDFSDK_AnnotHandlerMgr();
 
-  void RegisterAnnotHandler(CPDFSDK_AnnotHandler* pAnnotHandler);
-  void UnRegisterAnnotHandler(CPDFSDK_AnnotHandler* pAnnotHandler);
+ public:
+  void RegisterAnnotHandler(IPDFSDK_AnnotHandler* pAnnotHandler);
+  void UnRegisterAnnotHandler(IPDFSDK_AnnotHandler* pAnnotHandler);
 
   virtual CPDFSDK_Annot* NewAnnot(CPDF_Annot* pAnnot,
                                   CPDFSDK_PageView* pPageView);
@@ -128,7 +230,8 @@
   virtual void Annot_OnCreate(CPDFSDK_Annot* pAnnot);
   virtual void Annot_OnLoad(CPDFSDK_Annot* pAnnot);
 
-  CPDFSDK_AnnotHandler* GetAnnotHandler(CPDFSDK_Annot* pAnnot) const;
+ public:
+  IPDFSDK_AnnotHandler* GetAnnotHandler(CPDFSDK_Annot* pAnnot) const;
   virtual void Annot_OnDraw(CPDFSDK_PageView* pPageView,
                             CPDFSDK_Annot* pAnnot,
                             CFX_RenderDevice* pDevice,
@@ -191,11 +294,12 @@
                                   const CPDF_Point& point);
 
  private:
-  CPDFSDK_AnnotHandler* GetAnnotHandler(const CFX_ByteString& sType) const;
+  IPDFSDK_AnnotHandler* GetAnnotHandler(const CFX_ByteString& sType) const;
   CPDFSDK_Annot* GetNextAnnot(CPDFSDK_Annot* pSDKAnnot, FX_BOOL bNext);
 
+ private:
   CBA_AnnotHandlerArray m_Handlers;
-  std::map<CFX_ByteString, CPDFSDK_AnnotHandler*> m_mapType2Handler;
+  std::map<CFX_ByteString, IPDFSDK_AnnotHandler*> m_mapType2Handler;
   CPDFDoc_Environment* m_pApp;
 };
 
diff --git a/fpdfsdk/src/fsdk_annothandler.cpp b/fpdfsdk/src/fsdk_annothandler.cpp
index f1b6153..bb999e1 100644
--- a/fpdfsdk/src/fsdk_annothandler.cpp
+++ b/fpdfsdk/src/fsdk_annothandler.cpp
@@ -12,14 +12,14 @@
 CPDFSDK_AnnotHandlerMgr::CPDFSDK_AnnotHandlerMgr(CPDFDoc_Environment* pApp) {
   m_pApp = pApp;
 
-  CPDFSDK_AnnotHandler* pHandler = new CPDFSDK_AnnotHandler(m_pApp);
+  CPDFSDK_BFAnnotHandler* pHandler = new CPDFSDK_BFAnnotHandler(m_pApp);
   pHandler->SetFormFiller(m_pApp->GetIFormFiller());
   RegisterAnnotHandler(pHandler);
 }
 
 CPDFSDK_AnnotHandlerMgr::~CPDFSDK_AnnotHandlerMgr() {
   for (int i = 0; i < m_Handlers.GetSize(); i++) {
-    CPDFSDK_AnnotHandler* pHandler = m_Handlers.GetAt(i);
+    IPDFSDK_AnnotHandler* pHandler = m_Handlers.GetAt(i);
     delete pHandler;
   }
   m_Handlers.RemoveAll();
@@ -27,7 +27,7 @@
 }
 
 void CPDFSDK_AnnotHandlerMgr::RegisterAnnotHandler(
-    CPDFSDK_AnnotHandler* pAnnotHandler) {
+    IPDFSDK_AnnotHandler* pAnnotHandler) {
   ASSERT(!GetAnnotHandler(pAnnotHandler->GetType()));
 
   m_Handlers.Add(pAnnotHandler);
@@ -35,7 +35,7 @@
 }
 
 void CPDFSDK_AnnotHandlerMgr::UnRegisterAnnotHandler(
-    CPDFSDK_AnnotHandler* pAnnotHandler) {
+    IPDFSDK_AnnotHandler* pAnnotHandler) {
   m_mapType2Handler.erase(pAnnotHandler->GetType());
   for (int i = 0, sz = m_Handlers.GetSize(); i < sz; i++) {
     if (m_Handlers.GetAt(i) == pAnnotHandler) {
@@ -50,7 +50,7 @@
   ASSERT(pAnnot != NULL);
   ASSERT(pPageView != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler =
+  if (IPDFSDK_AnnotHandler* pAnnotHandler =
           GetAnnotHandler(pAnnot->GetSubType())) {
     return pAnnotHandler->NewAnnot(pAnnot, pPageView);
   }
@@ -63,7 +63,7 @@
 
   pAnnot->GetPDFPage();
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     pAnnotHandler->OnRelease(pAnnot);
     pAnnotHandler->ReleaseAnnot(pAnnot);
   } else {
@@ -80,7 +80,7 @@
   pPDFAnnot->GetAnnotDict()->SetAtString("M", curTime.ToPDFDateTimeString());
   pPDFAnnot->GetAnnotDict()->SetAtNumber("F", 0);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     pAnnotHandler->OnCreate(pAnnot);
   }
 }
@@ -88,12 +88,12 @@
 void CPDFSDK_AnnotHandlerMgr::Annot_OnLoad(CPDFSDK_Annot* pAnnot) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     pAnnotHandler->OnLoad(pAnnot);
   }
 }
 
-CPDFSDK_AnnotHandler* CPDFSDK_AnnotHandlerMgr::GetAnnotHandler(
+IPDFSDK_AnnotHandler* CPDFSDK_AnnotHandlerMgr::GetAnnotHandler(
     CPDFSDK_Annot* pAnnot) const {
   ASSERT(pAnnot != NULL);
 
@@ -103,7 +103,7 @@
   return GetAnnotHandler(pPDFAnnot->GetSubType());
 }
 
-CPDFSDK_AnnotHandler* CPDFSDK_AnnotHandlerMgr::GetAnnotHandler(
+IPDFSDK_AnnotHandler* CPDFSDK_AnnotHandlerMgr::GetAnnotHandler(
     const CFX_ByteString& sType) const {
   auto it = m_mapType2Handler.find(sType);
   return it != m_mapType2Handler.end() ? it->second : nullptr;
@@ -116,7 +116,7 @@
                                            FX_DWORD dwFlags) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     pAnnotHandler->OnDraw(pPageView, pAnnot, pDevice, pUser2Device, dwFlags);
   } else {
     pAnnot->DrawAppearance(pDevice, pUser2Device, CPDF_Annot::Normal, NULL);
@@ -130,7 +130,7 @@
     const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnLButtonDown(pPageView, pAnnot, nFlags, point);
   }
   return FALSE;
@@ -141,7 +141,7 @@
                                                    const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnLButtonUp(pPageView, pAnnot, nFlags, point);
   }
   return FALSE;
@@ -153,7 +153,7 @@
     const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnLButtonDblClk(pPageView, pAnnot, nFlags, point);
   }
   return FALSE;
@@ -164,7 +164,7 @@
                                                    const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnMouseMove(pPageView, pAnnot, nFlags, point);
   }
   return FALSE;
@@ -176,7 +176,7 @@
                                                     const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnMouseWheel(pPageView, pAnnot, nFlags, zDelta,
                                        point);
   }
@@ -189,7 +189,7 @@
     const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnRButtonDown(pPageView, pAnnot, nFlags, point);
   }
   return FALSE;
@@ -200,7 +200,7 @@
                                                    const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnRButtonUp(pPageView, pAnnot, nFlags, point);
   }
   return FALSE;
@@ -211,7 +211,7 @@
                                                  FX_DWORD nFlag) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     pAnnotHandler->OnMouseEnter(pPageView, pAnnot, nFlag);
   }
   return;
@@ -222,7 +222,7 @@
                                                 FX_DWORD nFlag) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     pAnnotHandler->OnMouseExit(pPageView, pAnnot, nFlag);
   }
   return;
@@ -231,7 +231,7 @@
 FX_BOOL CPDFSDK_AnnotHandlerMgr::Annot_OnChar(CPDFSDK_Annot* pAnnot,
                                               FX_DWORD nChar,
                                               FX_DWORD nFlags) {
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnChar(pAnnot, nChar, nFlags);
   }
   return FALSE;
@@ -255,7 +255,7 @@
     }
   }
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     return pAnnotHandler->OnKeyDown(pAnnot, nKeyCode, nFlag);
   }
   return FALSE;
@@ -270,7 +270,7 @@
                                                   FX_DWORD nFlag) {
   ASSERT(pAnnot != NULL);
 
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     if (pAnnotHandler->OnSetFocus(pAnnot, nFlag)) {
       CPDFSDK_PageView* pPage = pAnnot->GetPageView();
       pPage->GetSDKDocument();
@@ -283,7 +283,7 @@
 FX_BOOL CPDFSDK_AnnotHandlerMgr::Annot_OnKillFocus(CPDFSDK_Annot* pAnnot,
                                                    FX_DWORD nFlag) {
   ASSERT(pAnnot);
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot))
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot))
     return pAnnotHandler->OnKillFocus(pAnnot, nFlag);
 
   return FALSE;
@@ -293,7 +293,7 @@
     CPDFSDK_PageView* pPageView,
     CPDFSDK_Annot* pAnnot) {
   ASSERT(pAnnot);
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot))
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot))
     return pAnnotHandler->GetViewBBox(pPageView, pAnnot);
 
   return pAnnot->GetRect();
@@ -303,7 +303,7 @@
                                                  CPDFSDK_Annot* pAnnot,
                                                  const CPDF_Point& point) {
   ASSERT(pAnnot);
-  if (CPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
+  if (IPDFSDK_AnnotHandler* pAnnotHandler = GetAnnotHandler(pAnnot)) {
     if (pAnnotHandler->CanAnswer(pAnnot))
       return pAnnotHandler->HitTest(pPageView, pAnnot, point);
   }
@@ -316,7 +316,7 @@
   return bNext ? ai.GetNextAnnot(pSDKAnnot) : ai.GetPrevAnnot(pSDKAnnot);
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::CanAnswer(CPDFSDK_Annot* pAnnot) {
+FX_BOOL CPDFSDK_BFAnnotHandler::CanAnswer(CPDFSDK_Annot* pAnnot) {
   ASSERT(pAnnot->GetType() == "Widget");
   if (pAnnot->GetSubType() == BFFT_SIGNATURE)
     return FALSE;
@@ -339,8 +339,8 @@
          (dwPermissions & FPDFPERM_ANNOT_FORM);
 }
 
-CPDFSDK_Annot* CPDFSDK_AnnotHandler::NewAnnot(CPDF_Annot* pAnnot,
-                                              CPDFSDK_PageView* pPage) {
+CPDFSDK_Annot* CPDFSDK_BFAnnotHandler::NewAnnot(CPDF_Annot* pAnnot,
+                                                CPDFSDK_PageView* pPage) {
   CPDFSDK_Document* pSDKDoc = m_pApp->GetSDKDocument();
   CPDFSDK_InterForm* pInterForm = (CPDFSDK_InterForm*)pSDKDoc->GetInterForm();
   CPDF_FormControl* pCtrl = CPDFSDK_Widget::GetFormControl(
@@ -357,7 +357,7 @@
   return pWidget;
 }
 
-void CPDFSDK_AnnotHandler::ReleaseAnnot(CPDFSDK_Annot* pAnnot) {
+void CPDFSDK_BFAnnotHandler::ReleaseAnnot(CPDFSDK_Annot* pAnnot) {
   ASSERT(pAnnot != NULL);
 
   if (m_pFormFiller)
@@ -373,11 +373,11 @@
   delete pWidget;
 }
 
-void CPDFSDK_AnnotHandler::OnDraw(CPDFSDK_PageView* pPageView,
-                                  CPDFSDK_Annot* pAnnot,
-                                  CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device,
-                                  FX_DWORD dwFlags) {
+void CPDFSDK_BFAnnotHandler::OnDraw(CPDFSDK_PageView* pPageView,
+                                    CPDFSDK_Annot* pAnnot,
+                                    CFX_RenderDevice* pDevice,
+                                    CPDF_Matrix* pUser2Device,
+                                    FX_DWORD dwFlags) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -390,9 +390,9 @@
   }
 }
 
-void CPDFSDK_AnnotHandler::OnMouseEnter(CPDFSDK_PageView* pPageView,
-                                        CPDFSDK_Annot* pAnnot,
-                                        FX_DWORD nFlag) {
+void CPDFSDK_BFAnnotHandler::OnMouseEnter(CPDFSDK_PageView* pPageView,
+                                          CPDFSDK_Annot* pAnnot,
+                                          FX_DWORD nFlag) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -402,9 +402,9 @@
       m_pFormFiller->OnMouseEnter(pPageView, pAnnot, nFlag);
   }
 }
-void CPDFSDK_AnnotHandler::OnMouseExit(CPDFSDK_PageView* pPageView,
-                                       CPDFSDK_Annot* pAnnot,
-                                       FX_DWORD nFlag) {
+void CPDFSDK_BFAnnotHandler::OnMouseExit(CPDFSDK_PageView* pPageView,
+                                         CPDFSDK_Annot* pAnnot,
+                                         FX_DWORD nFlag) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -414,10 +414,10 @@
       m_pFormFiller->OnMouseExit(pPageView, pAnnot, nFlag);
   }
 }
-FX_BOOL CPDFSDK_AnnotHandler::OnLButtonDown(CPDFSDK_PageView* pPageView,
-                                            CPDFSDK_Annot* pAnnot,
-                                            FX_DWORD nFlags,
-                                            const CPDF_Point& point) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnLButtonDown(CPDFSDK_PageView* pPageView,
+                                              CPDFSDK_Annot* pAnnot,
+                                              FX_DWORD nFlags,
+                                              const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -430,10 +430,10 @@
   return FALSE;
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnLButtonUp(CPDFSDK_PageView* pPageView,
-                                          CPDFSDK_Annot* pAnnot,
-                                          FX_DWORD nFlags,
-                                          const CPDF_Point& point) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnLButtonUp(CPDFSDK_PageView* pPageView,
+                                            CPDFSDK_Annot* pAnnot,
+                                            FX_DWORD nFlags,
+                                            const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -446,10 +446,10 @@
   return FALSE;
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnLButtonDblClk(CPDFSDK_PageView* pPageView,
-                                              CPDFSDK_Annot* pAnnot,
-                                              FX_DWORD nFlags,
-                                              const CPDF_Point& point) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnLButtonDblClk(CPDFSDK_PageView* pPageView,
+                                                CPDFSDK_Annot* pAnnot,
+                                                FX_DWORD nFlags,
+                                                const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -462,10 +462,10 @@
   return FALSE;
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnMouseMove(CPDFSDK_PageView* pPageView,
-                                          CPDFSDK_Annot* pAnnot,
-                                          FX_DWORD nFlags,
-                                          const CPDF_Point& point) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnMouseMove(CPDFSDK_PageView* pPageView,
+                                            CPDFSDK_Annot* pAnnot,
+                                            FX_DWORD nFlags,
+                                            const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -478,11 +478,11 @@
   return FALSE;
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnMouseWheel(CPDFSDK_PageView* pPageView,
-                                           CPDFSDK_Annot* pAnnot,
-                                           FX_DWORD nFlags,
-                                           short zDelta,
-                                           const CPDF_Point& point) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnMouseWheel(CPDFSDK_PageView* pPageView,
+                                             CPDFSDK_Annot* pAnnot,
+                                             FX_DWORD nFlags,
+                                             short zDelta,
+                                             const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -496,10 +496,10 @@
   return FALSE;
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnRButtonDown(CPDFSDK_PageView* pPageView,
-                                            CPDFSDK_Annot* pAnnot,
-                                            FX_DWORD nFlags,
-                                            const CPDF_Point& point) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnRButtonDown(CPDFSDK_PageView* pPageView,
+                                              CPDFSDK_Annot* pAnnot,
+                                              FX_DWORD nFlags,
+                                              const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -511,10 +511,10 @@
 
   return FALSE;
 }
-FX_BOOL CPDFSDK_AnnotHandler::OnRButtonUp(CPDFSDK_PageView* pPageView,
-                                          CPDFSDK_Annot* pAnnot,
-                                          FX_DWORD nFlags,
-                                          const CPDF_Point& point) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnRButtonUp(CPDFSDK_PageView* pPageView,
+                                            CPDFSDK_Annot* pAnnot,
+                                            FX_DWORD nFlags,
+                                            const CPDF_Point& point) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -527,9 +527,9 @@
   return FALSE;
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnChar(CPDFSDK_Annot* pAnnot,
-                                     FX_DWORD nChar,
-                                     FX_DWORD nFlags) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnChar(CPDFSDK_Annot* pAnnot,
+                                       FX_DWORD nChar,
+                                       FX_DWORD nFlags) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -542,9 +542,9 @@
   return FALSE;
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnKeyDown(CPDFSDK_Annot* pAnnot,
-                                        int nKeyCode,
-                                        int nFlag) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnKeyDown(CPDFSDK_Annot* pAnnot,
+                                          int nKeyCode,
+                                          int nFlag) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -557,12 +557,12 @@
   return FALSE;
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnKeyUp(CPDFSDK_Annot* pAnnot,
-                                      int nKeyCode,
-                                      int nFlag) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnKeyUp(CPDFSDK_Annot* pAnnot,
+                                        int nKeyCode,
+                                        int nFlag) {
   return FALSE;
 }
-void CPDFSDK_AnnotHandler::OnCreate(CPDFSDK_Annot* pAnnot) {
+void CPDFSDK_BFAnnotHandler::OnCreate(CPDFSDK_Annot* pAnnot) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -573,7 +573,7 @@
   }
 }
 
-void CPDFSDK_AnnotHandler::OnLoad(CPDFSDK_Annot* pAnnot) {
+void CPDFSDK_BFAnnotHandler::OnLoad(CPDFSDK_Annot* pAnnot) {
   ASSERT(pAnnot != NULL);
 
   CFX_ByteString sSubType = pAnnot->GetSubType();
@@ -598,8 +598,8 @@
   }
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::OnSetFocus(CPDFSDK_Annot* pAnnot,
-                                         FX_DWORD nFlag) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnSetFocus(CPDFSDK_Annot* pAnnot,
+                                           FX_DWORD nFlag) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -611,8 +611,8 @@
 
   return TRUE;
 }
-FX_BOOL CPDFSDK_AnnotHandler::OnKillFocus(CPDFSDK_Annot* pAnnot,
-                                          FX_DWORD nFlag) {
+FX_BOOL CPDFSDK_BFAnnotHandler::OnKillFocus(CPDFSDK_Annot* pAnnot,
+                                            FX_DWORD nFlag) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -625,8 +625,8 @@
   return TRUE;
 }
 
-CPDF_Rect CPDFSDK_AnnotHandler::GetViewBBox(CPDFSDK_PageView* pPageView,
-                                            CPDFSDK_Annot* pAnnot) {
+CPDF_Rect CPDFSDK_BFAnnotHandler::GetViewBBox(CPDFSDK_PageView* pPageView,
+                                              CPDFSDK_Annot* pAnnot) {
   ASSERT(pAnnot != NULL);
   CFX_ByteString sSubType = pAnnot->GetSubType();
 
@@ -639,9 +639,9 @@
   return CPDF_Rect(0, 0, 0, 0);
 }
 
-FX_BOOL CPDFSDK_AnnotHandler::HitTest(CPDFSDK_PageView* pPageView,
-                                      CPDFSDK_Annot* pAnnot,
-                                      const CPDF_Point& point) {
+FX_BOOL CPDFSDK_BFAnnotHandler::HitTest(CPDFSDK_PageView* pPageView,
+                                        CPDFSDK_Annot* pAnnot,
+                                        const CPDF_Point& point) {
   ASSERT(pPageView);
   ASSERT(pAnnot);