Use override in more classes in fpdfsdk/

R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1287193005 .

60 files changed, 1087 insertions, 1117 deletions

diff --git a/core/include/fxge/fx_font.h b/core/include/fxge/fx_font.h
index ce06a8ac5f..8e0f5a1615 100644
--- a/core/include/fxge/fx_font.h
+++ b/core/include/fxge/fx_font.h
@@ -14,13 +14,13 @@
 
 typedef struct FT_FaceRec_* FXFT_Face;
 typedef void* FXFT_Library;
-class IFX_FontEncoding;
-class CFX_PathData;
-class CFX_SubstFont;
+class CFontFileFaceInfo;
 class CFX_FaceCache;
 class CFX_FontMapper;
+class CFX_PathData;
+class CFX_SubstFont;
 class IFX_SystemFontInfo;
-class CFontFileFaceInfo;
+
 #define FXFONT_FIXED_PITCH 0x01
 #define FXFONT_SERIF 0x02
 #define FXFONT_SYMBOLIC 0x04
@@ -133,6 +133,7 @@ class CFX_Font {
 };
 #define ENCODING_INTERNAL 0
 #define ENCODING_UNICODE 1
+
 class IFX_FontEncoding {
  public:
   virtual ~IFX_FontEncoding() {}
@@ -143,6 +144,7 @@ class IFX_FontEncoding {
 
   virtual FX_DWORD CharCodeFromUnicode(FX_WCHAR Unicode) const = 0;
 };
+
 IFX_FontEncoding* FXGE_CreateUnicodeEncoding(CFX_Font* pFont);
 #define FXFONT_SUBST_MM 0x01
 #define FXFONT_SUBST_GLYPHPATH 0x04
@@ -228,20 +230,26 @@ class CFX_FontMgr {
   FXFT_Library m_FTLibrary;
   FoxitFonts m_ExternalFonts[16];
 };
+
 class IFX_FontEnumerator {
  public:
-  virtual ~IFX_FontEnumerator() {}
-
   virtual void HitFont() = 0;
 
   virtual void Finish() = 0;
+
+ protected:
+  virtual ~IFX_FontEnumerator() {}
 };
+
 class IFX_AdditionalFontEnum {
  public:
-  virtual ~IFX_AdditionalFontEnum() {}
   virtual int CountFiles() = 0;
   virtual IFX_FileStream* GetFontFile(int index) = 0;
+
+ protected:
+  virtual ~IFX_AdditionalFontEnum() {}
 };
+
 class CFX_FontMapper {
  public:
   explicit CFX_FontMapper(CFX_FontMgr* mgr);
@@ -433,11 +441,14 @@ FX_RECT FXGE_GetGlyphsBBox(FXTEXT_GLYPHPOS* pGlyphAndPos,
                            int anti_alias,
                            FX_FLOAT retinaScaleX = 1.0f,
                            FX_FLOAT retinaScaleY = 1.0f);
+
 class IFX_GSUBTable {
  public:
   static IFX_GSUBTable* Create(CFX_Font* pFont);
-  virtual ~IFX_GSUBTable() {}
   virtual FX_BOOL GetVerticalGlyph(FX_DWORD glyphnum, FX_DWORD* vglyphnum) = 0;
+
+ protected:
+  virtual ~IFX_GSUBTable() {}
 };
 
 #endif  // CORE_INCLUDE_FXGE_FX_FONT_H_
diff --git a/fpdfsdk/include/formfiller/FFL_CBA_Fontmap.h b/fpdfsdk/include/formfiller/FFL_CBA_Fontmap.h
index 7978150736..3e1331839e 100644
--- a/fpdfsdk/include/formfiller/FFL_CBA_Fontmap.h
+++ b/fpdfsdk/include/formfiller/FFL_CBA_Fontmap.h
@@ -19,7 +19,7 @@ class CBA_FontMap : public CPWL_FontMap {
               CPDF_Dictionary* pAnnotDict,
               IFX_SystemHandler* pSystemHandler);
 
-  virtual ~CBA_FontMap();
+  ~CBA_FontMap() override;
 
   virtual void Initial(const FX_CHAR* fontname = NULL);
 
diff --git a/fpdfsdk/include/formfiller/FFL_CheckBox.h b/fpdfsdk/include/formfiller/FFL_CheckBox.h
index 0ac7170a16..27af16be5a 100644
--- a/fpdfsdk/include/formfiller/FFL_CheckBox.h
+++ b/fpdfsdk/include/formfiller/FFL_CheckBox.h
@@ -12,22 +12,21 @@
 class CFFL_CheckBox : public CFFL_Button {
  public:
   CFFL_CheckBox(CPDFDoc_Environment* pApp, CPDFSDK_Widget* pWidget);
-  virtual ~CFFL_CheckBox();
-
-  virtual CPWL_Wnd* NewPDFWindow(const PWL_CREATEPARAM& cp,
-                                 CPDFSDK_PageView* pPageView);
-
-  virtual FX_BOOL OnKeyDown(CPDFSDK_Annot* pAnnot,
-                            FX_UINT nKeyCode,
-                            FX_UINT nFlags);
-  virtual FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_UINT nChar, FX_UINT nFlags);
-  virtual FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
-                              CPDFSDK_Annot* pAnnot,
-                              FX_UINT nFlags,
-                              const CPDF_Point& point);
-
-  virtual FX_BOOL IsDataChanged(CPDFSDK_PageView* pPageView);
-  virtual void SaveData(CPDFSDK_PageView* pPageView);
+  ~CFFL_CheckBox() override;
+
+  // CFFL_Button
+  CPWL_Wnd* NewPDFWindow(const PWL_CREATEPARAM& cp,
+                         CPDFSDK_PageView* pPageView) override;
+  FX_BOOL OnKeyDown(CPDFSDK_Annot* pAnnot,
+                    FX_UINT nKeyCode,
+                    FX_UINT nFlags) override;
+  FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_UINT nChar, FX_UINT nFlags) override;
+  FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
+                      CPDFSDK_Annot* pAnnot,
+                      FX_UINT nFlags,
+                      const CPDF_Point& point) override;
+  FX_BOOL IsDataChanged(CPDFSDK_PageView* pPageView) override;
+  void SaveData(CPDFSDK_PageView* pPageView) override;
 };
 
 #endif  // FPDFSDK_INCLUDE_FORMFILLER_FFL_CHECKBOX_H_
diff --git a/fpdfsdk/include/formfiller/FFL_FormFiller.h b/fpdfsdk/include/formfiller/FFL_FormFiller.h
index 87fb7acec5..799154cedd 100644
--- a/fpdfsdk/include/formfiller/FFL_FormFiller.h
+++ b/fpdfsdk/include/formfiller/FFL_FormFiller.h
@@ -159,33 +159,34 @@ class CFFL_FormFiller : public IPWL_Provider, public CPWL_TimerHandler {
 class CFFL_Button : public CFFL_FormFiller {
  public:
   CFFL_Button(CPDFDoc_Environment* pApp, CPDFSDK_Annot* pWidget);
-  virtual ~CFFL_Button();
-
-  virtual void OnMouseEnter(CPDFSDK_PageView* pPageView, CPDFSDK_Annot* pAnnot);
-  virtual void OnMouseExit(CPDFSDK_PageView* pPageView, CPDFSDK_Annot* pAnnot);
-  virtual FX_BOOL OnLButtonDown(CPDFSDK_PageView* pPageView,
-                                CPDFSDK_Annot* pAnnot,
-                                FX_UINT nFlags,
-                                const CPDF_Point& point);
-  virtual FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
-                              CPDFSDK_Annot* pAnnot,
-                              FX_UINT nFlags,
-                              const CPDF_Point& point);
-  virtual FX_BOOL OnMouseMove(CPDFSDK_PageView* pPageView,
-                              CPDFSDK_Annot* pAnnot,
-                              FX_UINT nFlags,
-                              const CPDF_Point& point);
-  virtual void OnDraw(CPDFSDK_PageView* pPageView,
+  ~CFFL_Button() override;
+
+  // CFFL_FormFiller
+  void OnMouseEnter(CPDFSDK_PageView* pPageView,
+                    CPDFSDK_Annot* pAnnot) override;
+  void OnMouseExit(CPDFSDK_PageView* pPageView, CPDFSDK_Annot* pAnnot) override;
+  FX_BOOL OnLButtonDown(CPDFSDK_PageView* pPageView,
+                        CPDFSDK_Annot* pAnnot,
+                        FX_UINT nFlags,
+                        const CPDF_Point& point) override;
+  FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
+                      CPDFSDK_Annot* pAnnot,
+                      FX_UINT nFlags,
+                      const CPDF_Point& point) override;
+  FX_BOOL OnMouseMove(CPDFSDK_PageView* pPageView,
+                      CPDFSDK_Annot* pAnnot,
+                      FX_UINT nFlags,
+                      const CPDF_Point& point) override;
+  void OnDraw(CPDFSDK_PageView* pPageView,
+              CPDFSDK_Annot* pAnnot,
+              CFX_RenderDevice* pDevice,
+              CPDF_Matrix* pUser2Device,
+              FX_DWORD dwFlags) override;
+  void OnDrawDeactive(CPDFSDK_PageView* pPageView,
                       CPDFSDK_Annot* pAnnot,
                       CFX_RenderDevice* pDevice,
                       CPDF_Matrix* pUser2Device,
-                      FX_DWORD dwFlags);
-
-  virtual void OnDrawDeactive(CPDFSDK_PageView* pPageView,
-                              CPDFSDK_Annot* pAnnot,
-                              CFX_RenderDevice* pDevice,
-                              CPDF_Matrix* pUser2Device,
-                              FX_DWORD dwFlags);
+                      FX_DWORD dwFlags) override;
 
  protected:
   FX_BOOL m_bMouseIn;
diff --git a/fpdfsdk/include/formfiller/FFL_ListBox.h b/fpdfsdk/include/formfiller/FFL_ListBox.h
index 2e26069e2c..01ad2218d0 100644
--- a/fpdfsdk/include/formfiller/FFL_ListBox.h
+++ b/fpdfsdk/include/formfiller/FFL_ListBox.h
@@ -16,30 +16,26 @@ class CBA_FontMap;
 class CFFL_ListBox : public CFFL_FormFiller {
  public:
   CFFL_ListBox(CPDFDoc_Environment* pApp, CPDFSDK_Annot* pWidget);
-  virtual ~CFFL_ListBox();
-
-  virtual PWL_CREATEPARAM GetCreateParam();
-  virtual CPWL_Wnd* NewPDFWindow(const PWL_CREATEPARAM& cp,
-                                 CPDFSDK_PageView* pPageView);
-
-  virtual FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_UINT nChar, FX_UINT nFlags);
-
-  virtual FX_BOOL IsDataChanged(CPDFSDK_PageView* pPageView);
-  virtual void SaveData(CPDFSDK_PageView* pPageView);
-
-  virtual void GetActionData(CPDFSDK_PageView* pPageView,
-                             CPDF_AAction::AActionType type,
-                             PDFSDK_FieldAction& fa);
-  virtual void SetActionData(CPDFSDK_PageView* pPageView,
-                             CPDF_AAction::AActionType type,
-                             const PDFSDK_FieldAction& fa);
-
-  virtual void SaveState(CPDFSDK_PageView* pPageView);
-  virtual void RestoreState(CPDFSDK_PageView* pPageView);
-
-  virtual CPWL_Wnd* ResetPDFWindow(CPDFSDK_PageView* pPageView,
-                                   FX_BOOL bRestoreValue);
-  virtual void OnKeyStroke(FX_BOOL bKeyDown, FX_DWORD nFlag);
+  ~CFFL_ListBox() override;
+
+  // CFFL_FormFiller
+  PWL_CREATEPARAM GetCreateParam() override;
+  CPWL_Wnd* NewPDFWindow(const PWL_CREATEPARAM& cp,
+                         CPDFSDK_PageView* pPageView) override;
+  FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_UINT nChar, FX_UINT nFlags) override;
+  FX_BOOL IsDataChanged(CPDFSDK_PageView* pPageView) override;
+  void SaveData(CPDFSDK_PageView* pPageView) override;
+  void GetActionData(CPDFSDK_PageView* pPageView,
+                     CPDF_AAction::AActionType type,
+                     PDFSDK_FieldAction& fa) override;
+  void SetActionData(CPDFSDK_PageView* pPageView,
+                     CPDF_AAction::AActionType type,
+                     const PDFSDK_FieldAction& fa) override;
+  void SaveState(CPDFSDK_PageView* pPageView) override;
+  void RestoreState(CPDFSDK_PageView* pPageView) override;
+  CPWL_Wnd* ResetPDFWindow(CPDFSDK_PageView* pPageView,
+                           FX_BOOL bRestoreValue) override;
+  void OnKeyStroke(FX_BOOL bKeyDown, FX_DWORD nFlag) override;
 
  private:
   CBA_FontMap* m_pFontMap;
diff --git a/fpdfsdk/include/formfiller/FFL_PushButton.h b/fpdfsdk/include/formfiller/FFL_PushButton.h
index 5c4819400d..1bab968c88 100644
--- a/fpdfsdk/include/formfiller/FFL_PushButton.h
+++ b/fpdfsdk/include/formfiller/FFL_PushButton.h
@@ -12,17 +12,17 @@
 class CFFL_PushButton : public CFFL_Button {
  public:
   CFFL_PushButton(CPDFDoc_Environment* pApp, CPDFSDK_Annot* pAnnot);
-  virtual ~CFFL_PushButton();
+  ~CFFL_PushButton() override;
 
-  virtual CPWL_Wnd* NewPDFWindow(const PWL_CREATEPARAM& cp,
-                                 CPDFSDK_PageView* pPageView);
-
-  virtual FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_UINT nChar, FX_UINT nFlags);
-  virtual void OnDraw(CPDFSDK_PageView* pPageView,
-                      CPDFSDK_Annot* pAnnot,
-                      CFX_RenderDevice* pDevice,
-                      CPDF_Matrix* pUser2Device,
-                      FX_DWORD dwFlags);
+  // CFFL_Button
+  CPWL_Wnd* NewPDFWindow(const PWL_CREATEPARAM& cp,
+                         CPDFSDK_PageView* pPageView) override;
+  FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_UINT nChar, FX_UINT nFlags) override;
+  void OnDraw(CPDFSDK_PageView* pPageView,
+              CPDFSDK_Annot* pAnnot,
+              CFX_RenderDevice* pDevice,
+              CPDF_Matrix* pUser2Device,
+              FX_DWORD dwFlags) override;
 };
 
 #endif  // FPDFSDK_INCLUDE_FORMFILLER_FFL_PUSHBUTTON_H_
diff --git a/fpdfsdk/include/formfiller/FFL_RadioButton.h b/fpdfsdk/include/formfiller/FFL_RadioButton.h
index ba7bff4629..3a8280336a 100644
--- a/fpdfsdk/include/formfiller/FFL_RadioButton.h
+++ b/fpdfsdk/include/formfiller/FFL_RadioButton.h
@@ -12,20 +12,21 @@
 class CFFL_RadioButton : public CFFL_Button {
  public:
   CFFL_RadioButton(CPDFDoc_Environment* pApp, CPDFSDK_Annot* pAnnot);
-  virtual ~CFFL_RadioButton();
+  ~CFFL_RadioButton() override;
 
-  virtual CPWL_Wnd* NewPDFWindow(const PWL_CREATEPARAM& cp,
-                                 CPDFSDK_PageView* pPageView);
-  virtual FX_BOOL OnKeyDown(CPDFSDK_Annot* pAnnot,
-                            FX_UINT nKeyCode,
-                            FX_UINT nFlags);
-  virtual FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_UINT nChar, FX_UINT nFlags);
-  virtual FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
-                              CPDFSDK_Annot* pAnnot,
-                              FX_UINT nFlags,
-                              const CPDF_Point& point);
-  virtual FX_BOOL IsDataChanged(CPDFSDK_PageView* pPageView);
-  virtual void SaveData(CPDFSDK_PageView* pPageView);
+  // CFFL_Button
+  CPWL_Wnd* NewPDFWindow(const PWL_CREATEPARAM& cp,
+                         CPDFSDK_PageView* pPageView) override;
+  FX_BOOL OnKeyDown(CPDFSDK_Annot* pAnnot,
+                    FX_UINT nKeyCode,
+                    FX_UINT nFlags) override;
+  FX_BOOL OnChar(CPDFSDK_Annot* pAnnot, FX_UINT nChar, FX_UINT nFlags) override;
+  FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
+                      CPDFSDK_Annot* pAnnot,
+                      FX_UINT nFlags,
+                      const CPDF_Point& point) override;
+  FX_BOOL IsDataChanged(CPDFSDK_PageView* pPageView) override;
+  void SaveData(CPDFSDK_PageView* pPageView) override;
 };
 
 #endif  // FPDFSDK_INCLUDE_FORMFILLER_FFL_RADIOBUTTON_H_
diff --git a/fpdfsdk/include/fsdk_annothandler.h b/fpdfsdk/include/fsdk_annothandler.h
index 8bcf116e45..c5f2b95533 100644
--- a/fpdfsdk/include/fsdk_annothandler.h
+++ b/fpdfsdk/include/fsdk_annothandler.h
@@ -21,7 +21,7 @@ class CPDF_Rect;
 
 class IPDFSDK_AnnotHandler {
  public:
-  virtual ~IPDFSDK_AnnotHandler(){};
+  virtual ~IPDFSDK_AnnotHandler() {}
 
   virtual CFX_ByteString GetType() = 0;
 
@@ -122,104 +122,85 @@ class CPDFSDK_BFAnnotHandler : public IPDFSDK_AnnotHandler {
  public:
   CPDFSDK_BFAnnotHandler(CPDFDoc_Environment* pApp)
       : m_pApp(pApp), m_pFormFiller(NULL) {}
-  virtual ~CPDFSDK_BFAnnotHandler() {}
-
- public:
-  virtual CFX_ByteString GetType() { return CFX_ByteString("Widget"); }
-
-  virtual CFX_ByteString GetName() { return CFX_ByteString("WidgetHandler"); }
-
-  virtual FX_BOOL CanAnswer(CPDFSDK_Annot* pAnnot);
-
-  virtual CPDFSDK_Annot* NewAnnot(CPDF_Annot* pAnnot, CPDFSDK_PageView* pPage);
-
-  virtual void ReleaseAnnot(CPDFSDK_Annot* pAnnot);
-
-  virtual void DeleteAnnot(CPDFSDK_Annot* pAnnot) {}
-
-  virtual CPDF_Rect GetViewBBox(CPDFSDK_PageView* pPageView,
-                                CPDFSDK_Annot* pAnnot);
-
-  virtual FX_BOOL HitTest(CPDFSDK_PageView* pPageView,
+  ~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) override;
+  void OnDraw(CPDFSDK_PageView* pPageView,
+              CPDFSDK_Annot* pAnnot,
+              CFX_RenderDevice* pDevice,
+              CPDF_Matrix* pUser2Device,
+              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) 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) override;
+  void OnMouseExit(CPDFSDK_PageView* pPageView,
+                   CPDFSDK_Annot* pAnnot,
+                   FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonDown(CPDFSDK_PageView* pPageView,
+                        CPDFSDK_Annot* pAnnot,
+                        FX_DWORD nFlags,
+                        const CPDF_Point& point) override;
+  FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
+                      CPDFSDK_Annot* pAnnot,
+                      FX_DWORD nFlags,
+                      const CPDF_Point& point) override;
+  FX_BOOL OnLButtonDblClk(CPDFSDK_PageView* pPageView,
                           CPDFSDK_Annot* pAnnot,
-                          const CPDF_Point& point);
-
-  virtual void OnDraw(CPDFSDK_PageView* pPageView,
+                          FX_DWORD nFlags,
+                          const CPDF_Point& point) override;
+  FX_BOOL OnMouseMove(CPDFSDK_PageView* pPageView,
                       CPDFSDK_Annot* pAnnot,
-                      CFX_RenderDevice* pDevice,
-                      CPDF_Matrix* pUser2Device,
-                      FX_DWORD dwFlags);
-
-  virtual void OnDrawSleep(CPDFSDK_PageView* pPageView,
-                           CPDFSDK_Annot* pAnnot,
-                           CFX_RenderDevice* pDevice,
-                           CPDF_Matrix* pUser2Device,
-                           const CPDF_Rect& rcWindow,
-                           FX_DWORD dwFlags) {}
-
-  virtual void OnCreate(CPDFSDK_Annot* pAnnot);
-
-  virtual void OnLoad(CPDFSDK_Annot* pAnnot);
-
-  virtual void OnDelete(CPDFSDK_Annot* pAnnot) {}
-
-  virtual void OnRelease(CPDFSDK_Annot* pAnnot) {}
-
-  virtual void OnMouseEnter(CPDFSDK_PageView* pPageView,
-                            CPDFSDK_Annot* pAnnot,
-                            FX_DWORD nFlag);
-  virtual void OnMouseExit(CPDFSDK_PageView* pPageView,
-                           CPDFSDK_Annot* pAnnot,
-                           FX_DWORD nFlag);
-
-  virtual FX_BOOL OnLButtonDown(CPDFSDK_PageView* pPageView,
-                                CPDFSDK_Annot* pAnnot,
-                                FX_DWORD nFlags,
-                                const CPDF_Point& point);
-  virtual FX_BOOL OnLButtonUp(CPDFSDK_PageView* pPageView,
-                              CPDFSDK_Annot* pAnnot,
-                              FX_DWORD nFlags,
-                              const CPDF_Point& point);
-  virtual FX_BOOL OnLButtonDblClk(CPDFSDK_PageView* pPageView,
-                                  CPDFSDK_Annot* pAnnot,
-                                  FX_DWORD nFlags,
-                                  const CPDF_Point& point);
-  virtual FX_BOOL OnMouseMove(CPDFSDK_PageView* pPageView,
-                              CPDFSDK_Annot* pAnnot,
-                              FX_DWORD nFlags,
-                              const CPDF_Point& point);
-  virtual FX_BOOL OnMouseWheel(CPDFSDK_PageView* pPageView,
-                               CPDFSDK_Annot* pAnnot,
-                               FX_DWORD nFlags,
-                               short zDelta,
-                               const CPDF_Point& point);
-  virtual FX_BOOL OnRButtonDown(CPDFSDK_PageView* pPageView,
-                                CPDFSDK_Annot* pAnnot,
-                                FX_DWORD nFlags,
-                                const CPDF_Point& point);
-  virtual FX_BOOL OnRButtonUp(CPDFSDK_PageView* pPageView,
-                              CPDFSDK_Annot* pAnnot,
-                              FX_DWORD nFlags,
-                              const CPDF_Point& point);
-  virtual FX_BOOL OnRButtonDblClk(CPDFSDK_PageView* pPageView,
-                                  CPDFSDK_Annot* pAnnot,
-                                  FX_DWORD nFlags,
-                                  const CPDF_Point& point) {
+                      FX_DWORD nFlags,
+                      const CPDF_Point& point) override;
+  FX_BOOL OnMouseWheel(CPDFSDK_PageView* pPageView,
+                       CPDFSDK_Annot* pAnnot,
+                       FX_DWORD nFlags,
+                       short zDelta,
+                       const CPDF_Point& point) override;
+  FX_BOOL OnRButtonDown(CPDFSDK_PageView* pPageView,
+                        CPDFSDK_Annot* pAnnot,
+                        FX_DWORD nFlags,
+                        const CPDF_Point& point) override;
+  FX_BOOL OnRButtonUp(CPDFSDK_PageView* pPageView,
+                      CPDFSDK_Annot* pAnnot,
+                      FX_DWORD nFlags,
+                      const CPDF_Point& point) override;
+  FX_BOOL OnRButtonDblClk(CPDFSDK_PageView* pPageView,
+                          CPDFSDK_Annot* pAnnot,
+                          FX_DWORD nFlags,
+                          const CPDF_Point& point) override {
     return FALSE;
   }
-
-  // by wjm.
-  virtual FX_BOOL OnChar(CPDFSDK_Annot* pAnnot,
-                         FX_DWORD nChar,
-                         FX_DWORD nFlags);
-  virtual FX_BOOL OnKeyDown(CPDFSDK_Annot* pAnnot, int nKeyCode, int nFlag);
-  virtual FX_BOOL OnKeyUp(CPDFSDK_Annot* pAnnot, int nKeyCode, int nFlag);
-
-  virtual void OnDeSelected(CPDFSDK_Annot* pAnnot) {}
-  virtual void OnSelected(CPDFSDK_Annot* pAnnot) {}
-
-  virtual FX_BOOL OnSetFocus(CPDFSDK_Annot* pAnnot, FX_DWORD nFlag);
-  virtual 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; }
@@ -233,7 +214,7 @@ class CPDFSDK_BFAnnotHandler : public IPDFSDK_AnnotHandler {
 class CPDFSDK_AnnotHandlerMgr {
  public:
   // Destroy the handler
-  CPDFSDK_AnnotHandlerMgr(CPDFDoc_Environment* pApp);
+  explicit CPDFSDK_AnnotHandlerMgr(CPDFDoc_Environment* pApp);
   virtual ~CPDFSDK_AnnotHandlerMgr();
 
  public:
diff --git a/fpdfsdk/include/fsdk_baseform.h b/fpdfsdk/include/fsdk_baseform.h
index bb3e7cd653..514a2f8b9b 100644
--- a/fpdfsdk/include/fsdk_baseform.h
+++ b/fpdfsdk/include/fsdk_baseform.h
@@ -56,25 +56,25 @@ typedef struct _PDFSDK_FieldAction {
   FX_BOOL bFieldFull;        // in
   FX_BOOL bRC;               // in[out]
 } PDFSDK_FieldAction;
+
 class CPDFSDK_Widget : public CPDFSDK_Annot {
  public:
   CPDFSDK_Widget(CPDF_Annot* pAnnot,
                  CPDFSDK_PageView* pPageView,
                  CPDFSDK_InterForm* pInterForm);
-  virtual ~CPDFSDK_Widget();
+  ~CPDFSDK_Widget() override;
 
-  virtual CFX_ByteString GetSubType() const;
+  // CPDFSDK_Annot
+  CFX_ByteString GetSubType() const override;
+  CPDF_Action GetAAction(CPDF_AAction::AActionType eAAT) override;
 
-  virtual CPDF_Action GetAAction(CPDF_AAction::AActionType eAAT);
+  int GetLayoutOrder() const override { return 2; }
 
+  // Possible values from PDF 32000-1:2008, table 221.
+  // FIELDFLAG_READONLY
+  // FIELDFLAG_REQUIRED
+  // FIELDFLAG_NOEXPORT
   int GetFieldType() const;
-  // define layout order to 2.
-  virtual int GetLayoutOrder() const { return 2; }
-  /*
-  FIELDFLAG_READONLY
-  FIELDFLAG_REQUIRED
-  FIELDFLAG_NOEXPORT
-  */
 
   int GetFieldFlags() const;
   int GetRotate() const;
diff --git a/fpdfsdk/include/fsdk_define.h b/fpdfsdk/include/fsdk_define.h
index 310fa43bd0..2195d2d04a 100644
--- a/fpdfsdk/include/fsdk_define.h
+++ b/fpdfsdk/include/fsdk_define.h
@@ -46,15 +46,13 @@ class IFSDK_PAUSE_Adapter;
 class CPDF_CustomAccess final : public IFX_FileRead {
  public:
   CPDF_CustomAccess(FPDF_FILEACCESS* pFileAccess);
-  ~CPDF_CustomAccess() {}
+  ~CPDF_CustomAccess() override {}
 
-  virtual FX_FILESIZE GetSize() override { return m_FileAccess.m_FileLen; }
+  FX_FILESIZE GetSize() override { return m_FileAccess.m_FileLen; }
 
-  virtual void Release() override { delete this; }
+  void Release() override { delete this; }
 
-  virtual FX_BOOL ReadBlock(void* buffer,
-                            FX_FILESIZE offset,
-                            size_t size) override;
+  FX_BOOL ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override;
 
  private:
   FPDF_FILEACCESS m_FileAccess;
diff --git a/fpdfsdk/include/fsdk_mgr.h b/fpdfsdk/include/fsdk_mgr.h
index 4cb0ae8c15..6b7e2873e7 100644
--- a/fpdfsdk/include/fsdk_mgr.h
+++ b/fpdfsdk/include/fsdk_mgr.h
@@ -357,7 +357,7 @@ template <class TYPE>
 class CGW_ArrayTemplate : public CFX_ArrayTemplate<TYPE> {
  public:
   CGW_ArrayTemplate() {}
-  virtual ~CGW_ArrayTemplate() {}
+  ~CGW_ArrayTemplate() {}
 
   typedef int (*LP_COMPARE)(TYPE p1, TYPE p2);
 
diff --git a/fpdfsdk/include/fsdk_rendercontext.h b/fpdfsdk/include/fsdk_rendercontext.h
index 9d1dabd41c..16f8ff88cf 100644
--- a/fpdfsdk/include/fsdk_rendercontext.h
+++ b/fpdfsdk/include/fsdk_rendercontext.h
@@ -31,8 +31,10 @@ class CRenderContext {
 
 class IFSDK_PAUSE_Adapter : public IFX_Pause {
  public:
-  IFSDK_PAUSE_Adapter(IFSDK_PAUSE* IPause);
-  FX_BOOL NeedToPauseNow();
+  explicit IFSDK_PAUSE_Adapter(IFSDK_PAUSE* IPause);
+  ~IFSDK_PAUSE_Adapter() override;
+
+  FX_BOOL NeedToPauseNow() override;
 
  private:
   IFSDK_PAUSE* m_IPause;
diff --git a/fpdfsdk/include/fxedit/fx_edit.h b/fpdfsdk/include/fxedit/fx_edit.h
index bfe6a254ff..4f8b2fbd67 100644
--- a/fpdfsdk/include/fxedit/fx_edit.h
+++ b/fpdfsdk/include/fxedit/fx_edit.h
@@ -477,12 +477,11 @@ class IFX_Edit {
                                        FX_COLORREF color);
 
  protected:
-  ~IFX_Edit() {}
+  virtual ~IFX_Edit() {}
 };
 
 class IFX_List_Notify {
  public:
-  virtual ~IFX_List_Notify() {}
   // set the horizontal scrollbar information.
   virtual void IOnSetScrollInfoX(FX_FLOAT fPlateMin,
                                  FX_FLOAT fPlateMax,
@@ -503,6 +502,9 @@ class IFX_List_Notify {
   virtual void IOnSetScrollPosY(FX_FLOAT fy) = 0;
   // Invalidate the rectangle relative to the bounding box of edit.
   virtual void IOnInvalidateRect(CPDF_Rect* pRect) = 0;
+
+ protected:
+  virtual ~IFX_List_Notify() {}
 };
 
 class IFX_List {
@@ -563,7 +565,7 @@ class IFX_List {
   virtual FX_BOOL OnChar(FX_WORD nChar, FX_BOOL bShift, FX_BOOL bCtrl) = 0;
 
  protected:
-  ~IFX_List() {}
+  virtual ~IFX_List() {}
 };
 
 #endif  // FPDFSDK_INCLUDE_FXEDIT_FX_EDIT_H_
diff --git a/fpdfsdk/include/fxedit/fxet_edit.h b/fpdfsdk/include/fxedit/fxet_edit.h
index 2cb7c99720..c7c17a4378 100644
--- a/fpdfsdk/include/fxedit/fxet_edit.h
+++ b/fpdfsdk/include/fxedit/fxet_edit.h
@@ -269,6 +269,7 @@ class CFX_Edit_Undo {
 class CFX_Edit_UndoItem : public IFX_Edit_UndoItem {
  public:
   CFX_Edit_UndoItem() : m_bFirst(TRUE), m_bLast(TRUE) {}
+  ~CFX_Edit_UndoItem() override {}
 
   CFX_WideString GetUndoTitle() override { return L""; }
 
@@ -310,10 +311,11 @@ class CFXEU_InsertWord : public CFX_Edit_UndoItem {
                    FX_WORD word,
                    int32_t charset,
                    const CPVT_WordProps* pWordProps);
-  virtual ~CFXEU_InsertWord();
+  ~CFXEU_InsertWord() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -332,10 +334,11 @@ class CFXEU_InsertReturn : public CFX_Edit_UndoItem {
                      const CPVT_WordPlace& wpNewPlace,
                      const CPVT_SecProps* pSecProps,
                      const CPVT_WordProps* pWordProps);
-  virtual ~CFXEU_InsertReturn();
+  ~CFXEU_InsertReturn() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -355,10 +358,11 @@ class CFXEU_Backspace : public CFX_Edit_UndoItem {
                   int32_t charset,
                   const CPVT_SecProps& SecProps,
                   const CPVT_WordProps& WordProps);
-  virtual ~CFXEU_Backspace();
+  ~CFXEU_Backspace() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -381,10 +385,11 @@ class CFXEU_Delete : public CFX_Edit_UndoItem {
                const CPVT_SecProps& SecProps,
                const CPVT_WordProps& WordProps,
                FX_BOOL bSecEnd);
-  virtual ~CFXEU_Delete();
+  ~CFXEU_Delete() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -403,10 +408,11 @@ class CFXEU_Clear : public CFX_Edit_UndoItem {
   CFXEU_Clear(CFX_Edit* pEdit,
               const CPVT_WordRange& wrSel,
               const CFX_WideString& swText);
-  virtual ~CFXEU_Clear();
+  ~CFXEU_Clear() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -425,10 +431,11 @@ class CFXEU_ClearRich : public CFX_Edit_UndoItem {
                   int32_t charset,
                   const CPVT_SecProps& SecProps,
                   const CPVT_WordProps& WordProps);
-  virtual ~CFXEU_ClearRich();
+  ~CFXEU_ClearRich() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -451,10 +458,11 @@ class CFXEU_InsertText : public CFX_Edit_UndoItem {
                    int32_t charset,
                    const CPVT_SecProps* pSecProps,
                    const CPVT_WordProps* pWordProps);
-  virtual ~CFXEU_InsertText();
+  ~CFXEU_InsertText() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -477,10 +485,11 @@ class CFXEU_SetSecProps : public CFX_Edit_UndoItem {
                     const CPVT_SecProps& newsecprops,
                     const CPVT_WordProps& newwordprops,
                     const CPVT_WordRange& range);
-  virtual ~CFXEU_SetSecProps();
+  ~CFXEU_SetSecProps() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -502,10 +511,11 @@ class CFXEU_SetWordProps : public CFX_Edit_UndoItem {
                      const CPVT_WordProps& oldprops,
                      const CPVT_WordProps& newprops,
                      const CPVT_WordRange& range);
-  virtual ~CFXEU_SetWordProps();
+  ~CFXEU_SetWordProps() override;
 
-  void Redo();
-  void Undo();
+  // CFX_Edit_UndoItem
+  void Redo() override;
+  void Undo() override;
 
  private:
   CFX_Edit* m_pEdit;
@@ -533,79 +543,125 @@ class CFX_Edit : public IFX_Edit {
 
  public:
   CFX_Edit(IPDF_VariableText* pVT);
-  virtual ~CFX_Edit();
-
-  void SetFontMap(IFX_Edit_FontMap* pFontMap);
-  void SetVTProvider(IPDF_VariableText_Provider* pProvider);
-  void SetNotify(IFX_Edit_Notify* pNotify);
-  void SetOprNotify(IFX_Edit_OprNotify* pOprNotify);
-  IFX_Edit_Iterator* GetIterator();
-  IPDF_VariableText* GetVariableText();
-  IFX_Edit_FontMap* GetFontMap();
-
-  void Initialize();
-  void SetPlateRect(const CPDF_Rect& rect, FX_BOOL bPaint = TRUE);
-  void SetScrollPos(const CPDF_Point& point);
-
-  void SetAlignmentH(int32_t nFormat = 0, FX_BOOL bPaint = TRUE);
-  void SetAlignmentV(int32_t nFormat = 0, FX_BOOL bPaint = TRUE);
-  void SetPasswordChar(FX_WORD wSubWord = '*', FX_BOOL bPaint = TRUE);
-  void SetLimitChar(int32_t nLimitChar = 0, FX_BOOL bPaint = TRUE);
-  void SetCharArray(int32_t nCharArray = 0, FX_BOOL bPaint = TRUE);
-  void SetCharSpace(FX_FLOAT fCharSpace = 0.0f, FX_BOOL bPaint = TRUE);
-  void SetHorzScale(int32_t nHorzScale = 100, FX_BOOL bPaint = TRUE);
-  void SetLineLeading(FX_FLOAT fLineLeading, FX_BOOL bPaint = TRUE);
-  void SetMultiLine(FX_BOOL bMultiLine = TRUE, FX_BOOL bPaint = TRUE);
-  void SetAutoReturn(FX_BOOL bAuto = TRUE, FX_BOOL bPaint = TRUE);
-  void SetAutoFontSize(FX_BOOL bAuto = TRUE, FX_BOOL bPaint = TRUE);
-  void SetAutoScroll(FX_BOOL bAuto = TRUE, FX_BOOL bPaint = TRUE);
-  void SetFontSize(FX_FLOAT fFontSize, FX_BOOL bPaint = TRUE);
-  void SetTextOverflow(FX_BOOL bAllowed = FALSE, FX_BOOL bPaint = TRUE);
-
-  FX_BOOL IsRichText() const;
-  void SetRichText(FX_BOOL bRichText = TRUE, FX_BOOL bPaint = TRUE);
-  FX_BOOL SetRichFontSize(FX_FLOAT fFontSize);
-  FX_BOOL SetRichFontIndex(int32_t nFontIndex);
-  FX_BOOL SetRichTextColor(FX_COLORREF dwColor);
-  FX_BOOL SetRichTextScript(int32_t nScriptType);
-  FX_BOOL SetRichTextBold(FX_BOOL bBold = TRUE);
-  FX_BOOL SetRichTextItalic(FX_BOOL bItalic = TRUE);
-  FX_BOOL SetRichTextUnderline(FX_BOOL bUnderline = TRUE);
-  FX_BOOL SetRichTextCrossout(FX_BOOL bCrossout = TRUE);
-  FX_BOOL SetRichTextCharSpace(FX_FLOAT fCharSpace);
-  FX_BOOL SetRichTextHorzScale(int32_t nHorzScale = 100);
-  FX_BOOL SetRichTextLineLeading(FX_FLOAT fLineLeading);
-  FX_BOOL SetRichTextLineIndent(FX_FLOAT fLineIndent);
-  FX_BOOL SetRichTextAlignment(int32_t nAlignment);
-
-  void OnMouseDown(const CPDF_Point& point, FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnMouseMove(const CPDF_Point& point, FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_UP(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_DOWN(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_LEFT(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_RIGHT(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_HOME(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_END(FX_BOOL bShift, FX_BOOL bCtrl);
-
+  ~CFX_Edit() override;
+
+  // IFX_Edit
+  void SetFontMap(IFX_Edit_FontMap* pFontMap) override;
+  void SetVTProvider(IPDF_VariableText_Provider* pProvider) override;
+  void SetNotify(IFX_Edit_Notify* pNotify) override;
+  void SetOprNotify(IFX_Edit_OprNotify* pOprNotify) override;
+  IFX_Edit_Iterator* GetIterator() override;
+  IPDF_VariableText* GetVariableText() override;
+  IFX_Edit_FontMap* GetFontMap() override;
+  void Initialize() override;
+  void SetPlateRect(const CPDF_Rect& rect, FX_BOOL bPaint = TRUE) override;
+  void SetScrollPos(const CPDF_Point& point) override;
+  void SetAlignmentH(int32_t nFormat = 0, FX_BOOL bPaint = TRUE) override;
+  void SetAlignmentV(int32_t nFormat = 0, FX_BOOL bPaint = TRUE) override;
+  void SetPasswordChar(FX_WORD wSubWord = '*', FX_BOOL bPaint = TRUE) override;
+  void SetLimitChar(int32_t nLimitChar = 0, FX_BOOL bPaint = TRUE) override;
+  void SetCharArray(int32_t nCharArray = 0, FX_BOOL bPaint = TRUE) override;
+  void SetCharSpace(FX_FLOAT fCharSpace = 0.0f, FX_BOOL bPaint = TRUE) override;
+  void SetHorzScale(int32_t nHorzScale = 100, FX_BOOL bPaint = TRUE) override;
+  void SetLineLeading(FX_FLOAT fLineLeading, FX_BOOL bPaint = TRUE) override;
+  void SetMultiLine(FX_BOOL bMultiLine = TRUE, FX_BOOL bPaint = TRUE) override;
+  void SetAutoReturn(FX_BOOL bAuto = TRUE, FX_BOOL bPaint = TRUE) override;
+  void SetAutoFontSize(FX_BOOL bAuto = TRUE, FX_BOOL bPaint = TRUE) override;
+  void SetAutoScroll(FX_BOOL bAuto = TRUE, FX_BOOL bPaint = TRUE) override;
+  void SetFontSize(FX_FLOAT fFontSize, FX_BOOL bPaint = TRUE) override;
+  void SetTextOverflow(FX_BOOL bAllowed = FALSE,
+                       FX_BOOL bPaint = TRUE) override;
+  FX_BOOL IsRichText() const override;
+  void SetRichText(FX_BOOL bRichText = TRUE, FX_BOOL bPaint = TRUE) override;
+  FX_BOOL SetRichFontSize(FX_FLOAT fFontSize) override;
+  FX_BOOL SetRichFontIndex(int32_t nFontIndex) override;
+  FX_BOOL SetRichTextColor(FX_COLORREF dwColor) override;
+  FX_BOOL SetRichTextScript(int32_t nScriptType) override;
+  FX_BOOL SetRichTextBold(FX_BOOL bBold = TRUE) override;
+  FX_BOOL SetRichTextItalic(FX_BOOL bItalic = TRUE) override;
+  FX_BOOL SetRichTextUnderline(FX_BOOL bUnderline = TRUE) override;
+  FX_BOOL SetRichTextCrossout(FX_BOOL bCrossout = TRUE) override;
+  FX_BOOL SetRichTextCharSpace(FX_FLOAT fCharSpace) override;
+  FX_BOOL SetRichTextHorzScale(int32_t nHorzScale = 100) override;
+  FX_BOOL SetRichTextLineLeading(FX_FLOAT fLineLeading) override;
+  FX_BOOL SetRichTextLineIndent(FX_FLOAT fLineIndent) override;
+  FX_BOOL SetRichTextAlignment(int32_t nAlignment) override;
+  void OnMouseDown(const CPDF_Point& point,
+                   FX_BOOL bShift,
+                   FX_BOOL bCtrl) override;
+  void OnMouseMove(const CPDF_Point& point,
+                   FX_BOOL bShift,
+                   FX_BOOL bCtrl) override;
+  void OnVK_UP(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_DOWN(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_LEFT(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_RIGHT(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_HOME(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_END(FX_BOOL bShift, FX_BOOL bCtrl) override;
   void SetText(const FX_WCHAR* text,
                int32_t charset = DEFAULT_CHARSET,
                const CPVT_SecProps* pSecProps = NULL,
-               const CPVT_WordProps* pWordProps = NULL);
+               const CPVT_WordProps* pWordProps = NULL) override;
   FX_BOOL InsertWord(FX_WORD word,
                      int32_t charset = DEFAULT_CHARSET,
-                     const CPVT_WordProps* pWordProps = NULL);
+                     const CPVT_WordProps* pWordProps = NULL) override;
   FX_BOOL InsertReturn(const CPVT_SecProps* pSecProps = NULL,
-                       const CPVT_WordProps* pWordProps = NULL);
-  FX_BOOL Backspace();
-  FX_BOOL Delete();
-  FX_BOOL Clear();
-  FX_BOOL Empty();
+                       const CPVT_WordProps* pWordProps = NULL) override;
+  FX_BOOL Backspace() override;
+  FX_BOOL Delete() override;
+  FX_BOOL Clear() override;
   FX_BOOL InsertText(const FX_WCHAR* text,
                      int32_t charset = DEFAULT_CHARSET,
                      const CPVT_SecProps* pSecProps = NULL,
-                     const CPVT_WordProps* pWordProps = NULL);
-  FX_BOOL Redo();
-  FX_BOOL Undo();
+                     const CPVT_WordProps* pWordProps = NULL) override;
+  FX_BOOL Redo() override;
+  FX_BOOL Undo() override;
+  int32_t WordPlaceToWordIndex(const CPVT_WordPlace& place) const override;
+  CPVT_WordPlace WordIndexToWordPlace(int32_t index) const override;
+  CPVT_WordPlace GetLineBeginPlace(const CPVT_WordPlace& place) const override;
+  CPVT_WordPlace GetLineEndPlace(const CPVT_WordPlace& place) const override;
+  CPVT_WordPlace GetSectionBeginPlace(
+      const CPVT_WordPlace& place) const override;
+  CPVT_WordPlace GetSectionEndPlace(const CPVT_WordPlace& place) const override;
+  CPVT_WordPlace SearchWordPlace(const CPDF_Point& point) const override;
+  int32_t GetCaret() const override;
+  CPVT_WordPlace GetCaretWordPlace() const override;
+  CFX_WideString GetSelText() const override;
+  CFX_WideString GetText() const override;
+  FX_FLOAT GetFontSize() const override;
+  FX_WORD GetPasswordChar() const override;
+  CPDF_Point GetScrollPos() const override;
+  int32_t GetCharArray() const override;
+  CPDF_Rect GetPlateRect() const override;
+  CPDF_Rect GetContentRect() const override;
+  CFX_WideString GetRangeText(const CPVT_WordRange& range) const override;
+  int32_t GetHorzScale() const override;
+  FX_FLOAT GetCharSpace() const override;
+  int32_t GetTotalWords() const override;
+  void SetSel(int32_t nStartChar, int32_t nEndChar) override;
+  void GetSel(int32_t& nStartChar, int32_t& nEndChar) const override;
+  void SelectAll() override;
+  void SelectNone() override;
+  FX_BOOL IsSelected() const override;
+  void Paint() override;
+  void EnableNotify(FX_BOOL bNotify) override;
+  void EnableRefresh(FX_BOOL bRefresh) override;
+  void RefreshWordRange(const CPVT_WordRange& wr) override;
+  void SetCaret(int32_t nPos) override;
+  CPVT_WordRange GetWholeWordRange() const override;
+  CPVT_WordRange GetSelectWordRange() const override;
+  void EnableUndo(FX_BOOL bUndo) override;
+  void EnableOprNotify(FX_BOOL bNotify) override;
+  FX_BOOL IsTextFull() const override;
+  FX_BOOL IsTextOverflow() const;
+  FX_BOOL CanUndo() const override;
+  FX_BOOL CanRedo() const override;
+  FX_BOOL IsModified() const override;
+  CPVT_WordRange GetVisibleWordRange() const override;
+  void AddUndoItem(IFX_Edit_UndoItem* pUndoItem) override;
+
+  FX_BOOL Empty();
+
   CPVT_WordPlace DoInsertText(const CPVT_WordPlace& place,
                               const FX_WCHAR* text,
                               int32_t charset,
@@ -613,50 +669,19 @@ class CFX_Edit : public IFX_Edit {
                               const CPVT_WordProps* pWordProps);
   int32_t GetCharSetFromUnicode(FX_WORD word, int32_t nOldCharset);
 
-  int32_t WordPlaceToWordIndex(const CPVT_WordPlace& place) const;
-  CPVT_WordPlace WordIndexToWordPlace(int32_t index) const;
-
-  CPVT_WordPlace GetLineBeginPlace(const CPVT_WordPlace& place) const;
-  CPVT_WordPlace GetLineEndPlace(const CPVT_WordPlace& place) const;
-  CPVT_WordPlace GetSectionBeginPlace(const CPVT_WordPlace& place) const;
-  CPVT_WordPlace GetSectionEndPlace(const CPVT_WordPlace& place) const;
-  CPVT_WordPlace SearchWordPlace(const CPDF_Point& point) const;
-
-  int32_t GetCaret() const;
-  CPVT_WordPlace GetCaretWordPlace() const;
-  CFX_WideString GetSelText() const;
-  CFX_WideString GetText() const;
-  FX_FLOAT GetFontSize() const;
-  FX_WORD GetPasswordChar() const;
-  CPDF_Point GetScrollPos() const;
-  int32_t GetCharArray() const;
-  CPDF_Rect GetPlateRect() const;
-  CPDF_Rect GetContentRect() const;
-  CFX_WideString GetRangeText(const CPVT_WordRange& range) const;
-  int32_t GetHorzScale() const;
-  FX_FLOAT GetCharSpace() const;
-  int32_t GetTotalWords() const;
   int32_t GetTotalLines() const;
 
-  void SetSel(int32_t nStartChar, int32_t nEndChar);
-  void GetSel(int32_t& nStartChar, int32_t& nEndChar) const;
-
  private:
-  void SelectAll();
-  void SelectNone();
   void SetSel(const CPVT_WordPlace& begin, const CPVT_WordPlace& end);
-  FX_BOOL IsSelected() const;
 
   void RearrangeAll();
   void RearrangePart(const CPVT_WordRange& range);
-  void Paint();
   void ScrollToCaret();
   void SetScrollInfo();
   void SetScrollPosX(FX_FLOAT fx);
   void SetScrollPosY(FX_FLOAT fy);
   void SetScrollLimit();
   void SetContentChanged();
-  void EnableNotify(FX_BOOL bNotify);
 
   void SetText(const FX_WCHAR* text,
                int32_t charset,
@@ -705,40 +730,25 @@ class CFX_Edit : public IFX_Edit {
   inline CPDF_Rect VTToEdit(const CPDF_Rect& rect) const;
   inline CPDF_Rect EditToVT(const CPDF_Rect& rect) const;
 
-  void EnableRefresh(FX_BOOL bRefresh);
   void Refresh(REFRESH_PLAN_E ePlan,
                const CPVT_WordRange* pRange1 = NULL,
                const CPVT_WordRange* pRange2 = NULL);
   void RefreshPushLineRects(const CPVT_WordRange& wr);
   void RefreshPushRandomRects(const CPVT_WordRange& wr);
-  void RefreshWordRange(const CPVT_WordRange& wr);
 
-  void SetCaret(int32_t nPos);
   void SetCaret(const CPVT_WordPlace& place);
   void SetCaretInfo();
   void SetCaretOrigin();
   void SetCaretChange();
 
-  CPVT_WordRange GetWholeWordRange() const;
-  CPVT_WordRange GetVisibleWordRange() const;
   CPVT_WordRange GetLatinWordsRange(const CPVT_WordPlace& place) const;
   CPVT_WordRange CombineWordRange(const CPVT_WordRange& wr1,
                                   const CPVT_WordRange& wr2);
-  CPVT_WordRange GetSelectWordRange() const;
-
-  void EnableUndo(FX_BOOL bUndo);
-  void EnableOprNotify(FX_BOOL bNotify);
 
-  FX_BOOL IsTextFull() const;
-  FX_BOOL IsTextOverflow() const;
-  FX_BOOL CanUndo() const;
-  FX_BOOL CanRedo() const;
-  FX_BOOL IsModified() const;
 
   void BeginGroupUndo(const CFX_WideString& sTitle);
   void EndGroupUndo();
   void AddEditUndoItem(CFX_Edit_UndoItem* pEditUndoItem);
-  void AddUndoItem(IFX_Edit_UndoItem* pUndoItem);
 
   void SetPageInfo(const CPVT_WordPlace& place);
   CPVT_WordPlace SearchPageEndPlace(const CPVT_WordPlace& wpPageBegin,
@@ -779,22 +789,22 @@ class CFX_Edit : public IFX_Edit {
 class CFX_Edit_Iterator : public IFX_Edit_Iterator {
  public:
   CFX_Edit_Iterator(CFX_Edit* pEdit, IPDF_VariableText_Iterator* pVTIterator);
-  virtual ~CFX_Edit_Iterator();
-
-  FX_BOOL NextWord();
-  FX_BOOL NextLine();
-  FX_BOOL NextSection();
-  FX_BOOL PrevWord();
-  FX_BOOL PrevLine();
-  FX_BOOL PrevSection();
-
-  FX_BOOL GetWord(CPVT_Word& word) const;
-  FX_BOOL GetLine(CPVT_Line& line) const;
-  FX_BOOL GetSection(CPVT_Section& section) const;
-  void SetAt(int32_t nWordIndex);
-  void SetAt(const CPVT_WordPlace& place);
-  const CPVT_WordPlace& GetAt() const;
-  IFX_Edit* GetEdit() const;
+  ~CFX_Edit_Iterator() override;
+
+  // IFX_Edit_Iterator
+  FX_BOOL NextWord() override;
+  FX_BOOL NextLine() override;
+  FX_BOOL NextSection() override;
+  FX_BOOL PrevWord() override;
+  FX_BOOL PrevLine() override;
+  FX_BOOL PrevSection() override;
+  FX_BOOL GetWord(CPVT_Word& word) const override;
+  FX_BOOL GetLine(CPVT_Line& line) const override;
+  FX_BOOL GetSection(CPVT_Section& section) const override;
+  void SetAt(int32_t nWordIndex) override;
+  void SetAt(const CPVT_WordPlace& place) override;
+  const CPVT_WordPlace& GetAt() const override;
+  IFX_Edit* GetEdit() const override;
 
  private:
   CFX_Edit* m_pEdit;
diff --git a/fpdfsdk/include/fxedit/fxet_list.h b/fpdfsdk/include/fxedit/fxet_list.h
index 8c5584a118..f032078a1c 100644
--- a/fpdfsdk/include/fxedit/fxet_list.h
+++ b/fpdfsdk/include/fxedit/fxet_list.h
@@ -54,6 +54,8 @@ class CLST_Rect : public CPDF_Rect {
     bottom = rect.bottom;
   }
 
+  ~CLST_Rect() {}
+
   void Default() { left = top = right = bottom = 0.0f; }
 
   const CLST_Rect operator=(const CPDF_Rect& rect) {
@@ -285,45 +287,47 @@ class CPLST_Select {
 class CFX_ListCtrl : public CFX_List {
  public:
   CFX_ListCtrl();
-  virtual ~CFX_ListCtrl();
-
- public:
-  void SetNotify(IFX_List_Notify* pNotify);
-
-  void OnMouseDown(const CPDF_Point& point, FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnMouseMove(const CPDF_Point& point, FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_UP(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_DOWN(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_LEFT(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_RIGHT(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_HOME(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK_END(FX_BOOL bShift, FX_BOOL bCtrl);
-  void OnVK(int32_t nItemIndex, FX_BOOL bShift, FX_BOOL bCtrl);
-  FX_BOOL OnChar(FX_WORD nChar, FX_BOOL bShift, FX_BOOL bCtrl);
+  ~CFX_ListCtrl() override;
+
+  // CFX_List
+  void SetNotify(IFX_List_Notify* pNotify) override;
+  void OnMouseDown(const CPDF_Point& point,
+                   FX_BOOL bShift,
+                   FX_BOOL bCtrl) override;
+  void OnMouseMove(const CPDF_Point& point,
+                   FX_BOOL bShift,
+                   FX_BOOL bCtrl) override;
+  void OnVK_UP(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_DOWN(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_LEFT(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_RIGHT(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_HOME(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK_END(FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void OnVK(int32_t nItemIndex, FX_BOOL bShift, FX_BOOL bCtrl) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_BOOL bShift, FX_BOOL bCtrl) override;
+  void SetPlateRect(const CPDF_Rect& rect) override;
+  void SetScrollPos(const CPDF_Point& point) override;
+  void ScrollToListItem(int32_t nItemIndex) override;
+  CPDF_Rect GetItemRect(int32_t nIndex) const override;
+  int32_t GetCaret() const override { return m_nCaretIndex; }
+  int32_t GetSelect() const override { return m_nSelItem; }
+  int32_t GetTopItem() const override;
+  CPDF_Rect GetContentRect() const override;
+  int32_t GetItemIndex(const CPDF_Point& point) const override;
+  void AddString(const FX_WCHAR* string) override;
+  void SetTopItem(int32_t nIndex) override;
+  void Select(int32_t nItemIndex) override;
+  void SetCaret(int32_t nItemIndex) override;
+  void Empty() override;
+  void Cancel() override;
+  CFX_WideString GetText() const override;
+  void ReArrange(int32_t nItemIndex) override;
 
   virtual CPDF_Point InToOut(const CPDF_Point& point) const;
   virtual CPDF_Point OutToIn(const CPDF_Point& point) const;
   virtual CPDF_Rect InToOut(const CPDF_Rect& rect) const;
   virtual CPDF_Rect OutToIn(const CPDF_Rect& rect) const;
 
-  virtual void SetPlateRect(const CPDF_Rect& rect);
-  void SetScrollPos(const CPDF_Point& point);
-  void ScrollToListItem(int32_t nItemIndex);
-  virtual CPDF_Rect GetItemRect(int32_t nIndex) const;
-  int32_t GetCaret() const { return m_nCaretIndex; }
-  int32_t GetSelect() const { return m_nSelItem; }
-  int32_t GetTopItem() const;
-  virtual CPDF_Rect GetContentRect() const;
-  virtual int32_t GetItemIndex(const CPDF_Point& point) const;
-
-  void AddString(const FX_WCHAR* string);
-  void SetTopItem(int32_t nIndex);
-  void Select(int32_t nItemIndex);
-  virtual void SetCaret(int32_t nItemIndex);
-  virtual void Empty();
-  virtual void Cancel();
-  CFX_WideString GetText() const;
-
  private:
   void SetMultipleSelect(int32_t nItemIndex, FX_BOOL bSelected);
   void SetSingleSelect(int32_t nItemIndex);
@@ -332,7 +336,6 @@ class CFX_ListCtrl : public CFX_List {
   FX_BOOL IsItemVisible(int32_t nItemIndex) const;
   void SetScrollInfo();
   void SetScrollPosY(FX_FLOAT fy);
-  virtual void ReArrange(int32_t nItemIndex);
 
  private:
   IFX_List_Notify* m_pNotify;
diff --git a/fpdfsdk/include/javascript/Consts.h b/fpdfsdk/include/javascript/Consts.h
index c0abe4c7d4..79f85f8002 100644
--- a/fpdfsdk/include/javascript/Consts.h
+++ b/fpdfsdk/include/javascript/Consts.h
@@ -13,8 +13,8 @@
 
 class CJS_Border : public CJS_Object {
  public:
-  CJS_Border(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Border(void){};
+  explicit CJS_Border(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Border() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
@@ -23,8 +23,8 @@ class CJS_Border : public CJS_Object {
 
 class CJS_Display : public CJS_Object {
  public:
-  CJS_Display(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Display(void){};
+  explicit CJS_Display(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Display() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
@@ -33,8 +33,8 @@ class CJS_Display : public CJS_Object {
 
 class CJS_Font : public CJS_Object {
  public:
-  CJS_Font(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Font(void){};
+  explicit CJS_Font(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Font() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
@@ -43,8 +43,8 @@ class CJS_Font : public CJS_Object {
 
 class CJS_Highlight : public CJS_Object {
  public:
-  CJS_Highlight(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Highlight(void){};
+  explicit CJS_Highlight(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Highlight() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
@@ -53,8 +53,8 @@ class CJS_Highlight : public CJS_Object {
 
 class CJS_Position : public CJS_Object {
  public:
-  CJS_Position(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Position(void){};
+  explicit CJS_Position(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Position() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
@@ -63,8 +63,8 @@ class CJS_Position : public CJS_Object {
 
 class CJS_ScaleHow : public CJS_Object {
  public:
-  CJS_ScaleHow(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_ScaleHow(void){};
+  explicit CJS_ScaleHow(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_ScaleHow() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
@@ -73,8 +73,8 @@ class CJS_ScaleHow : public CJS_Object {
 
 class CJS_ScaleWhen : public CJS_Object {
  public:
-  CJS_ScaleWhen(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_ScaleWhen(void){};
+  explicit CJS_ScaleWhen(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_ScaleWhen() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
@@ -83,8 +83,8 @@ class CJS_ScaleWhen : public CJS_Object {
 
 class CJS_Style : public CJS_Object {
  public:
-  CJS_Style(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Style(void){};
+  explicit CJS_Style(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Style() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
@@ -93,8 +93,8 @@ class CJS_Style : public CJS_Object {
 
 class CJS_Zoomtype : public CJS_Object {
  public:
-  CJS_Zoomtype(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Zoomtype(void){};
+  explicit CJS_Zoomtype(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Zoomtype() override {}
 
   DECLARE_JS_CLASS_CONST();
 };
diff --git a/fpdfsdk/include/javascript/Document.h b/fpdfsdk/include/javascript/Document.h
index 7d0e05fc43..e139557f1b 100644
--- a/fpdfsdk/include/javascript/Document.h
+++ b/fpdfsdk/include/javascript/Document.h
@@ -12,7 +12,7 @@
 class PrintParamsObj : public CJS_EmbedObj {
  public:
   PrintParamsObj(CJS_Object* pJSObject);
-  virtual ~PrintParamsObj() {}
+  ~PrintParamsObj() override {}
 
  public:
   FX_BOOL bUI;
@@ -28,7 +28,7 @@ class PrintParamsObj : public CJS_EmbedObj {
 class CJS_PrintParamsObj : public CJS_Object {
  public:
   CJS_PrintParamsObj(JSFXObject pObject) : CJS_Object(pObject) {}
-  virtual ~CJS_PrintParamsObj() {}
+  ~CJS_PrintParamsObj() override {}
 
   DECLARE_JS_CLASS(CJS_PrintParamsObj);
 };
@@ -69,7 +69,7 @@ struct CJS_AnnotObj;
 class Document : public CJS_EmbedObj {
  public:
   Document(CJS_Object* pJSObject);
-  virtual ~Document();
+  ~Document() override;
 
  public:
   FX_BOOL ADBE(IFXJS_Context* cc, CJS_PropValue& vp, CFX_WideString& sError);
@@ -322,10 +322,11 @@ class Document : public CJS_EmbedObj {
 
 class CJS_Document : public CJS_Object {
  public:
-  CJS_Document(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Document(){};
+  explicit CJS_Document(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Document() override {}
 
-  virtual FX_BOOL InitInstance(IFXJS_Context* cc);
+  // CJS_Object
+  FX_BOOL InitInstance(IFXJS_Context* cc) override;
 
   DECLARE_JS_CLASS(CJS_Document);
 
diff --git a/fpdfsdk/include/javascript/Field.h b/fpdfsdk/include/javascript/Field.h
index afbf783bf2..ca37ae57bd 100644
--- a/fpdfsdk/include/javascript/Field.h
+++ b/fpdfsdk/include/javascript/Field.h
@@ -89,7 +89,7 @@ struct CJS_DelayData {
 class Field : public CJS_EmbedObj {
  public:
   Field(CJS_Object* pJSObject);
-  virtual ~Field(void);
+  ~Field() override;
 
   FX_BOOL alignment(IFXJS_Context* cc,
                     CJS_PropValue& vp,
@@ -533,10 +533,10 @@ class Field : public CJS_EmbedObj {
 
 class CJS_Field : public CJS_Object {
  public:
-  CJS_Field(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Field(void){};
+  CJS_Field(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Field(void) override {}
 
-  virtual FX_BOOL InitInstance(IFXJS_Context* cc);
+  FX_BOOL InitInstance(IFXJS_Context* cc) override;
 
   DECLARE_JS_CLASS(CJS_Field);
 
diff --git a/fpdfsdk/include/javascript/IJavaScript.h b/fpdfsdk/include/javascript/IJavaScript.h
index 53a4225aed..56922403e1 100644
--- a/fpdfsdk/include/javascript/IJavaScript.h
+++ b/fpdfsdk/include/javascript/IJavaScript.h
@@ -17,7 +17,6 @@ class CPDFSDK_Document;
 
 class IFXJS_Context {
  public:
-  virtual ~IFXJS_Context() {}
   virtual FX_BOOL Compile(const CFX_WideString& script,
                           CFX_WideString& info) = 0;
   virtual FX_BOOL RunScript(const CFX_WideString& script,
@@ -128,6 +127,9 @@ class IFXJS_Context {
   virtual void OnExternal_Exec() = 0;
 
   virtual void EnableMessageBox(FX_BOOL bEnable) = 0;
+
+ protected:
+  virtual ~IFXJS_Context() {}
 };
 
 class IFXJS_Runtime {
@@ -140,7 +142,7 @@ class IFXJS_Runtime {
   virtual CPDFSDK_Document* GetReaderDocument() = 0;
 
  protected:
-  ~IFXJS_Runtime() {}
+  virtual ~IFXJS_Runtime() {}
 };
 
 class CPDFDoc_Environment;
diff --git a/fpdfsdk/include/javascript/Icon.h b/fpdfsdk/include/javascript/Icon.h
index 0b549ec613..6d2f6e4645 100644
--- a/fpdfsdk/include/javascript/Icon.h
+++ b/fpdfsdk/include/javascript/Icon.h
@@ -12,7 +12,8 @@
 class Icon : public CJS_EmbedObj {
  public:
   Icon(CJS_Object* pJSObject);
-  virtual ~Icon();
+  ~Icon() override;
+
   FX_BOOL name(IFXJS_Context* cc, CJS_PropValue& vp, CFX_WideString& sError);
   void SetStream(CPDF_Stream* pIconStream);
   CPDF_Stream* GetStream();
@@ -26,8 +27,8 @@ class Icon : public CJS_EmbedObj {
 
 class CJS_Icon : public CJS_Object {
  public:
-  CJS_Icon(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Icon(){};
+  CJS_Icon(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Icon() override {}
 
  public:
   DECLARE_JS_CLASS(CJS_Icon);
diff --git a/fpdfsdk/include/javascript/JS_Context.h b/fpdfsdk/include/javascript/JS_Context.h
index f61f37cdc6..a716bc2ccb 100644
--- a/fpdfsdk/include/javascript/JS_Context.h
+++ b/fpdfsdk/include/javascript/JS_Context.h
@@ -17,121 +17,112 @@ class CJS_Runtime;
 class CJS_Context : public IFXJS_Context {
  public:
   CJS_Context(CJS_Runtime* pRuntime);
-  virtual ~CJS_Context();
+  ~CJS_Context() override;
+
+  // IFXJS_Context
+  FX_BOOL Compile(const CFX_WideString& script, CFX_WideString& info) override;
+  FX_BOOL RunScript(const CFX_WideString& script,
+                    CFX_WideString& info) override;
+  void OnApp_Init() override;
+  void OnDoc_Open(CPDFSDK_Document* pDoc,
+                  const CFX_WideString& strTargetName) override;
+  void OnDoc_WillPrint(CPDFSDK_Document* pDoc) override;
+  void OnDoc_DidPrint(CPDFSDK_Document* pDoc) override;
+  void OnDoc_WillSave(CPDFSDK_Document* pDoc) override;
+  void OnDoc_DidSave(CPDFSDK_Document* pDoc) override;
+  void OnDoc_WillClose(CPDFSDK_Document* pDoc) override;
+  void OnPage_Open(CPDFSDK_Document* pTarget) override;
+  void OnPage_Close(CPDFSDK_Document* pTarget) override;
+  void OnPage_InView(CPDFSDK_Document* pTarget) override;
+  void OnPage_OutView(CPDFSDK_Document* pTarget) override;
+  void OnField_MouseDown(FX_BOOL bModifier,
+                         FX_BOOL bShift,
+                         CPDF_FormField* pTarget) override;
+  void OnField_MouseEnter(FX_BOOL bModifier,
+                          FX_BOOL bShift,
+                          CPDF_FormField* pTarget) override;
+  void OnField_MouseExit(FX_BOOL bModifier,
+                         FX_BOOL bShift,
+                         CPDF_FormField* pTarget) override;
+  void OnField_MouseUp(FX_BOOL bModifier,
+                       FX_BOOL bShift,
+                       CPDF_FormField* pTarget) override;
+  void OnField_Focus(FX_BOOL bModifier,
+                     FX_BOOL bShift,
+                     CPDF_FormField* pTarget,
+                     const CFX_WideString& Value) override;
+  void OnField_Blur(FX_BOOL bModifier,
+                    FX_BOOL bShift,
+                    CPDF_FormField* pTarget,
+                    const CFX_WideString& Value) override;
+  void OnField_Calculate(CPDF_FormField* pSource,
+                         CPDF_FormField* pTarget,
+                         CFX_WideString& Value,
+                         FX_BOOL& bRc) override;
+  void OnField_Format(CPDF_FormField* pTarget,
+                      CFX_WideString& Value,
+                      FX_BOOL bWillCommit) override;
+  void OnField_Keystroke(CFX_WideString& strChange,
+                         const CFX_WideString& strChangeEx,
+                         FX_BOOL bKeyDown,
+                         FX_BOOL bModifier,
+                         int& nSelEnd,
+                         int& nSelStart,
+                         FX_BOOL bShift,
+                         CPDF_FormField* pTarget,
+                         CFX_WideString& Value,
+                         FX_BOOL bWillCommit,
+                         FX_BOOL bFieldFull,
+                         FX_BOOL& bRc) override;
+  void OnField_Validate(CFX_WideString& strChange,
+                        const CFX_WideString& strChangeEx,
+                        FX_BOOL bKeyDown,
+                        FX_BOOL bModifier,
+                        FX_BOOL bShift,
+                        CPDF_FormField* pTarget,
+                        CFX_WideString& Value,
+                        FX_BOOL& bRc) override;
+  void OnScreen_Focus(FX_BOOL bModifier,
+                      FX_BOOL bShift,
+                      CPDFSDK_Annot* pScreen) override;
+  void OnScreen_Blur(FX_BOOL bModifier,
+                     FX_BOOL bShift,
+                     CPDFSDK_Annot* pScreen) override;
+  void OnScreen_Open(FX_BOOL bModifier,
+                     FX_BOOL bShift,
+                     CPDFSDK_Annot* pScreen) override;
+  void OnScreen_Close(FX_BOOL bModifier,
+                      FX_BOOL bShift,
+                      CPDFSDK_Annot* pScreen) override;
+  void OnScreen_MouseDown(FX_BOOL bModifier,
+                          FX_BOOL bShift,
+                          CPDFSDK_Annot* pScreen) override;
+  void OnScreen_MouseUp(FX_BOOL bModifier,
+                        FX_BOOL bShift,
+                        CPDFSDK_Annot* pScreen) override;
+  void OnScreen_MouseEnter(FX_BOOL bModifier,
+                           FX_BOOL bShift,
+                           CPDFSDK_Annot* pScreen) override;
+  void OnScreen_MouseExit(FX_BOOL bModifier,
+                          FX_BOOL bShift,
+                          CPDFSDK_Annot* pScreen) override;
+  void OnScreen_InView(FX_BOOL bModifier,
+                       FX_BOOL bShift,
+                       CPDFSDK_Annot* pScreen) override;
+  void OnScreen_OutView(FX_BOOL bModifier,
+                        FX_BOOL bShift,
+                        CPDFSDK_Annot* pScreen) override;
+  void OnBookmark_MouseUp(CPDF_Bookmark* pBookMark) override;
+  void OnLink_MouseUp(CPDFSDK_Document* pTarget) override;
+  void OnMenu_Exec(CPDFSDK_Document* pTarget,
+                   const CFX_WideString& strTargetName) override;
+  void OnBatchExec(CPDFSDK_Document* pTarget) override;
+  void OnConsole_Exec() override;
+  void OnExternal_Exec() override;
+  void EnableMessageBox(FX_BOOL bEnable) override { m_bMsgBoxEnable = bEnable; }
 
- public:
-  virtual FX_BOOL Compile(const CFX_WideString& script, CFX_WideString& info);
-  virtual FX_BOOL RunScript(const CFX_WideString& script, CFX_WideString& info);
-
- public:
-  virtual void OnApp_Init();
-
-  virtual void OnDoc_Open(CPDFSDK_Document* pDoc,
-                          const CFX_WideString& strTargetName);
-  virtual void OnDoc_WillPrint(CPDFSDK_Document* pDoc);
-  virtual void OnDoc_DidPrint(CPDFSDK_Document* pDoc);
-  virtual void OnDoc_WillSave(CPDFSDK_Document* pDoc);
-  virtual void OnDoc_DidSave(CPDFSDK_Document* pDoc);
-  virtual void OnDoc_WillClose(CPDFSDK_Document* pDoc);
-
-  virtual void OnPage_Open(CPDFSDK_Document* pTarget);
-  virtual void OnPage_Close(CPDFSDK_Document* pTarget);
-  virtual void OnPage_InView(CPDFSDK_Document* pTarget);
-  virtual void OnPage_OutView(CPDFSDK_Document* pTarget);
-
-  virtual void OnField_MouseDown(FX_BOOL bModifier,
-                                 FX_BOOL bShift,
-                                 CPDF_FormField* pTarget);
-  virtual void OnField_MouseEnter(FX_BOOL bModifier,
-                                  FX_BOOL bShift,
-                                  CPDF_FormField* pTarget);
-  virtual void OnField_MouseExit(FX_BOOL bModifier,
-                                 FX_BOOL bShift,
-                                 CPDF_FormField* pTarget);
-  virtual void OnField_MouseUp(FX_BOOL bModifier,
-                               FX_BOOL bShift,
-                               CPDF_FormField* pTarget);
-  virtual void OnField_Focus(FX_BOOL bModifier,
-                             FX_BOOL bShift,
-                             CPDF_FormField* pTarget,
-                             const CFX_WideString& Value);
-  virtual void OnField_Blur(FX_BOOL bModifier,
-                            FX_BOOL bShift,
-                            CPDF_FormField* pTarget,
-                            const CFX_WideString& Value);
-
-  virtual void OnField_Calculate(CPDF_FormField* pSource,
-                                 CPDF_FormField* pTarget,
-                                 CFX_WideString& Value,
-                                 FX_BOOL& bRc);
-  virtual void OnField_Format(CPDF_FormField* pTarget,
-                              CFX_WideString& Value,
-                              FX_BOOL bWillCommit);
-  virtual void OnField_Keystroke(CFX_WideString& strChange,
-                                 const CFX_WideString& strChangeEx,
-                                 FX_BOOL bKeyDown,
-                                 FX_BOOL bModifier,
-                                 int& nSelEnd,
-                                 int& nSelStart,
-                                 FX_BOOL bShift,
-                                 CPDF_FormField* pTarget,
-                                 CFX_WideString& Value,
-                                 FX_BOOL bWillCommit,
-                                 FX_BOOL bFieldFull,
-                                 FX_BOOL& bRc);
-  virtual void OnField_Validate(CFX_WideString& strChange,
-                                const CFX_WideString& strChangeEx,
-                                FX_BOOL bKeyDown,
-                                FX_BOOL bModifier,
-                                FX_BOOL bShift,
-                                CPDF_FormField* pTarget,
-                                CFX_WideString& Value,
-                                FX_BOOL& bRc);
-
-  virtual void OnScreen_Focus(FX_BOOL bModifier,
-                              FX_BOOL bShift,
-                              CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_Blur(FX_BOOL bModifier,
-                             FX_BOOL bShift,
-                             CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_Open(FX_BOOL bModifier,
-                             FX_BOOL bShift,
-                             CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_Close(FX_BOOL bModifier,
-                              FX_BOOL bShift,
-                              CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_MouseDown(FX_BOOL bModifier,
-                                  FX_BOOL bShift,
-                                  CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_MouseUp(FX_BOOL bModifier,
-                                FX_BOOL bShift,
-                                CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_MouseEnter(FX_BOOL bModifier,
-                                   FX_BOOL bShift,
-                                   CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_MouseExit(FX_BOOL bModifier,
-                                  FX_BOOL bShift,
-                                  CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_InView(FX_BOOL bModifier,
-                               FX_BOOL bShift,
-                               CPDFSDK_Annot* pScreen);
-  virtual void OnScreen_OutView(FX_BOOL bModifier,
-                                FX_BOOL bShift,
-                                CPDFSDK_Annot* pScreen);
-
-  virtual void OnBookmark_MouseUp(CPDF_Bookmark* pBookMark);
-  virtual void OnLink_MouseUp(CPDFSDK_Document* pTarget);
-
-  virtual void OnMenu_Exec(CPDFSDK_Document* pTarget,
-                           const CFX_WideString& strTargetName);
-  virtual void OnBatchExec(CPDFSDK_Document* pTarget);
-  virtual void OnConsole_Exec();
-  virtual void OnExternal_Exec();
-
-  virtual void EnableMessageBox(FX_BOOL bEnable) { m_bMsgBoxEnable = bEnable; }
   FX_BOOL IsMsgBoxEnabled() const { return m_bMsgBoxEnable; }
 
- public:
   CPDFDoc_Environment* GetReaderApp();
   CJS_Runtime* GetJSRuntime() { return m_pRuntime; }
 
@@ -143,7 +134,6 @@ class CJS_Context : public IFXJS_Context {
  private:
   CJS_Runtime* m_pRuntime;
   CJS_EventHandler* m_pEventHandler;
-
   FX_BOOL m_bBusy;
   FX_BOOL m_bMsgBoxEnable;
 };
diff --git a/fpdfsdk/include/javascript/JS_Object.h b/fpdfsdk/include/javascript/JS_Object.h
index adcedb837c..9fd7bff3d4 100644
--- a/fpdfsdk/include/javascript/JS_Object.h
+++ b/fpdfsdk/include/javascript/JS_Object.h
@@ -49,7 +49,7 @@ class CJS_EmbedObj {
 class CJS_Object {
  public:
   explicit CJS_Object(JSFXObject pObject);
-  virtual ~CJS_Object(void);
+  virtual ~CJS_Object();
 
   void MakeWeak();
   void Dispose();
diff --git a/fpdfsdk/include/javascript/JS_Runtime.h b/fpdfsdk/include/javascript/JS_Runtime.h
index 3be0f76549..1d40a64509 100644
--- a/fpdfsdk/include/javascript/JS_Runtime.h
+++ b/fpdfsdk/include/javascript/JS_Runtime.h
@@ -31,14 +31,14 @@ class CJS_FieldEvent {
 class CJS_Runtime : public IFXJS_Runtime {
  public:
   CJS_Runtime(CPDFDoc_Environment* pApp);
-  virtual ~CJS_Runtime();
-
-  virtual IFXJS_Context* NewContext();
-  virtual void ReleaseContext(IFXJS_Context* pContext);
-  virtual IFXJS_Context* GetCurrentContext();
-
-  virtual void SetReaderDocument(CPDFSDK_Document* pReaderDoc);
-  virtual CPDFSDK_Document* GetReaderDocument() { return m_pDocument; }
+  ~CJS_Runtime() override;
+
+  // IFXJS_Runtime
+  IFXJS_Context* NewContext() override;
+  void ReleaseContext(IFXJS_Context* pContext) override;
+  IFXJS_Context* GetCurrentContext() override;
+  void SetReaderDocument(CPDFSDK_Document* pReaderDoc) override;
+  CPDFSDK_Document* GetReaderDocument() override { return m_pDocument; }
 
   CPDFDoc_Environment* GetReaderApp() { return m_pApp; }
 
diff --git a/fpdfsdk/include/javascript/PublicMethods.h b/fpdfsdk/include/javascript/PublicMethods.h
index c5d5ea6d46..96c5ea5ad0 100644
--- a/fpdfsdk/include/javascript/PublicMethods.h
+++ b/fpdfsdk/include/javascript/PublicMethods.h
@@ -11,8 +11,8 @@
 
 class CJS_PublicMethods : public CJS_Object {
  public:
-  CJS_PublicMethods(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_PublicMethods(void){};
+  CJS_PublicMethods(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_PublicMethods() override {}
 
  public:
   static FX_BOOL AFNumber_Format(IFXJS_Context* cc,
diff --git a/fpdfsdk/include/javascript/app.h b/fpdfsdk/include/javascript/app.h
index b13121323b..995c2605df 100644
--- a/fpdfsdk/include/javascript/app.h
+++ b/fpdfsdk/include/javascript/app.h
@@ -18,7 +18,7 @@ class CJS_Timer;
 class TimerObj : public CJS_EmbedObj {
  public:
   TimerObj(CJS_Object* pJSObject);
-  virtual ~TimerObj();
+  ~TimerObj() override;
 
  public:
   void SetTimer(CJS_Timer* pTimer);
@@ -31,7 +31,7 @@ class TimerObj : public CJS_EmbedObj {
 class CJS_TimerObj : public CJS_Object {
  public:
   CJS_TimerObj(JSFXObject pObject) : CJS_Object(pObject) {}
-  virtual ~CJS_TimerObj() {}
+  ~CJS_TimerObj() override {}
 
   DECLARE_JS_CLASS(CJS_TimerObj);
 };
@@ -39,7 +39,7 @@ class CJS_TimerObj : public CJS_Object {
 class app : public CJS_EmbedObj {
  public:
   app(CJS_Object* pJSObject);
-  virtual ~app();
+  ~app() override;
 
  public:
   FX_BOOL activeDocs(IFXJS_Context* cc,
@@ -160,24 +160,22 @@ class app : public CJS_EmbedObj {
                      CJS_Value& vRet,
                      CFX_WideString& sError);
 
- private:
-  void TimerProc(CJS_Timer* pTimer);
-  void RunJsScript(CJS_Runtime* pRuntime, const CFX_WideString& wsScript);
-
- public:
   static CFX_WideString SysPathToPDFPath(const CFX_WideString& sOldPath);
 
  private:
+  // CJS_EmbedObj
+  void TimerProc(CJS_Timer* pTimer) override;
+  void RunJsScript(CJS_Runtime* pRuntime, const CFX_WideString& wsScript);
+
   bool m_bCalculate;
   bool m_bRuntimeHighLight;
-
   CFX_ArrayTemplate<CJS_Timer*> m_aTimer;
 };
 
 class CJS_App : public CJS_Object {
  public:
-  CJS_App(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_App(void){};
+  explicit CJS_App(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_App() override {}
 
   DECLARE_JS_CLASS(CJS_App);
 
diff --git a/fpdfsdk/include/javascript/color.h b/fpdfsdk/include/javascript/color.h
index 45704efa80..cabd770ee8 100644
--- a/fpdfsdk/include/javascript/color.h
+++ b/fpdfsdk/include/javascript/color.h
@@ -13,7 +13,7 @@
 class color : public CJS_EmbedObj {
  public:
   color(CJS_Object* pJSObject);
-  virtual ~color(void);
+  ~color() override;
 
   FX_BOOL black(IFXJS_Context* cc, CJS_PropValue& vp, CFX_WideString& sError);
   FX_BOOL blue(IFXJS_Context* cc, CJS_PropValue& vp, CFX_WideString& sError);
@@ -60,8 +60,8 @@ class color : public CJS_EmbedObj {
 
 class CJS_Color : public CJS_Object {
  public:
-  CJS_Color(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Color(void){};
+  CJS_Color(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Color() override {}
 
   DECLARE_JS_CLASS(CJS_Color);
 
diff --git a/fpdfsdk/include/javascript/console.h b/fpdfsdk/include/javascript/console.h
index a04d87b007..e001695ebf 100644
--- a/fpdfsdk/include/javascript/console.h
+++ b/fpdfsdk/include/javascript/console.h
@@ -12,7 +12,7 @@
 class console : public CJS_EmbedObj {
  public:
   console(CJS_Object* pJSObject);
-  virtual ~console(void);
+  ~console() override;
 
  public:
   FX_BOOL clear(IFXJS_Context* cc,
@@ -35,8 +35,8 @@ class console : public CJS_EmbedObj {
 
 class CJS_Console : public CJS_Object {
  public:
-  CJS_Console(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Console(void){};
+  CJS_Console(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Console() override {}
 
   DECLARE_JS_CLASS(CJS_Console);
 
diff --git a/fpdfsdk/include/javascript/event.h b/fpdfsdk/include/javascript/event.h
index c7c899e69d..e48a659fc7 100644
--- a/fpdfsdk/include/javascript/event.h
+++ b/fpdfsdk/include/javascript/event.h
@@ -12,7 +12,7 @@
 class event : public CJS_EmbedObj {
  public:
   event(CJS_Object* pJSObject);
-  virtual ~event(void);
+  ~event() override;
 
  public:
   FX_BOOL change(IFXJS_Context* cc, CJS_PropValue& vp, CFX_WideString& sError);
@@ -59,8 +59,8 @@ class event : public CJS_EmbedObj {
 
 class CJS_Event : public CJS_Object {
  public:
-  CJS_Event(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Event(void){};
+  CJS_Event(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Event() override {}
 
   DECLARE_JS_CLASS(CJS_Event);
 
diff --git a/fpdfsdk/include/javascript/global.h b/fpdfsdk/include/javascript/global.h
index 303ac76a3e..369956749b 100644
--- a/fpdfsdk/include/javascript/global.h
+++ b/fpdfsdk/include/javascript/global.h
@@ -36,7 +36,7 @@ struct js_global_data {
 class global_alternate : public CJS_EmbedObj {
  public:
   global_alternate(CJS_Object* pJSObject);
-  virtual ~global_alternate();
+  ~global_alternate() override;
 
  public:
   FX_BOOL setPersistent(IFXJS_Context* cc,
@@ -81,10 +81,11 @@ class global_alternate : public CJS_EmbedObj {
 
 class CJS_Global : public CJS_Object {
  public:
-  CJS_Global(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Global(void){};
+  explicit CJS_Global(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Global() override {}
 
-  virtual FX_BOOL InitInstance(IFXJS_Context* cc);
+  // CJS_Object
+  FX_BOOL InitInstance(IFXJS_Context* cc) override;
 
   DECLARE_SPECIAL_JS_CLASS(CJS_Global);
 
diff --git a/fpdfsdk/include/javascript/report.h b/fpdfsdk/include/javascript/report.h
index a9004fd46a..52be2f36e2 100644
--- a/fpdfsdk/include/javascript/report.h
+++ b/fpdfsdk/include/javascript/report.h
@@ -12,7 +12,7 @@
 class Report : public CJS_EmbedObj {
  public:
   Report(CJS_Object* pJSObject);
-  virtual ~Report();
+  ~Report() override;
 
  public:
   FX_BOOL save(IFXJS_Context* cc,
@@ -27,8 +27,8 @@ class Report : public CJS_EmbedObj {
 
 class CJS_Report : public CJS_Object {
  public:
-  CJS_Report(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Report(){};
+  CJS_Report(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Report() override {}
 
  public:
   DECLARE_JS_CLASS(CJS_Report);
diff --git a/fpdfsdk/include/javascript/util.h b/fpdfsdk/include/javascript/util.h
index 2e65bd3f58..369985673a 100644
--- a/fpdfsdk/include/javascript/util.h
+++ b/fpdfsdk/include/javascript/util.h
@@ -14,7 +14,7 @@
 class util : public CJS_EmbedObj {
  public:
   util(CJS_Object* pJSObject);
-  virtual ~util(void);
+  ~util() override;
 
  public:
   FX_BOOL printd(IFXJS_Context* cc,
@@ -51,8 +51,8 @@ class util : public CJS_EmbedObj {
 
 class CJS_Util : public CJS_Object {
  public:
-  CJS_Util(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Util(void){};
+  CJS_Util(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Util() override {}
 
   DECLARE_JS_CLASS(CJS_Util);
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_Button.h b/fpdfsdk/include/pdfwindow/PWL_Button.h
index 363556762f..28a026c3bf 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Button.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Button.h
@@ -12,12 +12,13 @@
 class CPWL_Button : public CPWL_Wnd {
  public:
   CPWL_Button();
-  virtual ~CPWL_Button();
+  ~CPWL_Button() override;
 
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
 
  protected:
   FX_BOOL m_bMouseDown;
diff --git a/fpdfsdk/include/pdfwindow/PWL_Caret.h b/fpdfsdk/include/pdfwindow/PWL_Caret.h
index 7e61eeb66e..0fe4e89c2e 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Caret.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Caret.h
@@ -21,15 +21,17 @@ struct PWL_CARET_INFO {
 class CPWL_Caret : public CPWL_Wnd {
  public:
   CPWL_Caret();
-  virtual ~CPWL_Caret();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual void InvalidateRect(CPDF_Rect* pRect = NULL);
-  virtual void SetVisible(FX_BOOL bVisible) {}
-  virtual void TimerProc();
+  ~CPWL_Caret() override;
+
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void InvalidateRect(CPDF_Rect* pRect = NULL) override;
+  void SetVisible(FX_BOOL bVisible) override {}
+  void TimerProc() override;
+
   void SetCaret(FX_BOOL bVisible,
                 const CPDF_Point& ptHead,
                 const CPDF_Point& ptFoot);
diff --git a/fpdfsdk/include/pdfwindow/PWL_ComboBox.h b/fpdfsdk/include/pdfwindow/PWL_ComboBox.h
index 98ae7ca986..e29752326c 100644
--- a/fpdfsdk/include/pdfwindow/PWL_ComboBox.h
+++ b/fpdfsdk/include/pdfwindow/PWL_ComboBox.h
@@ -13,17 +13,17 @@
 
 class CPWL_CBEdit : public CPWL_Edit {
  public:
-  CPWL_CBEdit(){};
-  virtual ~CPWL_CBEdit(){};
+  CPWL_CBEdit() {}
+  ~CPWL_CBEdit() override {}
 };
 
 class CPWL_CBListBox : public CPWL_ListBox {
  public:
-  CPWL_CBListBox(){};
-  virtual ~CPWL_CBListBox(){};
+  CPWL_CBListBox() {}
+  ~CPWL_CBListBox() override {}
 
- public:
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
+  // CPWL_ListBox
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
 
   FX_BOOL OnKeyDownWithExit(FX_WORD nChar, FX_BOOL& bExit, FX_DWORD nFlag);
   FX_BOOL OnCharWithExit(FX_WORD nChar, FX_BOOL& bExit, FX_DWORD nFlag);
@@ -33,46 +33,40 @@ class CPWL_CBListBox : public CPWL_ListBox {
 
 class CPWL_CBButton : public CPWL_Wnd {
  public:
-  CPWL_CBButton(){};
-  virtual ~CPWL_CBButton(){};
-
- public:
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
+  CPWL_CBButton() {}
+  ~CPWL_CBButton() override {}
+
+  // CPWL_Wnd
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
 };
 
 class CPWL_ComboBox : public CPWL_Wnd {
  public:
   CPWL_ComboBox();
-  operator CPWL_Edit*() { return m_pEdit; }
-
- public:
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
-
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual void RePosChildWnd();
-
-  virtual CPDF_Rect GetFocusRect() const;
+  ~CPWL_ComboBox() {}
 
-  virtual void SetFocus();
-  virtual void KillFocus();
+  operator CPWL_Edit*() { return m_pEdit; }
 
-  FX_BOOL IsModified() const;
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void RePosChildWnd() override;
+  CPDF_Rect GetFocusRect() const override;
+  void SetFocus() override;
+  void KillFocus() override;
+  FX_BOOL IsModified() const override;
 
- public:
   void SetFillerNotify(IPWL_Filler_Notify* pNotify);
 
   CFX_WideString GetText() const;
@@ -90,28 +84,23 @@ class CPWL_ComboBox : public CPWL_Wnd {
 
   void SetSelectText();
 
+  void AttachFFLData(void* pData) { m_pFormFiller = pData; }
+
  private:
   void CreateEdit(const PWL_CREATEPARAM& cp);
   void CreateButton(const PWL_CREATEPARAM& cp);
   void CreateListBox(const PWL_CREATEPARAM& cp);
-
   void SetPopup(FX_BOOL bPopup);
 
- private:
   CPWL_CBEdit* m_pEdit;
   CPWL_CBButton* m_pButton;
   CPWL_CBListBox* m_pList;
-
   FX_BOOL m_bPopup;
   CPDF_Rect m_rcOldWindow;
   int32_t m_nPopupWhere;
   int32_t m_nSelectItem;
   IPWL_Filler_Notify* m_pFillerNotify;
 
- public:
-  void AttachFFLData(void* pData) { m_pFormFiller = pData; }
-
- private:
   void* m_pFormFiller;
 };
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_Edit.h b/fpdfsdk/include/pdfwindow/PWL_Edit.h
index 281bd268f4..11249a3193 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Edit.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Edit.h
@@ -44,32 +44,29 @@ class IPWL_Filler_Notify {
 class CPWL_Edit : public CPWL_EditCtrl, public IFX_Edit_OprNotify {
  public:
   CPWL_Edit();
-  virtual ~CPWL_Edit();
+  ~CPWL_Edit() override;
+
+  // CPWL_EditCtrl
+  CFX_ByteString GetClassName() const override;
+  void OnDestroy() override;
+  void OnCreated() override;
+  void RePosChildWnd() override;
+  CPDF_Rect GetClientRect() const override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonDblClk(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseWheel(short zDelta,
+                       const CPDF_Point& point,
+                       FX_DWORD nFlag) override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
+  CPDF_Rect GetFocusRect() const override;
+  void OnSetFocus() override;
+  void OnKillFocus() override;
 
- public:
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnDestroy();
-  virtual void OnCreated();
-  virtual void RePosChildWnd();
-  virtual CPDF_Rect GetClientRect() const;
-
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonDblClk(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseWheel(short zDelta,
-                               const CPDF_Point& point,
-                               FX_DWORD nFlag);
-
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
-
-  virtual CPDF_Rect GetFocusRect() const;
-
- public:
   void SetAlignFormatH(PWL_EDIT_ALIGNFORMAT_H nFormat = PEAH_LEFT,
                        FX_BOOL bPaint = TRUE);  // 0:left 1:right 2:middle
   void SetAlignFormatV(PWL_EDIT_ALIGNFORMAT_V nFormat = PEAV_TOP,
@@ -119,25 +116,22 @@ class CPWL_Edit : public CPWL_EditCtrl, public IFX_Edit_OprNotify {
                            const CPDF_Point& ptOffset);
 
  protected:
-  virtual void OnSetFocus();
-  virtual void OnKillFocus();
-
- protected:
-  virtual void OnInsertWord(const CPVT_WordPlace& place,
-                            const CPVT_WordPlace& oldplace);
-  virtual void OnInsertReturn(const CPVT_WordPlace& place,
-                              const CPVT_WordPlace& oldplace);
-  virtual void OnBackSpace(const CPVT_WordPlace& place,
-                           const CPVT_WordPlace& oldplace);
-  virtual void OnDelete(const CPVT_WordPlace& place,
-                        const CPVT_WordPlace& oldplace);
-  virtual void OnClear(const CPVT_WordPlace& place,
-                       const CPVT_WordPlace& oldplace);
-  virtual void OnSetText(const CPVT_WordPlace& place,
-                         const CPVT_WordPlace& oldplace);
-  virtual void OnInsertText(const CPVT_WordPlace& place,
-                            const CPVT_WordPlace& oldplace);
-  virtual void OnAddUndo(IFX_Edit_UndoItem* pUndoItem);
+  // IFX_Edit_OprNotify
+  void OnInsertWord(const CPVT_WordPlace& place,
+                    const CPVT_WordPlace& oldplace) override;
+  void OnInsertReturn(const CPVT_WordPlace& place,
+                      const CPVT_WordPlace& oldplace) override;
+  void OnBackSpace(const CPVT_WordPlace& place,
+                   const CPVT_WordPlace& oldplace) override;
+  void OnDelete(const CPVT_WordPlace& place,
+                const CPVT_WordPlace& oldplace) override;
+  void OnClear(const CPVT_WordPlace& place,
+               const CPVT_WordPlace& oldplace) override;
+  void OnSetText(const CPVT_WordPlace& place,
+                 const CPVT_WordPlace& oldplace) override;
+  void OnInsertText(const CPVT_WordPlace& place,
+                    const CPVT_WordPlace& oldplace) override;
+  void OnAddUndo(IFX_Edit_UndoItem* pUndoItem) override;
 
  private:
   CPVT_WordRange GetSelectWordRange() const;
diff --git a/fpdfsdk/include/pdfwindow/PWL_EditCtrl.h b/fpdfsdk/include/pdfwindow/PWL_EditCtrl.h
index 784ec61140..bd241a3a48 100644
--- a/fpdfsdk/include/pdfwindow/PWL_EditCtrl.h
+++ b/fpdfsdk/include/pdfwindow/PWL_EditCtrl.h
@@ -57,37 +57,10 @@ class CPWL_EditCtrl : public CPWL_Wnd, public IFX_Edit_Notify {
 
  public:
   CPWL_EditCtrl();
-  virtual ~CPWL_EditCtrl();
-
- public:
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-  virtual void OnCreated();
-
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual void RePosChildWnd();
-  virtual void SetFontSize(FX_FLOAT fFontSize);
-  virtual FX_FLOAT GetFontSize() const;
-
- public:
-  virtual void SetText(const FX_WCHAR* csText);
-
-  virtual void CopyText();
-  virtual void PasteText();
-  virtual void CutText();
+  ~CPWL_EditCtrl() override;
 
   CPDF_Rect GetContentRect() const;
   void GetCaretPos(int32_t& x, int32_t& y) const;
-  FX_BOOL IsModified() const;
 
   CFX_WideString GetText() const;
   void SetSel(int32_t nStartChar, int32_t nEndChar);
@@ -127,20 +100,64 @@ class CPWL_EditCtrl : public CPWL_Wnd, public IFX_Edit_Notify {
 
   void SetReadyToInput();
 
- protected:
-  virtual void ShowVScrollBar(FX_BOOL bShow);
+  // CPWL_Wnd
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  void OnCreated() override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void RePosChildWnd() override;
+  void SetFontSize(FX_FLOAT fFontSize) override;
+  FX_FLOAT GetFontSize() const override;
+  void SetCursor() override;
+  FX_BOOL IsModified() const override;
 
-  virtual void InsertWord(FX_WORD word, int32_t nCharset);
-  virtual void InsertReturn();
-  virtual void InsertText(const FX_WCHAR* csText);
+ protected:
+  // IFX_Edit_Notify
+  void IOnSetScrollInfoX(FX_FLOAT fPlateMin,
+                         FX_FLOAT fPlateMax,
+                         FX_FLOAT fContentMin,
+                         FX_FLOAT fContentMax,
+                         FX_FLOAT fSmallStep,
+                         FX_FLOAT fBigStep) override {}
+  void IOnSetScrollInfoY(FX_FLOAT fPlateMin,
+                         FX_FLOAT fPlateMax,
+                         FX_FLOAT fContentMin,
+                         FX_FLOAT fContentMax,
+                         FX_FLOAT fSmallStep,
+                         FX_FLOAT fBigStep) override;
+  void IOnSetScrollPosX(FX_FLOAT fx) override {}
+  void IOnSetScrollPosY(FX_FLOAT fy) override;
+  void IOnSetCaret(FX_BOOL bVisible,
+                   const CPDF_Point& ptHead,
+                   const CPDF_Point& ptFoot,
+                   const CPVT_WordPlace& place) override;
+  void IOnCaretChange(const CPVT_SecProps& secProps,
+                      const CPVT_WordProps& wordProps) override;
+  void IOnContentChange(const CPDF_Rect& rcContent) override;
+  void IOnInvalidateRect(CPDF_Rect* pRect) override;
+
+  void InsertText(const FX_WCHAR* csText);
+  void SetText(const FX_WCHAR* csText);
+  void CopyText();
+  void PasteText();
+  void CutText();
+  void ShowVScrollBar(FX_BOOL bShow);
+  void InsertWord(FX_WORD word, int32_t nCharset);
+  void InsertReturn();
 
-  virtual void SetCursor();
   FX_BOOL IsWndHorV();
 
   void Delete();
   void Backspace();
 
- protected:
   void GetCaretInfo(CPDF_Point& ptHead, CPDF_Point& ptFoot) const;
   void SetCaret(FX_BOOL bVisible,
                 const CPDF_Point& ptHead,
@@ -148,30 +165,6 @@ class CPWL_EditCtrl : public CPWL_Wnd, public IFX_Edit_Notify {
 
   void SetEditCaret(FX_BOOL bVisible);
 
- protected:
-  virtual void IOnSetScrollInfoX(FX_FLOAT fPlateMin,
-                                 FX_FLOAT fPlateMax,
-                                 FX_FLOAT fContentMin,
-                                 FX_FLOAT fContentMax,
-                                 FX_FLOAT fSmallStep,
-                                 FX_FLOAT fBigStep) {}
-  virtual void IOnSetScrollInfoY(FX_FLOAT fPlateMin,
-                                 FX_FLOAT fPlateMax,
-                                 FX_FLOAT fContentMin,
-                                 FX_FLOAT fContentMax,
-                                 FX_FLOAT fSmallStep,
-                                 FX_FLOAT fBigStep);
-  virtual void IOnSetScrollPosX(FX_FLOAT fx) {}
-  virtual void IOnSetScrollPosY(FX_FLOAT fy);
-  virtual void IOnSetCaret(FX_BOOL bVisible,
-                           const CPDF_Point& ptHead,
-                           const CPDF_Point& ptFoot,
-                           const CPVT_WordPlace& place);
-  virtual void IOnCaretChange(const CPVT_SecProps& secProps,
-                              const CPVT_WordProps& wordProps);
-  virtual void IOnContentChange(const CPDF_Rect& rcContent);
-  virtual void IOnInvalidateRect(CPDF_Rect* pRect);
-
  private:
   void CreateEditCaret(const PWL_CREATEPARAM& cp);
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_FontMap.h b/fpdfsdk/include/pdfwindow/PWL_FontMap.h
index 0f5124ca02..f91d7e823f 100644
--- a/fpdfsdk/include/pdfwindow/PWL_FontMap.h
+++ b/fpdfsdk/include/pdfwindow/PWL_FontMap.h
@@ -51,24 +51,20 @@ struct CPWL_FontMap_Native {
 class CPWL_FontMap : public IFX_Edit_FontMap {
  public:
   CPWL_FontMap(IFX_SystemHandler* pSystemHandler);
-  virtual ~CPWL_FontMap();
+  ~CPWL_FontMap() override;
 
-  virtual CPDF_Font* GetPDFFont(int32_t nFontIndex);
-  virtual CFX_ByteString GetPDFFontAlias(int32_t nFontIndex);
-  virtual int32_t GetWordFontIndex(FX_WORD word,
-                                   int32_t nCharset,
-                                   int32_t nFontIndex);
-  virtual int32_t CharCodeFromUnicode(int32_t nFontIndex, FX_WORD word);
-  virtual int32_t CharSetFromUnicode(FX_WORD word, int32_t nOldCharset);
+  // IFX_Edit_FontMap
+  CPDF_Font* GetPDFFont(int32_t nFontIndex) override;
+  CFX_ByteString GetPDFFontAlias(int32_t nFontIndex) override;
+  int32_t GetWordFontIndex(FX_WORD word,
+                           int32_t nCharset,
+                           int32_t nFontIndex) override;
+  int32_t CharCodeFromUnicode(int32_t nFontIndex, FX_WORD word) override;
+  int32_t CharSetFromUnicode(FX_WORD word, int32_t nOldCharset) override;
 
- public:
-  virtual void Initial(const FX_CHAR* fontname = NULL);
   void SetSystemHandler(IFX_SystemHandler* pSystemHandler);
-
   int32_t GetFontMapCount() const;
   const CPWL_FontMap_Data* GetFontMapData(int32_t nIndex) const;
-
- public:
   static int32_t GetNativeCharset();
   CFX_ByteString GetNativeFontName(int32_t nCharset);
 
@@ -84,12 +80,12 @@ class CPWL_FontMap : public IFX_Edit_FontMap {
                            uint8_t nCharset);
 
  protected:
-  virtual CPDF_Font* FindFontSameCharset(CFX_ByteString& sFontAlias,
-                                         int32_t nCharset);
-  virtual void AddedFont(CPDF_Font* pFont, const CFX_ByteString& sFontAlias);
-  FX_BOOL KnowWord(int32_t nFontIndex, FX_WORD word);
+  void Initial(const FX_CHAR* fontname = NULL);
+  CPDF_Document* GetDocument();
+  CPDF_Font* FindFontSameCharset(CFX_ByteString& sFontAlias, int32_t nCharset);
+  void AddedFont(CPDF_Font* pFont, const CFX_ByteString& sFontAlias);
 
-  virtual CPDF_Document* GetDocument();
+  FX_BOOL KnowWord(int32_t nFontIndex, FX_WORD word);
 
   void Empty();
   int32_t GetFontIndex(const CFX_ByteString& sFontName,
@@ -128,7 +124,7 @@ class CPWL_DocFontMap : public CPWL_FontMap {
  public:
   CPWL_DocFontMap(IFX_SystemHandler* pSystemHandler,
                   CPDF_Document* pAttachedDoc);
-  virtual ~CPWL_DocFontMap();
+  ~CPWL_DocFontMap() override;
 
   virtual CPDF_Document* GetDocument();
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_Icon.h b/fpdfsdk/include/pdfwindow/PWL_Icon.h
index 7183f0245c..95157cad1f 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Icon.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Icon.h
@@ -13,7 +13,7 @@
 class CPWL_Image : public CPWL_Wnd {
  public:
   CPWL_Image();
-  virtual ~CPWL_Image();
+  ~CPWL_Image() override;
 
   virtual CFX_ByteString GetImageAppStream();
 
@@ -36,12 +36,13 @@ class CPWL_Image : public CPWL_Wnd {
 class CPWL_Icon : public CPWL_Image {
  public:
   CPWL_Icon();
-  virtual ~CPWL_Icon();
+  ~CPWL_Icon() override;
 
   virtual CPDF_IconFit* GetIconFit() { return m_pIconFit; };
 
-  virtual void GetScale(FX_FLOAT& fHScale, FX_FLOAT& fVScale);
-  virtual void GetImageOffset(FX_FLOAT& x, FX_FLOAT& y);
+  // CPWL_Image
+  void GetScale(FX_FLOAT& fHScale, FX_FLOAT& fVScale) override;
+  void GetImageOffset(FX_FLOAT& x, FX_FLOAT& y) override;
 
   int32_t GetScaleMethod();
   FX_BOOL IsProportionalScale();
diff --git a/fpdfsdk/include/pdfwindow/PWL_IconList.h b/fpdfsdk/include/pdfwindow/PWL_IconList.h
index 30a12dcd9b..9ffb5ee8f5 100644
--- a/fpdfsdk/include/pdfwindow/PWL_IconList.h
+++ b/fpdfsdk/include/pdfwindow/PWL_IconList.h
@@ -26,11 +26,7 @@ class IPWL_IconList_Notify {
 class CPWL_IconList_Item : public CPWL_Wnd {
  public:
   CPWL_IconList_Item();
-  virtual ~CPWL_IconList_Item();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual void RePosChildWnd();
+  ~CPWL_IconList_Item() override;
 
   void SetSelect(FX_BOOL bSelected);
   FX_BOOL IsSelected() const;
@@ -41,12 +37,15 @@ class CPWL_IconList_Item : public CPWL_Wnd {
   CFX_WideString GetText() const;
 
  protected:
-  virtual FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual void OnEnabled();
-  virtual void OnDisabled();
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void RePosChildWnd() override;
+  FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void OnEnabled() override;
+  void OnDisabled() override;
 
  private:
   int32_t m_nIconIndex;
@@ -59,7 +58,7 @@ class CPWL_IconList_Item : public CPWL_Wnd {
 class CPWL_IconList_Content : public CPWL_ListCtrl {
  public:
   CPWL_IconList_Content(int32_t nListCount);
-  virtual ~CPWL_IconList_Content();
+  ~CPWL_IconList_Content() override;
 
   void SetSelect(int32_t nIndex);
   int32_t GetSelect() const;
@@ -74,11 +73,12 @@ class CPWL_IconList_Content : public CPWL_ListCtrl {
   void ScrollToItem(int32_t nItemIndex);
 
  protected:
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
+  // CPWL_ListCtrl
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
 
  private:
   CPWL_IconList_Item* GetListItem(int32_t nItemIndex) const;
@@ -95,11 +95,7 @@ class CPWL_IconList_Content : public CPWL_ListCtrl {
 class CPWL_IconList : public CPWL_Wnd {
  public:
   CPWL_IconList(int32_t nListCount);
-  virtual ~CPWL_IconList();
-
-  virtual FX_BOOL OnMouseWheel(short zDelta,
-                               const CPDF_Point& point,
-                               FX_DWORD nFlag);
+  ~CPWL_IconList() override;
 
   void SetSelect(int32_t nIndex);
   void SetTopItem(int32_t nIndex);
@@ -113,14 +109,17 @@ class CPWL_IconList : public CPWL_Wnd {
   CFX_WideString GetListString(int32_t nItemIndex) const;
 
  protected:
-  virtual void OnCreated();
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
+  // CPWL_Wnd
+  FX_BOOL OnMouseWheel(short zDelta,
+                       const CPDF_Point& point,
+                       FX_DWORD nFlag) override;
+  void OnCreated() override;
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
 
  private:
   CPWL_IconList_Content* m_pListContent;
diff --git a/fpdfsdk/include/pdfwindow/PWL_Label.h b/fpdfsdk/include/pdfwindow/PWL_Label.h
index b6cb7f557c..0504bb3e0b 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Label.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Label.h
@@ -14,11 +14,7 @@ class IFX_Edit;
 class CPWL_Label : public CPWL_Wnd {
  public:
   CPWL_Label();
-  virtual ~CPWL_Label();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void SetFontSize(FX_FLOAT fFontSize);
-  virtual FX_FLOAT GetFontSize() const;
+  ~CPWL_Label() override;
 
   void SetText(const FX_WCHAR* csText);
   CFX_WideString GetText() const;
@@ -30,11 +26,15 @@ class CPWL_Label : public CPWL_Wnd {
   CFX_ByteString GetTextAppearanceStream(const CPDF_Point& ptOffset) const;
 
  protected:
-  virtual void OnCreated();
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void RePosChildWnd();
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void SetFontSize(FX_FLOAT fFontSize) override;
+  FX_FLOAT GetFontSize() const override;
+  void OnCreated() override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void RePosChildWnd() override;
 
  private:
   void SetParamByFlag();
diff --git a/fpdfsdk/include/pdfwindow/PWL_ListBox.h b/fpdfsdk/include/pdfwindow/PWL_ListBox.h
index b9372eff9c..942a568836 100644
--- a/fpdfsdk/include/pdfwindow/PWL_ListBox.h
+++ b/fpdfsdk/include/pdfwindow/PWL_ListBox.h
@@ -18,29 +18,31 @@ class IPWL_Filler_Notify;
 class CPWL_List_Notify : public IFX_List_Notify {
  public:
   CPWL_List_Notify(CPWL_ListBox* pList);
-  virtual ~CPWL_List_Notify();
+  ~CPWL_List_Notify() override;
 
+  // IFX_List_Notify
   void IOnSetScrollInfoX(FX_FLOAT fPlateMin,
                          FX_FLOAT fPlateMax,
                          FX_FLOAT fContentMin,
                          FX_FLOAT fContentMax,
                          FX_FLOAT fSmallStep,
-                         FX_FLOAT fBigStep) {}
+                         FX_FLOAT fBigStep) override {}
   void IOnSetScrollInfoY(FX_FLOAT fPlateMin,
                          FX_FLOAT fPlateMax,
                          FX_FLOAT fContentMin,
                          FX_FLOAT fContentMax,
                          FX_FLOAT fSmallStep,
-                         FX_FLOAT fBigStep);
-  void IOnSetScrollPosX(FX_FLOAT fx) {}
-  void IOnSetScrollPosY(FX_FLOAT fy);
+                         FX_FLOAT fBigStep) override;
+  void IOnSetScrollPosX(FX_FLOAT fx) override {}
+  void IOnSetScrollPosY(FX_FLOAT fy) override;
+  void IOnInvalidateRect(CPDF_Rect* pRect) override;
+
   void IOnSetCaret(FX_BOOL bVisible,
                    const CPDF_Point& ptHead,
                    const CPDF_Point& ptFoot,
                    const CPVT_WordPlace& place);
   void IOnCaretChange(const CPVT_SecProps& secProps,
                       const CPVT_WordProps& wordProps);
-  void IOnInvalidateRect(CPDF_Rect* pRect);
 
  private:
   CPWL_ListBox* m_pList;
@@ -49,34 +51,34 @@ class CPWL_List_Notify : public IFX_List_Notify {
 class CPWL_ListBox : public CPWL_Wnd {
  public:
   CPWL_ListBox();
-  virtual ~CPWL_ListBox();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreated();
-  virtual void OnDestroy();
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseWheel(short zDelta,
-                               const CPDF_Point& point,
-                               FX_DWORD nFlag);
-  virtual void KillFocus();
-
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-  virtual void RePosChildWnd();
+  ~CPWL_ListBox() override;
+
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreated() override;
+  void OnDestroy() override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseWheel(short zDelta,
+                       const CPDF_Point& point,
+                       FX_DWORD nFlag) override;
+  void KillFocus() override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void RePosChildWnd() override;
+  CPDF_Rect GetFocusRect() const override;
+  void SetFontSize(FX_FLOAT fFontSize) override;
+  FX_FLOAT GetFontSize() const override;
+
   virtual CFX_WideString GetText() const;
-  virtual CPDF_Rect GetFocusRect() const;
-  virtual void SetFontSize(FX_FLOAT fFontSize);
-  virtual FX_FLOAT GetFontSize() const;
 
   void OnNotifySelChanged(FX_BOOL bKeyDown, FX_BOOL& bExit, FX_DWORD nFlag);
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_ListCtrl.h b/fpdfsdk/include/pdfwindow/PWL_ListCtrl.h
index cd90692150..dbaffc5b58 100644
--- a/fpdfsdk/include/pdfwindow/PWL_ListCtrl.h
+++ b/fpdfsdk/include/pdfwindow/PWL_ListCtrl.h
@@ -12,7 +12,7 @@
 class CPWL_ListCtrl : public CPWL_Wnd {
  public:
   CPWL_ListCtrl();
-  virtual ~CPWL_ListCtrl();
+  ~CPWL_ListCtrl() override;
 
   void SetScrollPos(const CPDF_Point& point);
   CPDF_Point GetScrollPos() const;
@@ -30,9 +30,10 @@ class CPWL_ListCtrl : public CPWL_Wnd {
   CPDF_Rect OutToIn(const CPDF_Rect& rect) const;
 
  protected:
-  virtual void RePosChildWnd();
-  virtual void DrawChildAppearance(CFX_RenderDevice* pDevice,
-                                   CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void RePosChildWnd() override;
+  void DrawChildAppearance(CFX_RenderDevice* pDevice,
+                           CPDF_Matrix* pUser2Device) override;
 
  private:
   void ResetAll(FX_BOOL bMove, int32_t nStart);
diff --git a/fpdfsdk/include/pdfwindow/PWL_Note.h b/fpdfsdk/include/pdfwindow/PWL_Note.h
index 4f18fa20d0..b25d989ec7 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Note.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Note.h
@@ -82,14 +82,14 @@ class IPWL_NoteItem {
 class CPWL_Note_Icon : public CPWL_Wnd {
  public:
   CPWL_Note_Icon();
-  virtual ~CPWL_Note_Icon();
+  ~CPWL_Note_Icon() override;
 
   void SetIconType(int32_t nType);
 
- public:
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
 
  private:
   int32_t m_nType;
@@ -98,13 +98,14 @@ class CPWL_Note_Icon : public CPWL_Wnd {
 class CPWL_Note_CloseBox : public CPWL_Button {
  public:
   CPWL_Note_CloseBox();
-  virtual ~CPWL_Note_CloseBox();
+  ~CPWL_Note_CloseBox() override;
 
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
+  // CPWL_Button
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
 
  private:
   FX_BOOL m_bMouseDown;
@@ -113,43 +114,44 @@ class CPWL_Note_CloseBox : public CPWL_Button {
 class CPWL_Note_LBBox : public CPWL_Wnd {
  public:
   CPWL_Note_LBBox();
-  virtual ~CPWL_Note_LBBox();
+  ~CPWL_Note_LBBox() override;
 
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
 };
 
 class CPWL_Note_RBBox : public CPWL_Wnd {
  public:
   CPWL_Note_RBBox();
-  virtual ~CPWL_Note_RBBox();
+  ~CPWL_Note_RBBox() override;
 
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
 };
 
 class CPWL_Note_Edit : public CPWL_Edit {
  public:
   CPWL_Note_Edit();
-  virtual ~CPWL_Note_Edit();
+  ~CPWL_Note_Edit() override;
 
   void EnableNotify(FX_BOOL bEnable) { m_bEnableNotify = bEnable; }
-  virtual FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth);
-  FX_FLOAT GetItemLeftMargin();
-  FX_FLOAT GetItemRightMargin();
-
-  virtual void SetText(const FX_WCHAR* csText);
 
- protected:
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-  virtual void RePosChildWnd();
-  virtual void OnSetFocus();
-  virtual void OnKillFocus();
+  // CPWL_Edit
+  FX_FLOAT GetItemLeftMargin() override;
+  FX_FLOAT GetItemRightMargin() override;
+  FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth) override;
+  void SetText(const FX_WCHAR* csText) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void RePosChildWnd() override;
+  void OnSetFocus() override;
+  void OnKillFocus() override;
 
  private:
   FX_BOOL m_bEnableNotify;
@@ -162,17 +164,17 @@ class CPWL_Note_Edit : public CPWL_Edit {
 class CPWL_Note_Options : public CPWL_Wnd {
  public:
   CPWL_Note_Options();
-  virtual ~CPWL_Note_Options();
+  ~CPWL_Note_Options() override;
 
   CPDF_Rect GetContentRect() const;
-  virtual void SetTextColor(const CPWL_Color& color);
   void SetText(const CFX_WideString& sText);
 
- protected:
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void SetTextColor(const CPWL_Color& color) override;
 
  private:
   CPWL_Label* m_pText;
@@ -181,19 +183,11 @@ class CPWL_Note_Options : public CPWL_Wnd {
 class CPWL_Note_Contents : public CPWL_ListCtrl {
  public:
   CPWL_Note_Contents();
-  virtual ~CPWL_Note_Contents();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
+  ~CPWL_Note_Contents() override;
 
   void SetEditFocus(FX_BOOL bLast);
   CPWL_Edit* GetEdit() const;
 
- public:
   void SetText(const CFX_WideString& sText);
   CFX_WideString GetText() const;
 
@@ -206,8 +200,14 @@ class CPWL_Note_Contents : public CPWL_ListCtrl {
   void EnableRead(FX_BOOL bEnabled);
   void EnableModify(FX_BOOL bEnabled);
 
- protected:
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
+  // CPWL_ListCtrl
+  CFX_ByteString GetClassName() const override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
 
  private:
   CPWL_Note_Edit* m_pEdit;
@@ -216,65 +216,60 @@ class CPWL_Note_Contents : public CPWL_ListCtrl {
 class CPWL_NoteItem : public CPWL_Wnd, public IPWL_NoteItem {
  public:
   CPWL_NoteItem();
-  virtual ~CPWL_NoteItem();
-
- public:
-  virtual void SetPrivateData(void* pData);
-  virtual void SetBkColor(const CPWL_Color& color);
-  virtual void SetSubjectName(const CFX_WideString& sName);
-  virtual void SetAuthorName(const CFX_WideString& sName);
-  virtual void SetDateTime(FX_SYSTEMTIME time);
-  virtual void SetContents(const CFX_WideString& sContents);
-
-  virtual IPWL_NoteItem* CreateSubItem();
-  virtual int32_t CountSubItems() const;
-  virtual IPWL_NoteItem* GetSubItems(int32_t index) const;
-  virtual void DeleteSubItem(IPWL_NoteItem* pNoteItem);
-  virtual void SetFocus() { SetNoteFocus(FALSE); }
-
-  virtual IPWL_NoteItem* GetParentItem() const;
-  virtual void* GetPrivateData() const;
-  virtual CFX_WideString GetAuthorName() const;
-  virtual CPWL_Color GetBkColor() const;
-  virtual CFX_WideString GetContents() const;
-  virtual FX_SYSTEMTIME GetDateTime() const;
-  virtual CFX_WideString GetSubjectName() const;
-  virtual FX_BOOL IsTopItem() const { return FALSE; }
-  virtual CPWL_Edit* GetEdit() const;
+  ~CPWL_NoteItem() override;
 
- public:
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual CFX_ByteString GetClassName() const;
   virtual IPWL_NoteItem* GetHitNoteItem(const CPDF_Point& point);
   virtual IPWL_NoteItem* GetFocusedNoteItem() const;
 
+  virtual FX_BOOL IsTopItem() const { return FALSE; }
+
   virtual void ResetSubjectName(int32_t nItemIndex);
   void EnableRead(FX_BOOL bEnabled);
   void EnableModify(FX_BOOL bEnabled);
 
- protected:
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
+  void OnContentsValidate();
+  void OnCreateNoteItem();
 
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
+  // IPWL_NoteItem
+  void SetPrivateData(void* pData) override;
+  void SetBkColor(const CPWL_Color& color) override;
+  void SetSubjectName(const CFX_WideString& sName) override;
+  void SetAuthorName(const CFX_WideString& sName) override;
+  void SetDateTime(FX_SYSTEMTIME time) override;
+  void SetContents(const CFX_WideString& sContents) override;
+  IPWL_NoteItem* CreateSubItem() override;
+  int32_t CountSubItems() const override;
+  IPWL_NoteItem* GetSubItems(int32_t index) const override;
+  void DeleteSubItem(IPWL_NoteItem* pNoteItem) override;
+  void SetFocus() override { SetNoteFocus(FALSE); }
+  IPWL_NoteItem* GetParentItem() const override;
+  void* GetPrivateData() const override;
+  CFX_WideString GetAuthorName() const override;
+  CPWL_Color GetBkColor() const override;
+  CFX_WideString GetContents() const override;
+  FX_SYSTEMTIME GetDateTime() const override;
+  CFX_WideString GetSubjectName() const override;
+  CPWL_Edit* GetEdit() const override;
+
+ protected:
+  // CPWL_Wnd
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  CFX_ByteString GetClassName() const override;
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth) override;
+  FX_FLOAT GetItemLeftMargin() override;
+  FX_FLOAT GetItemRightMargin() override;
 
- public:
-  virtual FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth);
-  virtual FX_FLOAT GetItemLeftMargin();
-  virtual FX_FLOAT GetItemRightMargin();
   CPWL_NoteItem* CreateNoteItem();
   CPWL_NoteItem* GetParentNoteItem() const;
 
   void SetNoteFocus(FX_BOOL bLast);
-  void OnContentsValidate();
-
-  void OnCreateNoteItem();
-
- protected:
   void PopupNoteItemMenu(const CPDF_Point& point);
 
   virtual const CPWL_Note* GetNote() const;
@@ -300,19 +295,8 @@ class CPWL_Note : public CPWL_NoteItem {
   CPWL_Note(IPopup_Note* pPopupNote,
             IPWL_NoteNotify* pNoteNotify,
             IPWL_NoteHandler* pNoteHandler);
-  virtual ~CPWL_Note();
+  ~CPWL_Note() override;
 
- public:
-  virtual void SetSubjectName(const CFX_WideString& sName);
-  virtual void SetAuthorName(const CFX_WideString& sName);
-  virtual CFX_WideString GetAuthorName() const;
-  virtual void SetBkColor(const CPWL_Color& color);
-  virtual void ResetSubjectName(int32_t nItemIndex) {}
-  virtual FX_BOOL IsTopItem() const { return TRUE; }
-  virtual const CPWL_Note* GetNote() const;
-  virtual IPWL_NoteNotify* GetNoteNotify() const;
-
- public:
   IPWL_NoteItem* Reply();
   void EnableNotify(FX_BOOL bEnabled);
   void SetIconType(int32_t nType);
@@ -329,22 +313,28 @@ class CPWL_Note : public CPWL_NoteItem {
   CPDF_Rect GetCaptionRect() const { return m_rcCaption; }
   IPopup_Note* GetPopupNote() const { return m_pPopupNote; }
 
- public:
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseWheel(short zDelta,
-                               const CPDF_Point& point,
-                               FX_DWORD nFlag);
+  // CPWL_NoteItem
+  void SetSubjectName(const CFX_WideString& sName) override;
+  void SetAuthorName(const CFX_WideString& sName) override;
+  CFX_WideString GetAuthorName() const override;
+  void SetBkColor(const CPWL_Color& color) override;
+  void ResetSubjectName(int32_t nItemIndex) override {}
+  FX_BOOL IsTopItem() const override { return TRUE; }
+  const CPWL_Note* GetNote() const override;
+  IPWL_NoteNotify* GetNoteNotify() const override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseWheel(short zDelta,
+                       const CPDF_Point& point,
+                       FX_DWORD nFlag) override;
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
 
  protected:
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-
   FX_BOOL ResetScrollBar();
   void RePosNoteChildren();
   FX_BOOL ScrollBarShouldVisible();
diff --git a/fpdfsdk/include/pdfwindow/PWL_ScrollBar.h b/fpdfsdk/include/pdfwindow/PWL_ScrollBar.h
index a149a01416..ec1b78ed5e 100644
--- a/fpdfsdk/include/pdfwindow/PWL_ScrollBar.h
+++ b/fpdfsdk/include/pdfwindow/PWL_ScrollBar.h
@@ -35,17 +35,17 @@ class CPWL_SBButton : public CPWL_Wnd {
  public:
   CPWL_SBButton(PWL_SCROLLBAR_TYPE eScrollBarType,
                 PWL_SBBUTTON_TYPE eButtonType);
-  virtual ~CPWL_SBButton();
-
- public:
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag);
+  ~CPWL_SBButton() override;
+
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag) override;
 
  protected:
   PWL_SCROLLBAR_TYPE m_eScrollBarType;
@@ -92,24 +92,23 @@ struct PWL_SCROLL_PRIVATEDATA {
 class CPWL_ScrollBar : public CPWL_Wnd {
  public:
   CPWL_ScrollBar(PWL_SCROLLBAR_TYPE sbType = SBT_HSCROLL);
-  virtual ~CPWL_ScrollBar();
-
- public:
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-  virtual void RePosChildWnd();
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
+  ~CPWL_ScrollBar() override;
+
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  void RePosChildWnd() override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void TimerProc() override;
 
   FX_FLOAT GetScrollBarWidth() const;
   PWL_SCROLLBAR_TYPE GetScrollBarType() const { return m_sbType; };
@@ -142,9 +141,6 @@ class CPWL_ScrollBar : public CPWL_Wnd {
   FX_FLOAT TrueToFace(FX_FLOAT);
   FX_FLOAT FaceToTrue(FX_FLOAT);
 
-  virtual void TimerProc();
-
- private:
   PWL_SCROLLBAR_TYPE m_sbType;
   PWL_SCROLL_INFO m_OriginInfo;
   CPWL_SBButton* m_pMinButton;
diff --git a/fpdfsdk/include/pdfwindow/PWL_Signature.h b/fpdfsdk/include/pdfwindow/PWL_Signature.h
index c48d4e9708..009dd87592 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Signature.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Signature.h
@@ -16,17 +16,17 @@ class CPWL_Label;
 class CPWL_Signature_Image : public CPWL_Image {
  public:
   CPWL_Signature_Image();
-  virtual ~CPWL_Signature_Image();
+  ~CPWL_Signature_Image() override;
 
   void SetImage(CFX_DIBSource* pImage);
   CFX_DIBSource* GetImage();
 
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-
-  virtual void GetScale(FX_FLOAT& fHScale, FX_FLOAT& fVScale);
+  // CPWL_Image
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void GetScale(FX_FLOAT& fHScale, FX_FLOAT& fVScale) override;
 
  private:
   CFX_DIBSource* m_pImage;
@@ -35,7 +35,7 @@ class CPWL_Signature_Image : public CPWL_Image {
 class CPWL_Signature : public CPWL_Wnd {
  public:
   CPWL_Signature();
-  virtual ~CPWL_Signature();
+  ~CPWL_Signature() override;
 
   void SetText(const FX_WCHAR* sText);
   void SetDescription(const FX_WCHAR* string);
@@ -47,12 +47,12 @@ class CPWL_Signature : public CPWL_Wnd {
   void SetFoxitFlag(FX_BOOL bFlagExist);
 
  protected:
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
+  // CPWL_Wnd
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
 
  private:
   CPWL_Label* m_pText;
diff --git a/fpdfsdk/include/pdfwindow/PWL_SpecialButton.h b/fpdfsdk/include/pdfwindow/PWL_SpecialButton.h
index 8cfe819a67..a62d18d257 100644
--- a/fpdfsdk/include/pdfwindow/PWL_SpecialButton.h
+++ b/fpdfsdk/include/pdfwindow/PWL_SpecialButton.h
@@ -12,20 +12,22 @@
 class CPWL_PushButton : public CPWL_Button {
  public:
   CPWL_PushButton();
-  virtual ~CPWL_PushButton();
+  ~CPWL_PushButton() override;
 
-  virtual CFX_ByteString GetClassName() const;
-  virtual CPDF_Rect GetFocusRect() const;
+  // CPWL_Button
+  CFX_ByteString GetClassName() const override;
+  CPDF_Rect GetFocusRect() const override;
 };
 
 class CPWL_CheckBox : public CPWL_Button {
  public:
   CPWL_CheckBox();
-  virtual ~CPWL_CheckBox();
+  ~CPWL_CheckBox() override;
 
-  virtual CFX_ByteString GetClassName() const;
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
+  // CPWL_Button
+  CFX_ByteString GetClassName() const override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
 
   void SetCheck(FX_BOOL bCheck);
   FX_BOOL IsChecked() const;
@@ -37,11 +39,12 @@ class CPWL_CheckBox : public CPWL_Button {
 class CPWL_RadioButton : public CPWL_Button {
  public:
   CPWL_RadioButton();
-  virtual ~CPWL_RadioButton();
+  ~CPWL_RadioButton() override;
 
-  virtual CFX_ByteString GetClassName() const;
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
+  // CPWL_Button
+  CFX_ByteString GetClassName() const override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
 
   void SetCheck(FX_BOOL bCheck);
   FX_BOOL IsChecked() const;
diff --git a/fpdfsdk/include/pdfwindow/PWL_Wnd.h b/fpdfsdk/include/pdfwindow/PWL_Wnd.h
index e66c15e5e7..37af083835 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Wnd.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Wnd.h
@@ -284,7 +284,7 @@ class CPWL_Wnd : public CPWL_TimerHandler {
 
  public:
   CPWL_Wnd();
-  virtual ~CPWL_Wnd();
+  ~CPWL_Wnd() override;
 
   void Create(const PWL_CREATEPARAM& cp);
   virtual CFX_ByteString GetClassName() const;
@@ -373,7 +373,6 @@ class CPWL_Wnd : public CPWL_TimerHandler {
 
   IFX_Edit_FontMap* GetFontMap() const;
   IPWL_Provider* GetProvider() const;
-  virtual IFX_SystemHandler* GetSystemHandler() const;
   IPWL_FocusHandler* GetFocusHandler() const;
 
   int32_t GetTransparency();
@@ -399,6 +398,9 @@ class CPWL_Wnd : public CPWL_TimerHandler {
   virtual void SetCursor();
 
  protected:
+  // CPWL_TimerHandler
+  IFX_SystemHandler* GetSystemHandler() const override;
+
   virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
   virtual void RePosChildWnd();
   void GetAppearanceStream(CFX_ByteTextBuf& sAppStream);
diff --git a/fpdfsdk/src/fpdf_dataavail.cpp b/fpdfsdk/src/fpdf_dataavail.cpp
index 8f9638d90a..cc0833bc98 100644
--- a/fpdfsdk/src/fpdf_dataavail.cpp
+++ b/fpdfsdk/src/fpdf_dataavail.cpp
@@ -11,10 +11,12 @@ extern void ProcessParseError(FX_DWORD err_code);
 class CFPDF_FileAvailWrap : public IFX_FileAvail {
  public:
   CFPDF_FileAvailWrap() { m_pfileAvail = NULL; }
+  ~CFPDF_FileAvailWrap() override {}
 
   void Set(FX_FILEAVAIL* pfileAvail) { m_pfileAvail = pfileAvail; }
 
-  virtual FX_BOOL IsDataAvail(FX_FILESIZE offset, FX_DWORD size) {
+  // IFX_FileAvail
+  FX_BOOL IsDataAvail(FX_FILESIZE offset, FX_DWORD size) override {
     return m_pfileAvail->IsDataAvail(m_pfileAvail, offset, size);
   }
 
@@ -25,17 +27,19 @@ class CFPDF_FileAvailWrap : public IFX_FileAvail {
 class CFPDF_FileAccessWrap : public IFX_FileRead {
  public:
   CFPDF_FileAccessWrap() { m_pFileAccess = NULL; }
+  ~CFPDF_FileAccessWrap() override {}
 
   void Set(FPDF_FILEACCESS* pFile) { m_pFileAccess = pFile; }
 
-  virtual FX_FILESIZE GetSize() { return m_pFileAccess->m_FileLen; }
+  // IFX_FileRead
+  FX_FILESIZE GetSize() override { return m_pFileAccess->m_FileLen; }
 
-  virtual FX_BOOL ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) {
+  FX_BOOL ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override {
     return m_pFileAccess->m_GetBlock(m_pFileAccess->m_Param, offset,
                                      (uint8_t*)buffer, size);
   }
 
-  virtual void Release() {}
+  void Release() override {}
 
  private:
   FPDF_FILEACCESS* m_pFileAccess;
@@ -43,12 +47,14 @@ class CFPDF_FileAccessWrap : public IFX_FileRead {
 
 class CFPDF_DownloadHintsWrap : public IFX_DownloadHints {
  public:
-  CFPDF_DownloadHintsWrap(FX_DOWNLOADHINTS* pDownloadHints) {
+  explicit CFPDF_DownloadHintsWrap(FX_DOWNLOADHINTS* pDownloadHints) {
     m_pDownloadHints = pDownloadHints;
   }
+  ~CFPDF_DownloadHintsWrap() override {}
 
  public:
-  virtual void AddSegment(FX_FILESIZE offset, FX_DWORD size) {
+  // IFX_DownloadHints
+  void AddSegment(FX_FILESIZE offset, FX_DWORD size) override {
     m_pDownloadHints->AddSegment(m_pDownloadHints, offset, size);
   }
 
diff --git a/fpdfsdk/src/fpdf_sysfontinfo.cpp b/fpdfsdk/src/fpdf_sysfontinfo.cpp
index 804efe3020..a004e86ba1 100644
--- a/fpdfsdk/src/fpdf_sysfontinfo.cpp
+++ b/fpdfsdk/src/fpdf_sysfontinfo.cpp
@@ -10,15 +10,15 @@
 
 class CFX_ExternalFontInfo final : public IFX_SystemFontInfo {
  public:
-  CFX_ExternalFontInfo(FPDF_SYSFONTINFO* pInfo) : m_pInfo(pInfo) {}
+  explicit CFX_ExternalFontInfo(FPDF_SYSFONTINFO* pInfo) : m_pInfo(pInfo) {}
 
-  virtual void Release() override {
+  void Release() override {
     if (m_pInfo->Release)
       m_pInfo->Release(m_pInfo);
     delete this;
   }
 
-  virtual FX_BOOL EnumFontList(CFX_FontMapper* pMapper) override {
+  FX_BOOL EnumFontList(CFX_FontMapper* pMapper) override {
     if (m_pInfo->EnumFonts) {
       m_pInfo->EnumFonts(m_pInfo, pMapper);
       return TRUE;
@@ -26,34 +26,34 @@ class CFX_ExternalFontInfo final : public IFX_SystemFontInfo {
     return FALSE;
   }
 
-  virtual void* MapFont(int weight,
-                        FX_BOOL bItalic,
-                        int charset,
-                        int pitch_family,
-                        const FX_CHAR* family,
-                        int& iExact) override {
+  void* MapFont(int weight,
+                FX_BOOL bItalic,
+                int charset,
+                int pitch_family,
+                const FX_CHAR* family,
+                int& iExact) override {
     if (m_pInfo->MapFont)
       return m_pInfo->MapFont(m_pInfo, weight, bItalic, charset, pitch_family,
                               family, &iExact);
     return NULL;
   }
 
-  virtual void* GetFont(const FX_CHAR* family) override {
+  void* GetFont(const FX_CHAR* family) override {
     if (m_pInfo->GetFont)
       return m_pInfo->GetFont(m_pInfo, family);
     return NULL;
   }
 
-  virtual FX_DWORD GetFontData(void* hFont,
-                               FX_DWORD table,
-                               uint8_t* buffer,
-                               FX_DWORD size) override {
+  FX_DWORD GetFontData(void* hFont,
+                       FX_DWORD table,
+                       uint8_t* buffer,
+                       FX_DWORD size) override {
     if (m_pInfo->GetFontData)
       return m_pInfo->GetFontData(m_pInfo, hFont, table, buffer, size);
     return 0;
   }
 
-  virtual FX_BOOL GetFaceName(void* hFont, CFX_ByteString& name) override {
+  FX_BOOL GetFaceName(void* hFont, CFX_ByteString& name) override {
     if (m_pInfo->GetFaceName == NULL)
       return FALSE;
     FX_DWORD size = m_pInfo->GetFaceName(m_pInfo, hFont, NULL, 0);
@@ -66,7 +66,7 @@ class CFX_ExternalFontInfo final : public IFX_SystemFontInfo {
     return TRUE;
   }
 
-  virtual FX_BOOL GetFontCharset(void* hFont, int& charset) override {
+  FX_BOOL GetFontCharset(void* hFont, int& charset) override {
     if (m_pInfo->GetFontCharset) {
       charset = m_pInfo->GetFontCharset(m_pInfo, hFont);
       return TRUE;
@@ -74,13 +74,13 @@ class CFX_ExternalFontInfo final : public IFX_SystemFontInfo {
     return FALSE;
   }
 
-  virtual void DeleteFont(void* hFont) override {
+  void DeleteFont(void* hFont) override {
     if (m_pInfo->DeleteFont)
       m_pInfo->DeleteFont(m_pInfo, hFont);
   }
 
  private:
-  ~CFX_ExternalFontInfo() {}
+  ~CFX_ExternalFontInfo() override {}
 
   FPDF_SYSFONTINFO* const m_pInfo;
 };
diff --git a/fpdfsdk/src/fpdfsave.cpp b/fpdfsdk/src/fpdfsave.cpp
index 54c9253d2e..36553092ee 100644
--- a/fpdfsdk/src/fpdfsave.cpp
+++ b/fpdfsdk/src/fpdfsave.cpp
@@ -18,10 +18,12 @@ class CFX_IFileWrite final : public IFX_StreamWrite {
  public:
   CFX_IFileWrite();
   FX_BOOL Init(FPDF_FILEWRITE* pFileWriteStruct);
-  virtual FX_BOOL WriteBlock(const void* pData, size_t size) override;
-  virtual void Release() override {}
+  FX_BOOL WriteBlock(const void* pData, size_t size) override;
+  void Release() override;
 
  protected:
+  ~CFX_IFileWrite() override {}
+
   FPDF_FILEWRITE* m_pFileWriteStruct;
 };
 
@@ -45,6 +47,10 @@ FX_BOOL CFX_IFileWrite::WriteBlock(const void* pData, size_t size) {
   return TRUE;
 }
 
+void CFX_IFileWrite::Release() {
+  delete this;
+}
+
 FPDF_BOOL _FPDF_Doc_Save(FPDF_DOCUMENT document,
                          FPDF_FILEWRITE* pFileWrite,
                          FPDF_DWORD flags,
@@ -70,7 +76,7 @@ FPDF_BOOL _FPDF_Doc_Save(FPDF_DOCUMENT document,
   pStreamWrite = new CFX_IFileWrite;
   pStreamWrite->Init(pFileWrite);
   bRet = FileMaker.Create(pStreamWrite, flags);
-  delete pStreamWrite;
+  pStreamWrite->Release();
   return bRet;
 }
 
diff --git a/fpdfsdk/src/fpdfview.cpp b/fpdfsdk/src/fpdfview.cpp
index 2700aebddc..a1d5689c79 100644
--- a/fpdfsdk/src/fpdfview.cpp
+++ b/fpdfsdk/src/fpdfview.cpp
@@ -71,9 +71,10 @@ CCodec_ModuleMgr* g_pCodecModule = nullptr;
 class CFontMapper : public IPDF_FontMapper {
  public:
   CFontMapper();
-  virtual ~CFontMapper();
+  ~CFontMapper() override;
 
-  virtual FT_Face FindSubstFont(
+  // IPDF_FontMapper
+  FT_Face FindSubstFont(
       CPDF_Document* pDoc,              // [IN] The PDF document
       const CFX_ByteString& face_name,  // [IN] Original name
       FX_BOOL bTrueType,                // [IN] TrueType or Type1
@@ -82,7 +83,7 @@ class CFontMapper : public IPDF_FontMapper {
       int CharsetCP,    // [IN] code page for charset (see Win32 GetACP())
       FX_BOOL bVertical,
       CPDF_SubstFont* pSubstFont  // [OUT] Subst font data
-      );
+      ) override;
 
   FT_Face m_SysFace;
 };
@@ -204,6 +205,8 @@ class CMemFile final : public IFX_FileRead {
   }
 
  private:
+  ~CMemFile() {}
+
   uint8_t* m_pBuf;
   FX_FILESIZE m_size;
 };
diff --git a/fpdfsdk/src/fsdk_mgr.cpp b/fpdfsdk/src/fsdk_mgr.cpp
index df9a0ff316..67dea80d0d 100644
--- a/fpdfsdk/src/fsdk_mgr.cpp
+++ b/fpdfsdk/src/fsdk_mgr.cpp
@@ -17,81 +17,64 @@
 #include <ctime>
 #endif
 
-// extern CPDFDoc_Environment* g_pFormFillApp;
 class CFX_SystemHandler : public IFX_SystemHandler {
  public:
   CFX_SystemHandler(CPDFDoc_Environment* pEnv) : m_pEnv(pEnv), m_nCharSet(-1) {}
+  ~CFX_SystemHandler() override {}
 
  public:
-  virtual void InvalidateRect(FX_HWND hWnd, FX_RECT rect);
-  virtual void OutputSelectedRect(void* pFormFiller, CPDF_Rect& rect);
-
-  virtual FX_BOOL IsSelectionImplemented();
-
-  virtual CFX_WideString GetClipboardText(FX_HWND hWnd) { return L""; }
-  virtual FX_BOOL SetClipboardText(FX_HWND hWnd, CFX_WideString string) {
+  // IFX_SystemHandler
+  void InvalidateRect(FX_HWND hWnd, FX_RECT rect) override;
+  void OutputSelectedRect(void* pFormFiller, CPDF_Rect& rect) override;
+  FX_BOOL IsSelectionImplemented() override;
+  CFX_WideString GetClipboardText(FX_HWND hWnd) override { return L""; }
+  FX_BOOL SetClipboardText(FX_HWND hWnd, CFX_WideString string) override {
     return FALSE;
   }
-
-  virtual void ClientToScreen(FX_HWND hWnd, int32_t& x, int32_t& y) {}
-  virtual void ScreenToClient(FX_HWND hWnd, int32_t& x, int32_t& y) {}
-
-  /*cursor style
-  FXCT_ARROW
-  FXCT_NESW
-  FXCT_NWSE
-  FXCT_VBEAM
-  FXCT_HBEAM
-  FXCT_HAND
-  */
-  virtual void SetCursor(int32_t nCursorType);
-
-  virtual FX_HMENU CreatePopupMenu() { return NULL; }
-  virtual FX_BOOL AppendMenuItem(FX_HMENU hMenu,
-                                 int32_t nIDNewItem,
-                                 CFX_WideString string) {
+  void ClientToScreen(FX_HWND hWnd, int32_t& x, int32_t& y) override {}
+  void ScreenToClient(FX_HWND hWnd, int32_t& x, int32_t& y) override {}
+  void SetCursor(int32_t nCursorType) override;
+  FX_HMENU CreatePopupMenu() override { return NULL; }
+  FX_BOOL AppendMenuItem(FX_HMENU hMenu,
+                         int32_t nIDNewItem,
+                         CFX_WideString string) override {
     return FALSE;
   }
-  virtual FX_BOOL EnableMenuItem(FX_HMENU hMenu,
-                                 int32_t nIDItem,
-                                 FX_BOOL bEnabled) {
+  FX_BOOL EnableMenuItem(FX_HMENU hMenu,
+                         int32_t nIDItem,
+                         FX_BOOL bEnabled) override {
     return FALSE;
   }
-  virtual int32_t TrackPopupMenu(FX_HMENU hMenu,
-                                 int32_t x,
-                                 int32_t y,
-                                 FX_HWND hParent) {
+  int32_t TrackPopupMenu(FX_HMENU hMenu,
+                         int32_t x,
+                         int32_t y,
+                         FX_HWND hParent) override {
     return -1;
   }
-  virtual void DestroyMenu(FX_HMENU hMenu) {}
-
-  virtual CFX_ByteString GetNativeTrueTypeFont(int32_t nCharset);
-  virtual FX_BOOL FindNativeTrueTypeFont(int32_t nCharset,
-                                         CFX_ByteString sFontFaceName);
-  virtual CPDF_Font* AddNativeTrueTypeFontToPDF(CPDF_Document* pDoc,
-                                                CFX_ByteString sFontFaceName,
-                                                uint8_t nCharset);
-
-  virtual int32_t SetTimer(int32_t uElapse, TimerCallback lpTimerFunc);
-  virtual void KillTimer(int32_t nID);
-
-  virtual FX_BOOL IsSHIFTKeyDown(FX_DWORD nFlag) {
+  void DestroyMenu(FX_HMENU hMenu) override {}
+  CFX_ByteString GetNativeTrueTypeFont(int32_t nCharset) override;
+  FX_BOOL FindNativeTrueTypeFont(int32_t nCharset,
+                                 CFX_ByteString sFontFaceName) override;
+  CPDF_Font* AddNativeTrueTypeFontToPDF(CPDF_Document* pDoc,
+                                        CFX_ByteString sFontFaceName,
+                                        uint8_t nCharset) override;
+  int32_t SetTimer(int32_t uElapse, TimerCallback lpTimerFunc) override;
+  void KillTimer(int32_t nID) override;
+  FX_BOOL IsSHIFTKeyDown(FX_DWORD nFlag) override {
     return m_pEnv->FFI_IsSHIFTKeyDown(nFlag);
   }
-  virtual FX_BOOL IsCTRLKeyDown(FX_DWORD nFlag) {
+  FX_BOOL IsCTRLKeyDown(FX_DWORD nFlag) override {
     return m_pEnv->FFI_IsCTRLKeyDown(nFlag);
   }
-  virtual FX_BOOL IsALTKeyDown(FX_DWORD nFlag) {
+  FX_BOOL IsALTKeyDown(FX_DWORD nFlag) override {
     return m_pEnv->FFI_IsALTKeyDown(nFlag);
   }
-  virtual FX_BOOL IsINSERTKeyDown(FX_DWORD nFlag) {
+  FX_BOOL IsINSERTKeyDown(FX_DWORD nFlag) override {
     return m_pEnv->FFI_IsINSERTKeyDown(nFlag);
   }
-
-  virtual FX_SYSTEMTIME GetLocalTime();
-
-  virtual int32_t GetCharSet() { return m_nCharSet; }
-  virtual void SetCharSet(int32_t nCharSet) { m_nCharSet = nCharSet; }
+  FX_SYSTEMTIME GetLocalTime() override;
+  int32_t GetCharSet() override { return m_nCharSet; }
+  void SetCharSet(int32_t nCharSet) override { m_nCharSet = nCharSet; }
 
  private:
   CPDFDoc_Environment* m_pEnv;
diff --git a/fpdfsdk/src/fsdk_rendercontext.cpp b/fpdfsdk/src/fsdk_rendercontext.cpp
index 1320824236..e282d01db7 100644
--- a/fpdfsdk/src/fsdk_rendercontext.cpp
+++ b/fpdfsdk/src/fsdk_rendercontext.cpp
@@ -36,6 +36,9 @@ IFSDK_PAUSE_Adapter::IFSDK_PAUSE_Adapter(IFSDK_PAUSE* IPause) {
   m_IPause = IPause;
 }
 
+IFSDK_PAUSE_Adapter::~IFSDK_PAUSE_Adapter() {
+}
+
 FX_BOOL IFSDK_PAUSE_Adapter::NeedToPauseNow() {
   if (m_IPause->NeedToPauseNow) {
     return m_IPause->NeedToPauseNow(m_IPause);
diff --git a/fpdfsdk/src/javascript/JS_Context.cpp b/fpdfsdk/src/javascript/JS_Context.cpp
index 6e935e8647..3fedd13b21 100644
--- a/fpdfsdk/src/javascript/JS_Context.cpp
+++ b/fpdfsdk/src/javascript/JS_Context.cpp
@@ -19,7 +19,7 @@ CJS_Context::CJS_Context(CJS_Runtime* pRuntime)
   m_pEventHandler = new CJS_EventHandler(this);
 }
 
-CJS_Context::~CJS_Context(void) {
+CJS_Context::~CJS_Context() {
   delete m_pEventHandler;
 }
 
diff --git a/fpdfsdk/src/javascript/JS_Object.cpp b/fpdfsdk/src/javascript/JS_Object.cpp
index 96e1d1d564..02978982d8 100644
--- a/fpdfsdk/src/javascript/JS_Object.cpp
+++ b/fpdfsdk/src/javascript/JS_Object.cpp
@@ -89,7 +89,7 @@ CJS_Object::CJS_Object(JSFXObject pObject) : m_pEmbedObj(NULL) {
   m_pObject.Reset(m_pIsolate, pObject);
 };
 
-CJS_Object::~CJS_Object(void) {
+CJS_Object::~CJS_Object() {
   m_pObject.Reset();
 };
 
diff --git a/fpdfsdk/src/javascript/app.cpp b/fpdfsdk/src/javascript/app.cpp
index 1b84508fd6..8d895ab260 100644
--- a/fpdfsdk/src/javascript/app.cpp
+++ b/fpdfsdk/src/javascript/app.cpp
@@ -112,7 +112,7 @@ IMPLEMENT_JS_CLASS(CJS_App, app)
 app::app(CJS_Object* pJSObject)
     : CJS_EmbedObj(pJSObject), m_bCalculate(true), m_bRuntimeHighLight(false) {}
 
-app::~app(void) {
+app::~app() {
   for (int i = 0, sz = m_aTimer.GetSize(); i < sz; i++)
     delete m_aTimer[i];
 
diff --git a/fpdfsdk/src/javascript/color.cpp b/fpdfsdk/src/javascript/color.cpp
index 0659ab94a4..c6d13fc284 100644
--- a/fpdfsdk/src/javascript/color.cpp
+++ b/fpdfsdk/src/javascript/color.cpp
@@ -65,7 +65,8 @@ color::color(CJS_Object* pJSObject) : CJS_EmbedObj(pJSObject) {
   m_crLTGray = CPWL_Color(COLORTYPE_GRAY, 0.75);
 }
 
-color::~color(void) {}
+color::~color() {
+}
 
 void color::ConvertPWLColorToArray(const CPWL_Color& color, CJS_Array& array) {
   switch (color.nColorType) {
diff --git a/fpdfsdk/src/javascript/event.cpp b/fpdfsdk/src/javascript/event.cpp
index 4bcdcce3a0..492f225d18 100644
--- a/fpdfsdk/src/javascript/event.cpp
+++ b/fpdfsdk/src/javascript/event.cpp
@@ -50,7 +50,8 @@ IMPLEMENT_JS_CLASS(CJS_Event, event)
 
 event::event(CJS_Object* pJsObject) : CJS_EmbedObj(pJsObject) {}
 
-event::~event(void) {}
+event::~event() {
+}
 
 FX_BOOL event::change(IFXJS_Context* cc,
                       CJS_PropValue& vp,
diff --git a/fpdfsdk/src/javascript/global.cpp b/fpdfsdk/src/javascript/global.cpp
index ee0591b950..17aa00e31d 100644
--- a/fpdfsdk/src/javascript/global.cpp
+++ b/fpdfsdk/src/javascript/global.cpp
@@ -106,7 +106,7 @@ FX_BOOL CJS_Global::InitInstance(IFXJS_Context* cc) {
 global_alternate::global_alternate(CJS_Object* pJSObject)
     : CJS_EmbedObj(pJSObject), m_pApp(NULL) {}
 
-global_alternate::~global_alternate(void) {
+global_alternate::~global_alternate() {
   DestroyGlobalPersisitentVariables();
   m_pApp->GetRuntimeFactory()->ReleaseGlobalData();
 }
diff --git a/fpdfsdk/src/javascript/util.cpp b/fpdfsdk/src/javascript/util.cpp
index c735b971dc..85092dab17 100644
--- a/fpdfsdk/src/javascript/util.cpp
+++ b/fpdfsdk/src/javascript/util.cpp
@@ -48,7 +48,8 @@ IMPLEMENT_JS_CLASS(CJS_Util, util)
 
 util::util(CJS_Object* pJSObject) : CJS_EmbedObj(pJSObject) {}
 
-util::~util(void) {}
+util::~util() {
+}
 
 struct stru_TbConvert {
   const FX_WCHAR* lpszJSMark;