Convert FWL_ERR into an enum class.

This Cl updates FWL_ERR to be an FWL_Error enum class. It removes FX_ERR and
replaces it with FWL_Error as well as the values were the same.

There were many places where we either returned other values for FWL_ERR
results.

This Cl is the same as: https://codereview.chromium.org/1943413002/ but I seem
to have messed up the base URL in that one.

TBR=tsepez@chromium.org

Review-Url: https://codereview.chromium.org/1952693003

24 files changed, 391 insertions, 386 deletions

diff --git a/xfa/fwl/core/cfwl_event.h b/xfa/fwl/core/cfwl_event.h
index 7af8cabbb2..d9decac334 100644
--- a/xfa/fwl/core/cfwl_event.h
+++ b/xfa/fwl/core/cfwl_event.h
@@ -70,8 +70,8 @@ class CFWL_Event {
       : m_pSrcTarget(nullptr), m_pDstTarget(nullptr), m_dwRefCount(1) {}
   virtual ~CFWL_Event() {}
 
-  virtual FWL_ERR GetClassName(CFX_WideString& wsClass) const {
-    return FWL_ERR_Succeeded;
+  virtual FWL_Error GetClassName(CFX_WideString& wsClass) const {
+    return FWL_Error::Succeeded;
   }
   virtual CFWL_EventType GetClassID() const { return CFWL_EventType::None; }
 
@@ -90,14 +90,14 @@ class CFWL_Event {
   uint32_t m_dwRefCount;
 };
 
-#define BEGIN_FWL_EVENT_DEF(classname, eventType)                 \
-  class classname : public CFWL_Event {                           \
-   public:                                                        \
-    classname() : CFWL_Event() {}                                 \
-    virtual FWL_ERR GetClassName(CFX_WideString& wsClass) const { \
-      wsClass = L## #classname;                                   \
-      return FWL_ERR_Succeeded;                                   \
-    }                                                             \
+#define BEGIN_FWL_EVENT_DEF(classname, eventType)                   \
+  class classname : public CFWL_Event {                             \
+   public:                                                          \
+    classname() : CFWL_Event() {}                                   \
+    virtual FWL_Error GetClassName(CFX_WideString& wsClass) const { \
+      wsClass = L## #classname;                                     \
+      return FWL_Error::Succeeded;                                  \
+    }                                                               \
     virtual CFWL_EventType GetClassID() const { return eventType; }
 
 #define END_FWL_EVENT_DEF \
diff --git a/xfa/fwl/core/cfwl_message.h b/xfa/fwl/core/cfwl_message.h
index 3a30c8fffd..74401c3e34 100644
--- a/xfa/fwl/core/cfwl_message.h
+++ b/xfa/fwl/core/cfwl_message.h
@@ -61,8 +61,8 @@ class CFWL_Message {
   virtual ~CFWL_Message() {}
 
   virtual CFWL_Message* Clone() { return nullptr; }
-  virtual FWL_ERR GetClassName(CFX_WideString& wsClass) const {
-    return FWL_ERR_Succeeded;
+  virtual FWL_Error GetClassName(CFX_WideString& wsClass) const {
+    return FWL_Error::Succeeded;
   }
   virtual CFWL_MessageType GetClassID() const { return CFWL_MessageType::None; }
 
@@ -87,15 +87,15 @@ class CFWL_Message {
   uint32_t m_dwRefCount;
 };
 
-#define BEGIN_FWL_MESSAGE_DEF(classname, msgType)                   \
-  class classname : public CFWL_Message {                           \
-   public:                                                          \
-    classname() : CFWL_Message() {}                                 \
-    CFWL_Message* Clone() override { return new classname(*this); } \
-    FWL_ERR GetClassName(CFX_WideString& wsClass) const override {  \
-      wsClass = L## #classname;                                     \
-      return FWL_ERR_Succeeded;                                     \
-    }                                                               \
+#define BEGIN_FWL_MESSAGE_DEF(classname, msgType)                    \
+  class classname : public CFWL_Message {                            \
+   public:                                                           \
+    classname() : CFWL_Message() {}                                  \
+    CFWL_Message* Clone() override { return new classname(*this); }  \
+    FWL_Error GetClassName(CFX_WideString& wsClass) const override { \
+      wsClass = L## #classname;                                      \
+      return FWL_Error::Succeeded;                                   \
+    }                                                                \
     CFWL_MessageType GetClassID() const override { return msgType; }
 
 #define END_FWL_MESSAGE_DEF \
diff --git a/xfa/fwl/core/fwl_appimp.cpp b/xfa/fwl/core/fwl_appimp.cpp
index ac00cca144..d7fa8bc1c0 100644
--- a/xfa/fwl/core/fwl_appimp.cpp
+++ b/xfa/fwl/core/fwl_appimp.cpp
@@ -20,11 +20,11 @@ IFWL_App* IFWL_App::Create(CXFA_FFApp* pAdapter) {
 
 void IFWL_App::Release() {}
 
-FWL_ERR IFWL_App::Initialize() {
+FWL_Error IFWL_App::Initialize() {
   return static_cast<CFWL_AppImp*>(GetImpl())->Initialize();
 }
 
-FWL_ERR IFWL_App::Finalize() {
+FWL_Error IFWL_App::Finalize() {
   return static_cast<CFWL_AppImp*>(GetImpl())->Finalize();
 }
 
@@ -62,15 +62,15 @@ CFWL_AppImp::~CFWL_AppImp() {
   CFWL_ToolTipContainer::DeleteInstance();
 }
 
-FWL_ERR CFWL_AppImp::Initialize() {
+FWL_Error CFWL_AppImp::Initialize() {
   if (!m_pWidgetMgr) {
     m_pWidgetMgr.reset(new CFWL_WidgetMgr(m_pAdapterNative));
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_AppImp::Finalize() {
+FWL_Error CFWL_AppImp::Finalize() {
   m_pWidgetMgr.reset();
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 CXFA_FFApp* CFWL_AppImp::GetAdapterNative() const {
   return m_pAdapterNative;
@@ -82,6 +82,7 @@ CXFA_FWLAdapterWidgetMgr* FWL_GetAdapterWidgetMgr() {
 IFWL_WidgetMgr* CFWL_AppImp::GetWidgetMgr() const {
   return m_pWidgetMgr.get();
 }
+
 void CFWL_AppImp::SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) {
   m_pThemeProvider = pThemeProvider;
 }
diff --git a/xfa/fwl/core/fwl_appimp.h b/xfa/fwl/core/fwl_appimp.h
index 64b7922a15..b138ccb5be 100644
--- a/xfa/fwl/core/fwl_appimp.h
+++ b/xfa/fwl/core/fwl_appimp.h
@@ -26,8 +26,8 @@ class CFWL_AppImp {
   IFWL_App* GetInterface() const { return m_pIface; }
   CFWL_NoteDriver* GetNoteDriver() const { return m_pNoteDriver.get(); }
 
-  FWL_ERR Initialize();
-  FWL_ERR Finalize();
+  FWL_Error Initialize();
+  FWL_Error Finalize();
   CXFA_FFApp* GetAdapterNative() const;
   IFWL_WidgetMgr* GetWidgetMgr() const;
   IFWL_ThemeProvider* GetThemeProvider() const;
diff --git a/xfa/fwl/core/fwl_error.h b/xfa/fwl/core/fwl_error.h
index 92a483f4e8..e29f89e012 100644
--- a/xfa/fwl/core/fwl_error.h
+++ b/xfa/fwl/core/fwl_error.h
@@ -7,16 +7,14 @@
 #ifndef XFA_FWL_CORE_FWL_ERROR_H_
 #define XFA_FWL_CORE_FWL_ERROR_H_
 
-#include <stdint.h>
-
-typedef int32_t FWL_ERR;
-
-#define FWL_ERR_Succeeded 0
-#define FWL_ERR_Indefinite -1
-#define FWL_ERR_Parameter_Invalid -100
-#define FWL_ERR_Property_Invalid -200
-#define FWL_ERR_Intermediate_Value__Invalid -300
-#define FWL_ERR_Method_Not_Supported -400
-#define FWL_ERR_Out_Of_Memory -500
+enum class FWL_Error {
+  Succeeded = 0,
+  Indefinite,
+  ParameterInvalid,
+  PropertyInvalid,
+  IntermediateValueInvalid,
+  MethodNotSupported,
+  OutOfMemory
+};
 
 #endif  // XFA_FWL_CORE_FWL_ERROR_H_
diff --git a/xfa/fwl/core/fwl_formimp.cpp b/xfa/fwl/core/fwl_formimp.cpp
index 78dc8b56a2..202a092395 100644
--- a/xfa/fwl/core/fwl_formimp.cpp
+++ b/xfa/fwl/core/fwl_formimp.cpp
@@ -48,7 +48,7 @@ IFWL_Form::IFWL_Form() {}
 FWL_FORMSIZE IFWL_Form::GetFormSize() {
   return static_cast<CFWL_FormImp*>(GetImpl())->GetFormSize();
 }
-FWL_ERR IFWL_Form::SetFormSize(FWL_FORMSIZE eFormSize) {
+FWL_Error IFWL_Form::SetFormSize(FWL_FORMSIZE eFormSize) {
   return static_cast<CFWL_FormImp*>(GetImpl())->SetFormSize(eFormSize);
 }
 IFWL_Widget* IFWL_Form::DoModal() {
@@ -57,10 +57,10 @@ IFWL_Widget* IFWL_Form::DoModal() {
 IFWL_Widget* IFWL_Form::DoModal(uint32_t& dwCommandID) {
   return static_cast<CFWL_FormImp*>(GetImpl())->DoModal(dwCommandID);
 }
-FWL_ERR IFWL_Form::EndDoModal() {
+FWL_Error IFWL_Form::EndDoModal() {
   return static_cast<CFWL_FormImp*>(GetImpl())->EndDoModal();
 }
-FWL_ERR IFWL_Form::SetBorderRegion(CFX_Path* pPath) {
+FWL_Error IFWL_Form::SetBorderRegion(CFX_Path* pPath) {
   return static_cast<CFWL_FormImp*>(GetImpl())->SetBorderRegion(pPath);
 }
 
@@ -99,9 +99,9 @@ CFWL_FormImp::~CFWL_FormImp() {
   delete m_pNoteLoop;
 }
 
-FWL_ERR CFWL_FormImp::GetClassName(CFX_WideString& wsClass) const {
+FWL_Error CFWL_FormImp::GetClassName(CFX_WideString& wsClass) const {
   wsClass = FWL_CLASS_Form;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 
 uint32_t CFWL_FormImp::GetClassID() const {
@@ -114,22 +114,22 @@ FX_BOOL CFWL_FormImp::IsInstance(const CFX_WideStringC& wsClass) const {
   return CFWL_WidgetImp::IsInstance(wsClass);
 }
 
-FWL_ERR CFWL_FormImp::Initialize() {
-  if (CFWL_WidgetImp::Initialize() != FWL_ERR_Succeeded)
-    return FWL_ERR_Indefinite;
+FWL_Error CFWL_FormImp::Initialize() {
+  if (CFWL_WidgetImp::Initialize() != FWL_Error::Succeeded)
+    return FWL_Error::Indefinite;
   RegisterForm();
   RegisterEventTarget();
   m_pDelegate = new CFWL_FormImpDelegate(this);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_FormImp::Finalize() {
+FWL_Error CFWL_FormImp::Finalize() {
   delete m_pDelegate;
   m_pDelegate = nullptr;
   UnregisterEventTarget();
   UnRegisterForm();
   return CFWL_WidgetImp::Finalize();
 }
-FWL_ERR CFWL_FormImp::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
+FWL_Error CFWL_FormImp::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
   if (bAutoSize) {
     rect.Reset();
     FX_FLOAT fCapHeight = GetCaptionHeight();
@@ -141,23 +141,23 @@ FWL_ERR CFWL_FormImp::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
   } else {
     rect = m_pProperties->m_rtWidget;
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_FormImp::GetClientRect(CFX_RectF& rect) {
+FWL_Error CFWL_FormImp::GetClientRect(CFX_RectF& rect) {
   if ((m_pProperties->m_dwStyles & FWL_WGTSTYLE_Caption) == 0) {
     rect = m_pProperties->m_rtWidget;
     rect.Offset(-rect.left, -rect.top);
-    return FWL_ERR_Succeeded;
+    return FWL_Error::Succeeded;
   }
 #ifdef FWL_UseMacSystemBorder
   rect = m_rtRelative;
   CFWL_WidgetMgr* pWidgetMgr = static_cast<CFWL_WidgetMgr*>(FWL_GetWidgetMgr());
   if (!pWidgetMgr)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
 
   rect.left = 0;
   rect.top = 0;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 #else
   FX_FLOAT x = 0;
   FX_FLOAT y = 0;
@@ -176,12 +176,12 @@ FWL_ERR CFWL_FormImp::GetClientRect(CFX_RectF& rect) {
   rect = m_pProperties->m_rtWidget;
   rect.Offset(-rect.left, -rect.top);
   rect.Deflate(x, t, x, y);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 #endif
 }
-FWL_ERR CFWL_FormImp::Update() {
+FWL_Error CFWL_FormImp::Update() {
   if (m_iLock > 0) {
-    return FWL_ERR_Succeeded;
+    return FWL_Error::Succeeded;
   }
   if (!m_pProperties->m_pThemeProvider) {
     m_pProperties->m_pThemeProvider = GetAvailableTheme();
@@ -195,7 +195,7 @@ FWL_ERR CFWL_FormImp::Update() {
 #endif
   UpdateCaption();
   Layout();
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 FWL_WidgetHit CFWL_FormImp::HitTest(FX_FLOAT fx, FX_FLOAT fy) {
   GetAvailableTheme();
@@ -249,12 +249,12 @@ FWL_WidgetHit CFWL_FormImp::HitTest(FX_FLOAT fx, FX_FLOAT fy) {
   }
   return FWL_WidgetHit::Client;
 }
-FWL_ERR CFWL_FormImp::DrawWidget(CFX_Graphics* pGraphics,
-                                 const CFX_Matrix* pMatrix) {
+FWL_Error CFWL_FormImp::DrawWidget(CFX_Graphics* pGraphics,
+                                   const CFX_Matrix* pMatrix) {
   if (!pGraphics)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   if (!m_pProperties->m_pThemeProvider)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   IFWL_ThemeProvider* pTheme = m_pProperties->m_pThemeProvider;
   FX_BOOL bInactive = !IsActive();
   int32_t iState = bInactive ? CFWL_PartState_Inactive : CFWL_PartState_Normal;
@@ -262,7 +262,7 @@ FWL_ERR CFWL_FormImp::DrawWidget(CFX_Graphics* pGraphics,
     DrawBackground(pGraphics, pTheme);
   }
 #ifdef FWL_UseMacSystemBorder
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 #endif
   CFWL_ThemeBackground param;
   param.m_pWidget = m_pInterface;
@@ -365,14 +365,14 @@ FWL_ERR CFWL_FormImp::DrawWidget(CFX_Graphics* pGraphics,
     }
   }
 #endif
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 FWL_FORMSIZE CFWL_FormImp::GetFormSize() {
   return m_eFormSize;
 }
-FWL_ERR CFWL_FormImp::SetFormSize(FWL_FORMSIZE eFormSize) {
+FWL_Error CFWL_FormImp::SetFormSize(FWL_FORMSIZE eFormSize) {
   m_eFormSize = eFormSize;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 IFWL_Widget* CFWL_FormImp::DoModal() {
   IFWL_App* pApp = GetOwnerApp();
@@ -399,31 +399,31 @@ IFWL_Widget* CFWL_FormImp::DoModal() {
 IFWL_Widget* CFWL_FormImp::DoModal(uint32_t& dwCommandID) {
   return DoModal();
 }
-FWL_ERR CFWL_FormImp::EndDoModal() {
+FWL_Error CFWL_FormImp::EndDoModal() {
   if (!m_pNoteLoop)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   m_bDoModalFlag = FALSE;
 #if (_FX_OS_ == _FX_MACOSX_)
   m_pNoteLoop->EndModalLoop();
   IFWL_App* pApp = GetOwnerApp();
   if (!pApp)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
 
   CFWL_NoteDriver* pDriver =
       static_cast<CFWL_NoteDriver*>(pApp->GetNoteDriver());
   if (!pDriver)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
 
   pDriver->PopNoteLoop();
   SetStates(FWL_WGTSTATE_Invisible, TRUE);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 #else
   SetStates(FWL_WGTSTATE_Invisible, TRUE);
   return m_pNoteLoop->EndModalLoop();
 #endif
 }
-FWL_ERR CFWL_FormImp::SetBorderRegion(CFX_Path* pPath) {
-  return FWL_ERR_Succeeded;
+FWL_Error CFWL_FormImp::SetBorderRegion(CFX_Path* pPath) {
+  return FWL_Error::Succeeded;
 }
 void CFWL_FormImp::DrawBackground(CFX_Graphics* pGraphics,
                                   IFWL_ThemeProvider* pTheme) {
@@ -842,9 +842,10 @@ CFWL_FormImpDelegate::CFWL_FormImpDelegate(CFWL_FormImp* pOwner)
     : m_pOwner(pOwner) {}
 
 #ifdef FWL_UseMacSystemBorder
-int32_t CFWL_FormImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
+void CFWL_FormImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
   if (!pMessage)
-    return 0;
+    return;
+
   switch (pMessage->GetClassID()) {
     case CFWL_MessageType::Activate: {
       m_pOwner->m_pProperties->m_dwStates &= ~FWL_WGTSTATE_Deactivated;
@@ -859,13 +860,12 @@ int32_t CFWL_FormImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
     default:
       break;
   }
-  return FWL_ERR_Succeeded;
 }
 #else
-int32_t CFWL_FormImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
+void CFWL_FormImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
   if (!pMessage)
-    return 0;
-  int32_t iRet = 1;
+    return;
+
   switch (pMessage->GetClassID()) {
     case CFWL_MessageType::Activate: {
       m_pOwner->m_pProperties->m_dwStates &= ~FWL_WGTSTATE_Deactivated;
@@ -938,7 +938,7 @@ int32_t CFWL_FormImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
       CFWL_WidgetMgr* pWidgetMgr =
           static_cast<CFWL_WidgetMgr*>(FWL_GetWidgetMgr());
       if (!pWidgetMgr)
-        return 0;
+        return;
 
       pWidgetMgr->AddRedrawCounts(m_pOwner->m_pInterface);
       if (!m_pOwner->m_bSetMaximize)
@@ -962,24 +962,19 @@ int32_t CFWL_FormImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
       break;
     }
     default: {
-      iRet = 0;
       break;
     }
   }
-  return iRet;
 }
 #endif  // FWL_UseMacSystemBorder
 
-FWL_ERR CFWL_FormImpDelegate::OnProcessEvent(CFWL_Event* pEvent) {
-  if (!pEvent)
-    return FWL_ERR_Indefinite;
-  return FWL_ERR_Succeeded;
-}
+void CFWL_FormImpDelegate::OnProcessEvent(CFWL_Event* pEvent) {}
 
-FWL_ERR CFWL_FormImpDelegate::OnDrawWidget(CFX_Graphics* pGraphics,
-                                           const CFX_Matrix* pMatrix) {
-  return m_pOwner->DrawWidget(pGraphics, pMatrix);
+void CFWL_FormImpDelegate::OnDrawWidget(CFX_Graphics* pGraphics,
+                                        const CFX_Matrix* pMatrix) {
+  m_pOwner->DrawWidget(pGraphics, pMatrix);
 }
+
 void CFWL_FormImpDelegate::OnLButtonDown(CFWL_MsgMouse* pMsg) {
   m_pOwner->SetGrab(TRUE);
   m_pOwner->m_bLButtonDown = TRUE;
diff --git a/xfa/fwl/core/fwl_formimp.h b/xfa/fwl/core/fwl_formimp.h
index d8bc80522e..f1bc51df37 100644
--- a/xfa/fwl/core/fwl_formimp.h
+++ b/xfa/fwl/core/fwl_formimp.h
@@ -69,24 +69,24 @@ class CFWL_FormImp : public CFWL_WidgetImp {
  public:
   CFWL_FormImp(const CFWL_WidgetImpProperties& properties, IFWL_Widget* pOuter);
   virtual ~CFWL_FormImp();
-  virtual FWL_ERR GetClassName(CFX_WideString& wsClass) const;
+  virtual FWL_Error GetClassName(CFX_WideString& wsClass) const;
   virtual uint32_t GetClassID() const;
   virtual FX_BOOL IsInstance(const CFX_WideStringC& wsClass) const;
-  virtual FWL_ERR Initialize();
-  virtual FWL_ERR Finalize();
+  virtual FWL_Error Initialize();
+  virtual FWL_Error Finalize();
 
-  virtual FWL_ERR GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
-  virtual FWL_ERR GetClientRect(CFX_RectF& rect);
-  virtual FWL_ERR Update();
+  virtual FWL_Error GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
+  virtual FWL_Error GetClientRect(CFX_RectF& rect);
+  virtual FWL_Error Update();
   virtual FWL_WidgetHit HitTest(FX_FLOAT fx, FX_FLOAT fy);
-  virtual FWL_ERR DrawWidget(CFX_Graphics* pGraphics,
-                             const CFX_Matrix* pMatrix = NULL);
+  virtual FWL_Error DrawWidget(CFX_Graphics* pGraphics,
+                               const CFX_Matrix* pMatrix = NULL);
   virtual FWL_FORMSIZE GetFormSize();
-  virtual FWL_ERR SetFormSize(FWL_FORMSIZE eFormSize);
+  virtual FWL_Error SetFormSize(FWL_FORMSIZE eFormSize);
   virtual IFWL_Widget* DoModal();
   virtual IFWL_Widget* DoModal(uint32_t& dwCommandID);
-  virtual FWL_ERR EndDoModal();
-  virtual FWL_ERR SetBorderRegion(CFX_Path* pPath);
+  virtual FWL_Error EndDoModal();
+  virtual FWL_Error SetBorderRegion(CFX_Path* pPath);
   virtual void DrawBackground(CFX_Graphics* pGraphics,
                               IFWL_ThemeProvider* pTheme);
   CFWL_WidgetImp* GetSubFocus();
@@ -168,10 +168,10 @@ class CFWL_FormImp : public CFWL_WidgetImp {
 class CFWL_FormImpDelegate : public CFWL_WidgetImpDelegate {
  public:
   CFWL_FormImpDelegate(CFWL_FormImp* pOwner);
-  int32_t OnProcessMessage(CFWL_Message* pMessage) override;
-  FWL_ERR OnProcessEvent(CFWL_Event* pEvent) override;
-  FWL_ERR OnDrawWidget(CFX_Graphics* pGraphics,
-                       const CFX_Matrix* pMatrix = NULL) override;
+  void OnProcessMessage(CFWL_Message* pMessage) override;
+  void OnProcessEvent(CFWL_Event* pEvent) override;
+  void OnDrawWidget(CFX_Graphics* pGraphics,
+                    const CFX_Matrix* pMatrix = NULL) override;
 
  protected:
   void OnLButtonDown(CFWL_MsgMouse* pMsg);
diff --git a/xfa/fwl/core/fwl_noteimp.cpp b/xfa/fwl/core/fwl_noteimp.cpp
index 5d439d7f0c..560dc3c535 100644
--- a/xfa/fwl/core/fwl_noteimp.cpp
+++ b/xfa/fwl/core/fwl_noteimp.cpp
@@ -20,22 +20,22 @@
 CFWL_NoteLoop::CFWL_NoteLoop(CFWL_WidgetImp* pForm)
     : m_pForm(pForm), m_bContinueModal(TRUE) {}
 
-FWL_ERR CFWL_NoteLoop::Idle(int32_t count) {
+FWL_Error CFWL_NoteLoop::Idle(int32_t count) {
 #if (_FX_OS_ == _FX_WIN32_DESKTOP_)
   if (count <= 0) {
 #endif
     CFWL_EvtIdle ev;
     IFWL_App* pApp = FWL_GetApp();
     if (!pApp)
-      return FWL_ERR_Indefinite;
+      return FWL_Error::Indefinite;
     CFWL_NoteDriver* pDriver = pApp->GetNoteDriver();
     if (!pDriver)
-      return FWL_ERR_Indefinite;
+      return FWL_Error::Indefinite;
     pDriver->SendEvent(&ev);
 #if (_FX_OS_ == _FX_WIN32_DESKTOP_)
   }
 #endif
-  return FWL_ERR_Indefinite;
+  return FWL_Error::Indefinite;
 }
 CFWL_WidgetImp* CFWL_NoteLoop::GetForm() {
   return m_pForm;
@@ -43,14 +43,14 @@ CFWL_WidgetImp* CFWL_NoteLoop::GetForm() {
 FX_BOOL CFWL_NoteLoop::ContinueModal() {
   return m_bContinueModal;
 }
-FWL_ERR CFWL_NoteLoop::EndModalLoop() {
+FWL_Error CFWL_NoteLoop::EndModalLoop() {
   m_bContinueModal = FALSE;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 
-FWL_ERR CFWL_NoteLoop::SetMainForm(CFWL_WidgetImp* pForm) {
+FWL_Error CFWL_NoteLoop::SetMainForm(CFWL_WidgetImp* pForm) {
   m_pForm = pForm;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 void CFWL_NoteLoop::GenerateCommondEvent(uint32_t dwCommand) {
   CFWL_EvtMenuCommand ev;
@@ -112,9 +112,9 @@ FX_BOOL CFWL_NoteDriver::SendEvent(CFWL_Event* pNote) {
 }
 
 #define FWL_NoteDriver_EventKey 1100
-FWL_ERR CFWL_NoteDriver::RegisterEventTarget(IFWL_Widget* pListener,
-                                             IFWL_Widget* pEventSource,
-                                             uint32_t dwFilter) {
+FWL_Error CFWL_NoteDriver::RegisterEventTarget(IFWL_Widget* pListener,
+                                               IFWL_Widget* pEventSource,
+                                               uint32_t dwFilter) {
   uint32_t dwkey = (uint32_t)(uintptr_t)pListener->GetPrivateData(
       (void*)(uintptr_t)FWL_NoteDriver_EventKey);
   if (dwkey == 0) {
@@ -130,19 +130,19 @@ FWL_ERR CFWL_NoteDriver::RegisterEventTarget(IFWL_Widget* pListener,
     m_eventTargets.SetAt((void*)(uintptr_t)dwkey, value);
   }
   value->SetEventSource(pEventSource, dwFilter);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_NoteDriver::UnregisterEventTarget(IFWL_Widget* pListener) {
+FWL_Error CFWL_NoteDriver::UnregisterEventTarget(IFWL_Widget* pListener) {
   uint32_t dwkey = (uint32_t)(uintptr_t)pListener->GetPrivateData(
       (void*)(uintptr_t)FWL_NoteDriver_EventKey);
   if (dwkey == 0) {
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   }
   CFWL_EventTarget* value = NULL;
   if (m_eventTargets.Lookup((void*)(uintptr_t)dwkey, (void*&)value)) {
     value->FlagInvalid();
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 void CFWL_NoteDriver::ClearEventTargets(FX_BOOL bRemoveAll) {
   ClearInvalidEventTargets(bRemoveAll);
@@ -150,9 +150,9 @@ void CFWL_NoteDriver::ClearEventTargets(FX_BOOL bRemoveAll) {
 IFWL_App* CFWL_NoteDriver::GetOwnerApp() const {
   return FWL_GetApp();
 }
-FWL_ERR CFWL_NoteDriver::PushNoteLoop(CFWL_NoteLoop* pNoteLoop) {
+FWL_Error CFWL_NoteDriver::PushNoteLoop(CFWL_NoteLoop* pNoteLoop) {
   m_noteLoopQueue.Add(pNoteLoop);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 CFWL_NoteLoop* CFWL_NoteDriver::PopNoteLoop() {
   int32_t pos = m_noteLoopQueue.GetSize();
@@ -203,10 +203,10 @@ FX_BOOL CFWL_NoteDriver::SetFocus(IFWL_Widget* pFocus, FX_BOOL bNotify) {
   }
   return TRUE;
 }
-FWL_ERR CFWL_NoteDriver::Run() {
+FWL_Error CFWL_NoteDriver::Run() {
   CFWL_WidgetMgr* pWidgetMgr = static_cast<CFWL_WidgetMgr*>(FWL_GetWidgetMgr());
   if (!pWidgetMgr)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
 
 #if (_FX_OS_ == _FX_LINUX_DESKTOP_ || _FX_OS_ == _FX_WIN32_DESKTOP_ || \
      _FX_OS_ == _FX_WIN64_)
@@ -220,7 +220,7 @@ FWL_ERR CFWL_NoteDriver::Run() {
   }
 #endif
 
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 
 IFWL_Widget* CFWL_NoteDriver::GetFocus() {
@@ -272,31 +272,31 @@ void CFWL_NoteDriver::NotifyTargetDestroy(IFWL_Widget* pNoteTarget) {
   }
 }
 
-FWL_ERR CFWL_NoteDriver::RegisterForm(CFWL_WidgetImp* pForm) {
+FWL_Error CFWL_NoteDriver::RegisterForm(CFWL_WidgetImp* pForm) {
   if (!pForm)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   if (m_forms.Find(pForm) >= 0) {
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   }
   m_forms.Add(pForm);
   if (m_forms.GetSize() == 1) {
     CFWL_NoteLoop* pLoop =
         static_cast<CFWL_NoteLoop*>(m_noteLoopQueue.GetAt(0));
     if (!pLoop)
-      return FWL_ERR_Indefinite;
+      return FWL_Error::Indefinite;
     pLoop->SetMainForm(pForm);
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_NoteDriver::UnRegisterForm(CFWL_WidgetImp* pForm) {
+FWL_Error CFWL_NoteDriver::UnRegisterForm(CFWL_WidgetImp* pForm) {
   if (!pForm)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   int32_t nIndex = m_forms.Find(pForm);
   if (nIndex < 0) {
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   }
   m_forms.RemoveAt(nIndex);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 FX_BOOL CFWL_NoteDriver::QueueMessage(CFWL_Message* pMessage) {
   pMessage->Retain();
@@ -688,7 +688,7 @@ void CFWL_NoteDriver::ClearInvalidEventTargets(FX_BOOL bRemoveAll) {
 }
 class CFWL_CoreToolTipDP : public IFWL_ToolTipDP {
  public:
-  FWL_ERR GetCaption(IFWL_Widget* pWidget, CFX_WideString& wsCaption);
+  FWL_Error GetCaption(IFWL_Widget* pWidget, CFX_WideString& wsCaption);
   int32_t GetInitialDelay(IFWL_Widget* pWidget);
   int32_t GetAutoPopDelay(IFWL_Widget* pWidget);
   CFX_DIBitmap* GetToolTipIcon(IFWL_Widget* pWidget);
@@ -706,10 +706,10 @@ CFWL_CoreToolTipDP::CFWL_CoreToolTipDP() {
   m_nAutoPopDelayTime = 50000;
   m_fAnchor.Set(0.0, 0.0, 0.0, 0.0);
 }
-FWL_ERR CFWL_CoreToolTipDP::GetCaption(IFWL_Widget* pWidget,
-                                       CFX_WideString& wsCaption) {
+FWL_Error CFWL_CoreToolTipDP::GetCaption(IFWL_Widget* pWidget,
+                                         CFX_WideString& wsCaption) {
   wsCaption = m_wsCaption;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 int32_t CFWL_CoreToolTipDP::GetInitialDelay(IFWL_Widget* pWidget) {
   return m_nInitDelayTime;
@@ -820,20 +820,21 @@ void CFWL_ToolTipContainer::DeleteInstance() {
   s_pInstance = NULL;
 }
 
-FX_ERR CFWL_ToolTipContainer::AddToolTipTarget(IFWL_ToolTipTarget* pTarget) {
+FWL_Error CFWL_ToolTipContainer::AddToolTipTarget(IFWL_ToolTipTarget* pTarget) {
   if (m_arrWidget.Find(pTarget) < 0) {
     m_arrWidget.Add(pTarget);
-    return FWL_ERR_Succeeded;
+    return FWL_Error::Succeeded;
   }
-  return FWL_ERR_Indefinite;
+  return FWL_Error::Indefinite;
 }
-FX_ERR CFWL_ToolTipContainer::RemoveToolTipTarget(IFWL_ToolTipTarget* pTarget) {
+FWL_Error CFWL_ToolTipContainer::RemoveToolTipTarget(
+    IFWL_ToolTipTarget* pTarget) {
   int index = m_arrWidget.Find(pTarget);
   if (index >= 0) {
     m_arrWidget.RemoveAt(index);
-    return FWL_ERR_Succeeded;
+    return FWL_Error::Succeeded;
   }
-  return FWL_ERR_Indefinite;
+  return FWL_Error::Indefinite;
 }
 FX_BOOL CFWL_ToolTipContainer::HasToolTip(IFWL_Widget* pWedget) {
   int32_t iCount = m_arrWidget.GetSize();
@@ -881,7 +882,7 @@ FX_BOOL CFWL_ToolTipContainer::ProcessEnter(CFWL_EvtMouse* pEvt,
         rt.height = r.height;
       }
       CFX_PointF pt(pEvt->m_fx, pEvt->m_fy);
-      if (pCurTarget->GetToolTipPos(pt) == FWL_ERR_Succeeded) {
+      if (pCurTarget->GetToolTipPos(pt) == FWL_Error::Succeeded) {
         rt.left = pt.x;
         rt.top = pt.y;
         m_pToolTipImp->ModifyStylesEx(FWL_STYLEEXT_TTP_NoAnchor, 0);
diff --git a/xfa/fwl/core/fwl_noteimp.h b/xfa/fwl/core/fwl_noteimp.h
index 723d2e5742..778eae6045 100644
--- a/xfa/fwl/core/fwl_noteimp.h
+++ b/xfa/fwl/core/fwl_noteimp.h
@@ -44,11 +44,11 @@ class CFWL_NoteLoop {
   CFWL_NoteLoop(CFWL_WidgetImp* pForm = nullptr);
   ~CFWL_NoteLoop() {}
 
-  FWL_ERR Idle(int32_t count);
+  FWL_Error Idle(int32_t count);
   CFWL_WidgetImp* GetForm();
   FX_BOOL ContinueModal();
-  FWL_ERR EndModalLoop();
-  FWL_ERR SetMainForm(CFWL_WidgetImp* pForm);
+  FWL_Error EndModalLoop();
+  FWL_Error SetMainForm(CFWL_WidgetImp* pForm);
 
  protected:
   void GenerateCommondEvent(uint32_t dwCommand);
@@ -63,25 +63,25 @@ class CFWL_NoteDriver {
   ~CFWL_NoteDriver();
 
   FX_BOOL SendEvent(CFWL_Event* pNote);
-  FWL_ERR RegisterEventTarget(IFWL_Widget* pListener,
-                              IFWL_Widget* pEventSource = nullptr,
-                              uint32_t dwFilter = FWL_EVENT_ALL_MASK);
-  FWL_ERR UnregisterEventTarget(IFWL_Widget* pListener);
+  FWL_Error RegisterEventTarget(IFWL_Widget* pListener,
+                                IFWL_Widget* pEventSource = nullptr,
+                                uint32_t dwFilter = FWL_EVENT_ALL_MASK);
+  FWL_Error UnregisterEventTarget(IFWL_Widget* pListener);
   void ClearEventTargets(FX_BOOL bRemoveAll);
   IFWL_App* GetOwnerApp() const;
-  FWL_ERR PushNoteLoop(CFWL_NoteLoop* pNoteLoop);
+  FWL_Error PushNoteLoop(CFWL_NoteLoop* pNoteLoop);
   CFWL_NoteLoop* PopNoteLoop();
   IFWL_Widget* GetFocus();
   FX_BOOL SetFocus(IFWL_Widget* pFocus, FX_BOOL bNotify = FALSE);
   void SetGrab(IFWL_Widget* pGrab, FX_BOOL bSet);
-  FWL_ERR Run();
+  FWL_Error Run();
 
   IFWL_Widget* GetHover();
   void SetHover(IFWL_Widget* pHover);
   void NotifyTargetHide(IFWL_Widget* pNoteTarget);
   void NotifyTargetDestroy(IFWL_Widget* pNoteTarget);
-  FWL_ERR RegisterForm(CFWL_WidgetImp* pForm);
-  FWL_ERR UnRegisterForm(CFWL_WidgetImp* pForm);
+  FWL_Error RegisterForm(CFWL_WidgetImp* pForm);
+  FWL_Error UnRegisterForm(CFWL_WidgetImp* pForm);
   FX_BOOL QueueMessage(CFWL_Message* pMessage);
   FX_BOOL UnqueueMessage(CFWL_NoteLoop* pNoteLoop);
   CFWL_NoteLoop* GetTopLoop();
@@ -141,8 +141,8 @@ class CFWL_ToolTipContainer {
   static CFWL_ToolTipContainer* getInstance();
   static void DeleteInstance();
 
-  FX_ERR AddToolTipTarget(IFWL_ToolTipTarget* pTarget);
-  FX_ERR RemoveToolTipTarget(IFWL_ToolTipTarget* pTarget);
+  FWL_Error AddToolTipTarget(IFWL_ToolTipTarget* pTarget);
+  FWL_Error RemoveToolTipTarget(IFWL_ToolTipTarget* pTarget);
   IFWL_ToolTipTarget* GetCurrentToolTipTarget();
 
   FX_BOOL HasToolTip(IFWL_Widget* pWidget);
diff --git a/xfa/fwl/core/fwl_timerimp.cpp b/xfa/fwl/core/fwl_timerimp.cpp
index 5adf8e158c..ced5adeb9d 100644
--- a/xfa/fwl/core/fwl_timerimp.cpp
+++ b/xfa/fwl/core/fwl_timerimp.cpp
@@ -23,12 +23,14 @@ FWL_HTIMER FWL_StartTimer(IFWL_Timer* pTimer,
   pAdapterTimerMgr->Start(pTimer, dwElapse, hTimer, bImmediately);
   return hTimer;
 }
-int32_t FWL_StopTimer(FWL_HTIMER hTimer) {
+
+FWL_Error FWL_StopTimer(FWL_HTIMER hTimer) {
   CXFA_FFApp* pAdapterNative = FWL_GetAdapterNative();
   if (!pAdapterNative)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
+
   IFWL_AdapterTimerMgr* pAdapterTimerMgr = pAdapterNative->GetTimerMgr();
   if (!pAdapterTimerMgr)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   return pAdapterTimerMgr->Stop(hTimer);
 }
diff --git a/xfa/fwl/core/fwl_widgetimp.cpp b/xfa/fwl/core/fwl_widgetimp.cpp
index 8863cef0f3..f45a66cc2d 100644
--- a/xfa/fwl/core/fwl_widgetimp.cpp
+++ b/xfa/fwl/core/fwl_widgetimp.cpp
@@ -28,7 +28,7 @@
 
 IFWL_Widget::~IFWL_Widget() {}
 
-FWL_ERR IFWL_Widget::GetClassName(CFX_WideString& wsClass) const {
+FWL_Error IFWL_Widget::GetClassName(CFX_WideString& wsClass) const {
   return m_pImpl->GetClassName(wsClass);
 }
 
@@ -40,37 +40,37 @@ FX_BOOL IFWL_Widget::IsInstance(const CFX_WideStringC& wsClass) const {
   return m_pImpl->IsInstance(wsClass);
 }
 
-FWL_ERR IFWL_Widget::Initialize() {
+FWL_Error IFWL_Widget::Initialize() {
   return m_pImpl->Initialize();
 }
 
-FWL_ERR IFWL_Widget::Finalize() {
+FWL_Error IFWL_Widget::Finalize() {
   return m_pImpl->Finalize();
 }
 
-FWL_ERR IFWL_Widget::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
+FWL_Error IFWL_Widget::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())
       ->GetWidgetRect(rect, bAutoSize);
 }
-FWL_ERR IFWL_Widget::GetGlobalRect(CFX_RectF& rect) {
+FWL_Error IFWL_Widget::GetGlobalRect(CFX_RectF& rect) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetGlobalRect(rect);
 }
-FWL_ERR IFWL_Widget::SetWidgetRect(const CFX_RectF& rect) {
+FWL_Error IFWL_Widget::SetWidgetRect(const CFX_RectF& rect) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->SetWidgetRect(rect);
 }
-FWL_ERR IFWL_Widget::GetClientRect(CFX_RectF& rect) {
+FWL_Error IFWL_Widget::GetClientRect(CFX_RectF& rect) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetClientRect(rect);
 }
 IFWL_Widget* IFWL_Widget::GetParent() {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetParent();
 }
-FWL_ERR IFWL_Widget::SetParent(IFWL_Widget* pParent) {
+FWL_Error IFWL_Widget::SetParent(IFWL_Widget* pParent) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->SetParent(pParent);
 }
 IFWL_Widget* IFWL_Widget::GetOwner() {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetOwner();
 }
-FWL_ERR IFWL_Widget::SetOwner(IFWL_Widget* pOwner) {
+FWL_Error IFWL_Widget::SetOwner(IFWL_Widget* pOwner) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->SetOwner(pOwner);
 }
 IFWL_Widget* IFWL_Widget::GetOuter() {
@@ -79,16 +79,16 @@ IFWL_Widget* IFWL_Widget::GetOuter() {
 uint32_t IFWL_Widget::GetStyles() {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetStyles();
 }
-FWL_ERR IFWL_Widget::ModifyStyles(uint32_t dwStylesAdded,
-                                  uint32_t dwStylesRemoved) {
+FWL_Error IFWL_Widget::ModifyStyles(uint32_t dwStylesAdded,
+                                    uint32_t dwStylesRemoved) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())
       ->ModifyStyles(dwStylesAdded, dwStylesRemoved);
 }
 uint32_t IFWL_Widget::GetStylesEx() {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetStylesEx();
 }
-FWL_ERR IFWL_Widget::ModifyStylesEx(uint32_t dwStylesExAdded,
-                                    uint32_t dwStylesExRemoved) {
+FWL_Error IFWL_Widget::ModifyStylesEx(uint32_t dwStylesExAdded,
+                                      uint32_t dwStylesExRemoved) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())
       ->ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
 }
@@ -98,54 +98,54 @@ uint32_t IFWL_Widget::GetStates() {
 void IFWL_Widget::SetStates(uint32_t dwStates, FX_BOOL bSet) {
   static_cast<CFWL_WidgetImp*>(GetImpl())->SetStates(dwStates, bSet);
 }
-FWL_ERR IFWL_Widget::SetPrivateData(void* module_id,
-                                    void* pData,
-                                    PD_CALLBACK_FREEDATA callback) {
+FWL_Error IFWL_Widget::SetPrivateData(void* module_id,
+                                      void* pData,
+                                      PD_CALLBACK_FREEDATA callback) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())
       ->SetPrivateData(module_id, pData, callback);
 }
 void* IFWL_Widget::GetPrivateData(void* module_id) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetPrivateData(module_id);
 }
-FWL_ERR IFWL_Widget::Update() {
+FWL_Error IFWL_Widget::Update() {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->Update();
 }
-FWL_ERR IFWL_Widget::LockUpdate() {
+FWL_Error IFWL_Widget::LockUpdate() {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->LockUpdate();
 }
-FWL_ERR IFWL_Widget::UnlockUpdate() {
+FWL_Error IFWL_Widget::UnlockUpdate() {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->UnlockUpdate();
 }
 FWL_WidgetHit IFWL_Widget::HitTest(FX_FLOAT fx, FX_FLOAT fy) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->HitTest(fx, fy);
 }
-FWL_ERR IFWL_Widget::TransformTo(IFWL_Widget* pWidget,
-                                 FX_FLOAT& fx,
-                                 FX_FLOAT& fy) {
+FWL_Error IFWL_Widget::TransformTo(IFWL_Widget* pWidget,
+                                   FX_FLOAT& fx,
+                                   FX_FLOAT& fy) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->TransformTo(pWidget, fx, fy);
 }
-FWL_ERR IFWL_Widget::TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt) {
+FWL_Error IFWL_Widget::TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->TransformTo(pWidget, rt);
 }
-FWL_ERR IFWL_Widget::GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal) {
+FWL_Error IFWL_Widget::GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetMatrix(matrix, bGlobal);
 }
-FWL_ERR IFWL_Widget::SetMatrix(const CFX_Matrix& matrix) {
+FWL_Error IFWL_Widget::SetMatrix(const CFX_Matrix& matrix) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->SetMatrix(matrix);
 }
-FWL_ERR IFWL_Widget::DrawWidget(CFX_Graphics* pGraphics,
-                                const CFX_Matrix* pMatrix) {
+FWL_Error IFWL_Widget::DrawWidget(CFX_Graphics* pGraphics,
+                                  const CFX_Matrix* pMatrix) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())
       ->DrawWidget(pGraphics, pMatrix);
 }
 IFWL_ThemeProvider* IFWL_Widget::GetThemeProvider() {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetThemeProvider();
 }
-FWL_ERR IFWL_Widget::SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) {
+FWL_Error IFWL_Widget::SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())
       ->SetThemeProvider(pThemeProvider);
 }
-FWL_ERR IFWL_Widget::SetDataProvider(IFWL_DataProvider* pDataProvider) {
+FWL_Error IFWL_Widget::SetDataProvider(IFWL_DataProvider* pDataProvider) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())
       ->SetDataProvider(pDataProvider);
 }
@@ -159,15 +159,17 @@ CFX_SizeF IFWL_Widget::GetOffsetFromParent(IFWL_Widget* pParent) {
   return static_cast<CFWL_WidgetImp*>(GetImpl())->GetOffsetFromParent(pParent);
 }
 
-FWL_ERR CFWL_WidgetImp::Initialize() {
+FWL_Error CFWL_WidgetImp::Initialize() {
   IFWL_App* pApp = FWL_GetApp();
   if (!pApp)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
+
   CXFA_FFApp* pAdapter = pApp->GetAdapterNative();
   if (!pAdapter)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
 
   SetOwnerApp(static_cast<CFWL_AppImp*>(FWL_GetApp()->GetImpl()));
+
   IFWL_Widget* pParent = m_pProperties->m_pParent;
   m_pWidgetMgr->InsertWidget(pParent, m_pInterface);
   if (!IsChild()) {
@@ -175,18 +177,18 @@ FWL_ERR CFWL_WidgetImp::Initialize() {
     if (pOwner)
       m_pWidgetMgr->SetOwner(pOwner, m_pInterface);
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 
-FWL_ERR CFWL_WidgetImp::Finalize() {
+FWL_Error CFWL_WidgetImp::Finalize() {
   NotifyDriver();
   m_pWidgetMgr->RemoveWidget(m_pInterface);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 
-FWL_ERR CFWL_WidgetImp::GetClassName(CFX_WideString& wsClass) const {
+FWL_Error CFWL_WidgetImp::GetClassName(CFX_WideString& wsClass) const {
   wsClass.clear();
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 
 uint32_t CFWL_WidgetImp::GetClassID() const {
@@ -197,7 +199,7 @@ FX_BOOL CFWL_WidgetImp::IsInstance(const CFX_WideStringC& wsClass) const {
   return FALSE;
 }
 
-FWL_ERR CFWL_WidgetImp::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
+FWL_Error CFWL_WidgetImp::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
   if (bAutoSize) {
     if (HasEdge()) {
       FX_FLOAT fEdge = GetEdgeWidth();
@@ -210,21 +212,21 @@ FWL_ERR CFWL_WidgetImp::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
   } else {
     rect = m_pProperties->m_rtWidget;
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_WidgetImp::GetGlobalRect(CFX_RectF& rect) {
+FWL_Error CFWL_WidgetImp::GetGlobalRect(CFX_RectF& rect) {
   IFWL_Widget* pForm =
       m_pWidgetMgr->GetWidget(m_pInterface, FWL_WGTRELATION_SystemForm);
   if (!pForm)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   rect.Set(0, 0, m_pProperties->m_rtWidget.width,
            m_pProperties->m_rtWidget.height);
   if (pForm == m_pInterface) {
-    return FWL_ERR_Succeeded;
+    return FWL_Error::Succeeded;
   }
   return TransformTo(pForm, rect);
 }
-FWL_ERR CFWL_WidgetImp::SetWidgetRect(const CFX_RectF& rect) {
+FWL_Error CFWL_WidgetImp::SetWidgetRect(const CFX_RectF& rect) {
   CFX_RectF rtOld = m_pProperties->m_rtWidget;
   m_pProperties->m_rtWidget = rect;
   if (IsChild()) {
@@ -239,34 +241,34 @@ FWL_ERR CFWL_WidgetImp::SetWidgetRect(const CFX_RectF& rect) {
         pDelegate->OnProcessEvent(&ev);
       }
     }
-    return FWL_ERR_Succeeded;
+    return FWL_Error::Succeeded;
   }
   m_pWidgetMgr->SetWidgetRect_Native(m_pInterface, rect);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_WidgetImp::GetClientRect(CFX_RectF& rect) {
+FWL_Error CFWL_WidgetImp::GetClientRect(CFX_RectF& rect) {
   GetEdgeRect(rect);
   if (HasEdge()) {
     FX_FLOAT fEdge = GetEdgeWidth();
     rect.Deflate(fEdge, fEdge);
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 IFWL_Widget* CFWL_WidgetImp::GetParent() {
   return m_pWidgetMgr->GetWidget(m_pInterface, FWL_WGTRELATION_Parent);
 }
-FWL_ERR CFWL_WidgetImp::SetParent(IFWL_Widget* pParent) {
+FWL_Error CFWL_WidgetImp::SetParent(IFWL_Widget* pParent) {
   m_pProperties->m_pParent = pParent;
   m_pWidgetMgr->SetParent(pParent, m_pInterface);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 IFWL_Widget* CFWL_WidgetImp::GetOwner() {
   return m_pWidgetMgr->GetWidget(m_pInterface, FWL_WGTRELATION_Owner);
 }
-FWL_ERR CFWL_WidgetImp::SetOwner(IFWL_Widget* pOwner) {
+FWL_Error CFWL_WidgetImp::SetOwner(IFWL_Widget* pOwner) {
   m_pProperties->m_pOwner = pOwner;
   m_pWidgetMgr->SetOwner(pOwner, m_pInterface);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 IFWL_Widget* CFWL_WidgetImp::GetOuter() {
   return m_pOuter;
@@ -274,20 +276,20 @@ IFWL_Widget* CFWL_WidgetImp::GetOuter() {
 uint32_t CFWL_WidgetImp::GetStyles() {
   return m_pProperties->m_dwStyles;
 }
-FWL_ERR CFWL_WidgetImp::ModifyStyles(uint32_t dwStylesAdded,
-                                     uint32_t dwStylesRemoved) {
+FWL_Error CFWL_WidgetImp::ModifyStyles(uint32_t dwStylesAdded,
+                                       uint32_t dwStylesRemoved) {
   m_pProperties->m_dwStyles =
       (m_pProperties->m_dwStyles & ~dwStylesRemoved) | dwStylesAdded;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 uint32_t CFWL_WidgetImp::GetStylesEx() {
   return m_pProperties->m_dwStyleExes;
 }
-FWL_ERR CFWL_WidgetImp::ModifyStylesEx(uint32_t dwStylesExAdded,
-                                       uint32_t dwStylesExRemoved) {
+FWL_Error CFWL_WidgetImp::ModifyStylesEx(uint32_t dwStylesExAdded,
+                                         uint32_t dwStylesExRemoved) {
   m_pProperties->m_dwStyleExes =
       (m_pProperties->m_dwStyleExes & ~dwStylesExRemoved) | dwStylesExAdded;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 uint32_t CFWL_WidgetImp::GetStates() {
   return m_pProperties->m_dwStates;
@@ -302,6 +304,7 @@ static void NotifyHideChildWidget(IFWL_WidgetMgr* widgetMgr,
     child = widgetMgr->GetWidget(child, FWL_WGTRELATION_NextSibling);
   }
 }
+
 void CFWL_WidgetImp::SetStates(uint32_t dwStates, FX_BOOL bSet) {
   bSet ? (m_pProperties->m_dwStates |= dwStates)
        : (m_pProperties->m_dwStates &= ~dwStates);
@@ -321,32 +324,32 @@ void CFWL_WidgetImp::SetStates(uint32_t dwStates, FX_BOOL bSet) {
   }
   return;
 }
-FWL_ERR CFWL_WidgetImp::SetPrivateData(void* module_id,
-                                       void* pData,
-                                       PD_CALLBACK_FREEDATA callback) {
+FWL_Error CFWL_WidgetImp::SetPrivateData(void* module_id,
+                                         void* pData,
+                                         PD_CALLBACK_FREEDATA callback) {
   if (!m_pPrivateData) {
     m_pPrivateData = new CFX_PrivateData;
   }
   m_pPrivateData->SetPrivateData(module_id, pData, callback);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 void* CFWL_WidgetImp::GetPrivateData(void* module_id) {
   if (!m_pPrivateData)
     return NULL;
   return m_pPrivateData->GetPrivateData(module_id);
 }
-FWL_ERR CFWL_WidgetImp::Update() {
-  return FWL_ERR_Succeeded;
+FWL_Error CFWL_WidgetImp::Update() {
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_WidgetImp::LockUpdate() {
+FWL_Error CFWL_WidgetImp::LockUpdate() {
   m_iLock++;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_WidgetImp::UnlockUpdate() {
+FWL_Error CFWL_WidgetImp::UnlockUpdate() {
   if (IsLocked()) {
     m_iLock--;
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 FWL_WidgetHit CFWL_WidgetImp::HitTest(FX_FLOAT fx, FX_FLOAT fy) {
   CFX_RectF rtClient;
@@ -367,9 +370,9 @@ FWL_WidgetHit CFWL_WidgetImp::HitTest(FX_FLOAT fx, FX_FLOAT fy) {
   }
   return FWL_WidgetHit::Unknown;
 }
-FWL_ERR CFWL_WidgetImp::TransformTo(IFWL_Widget* pWidget,
-                                    FX_FLOAT& fx,
-                                    FX_FLOAT& fy) {
+FWL_Error CFWL_WidgetImp::TransformTo(IFWL_Widget* pWidget,
+                                      FX_FLOAT& fx,
+                                      FX_FLOAT& fy) {
   if (m_pWidgetMgr->IsFormDisabled()) {
     CFX_SizeF szOffset;
     if (IsParent(pWidget)) {
@@ -381,7 +384,7 @@ FWL_ERR CFWL_WidgetImp::TransformTo(IFWL_Widget* pWidget,
     }
     fx += szOffset.x;
     fy += szOffset.y;
-    return FWL_ERR_Succeeded;
+    return FWL_Error::Succeeded;
   }
   CFX_RectF r;
   CFX_Matrix m;
@@ -396,17 +399,17 @@ FWL_ERR CFWL_WidgetImp::TransformTo(IFWL_Widget* pWidget,
   IFWL_Widget* form1 =
       m_pWidgetMgr->GetWidget(m_pInterface, FWL_WGTRELATION_SystemForm);
   if (!form1)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   if (!pWidget) {
     form1->GetWidgetRect(r);
     fx += r.left;
     fy += r.top;
-    return FWL_ERR_Succeeded;
+    return FWL_Error::Succeeded;
   }
   IFWL_Widget* form2 =
       m_pWidgetMgr->GetWidget(pWidget, FWL_WGTRELATION_SystemForm);
   if (!form2)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   if (form1 != form2) {
     form1->GetWidgetRect(r);
     fx += r.left;
@@ -426,14 +429,14 @@ FWL_ERR CFWL_WidgetImp::TransformTo(IFWL_Widget* pWidget,
     fx -= r.left;
     fy -= r.top;
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_WidgetImp::TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt) {
+FWL_Error CFWL_WidgetImp::TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt) {
   return TransformTo(pWidget, rt.left, rt.top);
 }
-FWL_ERR CFWL_WidgetImp::GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal) {
+FWL_Error CFWL_WidgetImp::GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal) {
   if (!m_pProperties)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   if (bGlobal) {
     IFWL_Widget* parent = GetParent();
     CFX_ArrayTemplate<IFWL_Widget*> parents;
@@ -457,32 +460,32 @@ FWL_ERR CFWL_WidgetImp::GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal) {
   } else {
     matrix = m_pProperties->m_ctmOnParent;
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_WidgetImp::SetMatrix(const CFX_Matrix& matrix) {
+FWL_Error CFWL_WidgetImp::SetMatrix(const CFX_Matrix& matrix) {
   if (!m_pProperties)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   IFWL_Widget* parent = GetParent();
   if (!parent) {
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   }
   m_pProperties->m_ctmOnParent = matrix;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_WidgetImp::DrawWidget(CFX_Graphics* pGraphics,
-                                   const CFX_Matrix* pMatrix) {
-  return FWL_ERR_Indefinite;
+FWL_Error CFWL_WidgetImp::DrawWidget(CFX_Graphics* pGraphics,
+                                     const CFX_Matrix* pMatrix) {
+  return FWL_Error::Indefinite;
 }
 IFWL_ThemeProvider* CFWL_WidgetImp::GetThemeProvider() {
   return m_pProperties->m_pThemeProvider;
 }
-FWL_ERR CFWL_WidgetImp::SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) {
+FWL_Error CFWL_WidgetImp::SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) {
   m_pProperties->m_pThemeProvider = pThemeProvider;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_WidgetImp::SetDataProvider(IFWL_DataProvider* pDataProvider) {
+FWL_Error CFWL_WidgetImp::SetDataProvider(IFWL_DataProvider* pDataProvider) {
   m_pProperties->m_pDataProvider = pDataProvider;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 IFWL_WidgetDelegate* CFWL_WidgetImp::SetDelegate(
     IFWL_WidgetDelegate* pDelegate) {
@@ -499,9 +502,9 @@ IFWL_WidgetDelegate* CFWL_WidgetImp::SetDelegate(
 IFWL_App* CFWL_WidgetImp::GetOwnerApp() const {
   return static_cast<IFWL_App*>(m_pOwnerApp->GetInterface());
 }
-FWL_ERR CFWL_WidgetImp::SetOwnerApp(CFWL_AppImp* pOwnerApp) {
+FWL_Error CFWL_WidgetImp::SetOwnerApp(CFWL_AppImp* pOwnerApp) {
   m_pOwnerApp = pOwnerApp;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 IFWL_Widget* CFWL_WidgetImp::GetInterface() const {
   return m_pInterface;
@@ -963,9 +966,9 @@ FX_BOOL CFWL_WidgetImp::IsParent(IFWL_Widget* pParent) {
 
 CFWL_WidgetImpDelegate::CFWL_WidgetImpDelegate() {}
 
-int32_t CFWL_WidgetImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
+void CFWL_WidgetImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
   if (!pMessage->m_pDstTarget)
-    return 0;
+    return;
 
   CFWL_WidgetImp* pWidget =
       static_cast<CFWL_WidgetImp*>(pMessage->m_pDstTarget->GetImpl());
@@ -1030,16 +1033,12 @@ int32_t CFWL_WidgetImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
     default:
       break;
   }
-  return 1;
 }
 
-FWL_ERR CFWL_WidgetImpDelegate::OnProcessEvent(CFWL_Event* pEvent) {
-  return FWL_ERR_Succeeded;
-}
+void CFWL_WidgetImpDelegate::OnProcessEvent(CFWL_Event* pEvent) {}
 
-FWL_ERR CFWL_WidgetImpDelegate::OnDrawWidget(CFX_Graphics* pGraphics,
-                                             const CFX_Matrix* pMatrix) {
+void CFWL_WidgetImpDelegate::OnDrawWidget(CFX_Graphics* pGraphics,
+                                          const CFX_Matrix* pMatrix) {
   CFWL_EvtDraw evt;
   evt.m_pGraphics = pGraphics;
-  return FWL_ERR_Succeeded;
 }
diff --git a/xfa/fwl/core/fwl_widgetimp.h b/xfa/fwl/core/fwl_widgetimp.h
index d20fe0d75e..4af2872f41 100644
--- a/xfa/fwl/core/fwl_widgetimp.h
+++ b/xfa/fwl/core/fwl_widgetimp.h
@@ -28,49 +28,51 @@ class CFWL_WidgetImp {
  public:
   virtual ~CFWL_WidgetImp();
 
-  virtual FWL_ERR Initialize();
-  virtual FWL_ERR Finalize();
-  virtual FWL_ERR GetClassName(CFX_WideString& wsClass) const;
+  virtual FWL_Error Initialize();
+  virtual FWL_Error Finalize();
+  virtual FWL_Error GetClassName(CFX_WideString& wsClass) const;
   virtual uint32_t GetClassID() const;
   virtual FX_BOOL IsInstance(const CFX_WideStringC& wsClass) const;
 
-  virtual FWL_ERR GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
-  virtual FWL_ERR GetGlobalRect(CFX_RectF& rect);
-  virtual FWL_ERR SetWidgetRect(const CFX_RectF& rect);
-  virtual FWL_ERR GetClientRect(CFX_RectF& rect);
+  virtual FWL_Error GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
+  virtual FWL_Error GetGlobalRect(CFX_RectF& rect);
+  virtual FWL_Error SetWidgetRect(const CFX_RectF& rect);
+  virtual FWL_Error GetClientRect(CFX_RectF& rect);
   virtual IFWL_Widget* GetParent();
-  virtual FWL_ERR SetParent(IFWL_Widget* pParent);
+  virtual FWL_Error SetParent(IFWL_Widget* pParent);
   virtual IFWL_Widget* GetOwner();
-  virtual FWL_ERR SetOwner(IFWL_Widget* pOwner);
+  virtual FWL_Error SetOwner(IFWL_Widget* pOwner);
   virtual IFWL_Widget* GetOuter();
   virtual uint32_t GetStyles();
-  virtual FWL_ERR ModifyStyles(uint32_t dwStylesAdded,
-                               uint32_t dwStylesRemoved);
+  virtual FWL_Error ModifyStyles(uint32_t dwStylesAdded,
+                                 uint32_t dwStylesRemoved);
   virtual uint32_t GetStylesEx();
-  virtual FWL_ERR ModifyStylesEx(uint32_t dwStylesExAdded,
-                                 uint32_t dwStylesExRemoved);
+  virtual FWL_Error ModifyStylesEx(uint32_t dwStylesExAdded,
+                                   uint32_t dwStylesExRemoved);
   virtual uint32_t GetStates();
   virtual void SetStates(uint32_t dwStates, FX_BOOL bSet = TRUE);
-  virtual FWL_ERR SetPrivateData(void* module_id,
-                                 void* pData,
-                                 PD_CALLBACK_FREEDATA callback);
+  virtual FWL_Error SetPrivateData(void* module_id,
+                                   void* pData,
+                                   PD_CALLBACK_FREEDATA callback);
   virtual void* GetPrivateData(void* module_id);
-  virtual FWL_ERR Update();
-  virtual FWL_ERR LockUpdate();
-  virtual FWL_ERR UnlockUpdate();
+  virtual FWL_Error Update();
+  virtual FWL_Error LockUpdate();
+  virtual FWL_Error UnlockUpdate();
   virtual FWL_WidgetHit HitTest(FX_FLOAT fx, FX_FLOAT fy);
-  virtual FWL_ERR TransformTo(IFWL_Widget* pWidget, FX_FLOAT& fx, FX_FLOAT& fy);
-  virtual FWL_ERR TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt);
-  virtual FWL_ERR GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal = FALSE);
-  virtual FWL_ERR SetMatrix(const CFX_Matrix& matrix);
-  virtual FWL_ERR DrawWidget(CFX_Graphics* pGraphics,
-                             const CFX_Matrix* pMatrix = NULL);
+  virtual FWL_Error TransformTo(IFWL_Widget* pWidget,
+                                FX_FLOAT& fx,
+                                FX_FLOAT& fy);
+  virtual FWL_Error TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt);
+  virtual FWL_Error GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal = FALSE);
+  virtual FWL_Error SetMatrix(const CFX_Matrix& matrix);
+  virtual FWL_Error DrawWidget(CFX_Graphics* pGraphics,
+                               const CFX_Matrix* pMatrix = NULL);
   virtual IFWL_ThemeProvider* GetThemeProvider();
-  virtual FWL_ERR SetThemeProvider(IFWL_ThemeProvider* pThemeProvider);
-  virtual FWL_ERR SetDataProvider(IFWL_DataProvider* pDataProvider);
+  virtual FWL_Error SetThemeProvider(IFWL_ThemeProvider* pThemeProvider);
+  virtual FWL_Error SetDataProvider(IFWL_DataProvider* pDataProvider);
   virtual IFWL_WidgetDelegate* SetDelegate(IFWL_WidgetDelegate* pDelegate);
   virtual IFWL_App* GetOwnerApp() const;
-  FWL_ERR SetOwnerApp(CFWL_AppImp* pOwnerApp);
+  FWL_Error SetOwnerApp(CFWL_AppImp* pOwnerApp);
   IFWL_Widget* GetInterface() const;
   void SetInterface(IFWL_Widget* pInterface);
   CFX_SizeF GetOffsetFromParent(IFWL_Widget* pParent);
@@ -163,10 +165,10 @@ class CFWL_WidgetImpDelegate : public IFWL_WidgetDelegate {
  public:
   CFWL_WidgetImpDelegate();
   ~CFWL_WidgetImpDelegate() override {}
-  int32_t OnProcessMessage(CFWL_Message* pMessage) override;
-  FWL_ERR OnProcessEvent(CFWL_Event* pEvent) override;
-  FWL_ERR OnDrawWidget(CFX_Graphics* pGraphics,
-                       const CFX_Matrix* pMatrix = NULL) override;
+  void OnProcessMessage(CFWL_Message* pMessage) override;
+  void OnProcessEvent(CFWL_Event* pEvent) override;
+  void OnDrawWidget(CFX_Graphics* pGraphics,
+                    const CFX_Matrix* pMatrix = NULL) override;
 };
 
 #endif  // XFA_FWL_CORE_FWL_WIDGETIMP_H_
diff --git a/xfa/fwl/core/fwl_widgetmgrimp.cpp b/xfa/fwl/core/fwl_widgetmgrimp.cpp
index e56c308be9..28500c2cb2 100644
--- a/xfa/fwl/core/fwl_widgetmgrimp.cpp
+++ b/xfa/fwl/core/fwl_widgetmgrimp.cpp
@@ -219,10 +219,10 @@ FX_BOOL CFWL_WidgetMgr::SetWidgetIndex(IFWL_Widget* pWidget, int32_t nIndex) {
   }
   return TRUE;
 }
-FWL_ERR CFWL_WidgetMgr::RepaintWidget(IFWL_Widget* pWidget,
-                                      const CFX_RectF* pRect) {
+FWL_Error CFWL_WidgetMgr::RepaintWidget(IFWL_Widget* pWidget,
+                                        const CFX_RectF* pRect) {
   if (!m_pAdapter)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   IFWL_Widget* pNative = pWidget;
   CFX_RectF rect(*pRect);
   if (IsFormDisabled()) {
@@ -238,7 +238,7 @@ FWL_ERR CFWL_WidgetMgr::RepaintWidget(IFWL_Widget* pWidget,
   } else if (!IsAbleNative(pWidget)) {
     pNative = GetWidget(pWidget, FWL_WGTRELATION_SystemForm);
     if (!pNative)
-      return FWL_ERR_Indefinite;
+      return FWL_Error::Indefinite;
     pWidget->TransformTo(pNative, rect.left, rect.top);
   }
   AddRedrawCounts(pNative);
@@ -371,8 +371,9 @@ FX_BOOL CFWL_WidgetMgr::IsChild(IFWL_Widget* pChild, IFWL_Widget* pParent) {
   } while (pTemp);
   return FALSE;
 }
-FWL_ERR CFWL_WidgetMgr::SetWidgetRect_Native(IFWL_Widget* pWidget,
-                                             const CFX_RectF& rect) {
+
+FWL_Error CFWL_WidgetMgr::SetWidgetRect_Native(IFWL_Widget* pWidget,
+                                               const CFX_RectF& rect) {
   if (FWL_UseOffscreen(pWidget)) {
     CFWL_WidgetMgrItem* pItem = GetWidgetMgrItem(pWidget);
     pItem->iRedrawCounter++;
@@ -391,8 +392,9 @@ FWL_ERR CFWL_WidgetMgr::SetWidgetRect_Native(IFWL_Widget* pWidget,
     pItem->bOutsideChanged = !m_rtScreen.Contains(rect);
 #endif
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
+
 IFWL_Widget* CFWL_WidgetMgr::GetWidgetAtPoint(IFWL_Widget* parent,
                                               FX_FLOAT x,
                                               FX_FLOAT y) {
@@ -631,25 +633,26 @@ FX_BOOL CFWL_WidgetMgr::GetAdapterPopupPos(IFWL_Widget* pWidget,
 }
 CFWL_WidgetMgrDelegate::CFWL_WidgetMgrDelegate(CFWL_WidgetMgr* pWidgetMgr)
     : m_pWidgetMgr(pWidgetMgr) {}
-FWL_ERR CFWL_WidgetMgrDelegate::OnSetCapability(uint32_t dwCapability) {
+FWL_Error CFWL_WidgetMgrDelegate::OnSetCapability(uint32_t dwCapability) {
   m_pWidgetMgr->m_dwCapability = dwCapability;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-int32_t CFWL_WidgetMgrDelegate::OnProcessMessageToForm(CFWL_Message* pMessage) {
+
+void CFWL_WidgetMgrDelegate::OnProcessMessageToForm(CFWL_Message* pMessage) {
   if (!pMessage)
-    return 0;
+    return;
   if (!pMessage->m_pDstTarget)
-    return 0;
+    return;
 
   IFWL_Widget* pDstWidget = pMessage->m_pDstTarget;
   IFWL_App* pApp = pDstWidget->GetOwnerApp();
   if (!pApp)
-    return 0;
+    return;
 
   CFWL_NoteDriver* pNoteDriver =
       static_cast<CFWL_NoteDriver*>(pApp->GetNoteDriver());
   if (!pNoteDriver)
-    return 0;
+    return;
 
   if (m_pWidgetMgr->IsThreadEnabled())
     pMessage = static_cast<CFWL_Message*>(pMessage->Clone());
@@ -660,23 +663,21 @@ int32_t CFWL_WidgetMgrDelegate::OnProcessMessageToForm(CFWL_Message* pMessage) {
 
 #if (_FX_OS_ == _FX_MACOSX_)
   CFWL_NoteLoop* pTopLoop = pNoteDriver->GetTopLoop();
-  if (pTopLoop) {
+  if (pTopLoop)
     pNoteDriver->UnqueueMessage(pTopLoop);
-  }
 #endif
-  if (m_pWidgetMgr->IsThreadEnabled()) {
+
+  if (m_pWidgetMgr->IsThreadEnabled())
     pMessage->Release();
-  }
-  return FWL_ERR_Succeeded;
+
+  return;
 }
 
-FWL_ERR CFWL_WidgetMgrDelegate::OnDrawWidget(IFWL_Widget* pWidget,
-                                             CFX_Graphics* pGraphics,
-                                             const CFX_Matrix* pMatrix) {
-  if (!pWidget)
-    return FWL_ERR_Indefinite;
-  if (!pGraphics)
-    return FWL_ERR_Indefinite;
+void CFWL_WidgetMgrDelegate::OnDrawWidget(IFWL_Widget* pWidget,
+                                          CFX_Graphics* pGraphics,
+                                          const CFX_Matrix* pMatrix) {
+  if (!pWidget || !pGraphics)
+    return;
 
   CFX_Graphics* pTemp = DrawWidgetBefore(pWidget, pGraphics, pMatrix);
   CFX_RectF clipCopy;
@@ -684,7 +685,7 @@ FWL_ERR CFWL_WidgetMgrDelegate::OnDrawWidget(IFWL_Widget* pWidget,
   clipCopy.left = clipCopy.top = 0;
   if (bUseOffscreenDirect(pWidget)) {
     DrawWidgetAfter(pWidget, pGraphics, clipCopy, pMatrix);
-    return FWL_ERR_Succeeded;
+    return;
   }
   CFX_RectF clipBounds;
 
@@ -718,7 +719,6 @@ FWL_ERR CFWL_WidgetMgrDelegate::OnDrawWidget(IFWL_Widget* pWidget,
 
   DrawWidgetAfter(pWidget, pGraphics, clipCopy, pMatrix);
   m_pWidgetMgr->ResetRedrawCounts(pWidget);
-  return FWL_ERR_Succeeded;
 }
 
 void CFWL_WidgetMgrDelegate::DrawChild(IFWL_Widget* parent,
diff --git a/xfa/fwl/core/fwl_widgetmgrimp.h b/xfa/fwl/core/fwl_widgetmgrimp.h
index ff732e5cc0..fe17613364 100644
--- a/xfa/fwl/core/fwl_widgetmgrimp.h
+++ b/xfa/fwl/core/fwl_widgetmgrimp.h
@@ -71,8 +71,8 @@ class CFWL_WidgetMgr : public IFWL_WidgetMgr {
                          FWL_WGTRELATION eRelation) override;
   int32_t GetWidgetIndex(IFWL_Widget* pWidget) override;
   FX_BOOL SetWidgetIndex(IFWL_Widget* pWidget, int32_t nIndex) override;
-  FWL_ERR RepaintWidget(IFWL_Widget* pWidget,
-                        const CFX_RectF* pRect = NULL) override;
+  FWL_Error RepaintWidget(IFWL_Widget* pWidget,
+                          const CFX_RectF* pRect = NULL) override;
   uint32_t GetCapability() override { return m_dwCapability; }
 
   void AddWidget(IFWL_Widget* pWidget);
@@ -83,7 +83,7 @@ class CFWL_WidgetMgr : public IFWL_WidgetMgr {
   void SetOwner(IFWL_Widget* pOwner, IFWL_Widget* pOwned);
   void SetParent(IFWL_Widget* pParent, IFWL_Widget* pChild);
   FX_BOOL IsChild(IFWL_Widget* pChild, IFWL_Widget* pParent);
-  FWL_ERR SetWidgetRect_Native(IFWL_Widget* pWidget, const CFX_RectF& rect);
+  FWL_Error SetWidgetRect_Native(IFWL_Widget* pWidget, const CFX_RectF& rect);
   IFWL_Widget* GetWidgetAtPoint(IFWL_Widget* pParent, FX_FLOAT fx, FX_FLOAT fy);
   void NotifySizeChanged(IFWL_Widget* pForm, FX_FLOAT fx, FX_FLOAT fy);
   IFWL_Widget* nextTab(IFWL_Widget* parent, IFWL_Widget* focus, FX_BOOL& bFind);
@@ -127,11 +127,11 @@ class CFWL_WidgetMgrDelegate {
   CFWL_WidgetMgrDelegate(CFWL_WidgetMgr* pWidgetMgr);
   ~CFWL_WidgetMgrDelegate() {}
 
-  FWL_ERR OnSetCapability(uint32_t dwCapability = FWL_WGTMGR_DisableThread);
-  int32_t OnProcessMessageToForm(CFWL_Message* pMessage);
-  FWL_ERR OnDrawWidget(IFWL_Widget* pWidget,
-                       CFX_Graphics* pGraphics,
-                       const CFX_Matrix* pMatrix);
+  FWL_Error OnSetCapability(uint32_t dwCapability = FWL_WGTMGR_DisableThread);
+  void OnProcessMessageToForm(CFWL_Message* pMessage);
+  void OnDrawWidget(IFWL_Widget* pWidget,
+                    CFX_Graphics* pGraphics,
+                    const CFX_Matrix* pMatrix);
 
  protected:
   void DrawChild(IFWL_Widget* pParent,
diff --git a/xfa/fwl/core/ifwl_app.h b/xfa/fwl/core/ifwl_app.h
index af5fafe0ad..41983ef8f5 100644
--- a/xfa/fwl/core/ifwl_app.h
+++ b/xfa/fwl/core/ifwl_app.h
@@ -34,8 +34,8 @@ class IFWL_App {
 
   virtual ~IFWL_App() {}
 
-  FWL_ERR Initialize();
-  FWL_ERR Finalize();
+  FWL_Error Initialize();
+  FWL_Error Finalize();
   CXFA_FFApp* GetAdapterNative();
   IFWL_WidgetMgr* GetWidgetMgr();
   IFWL_ThemeProvider* GetThemeProvider();
diff --git a/xfa/fwl/core/ifwl_dataprovider.h b/xfa/fwl/core/ifwl_dataprovider.h
index 271edb7ac8..5643a3d079 100644
--- a/xfa/fwl/core/ifwl_dataprovider.h
+++ b/xfa/fwl/core/ifwl_dataprovider.h
@@ -15,8 +15,8 @@ class IFWL_Widget;
 class IFWL_DataProvider {
  public:
   virtual ~IFWL_DataProvider() {}
-  virtual FWL_ERR GetCaption(IFWL_Widget* pWidget,
-                             CFX_WideString& wsCaption) = 0;
+  virtual FWL_Error GetCaption(IFWL_Widget* pWidget,
+                               CFX_WideString& wsCaption) = 0;
 };
 
 #endif  // XFA_FWL_CORE_IFWL_DATAPROVIDER_H_
diff --git a/xfa/fwl/core/ifwl_form.h b/xfa/fwl/core/ifwl_form.h
index 185e059826..22d6ecea12 100644
--- a/xfa/fwl/core/ifwl_form.h
+++ b/xfa/fwl/core/ifwl_form.h
@@ -53,11 +53,11 @@ class IFWL_Form : public IFWL_Widget {
                                     IFWL_Widget* pOuter);
 
   FWL_FORMSIZE GetFormSize();
-  FWL_ERR SetFormSize(FWL_FORMSIZE eFormSize);
+  FWL_Error SetFormSize(FWL_FORMSIZE eFormSize);
   IFWL_Widget* DoModal();
   IFWL_Widget* DoModal(uint32_t& dwCommandID);
-  FWL_ERR EndDoModal();
-  FWL_ERR SetBorderRegion(CFX_Path* pPath);
+  FWL_Error EndDoModal();
+  FWL_Error SetBorderRegion(CFX_Path* pPath);
 
  protected:
   IFWL_Form();
diff --git a/xfa/fwl/core/ifwl_themeprovider.h b/xfa/fwl/core/ifwl_themeprovider.h
index c790da5f4e..66e7e0c4fd 100644
--- a/xfa/fwl/core/ifwl_themeprovider.h
+++ b/xfa/fwl/core/ifwl_themeprovider.h
@@ -25,16 +25,17 @@ class IFWL_ThemeProvider {
   virtual uint32_t SetThemeID(IFWL_Widget* pWidget,
                               uint32_t dwThemeID,
                               FX_BOOL bChildren = TRUE) = 0;
-  virtual FWL_ERR GetThemeMatrix(IFWL_Widget* pWidget, CFX_Matrix& matrix) = 0;
-  virtual FWL_ERR SetThemeMatrix(IFWL_Widget* pWidget,
-                                 const CFX_Matrix& matrix) = 0;
+  virtual FWL_Error GetThemeMatrix(IFWL_Widget* pWidget,
+                                   CFX_Matrix& matrix) = 0;
+  virtual FWL_Error SetThemeMatrix(IFWL_Widget* pWidget,
+                                   const CFX_Matrix& matrix) = 0;
   virtual FX_BOOL DrawBackground(CFWL_ThemeBackground* pParams) = 0;
   virtual FX_BOOL DrawText(CFWL_ThemeText* pParams) = 0;
   virtual void* GetCapacity(CFWL_ThemePart* pThemePart,
                             CFWL_WidgetCapacity dwCapacity) = 0;
   virtual FX_BOOL IsCustomizedLayout(IFWL_Widget* pWidget) = 0;
-  virtual FWL_ERR GetPartRect(CFWL_ThemePart* pThemePart,
-                              CFX_RectF& rtPart) = 0;
+  virtual FWL_Error GetPartRect(CFWL_ThemePart* pThemePart,
+                                CFX_RectF& rtPart) = 0;
   virtual FX_BOOL IsInPart(CFWL_ThemePart* pThemePart,
                            FX_FLOAT fx,
                            FX_FLOAT fy) = 0;
diff --git a/xfa/fwl/core/ifwl_timer.h b/xfa/fwl/core/ifwl_timer.h
index 5f113bc021..0143560410 100644
--- a/xfa/fwl/core/ifwl_timer.h
+++ b/xfa/fwl/core/ifwl_timer.h
@@ -19,6 +19,6 @@ class IFWL_Timer {
 FWL_HTIMER FWL_StartTimer(IFWL_Timer* pTimer,
                           uint32_t dwElapse,
                           FX_BOOL bImmediately = TRUE);
-int32_t FWL_StopTimer(FWL_HTIMER hTimer);
+FWL_Error FWL_StopTimer(FWL_HTIMER hTimer);
 
 #endif  // XFA_FWL_CORE_IFWL_TIMER_H_
diff --git a/xfa/fwl/core/ifwl_tooltiptarget.h b/xfa/fwl/core/ifwl_tooltiptarget.h
index 0b364f2754..7489e73efd 100644
--- a/xfa/fwl/core/ifwl_tooltiptarget.h
+++ b/xfa/fwl/core/ifwl_tooltiptarget.h
@@ -20,13 +20,15 @@ class IFWL_ToolTipTarget {
   virtual ~IFWL_ToolTipTarget() {}
   virtual IFWL_Widget* GetWidget() = 0;
   virtual FX_BOOL IsShowed() = 0;
-  virtual FWL_ERR DrawToolTip(CFX_Graphics* pGraphics,
-                              const CFX_Matrix* pMatrix,
-                              IFWL_Widget* pToolTip) = 0;
+  virtual FWL_Error DrawToolTip(CFX_Graphics* pGraphics,
+                                const CFX_Matrix* pMatrix,
+                                IFWL_Widget* pToolTip) = 0;
   virtual FX_BOOL UseDefaultTheme() = 0;
-  virtual FWL_ERR GetCaption(CFX_WideString& wsCaption) = 0;
-  virtual FWL_ERR GetToolTipSize(CFX_SizeF& sz) = 0;
-  virtual FWL_ERR GetToolTipPos(CFX_PointF& pt) { return FWL_ERR_Indefinite; }
+  virtual FWL_Error GetCaption(CFX_WideString& wsCaption) = 0;
+  virtual FWL_Error GetToolTipSize(CFX_SizeF& sz) = 0;
+  virtual FWL_Error GetToolTipPos(CFX_PointF& pt) {
+    return FWL_Error::Indefinite;
+  }
 };
 
 #endif  // XFA_FWL_CORE_IFWL_TOOLTIPTARGET_H_
diff --git a/xfa/fwl/core/ifwl_widget.h b/xfa/fwl/core/ifwl_widget.h
index 8ec758a566..691e4606c5 100644
--- a/xfa/fwl/core/ifwl_widget.h
+++ b/xfa/fwl/core/ifwl_widget.h
@@ -39,48 +39,50 @@ class IFWL_Widget {
   IFWL_Widget() : m_pImpl(nullptr) {}
   virtual ~IFWL_Widget();
 
-  FWL_ERR GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
-  FWL_ERR GetGlobalRect(CFX_RectF& rect);
-  FWL_ERR SetWidgetRect(const CFX_RectF& rect);
-  FWL_ERR GetClientRect(CFX_RectF& rect);
+  FWL_Error GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
+  FWL_Error GetGlobalRect(CFX_RectF& rect);
+  FWL_Error SetWidgetRect(const CFX_RectF& rect);
+  FWL_Error GetClientRect(CFX_RectF& rect);
   IFWL_Widget* GetParent();
-  FWL_ERR SetParent(IFWL_Widget* pParent);
+  FWL_Error SetParent(IFWL_Widget* pParent);
   IFWL_Widget* GetOwner();
-  FWL_ERR SetOwner(IFWL_Widget* pOwner);
+  FWL_Error SetOwner(IFWL_Widget* pOwner);
   IFWL_Widget* GetOuter();
   uint32_t GetStyles();
-  FWL_ERR ModifyStyles(uint32_t dwStylesAdded, uint32_t dwStylesRemoved);
+  FWL_Error ModifyStyles(uint32_t dwStylesAdded, uint32_t dwStylesRemoved);
   uint32_t GetStylesEx();
-  FWL_ERR ModifyStylesEx(uint32_t dwStylesExAdded, uint32_t dwStylesExRemoved);
+  FWL_Error ModifyStylesEx(uint32_t dwStylesExAdded,
+                           uint32_t dwStylesExRemoved);
   uint32_t GetStates();
   void SetStates(uint32_t dwStates, FX_BOOL bSet = TRUE);
-  FWL_ERR SetPrivateData(void* module_id,
-                         void* pData,
-                         PD_CALLBACK_FREEDATA callback);
+  FWL_Error SetPrivateData(void* module_id,
+                           void* pData,
+                           PD_CALLBACK_FREEDATA callback);
   void* GetPrivateData(void* module_id);
-  FWL_ERR Update();
-  FWL_ERR LockUpdate();
-  FWL_ERR UnlockUpdate();
+  FWL_Error Update();
+  FWL_Error LockUpdate();
+  FWL_Error UnlockUpdate();
   FWL_WidgetHit HitTest(FX_FLOAT fx, FX_FLOAT fy);
-  FWL_ERR TransformTo(IFWL_Widget* pWidget, FX_FLOAT& fx, FX_FLOAT& fy);
-  FWL_ERR TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt);
-  FWL_ERR GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal = FALSE);
-  FWL_ERR SetMatrix(const CFX_Matrix& matrix);
-  FWL_ERR DrawWidget(CFX_Graphics* pGraphics, const CFX_Matrix* pMatrix = NULL);
+  FWL_Error TransformTo(IFWL_Widget* pWidget, FX_FLOAT& fx, FX_FLOAT& fy);
+  FWL_Error TransformTo(IFWL_Widget* pWidget, CFX_RectF& rt);
+  FWL_Error GetMatrix(CFX_Matrix& matrix, FX_BOOL bGlobal = FALSE);
+  FWL_Error SetMatrix(const CFX_Matrix& matrix);
+  FWL_Error DrawWidget(CFX_Graphics* pGraphics,
+                       const CFX_Matrix* pMatrix = NULL);
   IFWL_ThemeProvider* GetThemeProvider();
-  FWL_ERR SetThemeProvider(IFWL_ThemeProvider* pThemeProvider);
-  FWL_ERR SetDataProvider(IFWL_DataProvider* pDataProvider);
+  FWL_Error SetThemeProvider(IFWL_ThemeProvider* pThemeProvider);
+  FWL_Error SetDataProvider(IFWL_DataProvider* pDataProvider);
   IFWL_WidgetDelegate* SetDelegate(IFWL_WidgetDelegate* pDelegate);
   IFWL_App* GetOwnerApp() const;
   CFX_SizeF GetOffsetFromParent(IFWL_Widget* pParent);
 
   // These call into equivalent polymorphic methods of m_pImpl. There
   // should be no need to override these in subclasses.
-  FWL_ERR GetClassName(CFX_WideString& wsClass) const;
+  FWL_Error GetClassName(CFX_WideString& wsClass) const;
   uint32_t GetClassID() const;
   FX_BOOL IsInstance(const CFX_WideStringC& wsClass) const;
-  FWL_ERR Initialize();
-  FWL_ERR Finalize();
+  FWL_Error Initialize();
+  FWL_Error Finalize();
 
   CFWL_WidgetImp* GetImpl() const { return m_pImpl.get(); }
 
diff --git a/xfa/fwl/core/ifwl_widgetdelegate.h b/xfa/fwl/core/ifwl_widgetdelegate.h
index 7fb56d3ba1..820fb6b1c4 100644
--- a/xfa/fwl/core/ifwl_widgetdelegate.h
+++ b/xfa/fwl/core/ifwl_widgetdelegate.h
@@ -7,6 +7,8 @@
 #ifndef XFA_FWL_CORE_IFWL_WIDGETDELEGATE_H_
 #define XFA_FWL_CORE_IFWL_WIDGETDELEGATE_H_
 
+#include <stdint.h>
+
 #include "xfa/fwl/core/fwl_error.h"
 
 class CFWL_Event;
@@ -17,10 +19,10 @@ class CFX_Matrix;
 class IFWL_WidgetDelegate {
  public:
   virtual ~IFWL_WidgetDelegate() {}
-  virtual int32_t OnProcessMessage(CFWL_Message* pMessage) = 0;
-  virtual FWL_ERR OnProcessEvent(CFWL_Event* pEvent) = 0;
-  virtual FWL_ERR OnDrawWidget(CFX_Graphics* pGraphics,
-                               const CFX_Matrix* pMatrix = nullptr) = 0;
+  virtual void OnProcessMessage(CFWL_Message* pMessage) = 0;
+  virtual void OnProcessEvent(CFWL_Event* pEvent) = 0;
+  virtual void OnDrawWidget(CFX_Graphics* pGraphics,
+                            const CFX_Matrix* pMatrix = nullptr) = 0;
 };
 
 #endif  // XFA_FWL_CORE_IFWL_WIDGETDELEGATE_H_
diff --git a/xfa/fwl/core/ifwl_widgetmgr.h b/xfa/fwl/core/ifwl_widgetmgr.h
index 3924ba8a29..6e25b72290 100644
--- a/xfa/fwl/core/ifwl_widgetmgr.h
+++ b/xfa/fwl/core/ifwl_widgetmgr.h
@@ -37,8 +37,8 @@ class IFWL_WidgetMgr {
                                  FWL_WGTRELATION eRelation) = 0;
   virtual int32_t GetWidgetIndex(IFWL_Widget* pWidget) = 0;
   virtual FX_BOOL SetWidgetIndex(IFWL_Widget* pWidget, int32_t nIndex) = 0;
-  virtual FWL_ERR RepaintWidget(IFWL_Widget* pWidget,
-                                const CFX_RectF* pRect = NULL) = 0;
+  virtual FWL_Error RepaintWidget(IFWL_Widget* pWidget,
+                                  const CFX_RectF* pRect = NULL) = 0;
   virtual uint32_t GetCapability() = 0;
 };
 
diff --git a/xfa/fwl/core/include/ifwl_adaptertimermgr.h b/xfa/fwl/core/include/ifwl_adaptertimermgr.h
index 64fc260ce5..7859e31fd8 100644
--- a/xfa/fwl/core/include/ifwl_adaptertimermgr.h
+++ b/xfa/fwl/core/include/ifwl_adaptertimermgr.h
@@ -15,11 +15,11 @@ class IFWL_Timer;
 class IFWL_AdapterTimerMgr {
  public:
   virtual ~IFWL_AdapterTimerMgr() {}
-  virtual FWL_ERR Start(IFWL_Timer* pTimer,
-                        uint32_t dwElapse,
-                        FWL_HTIMER& hTimer,
-                        FX_BOOL bImmediately = TRUE) = 0;
-  virtual FWL_ERR Stop(FWL_HTIMER hTimer) = 0;
+  virtual FWL_Error Start(IFWL_Timer* pTimer,
+                          uint32_t dwElapse,
+                          FWL_HTIMER& hTimer,
+                          FX_BOOL bImmediately = TRUE) = 0;
+  virtual FWL_Error Stop(FWL_HTIMER hTimer) = 0;
 };
 
 #endif  // XFA_FWL_CORE_INCLUDE_IFWL_ADAPTERTIMERMGR_H_