Convert FWL_ERR into an enum class.

xfa/fwl/basewidget/fwl_comboboximp.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "xfa/fwl/basewidget/fwl_comboboximp.h"
 
 #include "xfa/fde/tto/fde_textout.h"
 #include "xfa/fee/fde_txtedtengine.h"
@@ skipping 19 matching lines @@
   IFWL_ComboBox* pComboBox = new IFWL_ComboBox;
   CFWL_ComboBoxImp* pComboBoxImpl = new CFWL_ComboBoxImp(properties, nullptr);
   pComboBox->SetImpl(pComboBoxImpl);
   pComboBoxImpl->SetInterface(pComboBox);
   return pComboBox;
 }
 IFWL_ComboBox::IFWL_ComboBox() {}
 int32_t IFWL_ComboBox::GetCurSel() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->GetCurSel();
 }
-FWL_ERR IFWL_ComboBox::SetCurSel(int32_t iSel) {
+FWL_Error IFWL_ComboBox::SetCurSel(int32_t iSel) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->SetCurSel(iSel);
 }
-FWL_ERR IFWL_ComboBox::SetEditText(const CFX_WideString& wsText) {
+FWL_Error IFWL_ComboBox::SetEditText(const CFX_WideString& wsText) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->SetEditText(wsText);
 }
 int32_t IFWL_ComboBox::GetEditTextLength() const {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->GetEditTextLength();
 }
-FWL_ERR IFWL_ComboBox::GetEditText(CFX_WideString& wsText,
-                                   int32_t nStart,
-                                   int32_t nCount) const {
+FWL_Error IFWL_ComboBox::GetEditText(CFX_WideString& wsText,
+                                     int32_t nStart,
+                                     int32_t nCount) const {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())
       ->GetEditText(wsText, nStart, nCount);
 }
-FWL_ERR IFWL_ComboBox::SetEditSelRange(int32_t nStart, int32_t nCount) {
+FWL_Error IFWL_ComboBox::SetEditSelRange(int32_t nStart, int32_t nCount) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())
       ->SetEditSelRange(nStart, nCount);
 }
 int32_t IFWL_ComboBox::GetEditSelRange(int32_t nIndex, int32_t& nStart) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())
       ->GetEditSelRange(nIndex, nStart);
 }
 int32_t IFWL_ComboBox::GetEditLimit() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->GetEditLimit();
 }
-FWL_ERR IFWL_ComboBox::SetEditLimit(int32_t nLimit) {
+FWL_Error IFWL_ComboBox::SetEditLimit(int32_t nLimit) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->SetEditLimit(nLimit);
 }
-FWL_ERR IFWL_ComboBox::EditDoClipboard(int32_t iCmd) {
+FWL_Error IFWL_ComboBox::EditDoClipboard(int32_t iCmd) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditDoClipboard(iCmd);
 }
 FX_BOOL IFWL_ComboBox::EditRedo(const CFX_ByteStringC& bsRecord) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditRedo(bsRecord);
 }
 FX_BOOL IFWL_ComboBox::EditUndo(const CFX_ByteStringC& bsRecord) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditUndo(bsRecord);
 }
 IFWL_ListBox* IFWL_ComboBox::GetListBoxt() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->GetListBoxt();
 }
 FX_BOOL IFWL_ComboBox::AfterFocusShowDropList() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->AfterFocusShowDropList();
 }
-FX_ERR IFWL_ComboBox::OpenDropDownList(FX_BOOL bActivate) {
+FWL_Error IFWL_ComboBox::OpenDropDownList(FX_BOOL bActivate) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->OpenDropDownList(bActivate);
 }
 FX_BOOL IFWL_ComboBox::EditCanUndo() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditCanUndo();
 }
 FX_BOOL IFWL_ComboBox::EditCanRedo() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditCanRedo();
 }
 FX_BOOL IFWL_ComboBox::EditUndo() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditUndo();
@@ skipping 21 matching lines @@
 }
 FX_BOOL IFWL_ComboBox::EditSelectAll() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditSelectAll();
 }
 FX_BOOL IFWL_ComboBox::EditDelete() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditDelete();
 }
 FX_BOOL IFWL_ComboBox::EditDeSelect() {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->EditDeSelect();
 }
-FWL_ERR IFWL_ComboBox::GetBBox(CFX_RectF& rect) {
+FWL_Error IFWL_ComboBox::GetBBox(CFX_RectF& rect) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())->GetBBox(rect);
 }
-FWL_ERR IFWL_ComboBox::EditModifyStylesEx(uint32_t dwStylesExAdded,
-                                          uint32_t dwStylesExRemoved) {
+FWL_Error IFWL_ComboBox::EditModifyStylesEx(uint32_t dwStylesExAdded,
+                                            uint32_t dwStylesExRemoved) {
   return static_cast<CFWL_ComboBoxImp*>(GetImpl())
       ->EditModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
 }
 
 CFWL_ComboEditImp::CFWL_ComboEditImp(const CFWL_WidgetImpProperties& properties,
                                      IFWL_Widget* pOuter)
     : CFWL_EditImp(properties, pOuter) {
   m_pOuter = static_cast<CFWL_ComboBoxImp*>(pOuter->GetImpl());
 }
 
 CFWL_ComboEditImpDelegate::CFWL_ComboEditImpDelegate(CFWL_ComboEditImp* pOwner)
     : CFWL_EditImpDelegate(pOwner), m_pOwner(pOwner) {}
 
-int32_t CFWL_ComboEditImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
+void CFWL_ComboEditImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
   if (!pMessage)
-    return 0;
+    return;
 
   FX_BOOL backDefault = TRUE;
   switch (pMessage->GetClassID()) {
     case CFWL_MessageType::SetFocus: {
       m_pOwner->m_pProperties->m_dwStates |= FWL_WGTSTATE_Focused;
       backDefault = FALSE;
       break;
     }
     case CFWL_MessageType::KillFocus: {
       m_pOwner->m_pProperties->m_dwStates &= ~FWL_WGTSTATE_Focused;
       backDefault = FALSE;
       break;
     }
     case CFWL_MessageType::Mouse: {
       CFWL_MsgMouse* pMsg = static_cast<CFWL_MsgMouse*>(pMessage);
       if ((pMsg->m_dwCmd == FWL_MouseCommand::LeftButtonDown) &&
           ((m_pOwner->m_pProperties->m_dwStates & FWL_WGTSTATE_Focused) == 0)) {
         m_pOwner->SetSelected();
         m_pOwner->SetComboBoxFocus(TRUE);
       }
       break;
     }
     default:
       break;
   }
-  if (!backDefault)
-    return 1;
-  return CFWL_EditImpDelegate::OnProcessMessage(pMessage);
+  if (backDefault)
+    CFWL_EditImpDelegate::OnProcessMessage(pMessage);
 }
 
 void CFWL_ComboEditImp::ClearSelected() {
   ClearSelections();
   Repaint(&m_rtClient);
 }
 void CFWL_ComboEditImp::SetSelected() {
   FlagFocus(TRUE);
   EndCaret();
   AddSelRange(0);
@@ skipping 10 matching lines @@
   }
 }
 void CFWL_ComboEditImp::SetComboBoxFocus(FX_BOOL bSet) {
   m_pOuter->SetFocus(bSet);
 }
 CFWL_ComboListImp::CFWL_ComboListImp(const CFWL_WidgetImpProperties& properties,
                                      IFWL_Widget* pOuter)
     : CFWL_ListBoxImp(properties, pOuter), m_bNotifyOwner(TRUE) {
   ASSERT(pOuter != NULL);
 }
-FWL_ERR CFWL_ComboListImp::Initialize() {
-  if (CFWL_ListBoxImp::Initialize() != FWL_ERR_Succeeded)
-    return FWL_ERR_Indefinite;
+FWL_Error CFWL_ComboListImp::Initialize() {
+  if (CFWL_ListBoxImp::Initialize() != FWL_Error::Succeeded)
+    return FWL_Error::Indefinite;
   delete m_pDelegate;
   m_pDelegate = new CFWL_ComboListImpDelegate(this);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_ComboListImp::Finalize() {
+FWL_Error CFWL_ComboListImp::Finalize() {
   delete m_pDelegate;
   m_pDelegate = nullptr;
   return CFWL_ListBoxImp::Finalize();
 }
 int32_t CFWL_ComboListImp::MatchItem(const CFX_WideString& wsMatch) {
   if (wsMatch.IsEmpty()) {
     return -1;
   }
   if (!m_pProperties->m_pDataProvider)
     return -1;
@@ skipping 56 matching lines @@
     return;
   pOwner->TransformTo(m_pOuter, fx, fy);
 }
 void CFWL_ComboListImp::SetFocus(FX_BOOL bSet) {
   CFWL_WidgetImp::SetFocus(bSet);
 }
 
 CFWL_ComboListImpDelegate::CFWL_ComboListImpDelegate(CFWL_ComboListImp* pOwner)
     : CFWL_ListBoxImpDelegate(pOwner), m_pOwner(pOwner) {}
 
-int32_t CFWL_ComboListImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
+void CFWL_ComboListImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
   if (!pMessage)
-    return 0;
+    return;
 
   CFWL_MessageType dwHashCode = pMessage->GetClassID();
   FX_BOOL backDefault = TRUE;
   if (dwHashCode == CFWL_MessageType::SetFocus ||
       dwHashCode == CFWL_MessageType::KillFocus) {
     OnDropListFocusChanged(pMessage, dwHashCode == CFWL_MessageType::SetFocus);
   } else if (dwHashCode == CFWL_MessageType::Mouse) {
     CFWL_MsgMouse* pMsg = static_cast<CFWL_MsgMouse*>(pMessage);
     if (m_pOwner->IsShowScrollBar(TRUE) && m_pOwner->m_pVertScrollBar) {
       CFX_RectF rect;
       m_pOwner->m_pVertScrollBar->GetWidgetRect(rect);
       if (rect.Contains(pMsg->m_fx, pMsg->m_fy)) {
         pMsg->m_fx -= rect.left;
         pMsg->m_fy -= rect.top;
         IFWL_WidgetDelegate* pDelegate =
             m_pOwner->m_pVertScrollBar->SetDelegate(NULL);
-        return pDelegate->OnProcessMessage(pMsg);
+        pDelegate->OnProcessMessage(pMsg);
+        return;
       }
     }
     switch (pMsg->m_dwCmd) {
       case FWL_MouseCommand::Move: {
         backDefault = FALSE;
         OnDropListMouseMove(pMsg);
         break;
       }
       case FWL_MouseCommand::LeftButtonDown: {
         backDefault = FALSE;
         OnDropListLButtonDown(pMsg);
         break;
       }
       case FWL_MouseCommand::LeftButtonUp: {
         backDefault = FALSE;
         OnDropListLButtonUp(pMsg);
         break;
       }
       default:
         break;
     }
   } else if (dwHashCode == CFWL_MessageType::Key) {
     backDefault = !OnDropListKey(static_cast<CFWL_MsgKey*>(pMessage));
   }
-  if (!backDefault)
-    return 1;
-  return CFWL_ListBoxImpDelegate::OnProcessMessage(pMessage);
+  if (backDefault)
+    CFWL_ListBoxImpDelegate::OnProcessMessage(pMessage);
 }
 
 void CFWL_ComboListImpDelegate::OnDropListFocusChanged(CFWL_Message* pMsg,
                                                        FX_BOOL bSet) {
   if (!bSet) {
     CFWL_MsgKillFocus* pKill = static_cast<CFWL_MsgKillFocus*>(pMsg);
     CFWL_ComboBoxImp* pOuter =
         static_cast<CFWL_ComboBoxImp*>(m_pOwner->m_pOuter->GetImpl());
     if (pKill->m_pSetFocus == m_pOwner->m_pOuter ||
         pKill->m_pSetFocus == pOuter->m_pEdit.get()) {
@@ skipping 130 matching lines @@
       m_pForm(NULL),
       m_bLButtonDown(FALSE),
       m_iCurSel(-1),
       m_iBtnState(CFWL_PartState_Normal),
       m_fComboFormHandler(0),
       m_bNeedShowList(FALSE) {
   m_rtClient.Reset();
   m_rtBtn.Reset();
   m_rtHandler.Reset();
 }
+
 CFWL_ComboBoxImp::~CFWL_ComboBoxImp() {}
-FWL_ERR CFWL_ComboBoxImp::GetClassName(CFX_WideString& wsClass) const {
+
+FWL_Error CFWL_ComboBoxImp::GetClassName(CFX_WideString& wsClass) const {
   wsClass = FWL_CLASS_ComboBox;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
+
 uint32_t CFWL_ComboBoxImp::GetClassID() const {
   return FWL_CLASSHASH_ComboBox;
 }
-FWL_ERR CFWL_ComboBoxImp::Initialize() {
-  if (m_pWidgetMgr->IsFormDisabled()) {
+
+FWL_Error CFWL_ComboBoxImp::Initialize() {
+  if (m_pWidgetMgr->IsFormDisabled())
     return DisForm_Initialize();
-  }
-  if (CFWL_WidgetImp::Initialize() != FWL_ERR_Succeeded)
-    return FWL_WGTSTATE_Invisible;  // Probably a bug; not a FWL_ERR_ value.
+  if (CFWL_WidgetImp::Initialize() != FWL_Error::Succeeded)
+    return FWL_Error::Indefinite;
+
   m_pDelegate = new CFWL_ComboBoxImpDelegate(this);
   CFWL_WidgetImpProperties prop;
   prop.m_pThemeProvider = m_pProperties->m_pThemeProvider;
   prop.m_dwStyles |= FWL_WGTSTYLE_Border | FWL_WGTSTYLE_VScroll;
-  if (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_ListItemIconText) {
+  if (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_ListItemIconText)
     prop.m_dwStyleExes |= FWL_STYLEEXT_LTB_Icon;
-  }
+
   prop.m_pDataProvider = m_pProperties->m_pDataProvider;
   m_pListBox.reset(IFWL_ListBox::CreateComboList(prop, m_pInterface));
   m_pListBox->Initialize();
   if ((m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_DropDown) && !m_pEdit) {
     CFWL_WidgetImpProperties prop2;
     m_pEdit.reset(IFWL_Edit::CreateComboEdit(prop2, m_pInterface));
     m_pEdit->Initialize();
     static_cast<CFWL_EditImp*>(m_pEdit->GetImpl())->SetOuter(m_pInterface);
   }
-  if (m_pEdit) {
+  if (m_pEdit)
     m_pEdit->SetParent(m_pInterface);
-  }
+
   SetStates(m_pProperties->m_dwStates);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_ComboBoxImp::Finalize() {
+
+FWL_Error CFWL_ComboBoxImp::Finalize() {
   if (m_pEdit) {
     m_pEdit->Finalize();
   }
   m_pListBox->Finalize();
   delete m_pDelegate;
   m_pDelegate = nullptr;
   return CFWL_WidgetImp::Finalize();
 }
-FWL_ERR CFWL_ComboBoxImp::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
+FWL_Error CFWL_ComboBoxImp::GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize) {
   if (bAutoSize) {
     rect.Reset();
     FX_BOOL bIsDropDown = IsDropDownStyle();
     if (bIsDropDown && m_pEdit) {
       m_pEdit->GetWidgetRect(rect, TRUE);
     } else {
       rect.width = 100;
       rect.height = 16;
     }
     if (!m_pProperties->m_pThemeProvider) {
       ReSetTheme();
     }
     FX_FLOAT* pFWidth = static_cast<FX_FLOAT*>(
         GetThemeCapacity(CFWL_WidgetCapacity::ScrollBarWidth));
     if (!pFWidth)
-      return FWL_ERR_Indefinite;
+      return FWL_Error::Indefinite;
     rect.Inflate(0, 0, *pFWidth, 0);
     CFWL_WidgetImp::GetWidgetRect(rect, TRUE);
   } else {
     rect = m_pProperties->m_rtWidget;
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_ComboBoxImp::ModifyStylesEx(uint32_t dwStylesExAdded,
-                                         uint32_t dwStylesExRemoved) {
+FWL_Error CFWL_ComboBoxImp::ModifyStylesEx(uint32_t dwStylesExAdded,
+                                           uint32_t dwStylesExRemoved) {
   if (m_pWidgetMgr->IsFormDisabled()) {
     return DisForm_ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
   }
   bool bAddDropDown = !!(dwStylesExAdded & FWL_STYLEEXT_CMB_DropDown);
   bool bRemoveDropDown = !!(dwStylesExRemoved & FWL_STYLEEXT_CMB_DropDown);
   if (bAddDropDown && !m_pEdit) {
     CFWL_WidgetImpProperties prop;
     m_pEdit.reset(IFWL_Edit::CreateComboEdit(prop, nullptr));
     m_pEdit->Initialize();
     static_cast<CFWL_EditImp*>(m_pEdit->GetImpl())->SetOuter(m_pInterface);
     m_pEdit->SetParent(m_pInterface);
   } else if (bRemoveDropDown && m_pEdit) {
     m_pEdit->SetStates(FWL_WGTSTATE_Invisible, TRUE);
   }
   return CFWL_WidgetImp::ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
 }
-FWL_ERR CFWL_ComboBoxImp::Update() {
+FWL_Error CFWL_ComboBoxImp::Update() {
   if (m_pWidgetMgr->IsFormDisabled()) {
     return DisForm_Update();
   }
   if (IsLocked()) {
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   }
   ReSetTheme();
   FX_BOOL bDropDown = IsDropDownStyle();
   if (bDropDown && m_pEdit) {
     ReSetEditAlignment();
   }
   if (m_pProperties->m_pThemeProvider == NULL) {
     m_pProperties->m_pThemeProvider = GetAvailableTheme();
   }
   Layout();
   CFWL_ThemePart part;
   part.m_pWidget = m_pInterface;
   m_fComboFormHandler =
       *static_cast<FX_FLOAT*>(m_pProperties->m_pThemeProvider->GetCapacity(
           &part, CFWL_WidgetCapacity::ComboFormHandler));
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 FWL_WidgetHit CFWL_ComboBoxImp::HitTest(FX_FLOAT fx, FX_FLOAT fy) {
   if (m_pWidgetMgr->IsFormDisabled()) {
     return DisForm_HitTest(fx, fy);
   }
   return CFWL_WidgetImp::HitTest(fx, fy);
 }
-FWL_ERR CFWL_ComboBoxImp::DrawWidget(CFX_Graphics* pGraphics,
-                                     const CFX_Matrix* pMatrix) {
+FWL_Error CFWL_ComboBoxImp::DrawWidget(CFX_Graphics* pGraphics,
+                                       const CFX_Matrix* pMatrix) {
   if (m_pWidgetMgr->IsFormDisabled()) {
     return DisForm_DrawWidget(pGraphics, 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 bIsDropDown = IsDropDownStyle();
   if (HasBorder()) {
     DrawBorder(pGraphics, CFWL_Part::Border, pTheme, pMatrix);
   }
   if (HasEdge()) {
     DrawEdge(pGraphics, CFWL_Part::Edge, pTheme, pMatrix);
   }
   if (!bIsDropDown) {
     CFX_RectF rtTextBk(m_rtClient);
@@ skipping 20 matching lines @@
       param.m_dwStates = CFWL_PartState_Disabled;
     } else if ((m_pProperties->m_dwStates & FWL_WGTSTATE_Focused) &&
                (m_iCurSel >= 0)) {
       param.m_dwStates = CFWL_PartState_Selected;
     } else {
       param.m_dwStates = CFWL_PartState_Normal;
     }
     pTheme->DrawBackground(&param);
     if (m_iCurSel >= 0) {
       if (!m_pListBox)
-        return FWL_ERR_Indefinite;
+        return FWL_Error::Indefinite;
       CFX_WideString wsText;
       IFWL_ComboBoxDP* pData =
           static_cast<IFWL_ComboBoxDP*>(m_pProperties->m_pDataProvider);
       FWL_HLISTITEM hItem = pData->GetItem(m_pInterface, m_iCurSel);
       static_cast<CFWL_ComboListImp*>(m_pListBox->GetImpl())
           ->GetItemText(hItem, wsText);
       CFWL_ThemeText param;
       param.m_pWidget = m_pInterface;
       param.m_iPart = CFWL_Part::Caption;
       param.m_dwStates = m_iBtnState;
@@ skipping 14 matching lines @@
     param.m_pWidget = m_pInterface;
     param.m_iPart = CFWL_Part::DropDownButton;
     param.m_dwStates = (m_pProperties->m_dwStates & FWL_WGTSTATE_Disabled)
                            ? CFWL_PartState_Disabled
                            : m_iBtnState;
     param.m_pGraphics = pGraphics;
     param.m_matrix.Concat(*pMatrix);
     param.m_rtPart = m_rtBtn;
     pTheme->DrawBackground(&param);
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_ComboBoxImp::SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) {
+FWL_Error CFWL_ComboBoxImp::SetThemeProvider(
+    IFWL_ThemeProvider* pThemeProvider) {
   if (!pThemeProvider)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   m_pProperties->m_pThemeProvider = pThemeProvider;
   if (m_pListBox && pThemeProvider->IsValidWidget(m_pListBox.get())) {
     m_pListBox->SetThemeProvider(pThemeProvider);
   }
   if (m_pEdit && pThemeProvider->IsValidWidget(m_pEdit.get())) {
     m_pEdit->SetThemeProvider(pThemeProvider);
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 int32_t CFWL_ComboBoxImp::GetCurSel() {
   return m_iCurSel;
 }
-FWL_ERR CFWL_ComboBoxImp::SetCurSel(int32_t iSel) {
+FWL_Error CFWL_ComboBoxImp::SetCurSel(int32_t iSel) {
   int32_t iCount =
       static_cast<CFWL_ComboListImp*>(m_pListBox->GetImpl())->CountItems();
   FX_BOOL bClearSel = iSel < 0 || iSel >= iCount;
   FX_BOOL bDropDown = IsDropDownStyle();
   if (bDropDown && m_pEdit) {
     if (bClearSel) {
       m_pEdit->SetText(CFX_WideString());
     } else {
       CFX_WideString wsText;
       IFWL_ComboBoxDP* pData =
           static_cast<IFWL_ComboBoxDP*>(m_pProperties->m_pDataProvider);
       FWL_HLISTITEM hItem = pData->GetItem(m_pInterface, iSel);
       static_cast<CFWL_ComboListImp*>(m_pListBox->GetImpl())
           ->GetItemText(hItem, wsText);
       m_pEdit->SetText(wsText);
     }
     m_pEdit->Update();
   }
   m_iCurSel = bClearSel ? -1 : iSel;
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_ComboBoxImp::SetStates(uint32_t dwStates, FX_BOOL bSet) {
+FWL_Error CFWL_ComboBoxImp::SetStates(uint32_t dwStates, FX_BOOL bSet) {
   FX_BOOL bIsDropDown = IsDropDownStyle();
   if (bIsDropDown && m_pEdit) {
     m_pEdit->SetStates(dwStates, bSet);
   }
   if (m_pListBox) {
     m_pListBox->SetStates(dwStates, bSet);
   }
   return CFWL_WidgetImp::SetStates(dwStates, bSet);
 }
-FWL_ERR CFWL_ComboBoxImp::SetEditText(const CFX_WideString& wsText) {
+FWL_Error CFWL_ComboBoxImp::SetEditText(const CFX_WideString& wsText) {
   if (!m_pEdit)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   m_pEdit->SetText(wsText);
   return m_pEdit->Update();
 }
 int32_t CFWL_ComboBoxImp::GetEditTextLength() const {
   if (!m_pEdit)
     return -1;
   return m_pEdit->GetTextLength();
 }
-FWL_ERR CFWL_ComboBoxImp::GetEditText(CFX_WideString& wsText,
-                                      int32_t nStart,
-                                      int32_t nCount) const {
+FWL_Error CFWL_ComboBoxImp::GetEditText(CFX_WideString& wsText,
+                                        int32_t nStart,
+                                        int32_t nCount) const {
   if (m_pEdit) {
     return m_pEdit->GetText(wsText, nStart, nCount);
   } else if (m_pListBox) {
     IFWL_ComboBoxDP* pData =
         static_cast<IFWL_ComboBoxDP*>(m_pProperties->m_pDataProvider);
     FWL_HLISTITEM hItem = pData->GetItem(m_pInterface, m_iCurSel);
     return m_pListBox->GetItemText(hItem, wsText);
   }
-  return FWL_ERR_Indefinite;
+  return FWL_Error::Indefinite;
 }
-FWL_ERR CFWL_ComboBoxImp::SetEditSelRange(int32_t nStart, int32_t nCount) {
+FWL_Error CFWL_ComboBoxImp::SetEditSelRange(int32_t nStart, int32_t nCount) {
   if (!m_pEdit)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   static_cast<CFWL_ComboEditImp*>(m_pEdit->GetImpl())->ClearSelected();
   m_pEdit->AddSelRange(nStart, nCount);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 int32_t CFWL_ComboBoxImp::GetEditSelRange(int32_t nIndex, int32_t& nStart) {
   if (!m_pEdit)
     return -1;
   return m_pEdit->GetSelRange(nIndex, nStart);
 }
 int32_t CFWL_ComboBoxImp::GetEditLimit() {
   if (!m_pEdit)
     return -1;
   return m_pEdit->GetLimit();
 }
-FWL_ERR CFWL_ComboBoxImp::SetEditLimit(int32_t nLimit) {
+FWL_Error CFWL_ComboBoxImp::SetEditLimit(int32_t nLimit) {
   if (!m_pEdit)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   return m_pEdit->SetLimit(nLimit);
 }
-FWL_ERR CFWL_ComboBoxImp::EditDoClipboard(int32_t iCmd) {
+FWL_Error CFWL_ComboBoxImp::EditDoClipboard(int32_t iCmd) {
   if (!m_pEdit)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   return m_pEdit->DoClipboard(iCmd);
 }
 FX_BOOL CFWL_ComboBoxImp::EditRedo(const CFX_ByteStringC& bsRecord) {
   if (!m_pEdit)
     return FALSE;
   return m_pEdit->Redo(bsRecord);
 }
 FX_BOOL CFWL_ComboBoxImp::EditUndo(const CFX_ByteStringC& bsRecord) {
   if (!m_pEdit)
     return FALSE;
   return m_pEdit->Undo(bsRecord);
 }
 IFWL_ListBox* CFWL_ComboBoxImp::GetListBoxt() {
   return m_pListBox.get();
 }
 FX_BOOL CFWL_ComboBoxImp::AfterFocusShowDropList() {
   if (!m_bNeedShowList) {
     return FALSE;
   }
   if (m_pEdit) {
     MatchEditText();
   }
   ShowDropList(TRUE);
   m_bNeedShowList = FALSE;
   return TRUE;
 }
-FX_ERR CFWL_ComboBoxImp::OpenDropDownList(FX_BOOL bActivate) {
+FWL_Error CFWL_ComboBoxImp::OpenDropDownList(FX_BOOL bActivate) {
   ShowDropList(bActivate);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 FX_BOOL CFWL_ComboBoxImp::EditCanUndo() {
   return m_pEdit->CanUndo();
 }
 FX_BOOL CFWL_ComboBoxImp::EditCanRedo() {
   return m_pEdit->CanRedo();
 }
 FX_BOOL CFWL_ComboBoxImp::EditUndo() {
   return m_pEdit->Undo();
 }
@@ skipping 15 matching lines @@
 FX_BOOL CFWL_ComboBoxImp::EditCopy(CFX_WideString& wsCopy) {
   return m_pEdit->Copy(wsCopy);
 }
 FX_BOOL CFWL_ComboBoxImp::EditCut(CFX_WideString& wsCut) {
   return m_pEdit->Cut(wsCut);
 }
 FX_BOOL CFWL_ComboBoxImp::EditPaste(const CFX_WideString& wsPaste) {
   return m_pEdit->Paste(wsPaste);
 }
 FX_BOOL CFWL_ComboBoxImp::EditSelectAll() {
-  return m_pEdit->AddSelRange(0) == FWL_ERR_Succeeded;
+  return m_pEdit->AddSelRange(0) == FWL_Error::Succeeded;
 }
 FX_BOOL CFWL_ComboBoxImp::EditDelete() {
-  return m_pEdit->ClearText() == FWL_ERR_Succeeded;
+  return m_pEdit->ClearText() == FWL_Error::Succeeded;
 }
 FX_BOOL CFWL_ComboBoxImp::EditDeSelect() {
-  return m_pEdit->ClearSelections() == FWL_ERR_Succeeded;
+  return m_pEdit->ClearSelections() == FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_ComboBoxImp::GetBBox(CFX_RectF& rect) {
+FWL_Error CFWL_ComboBoxImp::GetBBox(CFX_RectF& rect) {
   if (m_pWidgetMgr->IsFormDisabled()) {
     return DisForm_GetBBox(rect);
   }
   rect = m_pProperties->m_rtWidget;
   if (m_pListBox && IsDropListShowed()) {
     CFX_RectF rtList;
     m_pListBox->GetWidgetRect(rtList);
     rtList.Offset(rect.left, rect.top);
     rect.Union(rtList);
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_ComboBoxImp::EditModifyStylesEx(uint32_t dwStylesExAdded,
-                                             uint32_t dwStylesExRemoved) {
+FWL_Error CFWL_ComboBoxImp::EditModifyStylesEx(uint32_t dwStylesExAdded,
+                                               uint32_t dwStylesExRemoved) {
   if (m_pEdit != NULL) {
     return m_pEdit->ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
   } else {
-    return FWL_ERR_Parameter_Invalid;
+    return FWL_Error::ParameterInvalid;
   }
 }
 FX_FLOAT CFWL_ComboBoxImp::GetListHeight() {
   return static_cast<IFWL_ComboBoxDP*>(m_pProperties->m_pDataProvider)
       ->GetListHeight(m_pInterface);
 }
 void CFWL_ComboBoxImp::DrawStretchHandler(CFX_Graphics* pGraphics,
                                           const CFX_Matrix* pMatrix) {
   CFWL_ThemeBackground param;
   param.m_pGraphics = pGraphics;
@@ skipping 237 matching lines @@
       CFWL_EvtCmbSelChanged ev;
       ev.bLButtonUp = bLButtonUp;
       ev.m_pSrcTarget = m_pInterface;
       ev.iArraySels.Add(m_iCurSel);
       DispatchEvent(&ev);
     }
   } else {
     Repaint(&m_rtClient);
   }
 }
+
 void CFWL_ComboBoxImp::InitProxyForm() {
   if (m_pForm)
     return;
   if (!m_pListBox)
     return;
+
   CFWL_WidgetImpProperties propForm;
   propForm.m_pOwner = m_pInterface;
   propForm.m_dwStyles = FWL_WGTSTYLE_Popup;
   propForm.m_dwStates = FWL_WGTSTATE_Invisible;
   CFX_WideString className;
   m_pForm = IFWL_Form::CreateFormProxy(propForm, &className, m_pListBox.get());
   m_pForm->Initialize();
   m_pProxy = static_cast<CFWL_FormProxyImp*>(m_pForm->GetImpl());
   m_pListBox->SetParent(m_pForm);
   m_pListProxyDelegate = new CFWL_ComboProxyImpDelegate(m_pForm, this);
   m_pProxy->SetDelegate(m_pListProxyDelegate);
 }
-FWL_ERR CFWL_ComboBoxImp::DisForm_Initialize() {
-  if (CFWL_WidgetImp::Initialize() != FWL_ERR_Succeeded)
-    return FWL_WGTSTATE_Invisible;  // Ditto.
+
+FWL_Error CFWL_ComboBoxImp::DisForm_Initialize() {
+  if (CFWL_WidgetImp::Initialize() != FWL_Error::Succeeded)
+    return FWL_Error::Indefinite;
+
   m_pDelegate = new CFWL_ComboBoxImpDelegate(this);
   DisForm_InitComboList();
   DisForm_InitComboEdit();
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
+
 void CFWL_ComboBoxImp::DisForm_InitComboList() {
-  if (m_pListBox) {
+  if (m_pListBox)
     return;
-  }
+
   CFWL_WidgetImpProperties prop;
   prop.m_pParent = m_pInterface;
   prop.m_dwStyles = FWL_WGTSTYLE_Border | FWL_WGTSTYLE_VScroll;
   prop.m_dwStates = FWL_WGTSTATE_Invisible;
   prop.m_pDataProvider = m_pProperties->m_pDataProvider;
   prop.m_pThemeProvider = m_pProperties->m_pThemeProvider;
   m_pListBox.reset(IFWL_ListBox::CreateComboList(prop, m_pInterface));
   m_pListBox->Initialize();
 }
 void CFWL_ComboBoxImp::DisForm_InitComboEdit() {
@@ skipping 49 matching lines @@
     DispatchEvent(&postEvent);
   }
   CFX_RectF rect;
   m_pListBox->GetWidgetRect(rect);
   rect.Inflate(2, 2);
   Repaint(&rect);
 }
 FX_BOOL CFWL_ComboBoxImp::DisForm_IsDropListShowed() {
   return !(m_pListBox->GetStates() & FWL_WGTSTATE_Invisible);
 }
-FWL_ERR CFWL_ComboBoxImp::DisForm_ModifyStylesEx(uint32_t dwStylesExAdded,
-                                                 uint32_t dwStylesExRemoved) {
+FWL_Error CFWL_ComboBoxImp::DisForm_ModifyStylesEx(uint32_t dwStylesExAdded,
+                                                   uint32_t dwStylesExRemoved) {
   if (!m_pEdit) {
     DisForm_InitComboEdit();
   }
   bool bAddDropDown = !!(dwStylesExAdded & FWL_STYLEEXT_CMB_DropDown);
   bool bDelDropDown = !!(dwStylesExRemoved & FWL_STYLEEXT_CMB_DropDown);
   dwStylesExRemoved &= ~FWL_STYLEEXT_CMB_DropDown;
   m_pProperties->m_dwStyleExes |= FWL_STYLEEXT_CMB_DropDown;
   if (bAddDropDown) {
     m_pEdit->ModifyStylesEx(0, FWL_STYLEEXT_EDT_ReadOnly);
   } else if (bDelDropDown) {
     m_pEdit->ModifyStylesEx(FWL_STYLEEXT_EDT_ReadOnly, 0);
   }
   return CFWL_WidgetImp::ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
 }
-FWL_ERR CFWL_ComboBoxImp::DisForm_Update() {
+FWL_Error CFWL_ComboBoxImp::DisForm_Update() {
   if (m_iLock) {
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   }
   if (m_pEdit) {
     ReSetEditAlignment();
   }
   ReSetTheme();
   Layout();
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 FWL_WidgetHit CFWL_ComboBoxImp::DisForm_HitTest(FX_FLOAT fx, FX_FLOAT fy) {
   CFX_RectF rect;
   rect.Set(0, 0, m_pProperties->m_rtWidget.width - m_rtBtn.width,
            m_pProperties->m_rtWidget.height);
   if (rect.Contains(fx, fy))
     return FWL_WidgetHit::Edit;
   if (m_rtBtn.Contains(fx, fy))
     return FWL_WidgetHit::Client;
   if (DisForm_IsDropListShowed()) {
     m_pListBox->GetWidgetRect(rect);
     if (rect.Contains(fx, fy))
       return FWL_WidgetHit::Client;
   }
   return FWL_WidgetHit::Unknown;
 }
-FWL_ERR CFWL_ComboBoxImp::DisForm_DrawWidget(CFX_Graphics* pGraphics,
-                                             const CFX_Matrix* pMatrix) {
+FWL_Error CFWL_ComboBoxImp::DisForm_DrawWidget(CFX_Graphics* pGraphics,
+                                               const CFX_Matrix* pMatrix) {
   IFWL_ThemeProvider* pTheme = m_pProperties->m_pThemeProvider;
   CFX_Matrix mtOrg;
   mtOrg.Set(1, 0, 0, 1, 0, 0);
   if (pMatrix) {
     mtOrg = *pMatrix;
   }
   FX_BOOL bListShowed = m_pListBox && DisForm_IsDropListShowed();
   pGraphics->SaveGraphState();
   pGraphics->ConcatMatrix(&mtOrg);
   if (!m_rtBtn.IsEmpty(0.1f)) {
@@ skipping 15 matching lines @@
     m_pEdit->DrawWidget(pGraphics, &mt);
   }
   if (bListShowed) {
     CFX_RectF rtList;
     m_pListBox->GetWidgetRect(rtList);
     CFX_Matrix mt;
     mt.Set(1, 0, 0, 1, rtList.left, rtList.top);
     mt.Concat(mtOrg);
     m_pListBox->DrawWidget(pGraphics, &mt);
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
-FWL_ERR CFWL_ComboBoxImp::DisForm_GetBBox(CFX_RectF& rect) {
+FWL_Error CFWL_ComboBoxImp::DisForm_GetBBox(CFX_RectF& rect) {
   rect = m_pProperties->m_rtWidget;
   if (m_pListBox && DisForm_IsDropListShowed()) {
     CFX_RectF rtList;
     m_pListBox->GetWidgetRect(rtList);
     rtList.Offset(rect.left, rect.top);
     rect.Union(rtList);
   }
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 void CFWL_ComboBoxImp::DisForm_Layout() {
   GetClientRect(m_rtClient);
   m_rtContent = m_rtClient;
   FX_FLOAT* pFWidth = static_cast<FX_FLOAT*>(
       GetThemeCapacity(CFWL_WidgetCapacity::ScrollBarWidth));
   if (!pFWidth)
     return;
   FX_FLOAT borderWidth = 1;
   FX_FLOAT fBtn = *pFWidth;
@@ skipping 24 matching lines @@
       m_pEdit->SetText(wsText);
       m_pEdit->UnlockUpdate();
     }
     m_pEdit->Update();
   }
 }
 
 CFWL_ComboBoxImpDelegate::CFWL_ComboBoxImpDelegate(CFWL_ComboBoxImp* pOwner)
     : m_pOwner(pOwner) {}
 
-int32_t CFWL_ComboBoxImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
-  if (m_pOwner->m_pWidgetMgr->IsFormDisabled())
-    return DisForm_OnProcessMessage(pMessage);
+void CFWL_ComboBoxImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
+  if (m_pOwner->m_pWidgetMgr->IsFormDisabled()) {
+    DisForm_OnProcessMessage(pMessage);
+    return;
+  }
+  if (!pMessage)
+    return;
 
-  if (!pMessage)
-    return 0;
-
-  FX_BOOL iRet = 1;
   switch (pMessage->GetClassID()) {
     case CFWL_MessageType::SetFocus: {
       OnFocusChanged(pMessage, TRUE);
       break;
     }
     case CFWL_MessageType::KillFocus: {
       OnFocusChanged(pMessage, FALSE);
       break;
     }
     case CFWL_MessageType::Mouse: {
@@ skipping 18 matching lines @@
         default:
           break;
       }
       break;
     }
     case CFWL_MessageType::Key: {
       OnKey(static_cast<CFWL_MsgKey*>(pMessage));
       break;
     }
     default: {
-      iRet = 0;
       break;
     }
   }
 
   CFWL_WidgetImpDelegate::OnProcessMessage(pMessage);
-  return iRet;
 }
 
-FWL_ERR CFWL_ComboBoxImpDelegate::OnProcessEvent(CFWL_Event* pEvent) {
+void CFWL_ComboBoxImpDelegate::OnProcessEvent(CFWL_Event* pEvent) {
   CFWL_EventType dwFlag = pEvent->GetClassID();
   if (dwFlag == CFWL_EventType::DrawItem) {
     CFWL_EvtLtbDrawItem* pDrawItemEvent =
         static_cast<CFWL_EvtLtbDrawItem*>(pEvent);
     CFWL_EvtCmbDrawItem pTemp;
     pTemp.m_pSrcTarget = m_pOwner->m_pInterface;
     pTemp.m_pGraphics = pDrawItemEvent->m_pGraphics;
     pTemp.m_index = pDrawItemEvent->m_index;
     pTemp.m_rtItem = pDrawItemEvent->m_rect;
     m_pOwner->DispatchEvent(&pTemp);
   } else if (dwFlag == CFWL_EventType::Scroll) {
     CFWL_EvtScroll* pScrollEvent = static_cast<CFWL_EvtScroll*>(pEvent);
     CFWL_EvtScroll pScrollEv;
     pScrollEv.m_pSrcTarget = m_pOwner->m_pInterface;
     pScrollEv.m_iScrollCode = pScrollEvent->m_iScrollCode;
     pScrollEv.m_fPos = pScrollEvent->m_fPos;
     m_pOwner->DispatchEvent(&pScrollEv);
   } else if (dwFlag == CFWL_EventType::TextChanged) {
     CFWL_EvtEdtTextChanged* pTextChangedEvent =
         static_cast<CFWL_EvtEdtTextChanged*>(pEvent);
     CFWL_EvtCmbEditChanged pTemp;
     pTemp.m_pSrcTarget = m_pOwner->m_pInterface;
     pTemp.wsInsert = pTextChangedEvent->wsInsert;
     pTemp.wsDelete = pTextChangedEvent->wsDelete;
     pTemp.nChangeType = pTextChangedEvent->nChangeType;
     m_pOwner->DispatchEvent(&pTemp);
   }
-  return FWL_ERR_Succeeded;
 }
 
-FWL_ERR CFWL_ComboBoxImpDelegate::OnDrawWidget(CFX_Graphics* pGraphics,
-                                               const CFX_Matrix* pMatrix) {
-  return m_pOwner->DrawWidget(pGraphics, pMatrix);
+void CFWL_ComboBoxImpDelegate::OnDrawWidget(CFX_Graphics* pGraphics,
+                                            const CFX_Matrix* pMatrix) {
+  m_pOwner->DrawWidget(pGraphics, pMatrix);
 }
+
 void CFWL_ComboBoxImpDelegate::OnFocusChanged(CFWL_Message* pMsg,
                                               FX_BOOL bSet) {
   IFWL_Widget* pDstTarget = pMsg->m_pDstTarget;
   IFWL_Widget* pSrcTarget = pMsg->m_pSrcTarget;
   FX_BOOL bDropDown = m_pOwner->IsDropDownStyle();
   if (bSet) {
     m_pOwner->m_pProperties->m_dwStates |= FWL_WGTSTATE_Focused;
     if (bDropDown && pSrcTarget != m_pOwner->m_pListBox.get()) {
       if (!m_pOwner->m_pEdit)
         return;
@@ skipping 123 matching lines @@
       m_pOwner->Repaint(&m_pOwner->m_rtClient);
     }
     return;
   }
   FX_BOOL bDropDown = m_pOwner->IsDropDownStyle();
   if (bDropDown) {
     IFWL_WidgetDelegate* pDelegate = m_pOwner->m_pEdit->SetDelegate(NULL);
     pDelegate->OnProcessMessage(pMsg);
   }
 }
-int32_t CFWL_ComboBoxImpDelegate::DisForm_OnProcessMessage(
+void CFWL_ComboBoxImpDelegate::DisForm_OnProcessMessage(
     CFWL_Message* pMessage) {
   if (!pMessage)
-    return 0;
+    return;
 
   FX_BOOL backDefault = TRUE;
   switch (pMessage->GetClassID()) {
     case CFWL_MessageType::SetFocus: {
       backDefault = FALSE;
       DisForm_OnFocusChanged(pMessage, TRUE);
       break;
     }
     case CFWL_MessageType::KillFocus: {
       backDefault = FALSE;
@@ skipping 34 matching lines @@
           pDelegate->OnProcessMessage(pMessage);
           break;
         }
       }
       DisForm_OnKey(pKey);
       break;
     }
     default:
       break;
   }
-  if (!backDefault)
-    return 1;
-  return CFWL_WidgetImpDelegate::OnProcessMessage(pMessage);
+  if (backDefault)
+    CFWL_WidgetImpDelegate::OnProcessMessage(pMessage);
 }
 
 void CFWL_ComboBoxImpDelegate::DisForm_OnLButtonDown(CFWL_MsgMouse* pMsg) {
   FX_BOOL bDropDown = m_pOwner->DisForm_IsDropListShowed();
   CFX_RectF& rtBtn = bDropDown ? m_pOwner->m_rtBtn : m_pOwner->m_rtClient;
   FX_BOOL bClickBtn = rtBtn.Contains(pMsg->m_fx, pMsg->m_fy);
   if (bClickBtn) {
     if (m_pOwner->DisForm_IsDropListShowed()) {
       m_pOwner->DisForm_ShowDropList(FALSE);
       return;
@@ skipping 75 matching lines @@
 
 CFWL_ComboProxyImpDelegate::CFWL_ComboProxyImpDelegate(
     IFWL_Form* pForm,
     CFWL_ComboBoxImp* pComboBox)
     : m_bLButtonDown(FALSE),
       m_bLButtonUpSelf(FALSE),
       m_fStartPos(0),
       m_pForm(pForm),
       m_pComboBox(pComboBox) {}
 
-int32_t CFWL_ComboProxyImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
+void CFWL_ComboProxyImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
   if (!pMessage)
-    return 0;
+    return;
 
   switch (pMessage->GetClassID()) {
     case CFWL_MessageType::Mouse: {
       CFWL_MsgMouse* pMsg = static_cast<CFWL_MsgMouse*>(pMessage);
       switch (pMsg->m_dwCmd) {
         case FWL_MouseCommand::LeftButtonDown: {
           OnLButtonDown(pMsg);
           break;
         }
         case FWL_MouseCommand::LeftButtonUp: {
@@ skipping 17 matching lines @@
       OnFocusChanged(static_cast<CFWL_MsgKillFocus*>(pMessage), FALSE);
       break;
     }
     case CFWL_MessageType::SetFocus: {
       OnFocusChanged(static_cast<CFWL_MsgKillFocus*>(pMessage), TRUE);
       break;
     }
     default:
       break;
   }
-  return CFWL_WidgetImpDelegate::OnProcessMessage(pMessage);
+  CFWL_WidgetImpDelegate::OnProcessMessage(pMessage);
 }
 
-FWL_ERR CFWL_ComboProxyImpDelegate::OnDrawWidget(CFX_Graphics* pGraphics,
-                                                 const CFX_Matrix* pMatrix) {
+void CFWL_ComboProxyImpDelegate::OnDrawWidget(CFX_Graphics* pGraphics,
+                                              const CFX_Matrix* pMatrix) {
   m_pComboBox->DrawStretchHandler(pGraphics, pMatrix);
-  return FWL_ERR_Succeeded;
 }
+
 void CFWL_ComboProxyImpDelegate::OnLButtonDown(CFWL_MsgMouse* pMsg) {
   IFWL_App* pApp = m_pForm->GetOwnerApp();
   if (!pApp)
     return;
 
   CFWL_NoteDriver* pDriver =
       static_cast<CFWL_NoteDriver*>(pApp->GetNoteDriver());
   CFX_RectF rtWidget;
   m_pForm->GetWidgetRect(rtWidget);
   rtWidget.left = rtWidget.top = 0;
@@ skipping 32 matching lines @@
   m_pComboBox->ShowDropList(FALSE);
 }
 void CFWL_ComboProxyImpDelegate::OnFocusChanged(CFWL_MsgKillFocus* pMsg,
                                                 FX_BOOL bSet) {
   if (!bSet) {
     if (pMsg->m_pSetFocus == NULL) {
       m_pComboBox->ShowDropList(FALSE);
     }
   }
 }