Merge IFWL and CFWL classes.

xfa/fwl/core/cfwl_combobox.cpp

Index: xfa/fwl/core/cfwl_combobox.cpp
diff --git a/xfa/fwl/core/cfwl_combobox.cpp b/xfa/fwl/core/cfwl_combobox.cpp
index 532f49fdd2bf37dd293f61e7c462eed38d9fead2..b7be67d1bdd682549137f1f280da0da1a3bde452 100644
--- a/xfa/fwl/core/cfwl_combobox.cpp
+++ b/xfa/fwl/core/cfwl_combobox.cpp
@@ -6,144 +6,1124 @@
 
 #include "xfa/fwl/core/cfwl_combobox.h"
 
+#include <algorithm>
+#include <memory>
 #include <utility>
 
 #include "third_party/base/ptr_util.h"
-#include "xfa/fwl/core/fwl_error.h"
-#include "xfa/fwl/core/ifwl_combobox.h"
-#include "xfa/fwl/core/ifwl_widget.h"
+#include "xfa/fde/cfde_txtedtengine.h"
+#include "xfa/fde/tto/fde_textout.h"
+#include "xfa/fwl/core/cfwl_app.h"
+#include "xfa/fwl/core/cfwl_evteditchanged.h"
+#include "xfa/fwl/core/cfwl_evtpostdropdown.h"
+#include "xfa/fwl/core/cfwl_evtpredropdown.h"
+#include "xfa/fwl/core/cfwl_evtselectchanged.h"
+#include "xfa/fwl/core/cfwl_evttextchanged.h"
+#include "xfa/fwl/core/cfwl_formproxy.h"
+#include "xfa/fwl/core/cfwl_listbox.h"
+#include "xfa/fwl/core/cfwl_msgkey.h"
+#include "xfa/fwl/core/cfwl_msgkillfocus.h"
+#include "xfa/fwl/core/cfwl_msgmouse.h"
+#include "xfa/fwl/core/cfwl_msgsetfocus.h"
+#include "xfa/fwl/core/cfwl_notedriver.h"
+#include "xfa/fwl/core/cfwl_themebackground.h"
+#include "xfa/fwl/core/cfwl_themepart.h"
+#include "xfa/fwl/core/cfwl_themetext.h"
+#include "xfa/fwl/core/cfwl_widgetmgr.h"
+#include "xfa/fwl/core/ifwl_themeprovider.h"
 
-namespace {
+CFWL_ComboBox::CFWL_ComboBox(const CFWL_App* app)
+    : CFWL_Widget(app, pdfium::MakeUnique<CFWL_WidgetProperties>(), nullptr),
+      m_pComboBoxProxy(nullptr),
+      m_bLButtonDown(false),
+      m_iCurSel(-1),
+      m_iBtnState(CFWL_PartState_Normal),
+      m_fComboFormHandler(0) {
+  m_rtClient.Reset();
+  m_rtBtn.Reset();
+  m_rtHandler.Reset();
 
-IFWL_ComboBox* ToComboBox(IFWL_Widget* widget) {
-  return static_cast<IFWL_ComboBox*>(widget);
-}
+  if (m_pWidgetMgr->IsFormDisabled()) {
+    DisForm_InitComboList();
+    DisForm_InitComboEdit();
+    return;
+  }
+
+  auto prop = pdfium::MakeUnique<CFWL_WidgetProperties>();
+  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)
+    prop->m_dwStyleExes |= FWL_STYLEEXT_LTB_Icon;
+  m_pListBox =
+      pdfium::MakeUnique<CFWL_ComboList>(m_pOwnerApp, std::move(prop), this);
 
-}  // namespace
+  if ((m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_DropDown) && !m_pEdit) {
+    m_pEdit.reset(new CFWL_ComboEdit(
+        m_pOwnerApp, pdfium::MakeUnique<CFWL_WidgetProperties>(), this));
+    m_pEdit->SetOuter(this);
+  }
+  if (m_pEdit)
+    m_pEdit->SetParent(this);
 
-CFWL_ComboBox::CFWL_ComboBox(const CFWL_App* app) : CFWL_Widget(app) {}
+  SetStates(m_pProperties->m_dwStates);
+}
 
 CFWL_ComboBox::~CFWL_ComboBox() {}
 
-void CFWL_ComboBox::Initialize() {
-  ASSERT(!m_pIface);
+FWL_Type CFWL_ComboBox::GetClassID() const {
+  return FWL_Type::ComboBox;
+}
 
-  m_pIface = pdfium::MakeUnique<IFWL_ComboBox>(
-      m_pApp, pdfium::MakeUnique<CFWL_WidgetProperties>());
+void CFWL_ComboBox::GetWidgetRect(CFX_RectF& rect, bool bAutoSize) {
+  if (!bAutoSize) {
+    rect = m_pProperties->m_rtWidget;
+    return;
+  }
+
+  rect.Reset();
+  if (IsDropDownStyle() && m_pEdit) {
+    m_pEdit->GetWidgetRect(rect, true);
+  } else {
+    rect.width = 100;
+    rect.height = 16;
+  }
+  if (!m_pProperties->m_pThemeProvider)
+    ResetTheme();
 
-  CFWL_Widget::Initialize();
+  FX_FLOAT* pFWidth = static_cast<FX_FLOAT*>(
+      GetThemeCapacity(CFWL_WidgetCapacity::ScrollBarWidth));
+  if (!pFWidth)
+    return;
+
+  rect.Inflate(0, 0, *pFWidth, 0);
+  CFWL_Widget::GetWidgetRect(rect, true);
 }
 
 void CFWL_ComboBox::AddString(const CFX_WideStringC& wsText) {
-  if (GetWidget())
-    ToComboBox(GetWidget())->AddString(wsText);
+  m_pListBox->AddString(wsText);
 }
 
 bool CFWL_ComboBox::RemoveAt(int32_t iIndex) {
-  return GetWidget() && ToComboBox(GetWidget())->RemoveAt(iIndex);
+  return m_pListBox->RemoveAt(iIndex);
 }
 
 void CFWL_ComboBox::RemoveAll() {
-  if (GetWidget())
-    ToComboBox(GetWidget())->RemoveAll();
+  m_pListBox->DeleteAll();
 }
 
-void CFWL_ComboBox::GetTextByIndex(int32_t iIndex,
-                                   CFX_WideString& wsText) const {
-  if (!GetWidget())
+void CFWL_ComboBox::ModifyStylesEx(uint32_t dwStylesExAdded,
+                                   uint32_t dwStylesExRemoved) {
+  if (m_pWidgetMgr->IsFormDisabled()) {
+    DisForm_ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
+    return;
+  }
+
+  bool bAddDropDown = !!(dwStylesExAdded & FWL_STYLEEXT_CMB_DropDown);
+  bool bRemoveDropDown = !!(dwStylesExRemoved & FWL_STYLEEXT_CMB_DropDown);
+  if (bAddDropDown && !m_pEdit) {
+    m_pEdit = pdfium::MakeUnique<CFWL_ComboEdit>(
+        m_pOwnerApp, pdfium::MakeUnique<CFWL_WidgetProperties>(), nullptr);
+    m_pEdit->SetOuter(this);
+    m_pEdit->SetParent(this);
+  } else if (bRemoveDropDown && m_pEdit) {
+    m_pEdit->SetStates(FWL_WGTSTATE_Invisible, true);
+  }
+  CFWL_Widget::ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
+}
+
+void CFWL_ComboBox::Update() {
+  if (m_pWidgetMgr->IsFormDisabled()) {
+    DisForm_Update();
+    return;
+  }
+  if (IsLocked())
+    return;
+
+  ResetTheme();
+  if (IsDropDownStyle() && m_pEdit)
+    ResetEditAlignment();
+  if (!m_pProperties->m_pThemeProvider)
+    m_pProperties->m_pThemeProvider = GetAvailableTheme();
+
+  Layout();
+  CFWL_ThemePart part;
+  part.m_pWidget = this;
+  m_fComboFormHandler =
+      *static_cast<FX_FLOAT*>(m_pProperties->m_pThemeProvider->GetCapacity(
+          &part, CFWL_WidgetCapacity::ComboFormHandler));
+}
+
+FWL_WidgetHit CFWL_ComboBox::HitTest(FX_FLOAT fx, FX_FLOAT fy) {
+  if (m_pWidgetMgr->IsFormDisabled())
+    return DisForm_HitTest(fx, fy);
+  return CFWL_Widget::HitTest(fx, fy);
+}
+
+void CFWL_ComboBox::DrawWidget(CFX_Graphics* pGraphics,
+                               const CFX_Matrix* pMatrix) {
+  if (m_pWidgetMgr->IsFormDisabled()) {
+    DisForm_DrawWidget(pGraphics, pMatrix);
+    return;
+  }
+
+  if (!pGraphics)
     return;
-  ToComboBox(GetWidget())->GetTextByIndex(iIndex, wsText);
+  if (!m_pProperties->m_pThemeProvider)
+    return;
+
+  IFWL_ThemeProvider* pTheme = m_pProperties->m_pThemeProvider;
+  if (HasBorder())
+    DrawBorder(pGraphics, CFWL_Part::Border, pTheme, pMatrix);
+  if (HasEdge())
+    DrawEdge(pGraphics, CFWL_Part::Edge, pTheme, pMatrix);
+
+  if (!IsDropDownStyle()) {
+    CFX_RectF rtTextBk(m_rtClient);
+    rtTextBk.width -= m_rtBtn.width;
+
+    CFWL_ThemeBackground param;
+    param.m_pWidget = this;
+    param.m_iPart = CFWL_Part::Background;
+    param.m_pGraphics = pGraphics;
+    if (pMatrix)
+      param.m_matrix.Concat(*pMatrix);
+    param.m_rtPart = rtTextBk;
+
+    if (m_iCurSel >= 0) {
+      if (void* p = m_pListBox->GetItemData(
+              m_pListBox.get(),
+              m_pListBox->GetItem(m_pListBox.get(), m_iCurSel))) {
+        param.m_pData = p;
+      }
+    }
+
+    if (m_pProperties->m_dwStates & FWL_WGTSTATE_Disabled) {
+      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;
+
+      CFX_WideString wsText;
+      CFWL_ListItem* hItem = m_pListBox->GetItem(this, m_iCurSel);
+      m_pListBox->GetDataProviderItemText(hItem, wsText);
+
+      CFWL_ThemeText theme_text;
+      theme_text.m_pWidget = this;
+      theme_text.m_iPart = CFWL_Part::Caption;
+      theme_text.m_dwStates = m_iBtnState;
+      theme_text.m_pGraphics = pGraphics;
+      theme_text.m_matrix.Concat(*pMatrix);
+      theme_text.m_rtPart = rtTextBk;
+      theme_text.m_dwStates = (m_pProperties->m_dwStates & FWL_WGTSTATE_Focused)
+                                  ? CFWL_PartState_Selected
+                                  : CFWL_PartState_Normal;
+      theme_text.m_wsText = wsText;
+      theme_text.m_dwTTOStyles = FDE_TTOSTYLE_SingleLine;
+      theme_text.m_iTTOAlign = FDE_TTOALIGNMENT_CenterLeft;
+      pTheme->DrawText(&theme_text);
+    }
+  }
+
+  CFWL_ThemeBackground param;
+  param.m_pWidget = this;
+  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);
 }
 
-int32_t CFWL_ComboBox::GetCurSel() const {
-  return GetWidget() ? ToComboBox(GetWidget())->GetCurSel() : -1;
+void CFWL_ComboBox::SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) {
+  if (!pThemeProvider)
+    return;
+
+  m_pProperties->m_pThemeProvider = pThemeProvider;
+  if (m_pListBox)
+    m_pListBox->SetThemeProvider(pThemeProvider);
+  if (m_pEdit)
+    m_pEdit->SetThemeProvider(pThemeProvider);
+}
+
+void CFWL_ComboBox::GetTextByIndex(int32_t iIndex,
+                                   CFX_WideString& wsText) const {
+  CFWL_ListItem* pItem = static_cast<CFWL_ListItem*>(
+      m_pListBox->GetItem(m_pListBox.get(), iIndex));
+  if (pItem)
+    wsText = pItem->m_wsText;
 }
 
 void CFWL_ComboBox::SetCurSel(int32_t iSel) {
-  if (GetWidget())
-    ToComboBox(GetWidget())->SetCurSel(iSel);
+  int32_t iCount = m_pListBox->CountItems(nullptr);
+  bool bClearSel = iSel < 0 || iSel >= iCount;
+  if (IsDropDownStyle() && m_pEdit) {
+    if (bClearSel) {
+      m_pEdit->SetText(CFX_WideString());
+    } else {
+      CFX_WideString wsText;
+      CFWL_ListItem* hItem = m_pListBox->GetItem(this, iSel);
+      m_pListBox->GetDataProviderItemText(hItem, wsText);
+      m_pEdit->SetText(wsText);
+    }
+    m_pEdit->Update();
+  }
+  m_iCurSel = bClearSel ? -1 : iSel;
+}
+
+void CFWL_ComboBox::SetStates(uint32_t dwStates, bool bSet) {
+  if (IsDropDownStyle() && m_pEdit)
+    m_pEdit->SetStates(dwStates, bSet);
+  if (m_pListBox)
+    m_pListBox->SetStates(dwStates, bSet);
+  CFWL_Widget::SetStates(dwStates, bSet);
 }
 
 void CFWL_ComboBox::SetEditText(const CFX_WideString& wsText) {
-  if (GetWidget())
-    ToComboBox(GetWidget())->SetEditText(wsText);
+  if (!m_pEdit)
+    return;
+
+  m_pEdit->SetText(wsText);
+  m_pEdit->Update();
 }
 
 void CFWL_ComboBox::GetEditText(CFX_WideString& wsText,
                                 int32_t nStart,
                                 int32_t nCount) const {
-  if (GetWidget())
-    ToComboBox(GetWidget())->GetEditText(wsText, nStart, nCount);
+  if (m_pEdit) {
+    m_pEdit->GetText(wsText, nStart, nCount);
+    return;
+  }
+  if (!m_pListBox)
+    return;
+
+  CFWL_ListItem* hItem = m_pListBox->GetItem(this, m_iCurSel);
+  m_pListBox->GetDataProviderItemText(hItem, wsText);
 }
 
 void CFWL_ComboBox::OpenDropDownList(bool bActivate) {
-  ToComboBox(GetWidget())->OpenDropDownList(bActivate);
+  ShowDropList(bActivate);
 }
 
-bool CFWL_ComboBox::EditCanUndo() {
-  return GetWidget() ? ToComboBox(GetWidget())->EditCanUndo() : false;
+void CFWL_ComboBox::GetBBox(CFX_RectF& rect) const {
+  if (m_pWidgetMgr->IsFormDisabled()) {
+    DisForm_GetBBox(rect);
+    return;
+  }
+
+  rect = m_pProperties->m_rtWidget;
+  if (!m_pListBox || !IsDropListVisible())
+    return;
+
+  CFX_RectF rtList;
+  m_pListBox->GetWidgetRect(rtList);
+  rtList.Offset(rect.left, rect.top);
+  rect.Union(rtList);
 }
 
-bool CFWL_ComboBox::EditCanRedo() {
-  return GetWidget() ? ToComboBox(GetWidget())->EditCanRedo() : false;
+void CFWL_ComboBox::EditModifyStylesEx(uint32_t dwStylesExAdded,
+                                       uint32_t dwStylesExRemoved) {
+  if (m_pEdit)
+    m_pEdit->ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
 }
 
-bool CFWL_ComboBox::EditUndo() {
-  return GetWidget() ? ToComboBox(GetWidget())->EditUndo() : false;
+void CFWL_ComboBox::DrawStretchHandler(CFX_Graphics* pGraphics,
+                                       const CFX_Matrix* pMatrix) {
+  CFWL_ThemeBackground param;
+  param.m_pGraphics = pGraphics;
+  param.m_iPart = CFWL_Part::StretchHandler;
+  param.m_dwStates = CFWL_PartState_Normal;
+  param.m_pWidget = this;
+  if (pMatrix)
+    param.m_matrix.Concat(*pMatrix);
+  param.m_rtPart = m_rtHandler;
+  m_pProperties->m_pThemeProvider->DrawBackground(&param);
 }
 
-bool CFWL_ComboBox::EditRedo() {
-  return GetWidget() ? ToComboBox(GetWidget())->EditRedo() : false;
+void CFWL_ComboBox::ShowDropList(bool bActivate) {
+  if (m_pWidgetMgr->IsFormDisabled())
+    return DisForm_ShowDropList(bActivate);
+  if (IsDropListVisible() == bActivate)
+    return;
+  if (!m_pComboBoxProxy)
+    InitProxyForm();
+
+  m_pComboBoxProxy->Reset();
+  if (!bActivate) {
+    m_pComboBoxProxy->EndDoModal();
+
+    m_bLButtonDown = false;
+    m_pListBox->SetNotifyOwner(true);
+    SetFocus(true);
+    return;
+  }
+
+  m_pListBox->ChangeSelected(m_iCurSel);
+  ResetListItemAlignment();
+
+  uint32_t dwStyleAdd = m_pProperties->m_dwStyleExes &
+                        (FWL_STYLEEXT_CMB_Sort | FWL_STYLEEXT_CMB_OwnerDraw);
+  m_pListBox->ModifyStylesEx(dwStyleAdd, 0);
+  m_pListBox->GetWidgetRect(m_rtList, true);
+
+  CFX_RectF rtAnchor;
+  rtAnchor.Set(0, 0, m_pProperties->m_rtWidget.width,
+               m_pProperties->m_rtWidget.height);
+
+  m_rtList.width = std::max(m_rtList.width, m_rtClient.width);
+  m_rtProxy = m_rtList;
+  if (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_ListDrag)
+    m_rtProxy.height += m_fComboFormHandler;
+
+  GetPopupPos(0, m_rtProxy.height, rtAnchor, m_rtProxy);
+  if (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_ListDrag) {
+    FX_FLOAT fx = 0;
+    FX_FLOAT fy = m_rtClient.top + m_rtClient.height / 2;
+    TransformTo(nullptr, fx, fy);
+
+    m_bUpFormHandler = fy > m_rtProxy.top;
+    if (m_bUpFormHandler) {
+      m_rtHandler.Set(0, 0, m_rtList.width, m_fComboFormHandler);
+      m_rtList.top = m_fComboFormHandler;
+    } else {
+      m_rtHandler.Set(0, m_rtList.height, m_rtList.width, m_fComboFormHandler);
+    }
+  }
+  m_pComboBoxProxy->SetWidgetRect(m_rtProxy);
+  m_pComboBoxProxy->Update();
+  m_pListBox->SetWidgetRect(m_rtList);
+  m_pListBox->Update();
+
+  CFWL_EvtPreDropDown ev;
+  ev.m_pSrcTarget = this;
+  DispatchEvent(&ev);
+
+  m_fItemHeight = m_pListBox->GetItemHeight();
+  m_pListBox->SetFocus(true);
+  m_pComboBoxProxy->DoModal();
+  m_pListBox->SetFocus(false);
 }
 
-bool CFWL_ComboBox::EditCanCopy() {
-  return GetWidget() ? ToComboBox(GetWidget())->EditCanCopy() : false;
+void CFWL_ComboBox::MatchEditText() {
+  CFX_WideString wsText;
+  m_pEdit->GetText(wsText);
+  int32_t iMatch = m_pListBox->MatchItem(wsText);
+  if (iMatch != m_iCurSel) {
+    m_pListBox->ChangeSelected(iMatch);
+    if (iMatch >= 0)
+      SyncEditText(iMatch);
+  } else if (iMatch >= 0) {
+    m_pEdit->SetSelected();
+  }
+  m_iCurSel = iMatch;
 }
 
-bool CFWL_ComboBox::EditCanCut() {
-  return GetWidget() ? ToComboBox(GetWidget())->EditCanCut() : false;
+void CFWL_ComboBox::SyncEditText(int32_t iListItem) {
+  CFX_WideString wsText;
+  CFWL_ListItem* hItem = m_pListBox->GetItem(this, iListItem);
+  m_pListBox->GetDataProviderItemText(hItem, wsText);
+  m_pEdit->SetText(wsText);
+  m_pEdit->Update();
+  m_pEdit->SetSelected();
 }
 
-bool CFWL_ComboBox::EditCanSelectAll() {
-  return GetWidget() ? ToComboBox(GetWidget())->EditCanSelectAll() : false;
+void CFWL_ComboBox::Layout() {
+  if (m_pWidgetMgr->IsFormDisabled())
+    return DisForm_Layout();
+
+  GetClientRect(m_rtClient);
+  FX_FLOAT* pFWidth = static_cast<FX_FLOAT*>(
+      GetThemeCapacity(CFWL_WidgetCapacity::ScrollBarWidth));
+  if (!pFWidth)
+    return;
+
+  FX_FLOAT fBtn = *pFWidth;
+  m_rtBtn.Set(m_rtClient.right() - fBtn, m_rtClient.top, fBtn,
+              m_rtClient.height);
+  if (!IsDropDownStyle() || !m_pEdit)
+    return;
+
+  CFX_RectF rtEdit;
+  rtEdit.Set(m_rtClient.left, m_rtClient.top, m_rtClient.width - fBtn,
+             m_rtClient.height);
+  m_pEdit->SetWidgetRect(rtEdit);
+
+  if (m_iCurSel >= 0) {
+    CFX_WideString wsText;
+    CFWL_ListItem* hItem = m_pListBox->GetItem(this, m_iCurSel);
+    m_pListBox->GetDataProviderItemText(hItem, wsText);
+    m_pEdit->LockUpdate();
+    m_pEdit->SetText(wsText);
+    m_pEdit->UnlockUpdate();
+  }
+  m_pEdit->Update();
 }
 
-bool CFWL_ComboBox::EditCopy(CFX_WideString& wsCopy) {
-  return GetWidget() ? ToComboBox(GetWidget())->EditCopy(wsCopy) : false;
+void CFWL_ComboBox::ResetTheme() {
+  IFWL_ThemeProvider* pTheme = m_pProperties->m_pThemeProvider;
+  if (!pTheme) {
+    pTheme = GetAvailableTheme();
+    m_pProperties->m_pThemeProvider = pTheme;
+  }
+  if (m_pListBox && !m_pListBox->GetThemeProvider())
+    m_pListBox->SetThemeProvider(pTheme);
+  if (m_pEdit && !m_pEdit->GetThemeProvider())
+    m_pEdit->SetThemeProvider(pTheme);
 }
 
-bool CFWL_ComboBox::EditCut(CFX_WideString& wsCut) {
-  return GetWidget() ? ToComboBox(GetWidget())->EditCut(wsCut) : false;
+void CFWL_ComboBox::ResetEditAlignment() {
+  if (!m_pEdit)
+    return;
+
+  uint32_t dwAdd = 0;
+  switch (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_EditHAlignMask) {
+    case FWL_STYLEEXT_CMB_EditHCenter: {
+      dwAdd |= FWL_STYLEEXT_EDT_HCenter;
+      break;
+    }
+    case FWL_STYLEEXT_CMB_EditHFar: {
+      dwAdd |= FWL_STYLEEXT_EDT_HFar;
+      break;
+    }
+    default: { dwAdd |= FWL_STYLEEXT_EDT_HNear; }
+  }
+  switch (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_EditVAlignMask) {
+    case FWL_STYLEEXT_CMB_EditVCenter: {
+      dwAdd |= FWL_STYLEEXT_EDT_VCenter;
+      break;
+    }
+    case FWL_STYLEEXT_CMB_EditVFar: {
+      dwAdd |= FWL_STYLEEXT_EDT_VFar;
+      break;
+    }
+    default: {
+      dwAdd |= FWL_STYLEEXT_EDT_VNear;
+      break;
+    }
+  }
+  if (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_EditJustified)
+    dwAdd |= FWL_STYLEEXT_EDT_Justified;
+  if (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_EditDistributed)
+    dwAdd |= FWL_STYLEEXT_EDT_Distributed;
+
+  m_pEdit->ModifyStylesEx(dwAdd, FWL_STYLEEXT_EDT_HAlignMask |
+                                     FWL_STYLEEXT_EDT_HAlignModeMask |
+                                     FWL_STYLEEXT_EDT_VAlignMask);
 }
 
-bool CFWL_ComboBox::EditPaste(const CFX_WideString& wsPaste) {
-  return GetWidget() ? ToComboBox(GetWidget())->EditPaste(wsPaste) : false;
+void CFWL_ComboBox::ResetListItemAlignment() {
+  if (!m_pListBox)
+    return;
+
+  uint32_t dwAdd = 0;
+  switch (m_pProperties->m_dwStyleExes & FWL_STYLEEXT_CMB_ListItemAlignMask) {
+    case FWL_STYLEEXT_CMB_ListItemCenterAlign: {
+      dwAdd |= FWL_STYLEEXT_LTB_CenterAlign;
+      break;
+    }
+    case FWL_STYLEEXT_CMB_ListItemRightAlign: {
+      dwAdd |= FWL_STYLEEXT_LTB_RightAlign;
+      break;
+    }
+    default: {
+      dwAdd |= FWL_STYLEEXT_LTB_LeftAlign;
+      break;
+    }
+  }
+  m_pListBox->ModifyStylesEx(dwAdd, FWL_STYLEEXT_CMB_ListItemAlignMask);
 }
 
-void CFWL_ComboBox::EditSelectAll() {
-  if (GetWidget())
-    ToComboBox(GetWidget())->EditSelectAll();
+void CFWL_ComboBox::ProcessSelChanged(bool bLButtonUp) {
+  m_iCurSel = m_pListBox->GetItemIndex(this, m_pListBox->GetSelItem(0));
+  if (!IsDropDownStyle()) {
+    Repaint(&m_rtClient);
+    return;
+  }
+
+  CFWL_ListItem* hItem = m_pListBox->GetItem(this, m_iCurSel);
+  if (!hItem)
+    return;
+
+  CFX_WideString wsText;
+  m_pListBox->GetItemText(this, hItem, wsText);
+  if (m_pEdit) {
+    m_pEdit->SetText(wsText);
+    m_pEdit->Update();
+    m_pEdit->SetSelected();
+  }
+
+  CFWL_EvtSelectChanged ev;
+  ev.bLButtonUp = bLButtonUp;
+  ev.m_pSrcTarget = this;
+  DispatchEvent(&ev);
 }
 
-void CFWL_ComboBox::EditDelete() {
-  if (GetWidget())
-    ToComboBox(GetWidget())->EditDelete();
+void CFWL_ComboBox::InitProxyForm() {
+  if (m_pComboBoxProxy)
+    return;
+  if (!m_pListBox)
+    return;
+
+  auto prop = pdfium::MakeUnique<CFWL_WidgetProperties>();
+  prop->m_pOwner = this;
+  prop->m_dwStyles = FWL_WGTSTYLE_Popup;
+  prop->m_dwStates = FWL_WGTSTATE_Invisible;
+
+  // TODO(dsinclair): Does this leak? I don't see a delete, but I'm not sure
+  // if the SetParent call is going to transfer ownership.
+  m_pComboBoxProxy = new CFWL_ComboBoxProxy(this, m_pOwnerApp, std::move(prop),
+                                            m_pListBox.get());
+  m_pListBox->SetParent(m_pComboBoxProxy);
 }
 
-void CFWL_ComboBox::EditDeSelect() {
-  if (GetWidget())
-    ToComboBox(GetWidget())->EditDeSelect();
+void CFWL_ComboBox::DisForm_InitComboList() {
+  if (m_pListBox)
+    return;
+
+  auto prop = pdfium::MakeUnique<CFWL_WidgetProperties>();
+  prop->m_pParent = this;
+  prop->m_dwStyles = FWL_WGTSTYLE_Border | FWL_WGTSTYLE_VScroll;
+  prop->m_dwStates = FWL_WGTSTATE_Invisible;
+  prop->m_pThemeProvider = m_pProperties->m_pThemeProvider;
+  m_pListBox =
+      pdfium::MakeUnique<CFWL_ComboList>(m_pOwnerApp, std::move(prop), this);
 }
 
-void CFWL_ComboBox::GetBBox(CFX_RectF& rect) {
-  if (GetWidget())
-    ToComboBox(GetWidget())->GetBBox(rect);
+void CFWL_ComboBox::DisForm_InitComboEdit() {
+  if (m_pEdit)
+    return;
+
+  auto prop = pdfium::MakeUnique<CFWL_WidgetProperties>();
+  prop->m_pParent = this;
+  prop->m_pThemeProvider = m_pProperties->m_pThemeProvider;
+
+  m_pEdit =
+      pdfium::MakeUnique<CFWL_ComboEdit>(m_pOwnerApp, std::move(prop), this);
+  m_pEdit->SetOuter(this);
 }
 
-void CFWL_ComboBox::EditModifyStylesEx(uint32_t dwStylesExAdded,
-                                       uint32_t dwStylesExRemoved) {
-  if (GetWidget()) {
-    ToComboBox(GetWidget())
-        ->EditModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
+void CFWL_ComboBox::DisForm_ShowDropList(bool bActivate) {
+  if (DisForm_IsDropListVisible() == bActivate)
+    return;
+
+  if (bActivate) {
+    CFWL_EvtPreDropDown preEvent;
+    preEvent.m_pSrcTarget = this;
+    DispatchEvent(&preEvent);
+
+    CFWL_ComboList* pComboList = m_pListBox.get();
+    int32_t iItems = pComboList->CountItems(nullptr);
+    if (iItems < 1)
+      return;
+
+    ResetListItemAlignment();
+    pComboList->ChangeSelected(m_iCurSel);
+
+    FX_FLOAT fItemHeight = pComboList->CalcItemHeight();
+    FX_FLOAT fBorder = GetBorderSize();
+    FX_FLOAT fPopupMin = 0.0f;
+    if (iItems > 3)
+      fPopupMin = fItemHeight * 3 + fBorder * 2;
+
+    FX_FLOAT fPopupMax = fItemHeight * iItems + fBorder * 2;
+    CFX_RectF rtList;
+    rtList.left = m_rtClient.left;
+    rtList.width = m_pProperties->m_rtWidget.width;
+    rtList.top = 0;
+    rtList.height = 0;
+    GetPopupPos(fPopupMin, fPopupMax, m_pProperties->m_rtWidget, rtList);
+
+    m_pListBox->SetWidgetRect(rtList);
+    m_pListBox->Update();
+  } else {
+    SetFocus(true);
+  }
+
+  m_pListBox->SetStates(FWL_WGTSTATE_Invisible, !bActivate);
+  if (bActivate) {
+    CFWL_EvtPostDropDown postEvent;
+    postEvent.m_pSrcTarget = this;
+    DispatchEvent(&postEvent);
+  }
+
+  CFX_RectF rect;
+  m_pListBox->GetWidgetRect(rect);
+  rect.Inflate(2, 2);
+  Repaint(&rect);
+}
+
+void CFWL_ComboBox::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);
+  CFWL_Widget::ModifyStylesEx(dwStylesExAdded, dwStylesExRemoved);
+}
+
+void CFWL_ComboBox::DisForm_Update() {
+  if (m_iLock)
+    return;
+  if (m_pEdit)
+    ResetEditAlignment();
+  ResetTheme();
+  Layout();
+}
+
+FWL_WidgetHit CFWL_ComboBox::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_IsDropListVisible()) {
+    m_pListBox->GetWidgetRect(rect);
+    if (rect.Contains(fx, fy))
+      return FWL_WidgetHit::Client;
+  }
+  return FWL_WidgetHit::Unknown;
+}
+
+void CFWL_ComboBox::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;
+
+  pGraphics->SaveGraphState();
+  pGraphics->ConcatMatrix(&mtOrg);
+  if (!m_rtBtn.IsEmpty(0.1f)) {
+    CFWL_ThemeBackground param;
+    param.m_pWidget = this;
+    param.m_iPart = CFWL_Part::DropDownButton;
+    param.m_dwStates = m_iBtnState;
+    param.m_pGraphics = pGraphics;
+    param.m_rtPart = m_rtBtn;
+    pTheme->DrawBackground(&param);
+  }
+  pGraphics->RestoreGraphState();
+
+  if (m_pEdit) {
+    CFX_RectF rtEdit;
+    m_pEdit->GetWidgetRect(rtEdit);
+    CFX_Matrix mt;
+    mt.Set(1, 0, 0, 1, rtEdit.left, rtEdit.top);
+    mt.Concat(mtOrg);
+    m_pEdit->DrawWidget(pGraphics, &mt);
+  }
+  if (m_pListBox && DisForm_IsDropListVisible()) {
+    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);
+  }
+}
+
+void CFWL_ComboBox::DisForm_GetBBox(CFX_RectF& rect) const {
+  rect = m_pProperties->m_rtWidget;
+  if (!m_pListBox || !DisForm_IsDropListVisible())
+    return;
+
+  CFX_RectF rtList;
+  m_pListBox->GetWidgetRect(rtList);
+  rtList.Offset(rect.left, rect.top);
+  rect.Union(rtList);
+}
+
+void CFWL_ComboBox::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;
+  if (!(GetStylesEx() & FWL_STYLEEXT_CMB_ReadOnly)) {
+    m_rtBtn.Set(m_rtClient.right() - fBtn, m_rtClient.top + borderWidth,
+                fBtn - borderWidth, m_rtClient.height - 2 * borderWidth);
+  }
+
+  CFX_RectF* pUIMargin =
+      static_cast<CFX_RectF*>(GetThemeCapacity(CFWL_WidgetCapacity::UIMargin));
+  if (pUIMargin) {
+    m_rtContent.Deflate(pUIMargin->left, pUIMargin->top, pUIMargin->width,
+                        pUIMargin->height);
+  }
+
+  if (!IsDropDownStyle() || !m_pEdit)
+    return;
+
+  CFX_RectF rtEdit;
+  rtEdit.Set(m_rtContent.left, m_rtContent.top, m_rtContent.width - fBtn,
+             m_rtContent.height);
+  m_pEdit->SetWidgetRect(rtEdit);
+
+  if (m_iCurSel >= 0) {
+    CFX_WideString wsText;
+    CFWL_ListItem* hItem = m_pListBox->GetItem(this, m_iCurSel);
+    m_pListBox->GetDataProviderItemText(hItem, wsText);
+    m_pEdit->LockUpdate();
+    m_pEdit->SetText(wsText);
+    m_pEdit->UnlockUpdate();
+  }
+  m_pEdit->Update();
+}
+
+void CFWL_ComboBox::OnProcessMessage(CFWL_Message* pMessage) {
+  if (m_pWidgetMgr->IsFormDisabled()) {
+    DisForm_OnProcessMessage(pMessage);
+    return;
+  }
+  if (!pMessage)
+    return;
+
+  switch (pMessage->GetClassID()) {
+    case CFWL_MessageType::SetFocus:
+      OnFocusChanged(pMessage, true);
+      break;
+    case CFWL_MessageType::KillFocus:
+      OnFocusChanged(pMessage, false);
+      break;
+    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:
+          OnLButtonUp(pMsg);
+          break;
+        case FWL_MouseCommand::Move:
+          OnMouseMove(pMsg);
+          break;
+        case FWL_MouseCommand::Leave:
+          OnMouseLeave(pMsg);
+          break;
+        default:
+          break;
+      }
+      break;
+    }
+    case CFWL_MessageType::Key:
+      OnKey(static_cast<CFWL_MsgKey*>(pMessage));
+      break;
+    default:
+      break;
+  }
+
+  CFWL_Widget::OnProcessMessage(pMessage);
+}
+
+void CFWL_ComboBox::OnProcessEvent(CFWL_Event* pEvent) {
+  CFWL_EventType dwFlag = pEvent->GetClassID();
+  if (dwFlag == CFWL_EventType::Scroll) {
+    CFWL_EvtScroll* pScrollEvent = static_cast<CFWL_EvtScroll*>(pEvent);
+    CFWL_EvtScroll pScrollEv;
+    pScrollEv.m_pSrcTarget = this;
+    pScrollEv.m_iScrollCode = pScrollEvent->m_iScrollCode;
+    pScrollEv.m_fPos = pScrollEvent->m_fPos;
+    DispatchEvent(&pScrollEv);
+  } else if (dwFlag == CFWL_EventType::TextChanged) {
+    CFWL_EvtEditChanged pTemp;
+    pTemp.m_pSrcTarget = this;
+    DispatchEvent(&pTemp);
+  }
+}
+
+void CFWL_ComboBox::OnDrawWidget(CFX_Graphics* pGraphics,
+                                 const CFX_Matrix* pMatrix) {
+  DrawWidget(pGraphics, pMatrix);
+}
+
+void CFWL_ComboBox::OnFocusChanged(CFWL_Message* pMsg, bool bSet) {
+  if (bSet) {
+    m_pProperties->m_dwStates |= FWL_WGTSTATE_Focused;
+    if (IsDropDownStyle() && pMsg->m_pSrcTarget != m_pListBox.get()) {
+      if (!m_pEdit)
+        return;
+      m_pEdit->SetSelected();
+      return;
+    }
+
+    Repaint(&m_rtClient);
+    return;
+  }
+
+  m_pProperties->m_dwStates &= ~FWL_WGTSTATE_Focused;
+  if (!IsDropDownStyle() || pMsg->m_pDstTarget == m_pListBox.get()) {
+    Repaint(&m_rtClient);
+    return;
+  }
+  if (!m_pEdit)
+    return;
+
+  m_pEdit->FlagFocus(false);
+  m_pEdit->ClearSelected();
+}
+
+void CFWL_ComboBox::OnLButtonDown(CFWL_MsgMouse* pMsg) {
+  if (m_pProperties->m_dwStates & FWL_WGTSTATE_Disabled)
+    return;
+
+  CFX_RectF& rtBtn = IsDropDownStyle() ? m_rtBtn : m_rtClient;
+  if (!rtBtn.Contains(pMsg->m_fx, pMsg->m_fy))
+    return;
+
+  if (IsDropDownStyle() && m_pEdit)
+    MatchEditText();
+
+  m_bLButtonDown = true;
+  m_iBtnState = CFWL_PartState_Pressed;
+  Repaint(&m_rtClient);
+
+  ShowDropList(true);
+  m_iBtnState = CFWL_PartState_Normal;
+  Repaint(&m_rtClient);
+}
+
+void CFWL_ComboBox::OnLButtonUp(CFWL_MsgMouse* pMsg) {
+  m_bLButtonDown = false;
+  if (m_rtBtn.Contains(pMsg->m_fx, pMsg->m_fy))
+    m_iBtnState = CFWL_PartState_Hovered;
+  else
+    m_iBtnState = CFWL_PartState_Normal;
+
+  Repaint(&m_rtBtn);
+}
+
+void CFWL_ComboBox::OnMouseMove(CFWL_MsgMouse* pMsg) {
+  int32_t iOldState = m_iBtnState;
+  if (m_rtBtn.Contains(pMsg->m_fx, pMsg->m_fy)) {
+    m_iBtnState =
+        m_bLButtonDown ? CFWL_PartState_Pressed : CFWL_PartState_Hovered;
+  } else {
+    m_iBtnState = CFWL_PartState_Normal;
+  }
+  if ((iOldState != m_iBtnState) &&
+      !((m_pProperties->m_dwStates & FWL_WGTSTATE_Disabled) ==
+        FWL_WGTSTATE_Disabled)) {
+    Repaint(&m_rtBtn);
+  }
+}
+
+void CFWL_ComboBox::OnMouseLeave(CFWL_MsgMouse* pMsg) {
+  if (!IsDropListVisible() &&
+      !((m_pProperties->m_dwStates & FWL_WGTSTATE_Disabled) ==
+        FWL_WGTSTATE_Disabled)) {
+    m_iBtnState = CFWL_PartState_Normal;
+    Repaint(&m_rtBtn);
+  }
+}
+
+void CFWL_ComboBox::OnKey(CFWL_MsgKey* pMsg) {
+  uint32_t dwKeyCode = pMsg->m_dwKeyCode;
+  if (dwKeyCode == FWL_VKEY_Tab) {
+    DispatchKeyEvent(pMsg);
+    return;
+  }
+  if (pMsg->m_pDstTarget == this)
+    DoSubCtrlKey(pMsg);
+}
+
+void CFWL_ComboBox::DoSubCtrlKey(CFWL_MsgKey* pMsg) {
+  uint32_t dwKeyCode = pMsg->m_dwKeyCode;
+  const bool bUp = dwKeyCode == FWL_VKEY_Up;
+  const bool bDown = dwKeyCode == FWL_VKEY_Down;
+  if (bUp || bDown) {
+    int32_t iCount = m_pListBox->CountItems(nullptr);
+    if (iCount < 1)
+      return;
+
+    bool bMatchEqual = false;
+    int32_t iCurSel = m_iCurSel;
+    bool bDropDown = IsDropDownStyle();
+    if (bDropDown && m_pEdit) {
+      CFX_WideString wsText;
+      m_pEdit->GetText(wsText);
+      iCurSel = m_pListBox->MatchItem(wsText);
+      if (iCurSel >= 0) {
+        CFX_WideString wsTemp;
+        CFWL_ListItem* hItem = m_pListBox->GetItem(this, iCurSel);
+        m_pListBox->GetDataProviderItemText(hItem, wsTemp);
+        bMatchEqual = wsText == wsTemp;
+      }
+    }
+    if (iCurSel < 0) {
+      iCurSel = 0;
+    } else if (!bDropDown || bMatchEqual) {
+      if ((bUp && iCurSel == 0) || (bDown && iCurSel == iCount - 1))
+        return;
+      if (bUp)
+        iCurSel--;
+      else
+        iCurSel++;
+    }
+    m_iCurSel = iCurSel;
+    if (bDropDown && m_pEdit)
+      SyncEditText(m_iCurSel);
+    else
+      Repaint(&m_rtClient);
+    return;
+  }
+
+  if (IsDropDownStyle())
+    m_pEdit->GetDelegate()->OnProcessMessage(pMsg);
+}
+
+void CFWL_ComboBox::DisForm_OnProcessMessage(CFWL_Message* pMessage) {
+  if (!pMessage)
+    return;
+
+  bool backDefault = true;
+  switch (pMessage->GetClassID()) {
+    case CFWL_MessageType::SetFocus: {
+      backDefault = false;
+      DisForm_OnFocusChanged(pMessage, true);
+      break;
+    }
+    case CFWL_MessageType::KillFocus: {
+      backDefault = false;
+      DisForm_OnFocusChanged(pMessage, false);
+      break;
+    }
+    case CFWL_MessageType::Mouse: {
+      backDefault = false;
+      CFWL_MsgMouse* pMsg = static_cast<CFWL_MsgMouse*>(pMessage);
+      switch (pMsg->m_dwCmd) {
+        case FWL_MouseCommand::LeftButtonDown:
+          DisForm_OnLButtonDown(pMsg);
+          break;
+        case FWL_MouseCommand::LeftButtonUp:
+          OnLButtonUp(pMsg);
+          break;
+        default:
+          break;
+      }
+      break;
+    }
+    case CFWL_MessageType::Key: {
+      backDefault = false;
+      CFWL_MsgKey* pKey = static_cast<CFWL_MsgKey*>(pMessage);
+      if (pKey->m_dwCmd == FWL_KeyCommand::KeyUp)
+        break;
+      if (DisForm_IsDropListVisible() &&
+          pKey->m_dwCmd == FWL_KeyCommand::KeyDown) {
+        bool bListKey = pKey->m_dwKeyCode == FWL_VKEY_Up ||
+                        pKey->m_dwKeyCode == FWL_VKEY_Down ||
+                        pKey->m_dwKeyCode == FWL_VKEY_Return ||
+                        pKey->m_dwKeyCode == FWL_VKEY_Escape;
+        if (bListKey) {
+          m_pListBox->GetDelegate()->OnProcessMessage(pMessage);
+          break;
+        }
+      }
+      DisForm_OnKey(pKey);
+      break;
+    }
+    default:
+      break;
+  }
+  if (backDefault)
+    CFWL_Widget::OnProcessMessage(pMessage);
+}
+
+void CFWL_ComboBox::DisForm_OnLButtonDown(CFWL_MsgMouse* pMsg) {
+  bool bDropDown = DisForm_IsDropListVisible();
+  CFX_RectF& rtBtn = bDropDown ? m_rtBtn : m_rtClient;
+  if (!rtBtn.Contains(pMsg->m_fx, pMsg->m_fy))
+    return;
+
+  if (DisForm_IsDropListVisible()) {
+    DisForm_ShowDropList(false);
+    return;
+  }
+  if (m_pEdit)
+    MatchEditText();
+  DisForm_ShowDropList(true);
+}
+
+void CFWL_ComboBox::DisForm_OnFocusChanged(CFWL_Message* pMsg, bool bSet) {
+  if (bSet) {
+    m_pProperties->m_dwStates |= FWL_WGTSTATE_Focused;
+    if ((m_pEdit->GetStates() & FWL_WGTSTATE_Focused) == 0) {
+      CFWL_MsgSetFocus msg;
+      msg.m_pDstTarget = m_pEdit.get();
+      msg.m_pSrcTarget = nullptr;
+      m_pEdit->GetDelegate()->OnProcessMessage(&msg);
+    }
+  } else {
+    m_pProperties->m_dwStates &= ~FWL_WGTSTATE_Focused;
+    DisForm_ShowDropList(false);
+    CFWL_MsgKillFocus msg;
+    msg.m_pDstTarget = nullptr;
+    msg.m_pSrcTarget = m_pEdit.get();
+    m_pEdit->GetDelegate()->OnProcessMessage(&msg);
+  }
+}
+
+void CFWL_ComboBox::DisForm_OnKey(CFWL_MsgKey* pMsg) {
+  uint32_t dwKeyCode = pMsg->m_dwKeyCode;
+  const bool bUp = dwKeyCode == FWL_VKEY_Up;
+  const bool bDown = dwKeyCode == FWL_VKEY_Down;
+  if (bUp || bDown) {
+    CFWL_ComboList* pComboList = m_pListBox.get();
+    int32_t iCount = pComboList->CountItems(nullptr);
+    if (iCount < 1)
+      return;
+
+    bool bMatchEqual = false;
+    int32_t iCurSel = m_iCurSel;
+    if (m_pEdit) {
+      CFX_WideString wsText;
+      m_pEdit->GetText(wsText);
+      iCurSel = pComboList->MatchItem(wsText);
+      if (iCurSel >= 0) {
+        CFX_WideString wsTemp;
+        CFWL_ListItem* item = m_pListBox->GetSelItem(iCurSel);
+        m_pListBox->GetDataProviderItemText(item, wsTemp);
+        bMatchEqual = wsText == wsTemp;
+      }
+    }
+    if (iCurSel < 0) {
+      iCurSel = 0;
+    } else if (bMatchEqual) {
+      if ((bUp && iCurSel == 0) || (bDown && iCurSel == iCount - 1))
+        return;
+      if (bUp)
+        iCurSel--;
+      else
+        iCurSel++;
+    }
+    m_iCurSel = iCurSel;
+    SyncEditText(m_iCurSel);
+    return;
   }
+  if (m_pEdit)
+    m_pEdit->GetDelegate()->OnProcessMessage(pMsg);
 }