diff --git a/core/fpdfdoc/cpdf_formfield.cpp b/core/fpdfdoc/cpdf_formfield.cpp
index 2502fe6..df59369 100644
--- a/core/fpdfdoc/cpdf_formfield.cpp
+++ b/core/fpdfdoc/cpdf_formfield.cpp
@@ -45,6 +45,14 @@
 
 }  // namespace
 
+Optional<FormFieldType> IntToFormFieldType(int value) {
+  if (value >= static_cast<int>(FormFieldType::kUnknown) &&
+      value < static_cast<int>(kFormFieldTypeCount)) {
+    return {static_cast<FormFieldType>(value)};
+  }
+  return {};
+}
+
 CPDF_Object* FPDF_GetFieldAttr(const CPDF_Dictionary* pFieldDict,
                                const char* name,
                                int nLevel) {
@@ -238,28 +246,27 @@
   return it != m_ControlList.end() ? it - m_ControlList.begin() : -1;
 }
 
-int CPDF_FormField::GetFieldType() const {
+FormFieldType CPDF_FormField::GetFieldType() const {
   switch (m_Type) {
     case PushButton:
-      return FIELDTYPE_PUSHBUTTON;
+      return FormFieldType::kPushButton;
     case CheckBox:
-      return FIELDTYPE_CHECKBOX;
+      return FormFieldType::kCheckBox;
     case RadioButton:
-      return FIELDTYPE_RADIOBUTTON;
+      return FormFieldType::kRadioButton;
     case ComboBox:
-      return FIELDTYPE_COMBOBOX;
+      return FormFieldType::kComboBox;
     case ListBox:
-      return FIELDTYPE_LISTBOX;
+      return FormFieldType::kListBox;
     case Text:
     case RichText:
     case File:
-      return FIELDTYPE_TEXTFIELD;
+      return FormFieldType::kTextField;
     case Sign:
-      return FIELDTYPE_SIGNATURE;
+      return FormFieldType::kSignature;
     default:
-      break;
+      return FormFieldType::kUnknown;
   }
-  return FIELDTYPE_UNKNOWN;
 }
 
 CPDF_AAction CPDF_FormField::GetAdditionalAction() const {
diff --git a/core/fpdfdoc/cpdf_formfield.h b/core/fpdfdoc/cpdf_formfield.h
index db1c514..1f1205d 100644
--- a/core/fpdfdoc/cpdf_formfield.h
+++ b/core/fpdfdoc/cpdf_formfield.h
@@ -18,14 +18,38 @@
 #include "core/fxcrt/unowned_ptr.h"
 #include "third_party/base/stl_util.h"
 
-#define FIELDTYPE_UNKNOWN 0
-#define FIELDTYPE_PUSHBUTTON 1
-#define FIELDTYPE_CHECKBOX 2
-#define FIELDTYPE_RADIOBUTTON 3
-#define FIELDTYPE_COMBOBOX 4
-#define FIELDTYPE_LISTBOX 5
-#define FIELDTYPE_TEXTFIELD 6
-#define FIELDTYPE_SIGNATURE 7
+enum class FormFieldType : uint8_t {
+  kUnknown = 0,
+  kPushButton = 1,
+  kCheckBox = 2,
+  kRadioButton = 3,
+  kComboBox = 4,
+  kListBox = 5,
+  kTextField = 6,
+  kSignature = 7,
+#ifdef PDF_ENABLE_XFA
+  kXFA = 8,  // Generic XFA field.
+#endif       // PDF_ENABLE_XFA
+};
+
+Optional<FormFieldType> IntToFormFieldType(int value);
+
+// If values are added to FormFieldType, these will need to be updated.
+#ifdef PDF_ENABLE_XFA
+constexpr size_t kFormFieldTypeCount = 9;
+#else
+constexpr size_t kFormFieldTypeCount = 8;
+#endif  // PDF_ENABLE_XFA
+
+constexpr FormFieldType kFormFieldTypes[kFormFieldTypeCount] = {
+    FormFieldType::kUnknown,   FormFieldType::kPushButton,
+    FormFieldType::kCheckBox,  FormFieldType::kRadioButton,
+    FormFieldType::kComboBox,  FormFieldType::kListBox,
+    FormFieldType::kTextField, FormFieldType::kSignature,
+#ifdef PDF_ENABLE_XFA
+    FormFieldType::kXFA,
+#endif  // PDF_ENABLE_XFA
+};
 
 #define FORMFLAG_READONLY 0x01
 #define FORMFLAG_REQUIRED 0x02
@@ -79,7 +103,7 @@
   }
 
   int GetControlIndex(const CPDF_FormControl* pControl) const;
-  int GetFieldType() const;
+  FormFieldType GetFieldType() const;
 
   CPDF_AAction GetAdditionalAction() const;
   WideString GetAlternateName() const;
diff --git a/core/fpdfdoc/cpdf_interform.cpp b/core/fpdfdoc/cpdf_interform.cpp
index 281d4d3..1596b17 100644
--- a/core/fpdfdoc/cpdf_interform.cpp
+++ b/core/fpdfdoc/cpdf_interform.cpp
@@ -1206,12 +1206,13 @@
     return;
 
   WideString csWValue = GetFieldValue(*pFieldDict, m_bsEncoding);
-  int iType = pField->GetFieldType();
+  FormFieldType fieldType = pField->GetFieldType();
   if (bNotify && m_pFormNotify) {
-    if (iType == FIELDTYPE_LISTBOX) {
+    if (fieldType == FormFieldType::kListBox) {
       if (m_pFormNotify->BeforeSelectionChange(pField, csWValue) < 0)
         return;
-    } else if (iType == FIELDTYPE_COMBOBOX || iType == FIELDTYPE_TEXTFIELD) {
+    } else if (fieldType == FormFieldType::kComboBox ||
+               fieldType == FormFieldType::kTextField) {
       if (m_pFormNotify->BeforeValueChange(pField, csWValue) < 0)
         return;
     }
@@ -1224,12 +1225,15 @@
   }
 
   if (bNotify && m_pFormNotify) {
-    if (iType == FIELDTYPE_CHECKBOX || iType == FIELDTYPE_RADIOBUTTON)
+    if (fieldType == FormFieldType::kCheckBox ||
+        fieldType == FormFieldType::kRadioButton) {
       m_pFormNotify->AfterCheckedStatusChange(pField);
-    else if (iType == FIELDTYPE_LISTBOX)
+    } else if (fieldType == FormFieldType::kListBox) {
       m_pFormNotify->AfterSelectionChange(pField);
-    else if (iType == FIELDTYPE_COMBOBOX || iType == FIELDTYPE_TEXTFIELD)
+    } else if (fieldType == FormFieldType::kComboBox ||
+               fieldType == FormFieldType::kTextField) {
       m_pFormNotify->AfterValueChange(pField);
+    }
   }
 }
 
diff --git a/fpdfsdk/cpdfsdk_formfillenvironment.cpp b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
index b72a10b..955c184 100644
--- a/fpdfsdk/cpdfsdk_formfillenvironment.cpp
+++ b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
@@ -718,8 +718,9 @@
 
   if (pFocusAnnot->GetAnnotSubtype() == CPDF_Annot::Subtype::WIDGET) {
     CPDFSDK_Widget* pWidget = static_cast<CPDFSDK_Widget*>(pFocusAnnot.Get());
-    int nFieldType = pWidget->GetFieldType();
-    if (FIELDTYPE_TEXTFIELD == nFieldType || FIELDTYPE_COMBOBOX == nFieldType) {
+    FormFieldType fieldType = pWidget->GetFieldType();
+    if (fieldType == FormFieldType::kTextField ||
+        fieldType == FormFieldType::kComboBox) {
       OnSetFieldInputFocus(nullptr, 0, false);
     }
   }
diff --git a/fpdfsdk/cpdfsdk_interform.cpp b/fpdfsdk/cpdfsdk_interform.cpp
index 4f0012d..04ccc35 100644
--- a/fpdfsdk/cpdfsdk_interform.cpp
+++ b/fpdfsdk/cpdfsdk_interform.cpp
@@ -45,6 +45,20 @@
 #include "xfa/fxfa/cxfa_ffwidgethandler.h"
 #endif  // PDF_ENABLE_XFA
 
+namespace {
+
+bool IsFormFieldTypeComboOrText(FormFieldType fieldType) {
+  switch (fieldType) {
+    case FormFieldType::kComboBox:
+    case FormFieldType::kTextField:
+      return true;
+    default:
+      return false;
+  }
+}
+
+}  // namespace
+
 CPDFSDK_InterForm::CPDFSDK_InterForm(CPDFSDK_FormFillEnvironment* pFormFillEnv)
     : m_pFormFillEnv(pFormFillEnv),
       m_pInterForm(
@@ -55,10 +69,9 @@
 #endif  // PDF_ENABLE_XFA
       m_bCalculate(true),
       m_bBusy(false),
-      m_iHighlightAlpha(0) {
+      m_HighlightAlpha(0) {
   m_pInterForm->SetFormNotify(this);
-  for (int i = 0; i < kNumFieldTypes; ++i)
-    m_bNeedHightlight[i] = false;
+  RemoveAllHighLights();
 }
 
 CPDFSDK_InterForm::~CPDFSDK_InterForm() {
@@ -238,8 +251,8 @@
     if (!pField)
       continue;
 
-    int nType = pField->GetFieldType();
-    if (nType != FIELDTYPE_COMBOBOX && nType != FIELDTYPE_TEXTFIELD)
+    FormFieldType fieldType = pField->GetFieldType();
+    if (!IsFormFieldTypeComboOrText(fieldType))
       continue;
 
     CPDF_AAction aAction = pField->GetAdditionalAction();
@@ -278,7 +291,7 @@
   }
 
   IJS_Runtime* pRuntime = m_pFormFillEnv->GetJSRuntime();
-  if (pFormField->GetFieldType() == FIELDTYPE_COMBOBOX &&
+  if (pFormField->GetFieldType() == FormFieldType::kComboBox &&
       pFormField->CountSelectedItems() > 0) {
     int index = pFormField->GetSelectedIndex(0);
     if (index >= 0)
@@ -598,8 +611,8 @@
 
 int CPDFSDK_InterForm::BeforeValueChange(CPDF_FormField* pField,
                                          const WideString& csValue) {
-  int nType = pField->GetFieldType();
-  if (nType != FIELDTYPE_COMBOBOX && nType != FIELDTYPE_TEXTFIELD)
+  FormFieldType fieldType = pField->GetFieldType();
+  if (!IsFormFieldTypeComboOrText(fieldType))
     return 0;
 
   if (!OnKeyStrokeCommit(pField, csValue))
@@ -615,8 +628,8 @@
 #ifdef PDF_ENABLE_XFA
   SynchronizeField(pField, false);
 #endif  // PDF_ENABLE_XFA
-  int nType = pField->GetFieldType();
-  if (nType == FIELDTYPE_COMBOBOX || nType == FIELDTYPE_TEXTFIELD) {
+  FormFieldType fieldType = pField->GetFieldType();
+  if (IsFormFieldTypeComboOrText(fieldType)) {
     OnCalculate(pField);
     bool bFormatted = false;
     WideString sValue = OnFormat(pField, bFormatted);
@@ -627,7 +640,7 @@
 
 int CPDFSDK_InterForm::BeforeSelectionChange(CPDF_FormField* pField,
                                              const WideString& csValue) {
-  if (pField->GetFieldType() != FIELDTYPE_LISTBOX)
+  if (pField->GetFieldType() != FormFieldType::kListBox)
     return 0;
 
   if (!OnKeyStrokeCommit(pField, csValue))
@@ -640,7 +653,7 @@
 }
 
 void CPDFSDK_InterForm::AfterSelectionChange(CPDF_FormField* pField) {
-  if (pField->GetFieldType() != FIELDTYPE_LISTBOX)
+  if (pField->GetFieldType() != FormFieldType::kListBox)
     return;
 
   OnCalculate(pField);
@@ -649,8 +662,9 @@
 }
 
 void CPDFSDK_InterForm::AfterCheckedStatusChange(CPDF_FormField* pField) {
-  int nType = pField->GetFieldType();
-  if (nType != FIELDTYPE_CHECKBOX && nType != FIELDTYPE_RADIOBUTTON)
+  FormFieldType fieldType = pField->GetFieldType();
+  if (fieldType != FormFieldType::kCheckBox &&
+      fieldType != FormFieldType::kRadioButton)
     return;
 
   OnCalculate(pField);
@@ -673,40 +687,38 @@
   OnCalculate(nullptr);
 }
 
-bool CPDFSDK_InterForm::IsNeedHighLight(int nFieldType) {
-  if (nFieldType < 1 || nFieldType > kNumFieldTypes)
+bool CPDFSDK_InterForm::IsNeedHighLight(FormFieldType fieldType) {
+  if (fieldType == FormFieldType::kUnknown)
     return false;
-  return m_bNeedHightlight[nFieldType - 1];
+
+  return m_NeedsHighlight[static_cast<size_t>(fieldType)];
 }
 
-void CPDFSDK_InterForm::RemoveAllHighLight() {
-  for (int i = 0; i < kNumFieldTypes; ++i)
-    m_bNeedHightlight[i] = false;
+void CPDFSDK_InterForm::RemoveAllHighLights() {
+  std::fill(m_HighlightColor, m_HighlightColor + kFormFieldTypeCount,
+            FXSYS_RGB(255, 255, 255));
+  std::fill(m_NeedsHighlight, m_NeedsHighlight + kFormFieldTypeCount, false);
 }
 
-void CPDFSDK_InterForm::SetHighlightColor(FX_COLORREF clr, int nFieldType) {
-  if (nFieldType < 0 || nFieldType > kNumFieldTypes)
+void CPDFSDK_InterForm::SetHighlightColor(FX_COLORREF clr,
+                                          FormFieldType fieldType) {
+  if (fieldType == FormFieldType::kUnknown)
     return;
-  switch (nFieldType) {
-    case 0: {
-      for (int i = 0; i < kNumFieldTypes; ++i) {
-        m_aHighlightColor[i] = clr;
-        m_bNeedHightlight[i] = true;
-      }
-      break;
-    }
-    default: {
-      m_aHighlightColor[nFieldType - 1] = clr;
-      m_bNeedHightlight[nFieldType - 1] = true;
-      break;
-    }
+
+  m_HighlightColor[static_cast<size_t>(fieldType)] = clr;
+  m_NeedsHighlight[static_cast<size_t>(fieldType)] = true;
+}
+
+void CPDFSDK_InterForm::SetAllHighlightColors(FX_COLORREF clr) {
+  for (auto type : kFormFieldTypes) {
+    m_HighlightColor[static_cast<size_t>(type)] = clr;
+    m_NeedsHighlight[static_cast<size_t>(type)] = true;
   }
 }
 
-FX_COLORREF CPDFSDK_InterForm::GetHighlightColor(int nFieldType) {
-  if (nFieldType < 0 || nFieldType > kNumFieldTypes)
+FX_COLORREF CPDFSDK_InterForm::GetHighlightColor(FormFieldType fieldType) {
+  if (fieldType == FormFieldType::kUnknown)
     return FXSYS_RGB(255, 255, 255);
-  if (nFieldType == 0)
-    return m_aHighlightColor[0];
-  return m_aHighlightColor[nFieldType - 1];
+
+  return m_HighlightColor[static_cast<size_t>(fieldType)];
 }
diff --git a/fpdfsdk/cpdfsdk_interform.h b/fpdfsdk/cpdfsdk_interform.h
index dc9ac64b..ee960ff 100644
--- a/fpdfsdk/cpdfsdk_interform.h
+++ b/fpdfsdk/cpdfsdk_interform.h
@@ -93,12 +93,13 @@
       const std::vector<CPDF_FormField*>& fields,
       bool bIncludeOrExclude);
 
-  bool IsNeedHighLight(int nFieldType);
-  void RemoveAllHighLight();
-  void SetHighlightAlpha(uint8_t alpha) { m_iHighlightAlpha = alpha; }
-  uint8_t GetHighlightAlpha() { return m_iHighlightAlpha; }
-  void SetHighlightColor(FX_COLORREF clr, int nFieldType);
-  FX_COLORREF GetHighlightColor(int nFieldType);
+  bool IsNeedHighLight(FormFieldType fieldType);
+  void RemoveAllHighLights();
+  void SetHighlightAlpha(uint8_t alpha) { m_HighlightAlpha = alpha; }
+  uint8_t GetHighlightAlpha() { return m_HighlightAlpha; }
+  void SetHighlightColor(FX_COLORREF clr, FormFieldType fieldType);
+  void SetAllHighlightColors(FX_COLORREF clr);
+  FX_COLORREF GetHighlightColor(FormFieldType fieldType);
 
  private:
   // IPDF_FormNotify:
@@ -127,16 +128,13 @@
   std::map<CXFA_FFWidget*, CPDFSDK_XFAWidget*> m_XFAMap;
   bool m_bXfaCalculate;
   bool m_bXfaValidationsEnabled;
-  static const int kNumFieldTypes = 7;
-#else   // PDF_ENABLE_XFA
-  static const int kNumFieldTypes = 6;
 #endif  // PDF_ENABLE_XFA
   bool m_bCalculate;
   bool m_bBusy;
 
-  FX_COLORREF m_aHighlightColor[kNumFieldTypes];
-  uint8_t m_iHighlightAlpha;
-  bool m_bNeedHightlight[kNumFieldTypes];
+  uint8_t m_HighlightAlpha;
+  FX_COLORREF m_HighlightColor[kFormFieldTypeCount];
+  bool m_NeedsHighlight[kFormFieldTypeCount];
 };
 
 #endif  // FPDFSDK_CPDFSDK_INTERFORM_H_
diff --git a/fpdfsdk/cpdfsdk_widget.cpp b/fpdfsdk/cpdfsdk_widget.cpp
index eb42ba6..2adc46f 100644
--- a/fpdfsdk/cpdfsdk_widget.cpp
+++ b/fpdfsdk/cpdfsdk_widget.cpp
@@ -77,7 +77,7 @@
     if (!m_hMixXFAWidget) {
       if (CXFA_FFDocView* pDocView = pContext->GetXFADocView()) {
         WideString sName;
-        if (GetFieldType() == FIELDTYPE_RADIOBUTTON) {
+        if (GetFieldType() == FormFieldType::kRadioButton) {
           sName = GetAnnotName();
           if (sName.IsEmpty())
             sName = GetName();
@@ -206,7 +206,7 @@
   XFA_EVENTTYPE eEventType = GetXFAEventType(eXFAAAT);
 
   if ((eEventType == XFA_EVENT_Click || eEventType == XFA_EVENT_Change) &&
-      GetFieldType() == FIELDTYPE_RADIOBUTTON) {
+      GetFieldType() == FormFieldType::kRadioButton) {
     if (CXFA_FFWidget* hGroupWidget = GetGroupMixXFAWidget()) {
       if (pXFAWidgetHandler->HasEvent(hGroupWidget->GetNode()->GetWidgetAcc(),
                                       eEventType)) {
@@ -255,7 +255,7 @@
 
   param.m_wsPrevText = data.sValue;
   if ((eEventType == XFA_EVENT_Click || eEventType == XFA_EVENT_Change) &&
-      GetFieldType() == FIELDTYPE_RADIOBUTTON) {
+      GetFieldType() == FormFieldType::kRadioButton) {
     if (CXFA_FFWidget* hGroupWidget = GetGroupMixXFAWidget()) {
       CXFA_WidgetAcc* pAcc = hGroupWidget->GetNode()->GetWidgetAcc();
       param.m_pTarget = pAcc;
@@ -286,18 +286,18 @@
 
   CPDF_FormField* pFormField = GetFormField();
   switch (GetFieldType()) {
-    case FIELDTYPE_CHECKBOX:
-    case FIELDTYPE_RADIOBUTTON: {
+    case FormFieldType::kCheckBox:
+    case FormFieldType::kRadioButton: {
       CPDF_FormControl* pFormCtrl = GetFormControl();
       XFA_CHECKSTATE eCheckState =
           pFormCtrl->IsChecked() ? XFA_CHECKSTATE_On : XFA_CHECKSTATE_Off;
       pWidgetAcc->SetCheckState(eCheckState, true);
       break;
     }
-    case FIELDTYPE_TEXTFIELD:
+    case FormFieldType::kTextField:
       pWidgetAcc->SetValue(XFA_VALUEPICTURE_Edit, pFormField->GetValue());
       break;
-    case FIELDTYPE_LISTBOX: {
+    case FormFieldType::kListBox: {
       pWidgetAcc->ClearAllSelections();
 
       for (int i = 0, sz = pFormField->CountSelectedItems(); i < sz; i++) {
@@ -307,7 +307,7 @@
       }
       break;
     }
-    case FIELDTYPE_COMBOBOX: {
+    case FormFieldType::kComboBox: {
       pWidgetAcc->ClearAllSelections();
 
       for (int i = 0, sz = pFormField->CountSelectedItems(); i < sz; i++) {
@@ -318,6 +318,8 @@
       pWidgetAcc->SetValue(XFA_VALUEPICTURE_Edit, pFormField->GetValue());
       break;
     }
+    default:
+      break;
   }
 
   if (bSynchronizeElse) {
@@ -360,7 +362,7 @@
   ASSERT(pFormControl);
 
   switch (pFormField->GetFieldType()) {
-    case FIELDTYPE_CHECKBOX: {
+    case FormFieldType::kCheckBox: {
       if (CXFA_WidgetAcc* pWidgetAcc = hWidget->GetNode()->GetWidgetAcc()) {
         pFormField->CheckControl(
             pFormField->GetControlIndex(pFormControl),
@@ -368,7 +370,7 @@
       }
       break;
     }
-    case FIELDTYPE_RADIOBUTTON: {
+    case FormFieldType::kRadioButton: {
       // TODO(weili): Check whether we need to handle checkbox and radio
       // button differently, otherwise, merge these two cases.
       if (CXFA_WidgetAcc* pWidgetAcc = hWidget->GetNode()->GetWidgetAcc()) {
@@ -378,14 +380,14 @@
       }
       break;
     }
-    case FIELDTYPE_TEXTFIELD: {
+    case FormFieldType::kTextField: {
       if (CXFA_WidgetAcc* pWidgetAcc = hWidget->GetNode()->GetWidgetAcc()) {
         pFormField->SetValue(pWidgetAcc->GetValue(XFA_VALUEPICTURE_Display),
                              true);
       }
       break;
     }
-    case FIELDTYPE_LISTBOX: {
+    case FormFieldType::kListBox: {
       pFormField->ClearSelection(false);
 
       if (CXFA_WidgetAcc* pWidgetAcc = hWidget->GetNode()->GetWidgetAcc()) {
@@ -399,7 +401,7 @@
       }
       break;
     }
-    case FIELDTYPE_COMBOBOX: {
+    case FormFieldType::kComboBox: {
       pFormField->ClearSelection(false);
 
       if (CXFA_WidgetAcc* pWidgetAcc = hWidget->GetNode()->GetWidgetAcc()) {
@@ -415,6 +417,8 @@
       }
       break;
     }
+    default:
+      break;
   }
 }
 
@@ -425,7 +429,7 @@
   ASSERT(hWidget);
 
   switch (pFormField->GetFieldType()) {
-    case FIELDTYPE_LISTBOX: {
+    case FormFieldType::kListBox: {
       pFormField->ClearSelection(false);
       pFormField->ClearOptions(true);
 
@@ -438,7 +442,7 @@
       }
       break;
     }
-    case FIELDTYPE_COMBOBOX: {
+    case FormFieldType::kComboBox: {
       pFormField->ClearSelection(false);
       pFormField->ClearOptions(false);
 
@@ -453,6 +457,8 @@
       pFormField->SetValue(L"", true);
       break;
     }
+    default:
+      break;
   }
 }
 #endif  // PDF_ENABLE_XFA
@@ -476,27 +482,28 @@
   if (!psub)
     return false;
 
-  int nFieldType = GetFieldType();
-  switch (nFieldType) {
-    case FIELDTYPE_PUSHBUTTON:
-    case FIELDTYPE_COMBOBOX:
-    case FIELDTYPE_LISTBOX:
-    case FIELDTYPE_TEXTFIELD:
-    case FIELDTYPE_SIGNATURE:
+  FormFieldType fieldType = GetFieldType();
+  switch (fieldType) {
+    case FormFieldType::kPushButton:
+    case FormFieldType::kComboBox:
+    case FormFieldType::kListBox:
+    case FormFieldType::kTextField:
+    case FormFieldType::kSignature:
       return psub->IsStream();
-    case FIELDTYPE_CHECKBOX:
-    case FIELDTYPE_RADIOBUTTON:
+    case FormFieldType::kCheckBox:
+    case FormFieldType::kRadioButton:
       if (CPDF_Dictionary* pSubDict = psub->AsDictionary()) {
         return !!pSubDict->GetStreamFor(GetAppState());
       }
       return false;
+    default:
+      return true;
   }
-  return true;
 }
 
-int CPDFSDK_Widget::GetFieldType() const {
+FormFieldType CPDFSDK_Widget::GetFieldType() const {
   CPDF_FormField* pField = GetFormField();
-  return pField ? pField->GetFieldType() : FIELDTYPE_UNKNOWN;
+  return pField ? pField->GetFieldType() : FormFieldType::kUnknown;
 }
 
 bool CPDFSDK_Widget::IsAppearanceValid() {
@@ -522,7 +529,7 @@
 }
 
 bool CPDFSDK_Widget::IsSignatureWidget() const {
-  return GetFieldType() == FIELDTYPE_SIGNATURE;
+  return GetFieldType() == FormFieldType::kSignature;
 }
 
 CPDF_FormField* CPDFSDK_Widget::GetFormField() const {
@@ -733,8 +740,8 @@
 #ifdef PDF_ENABLE_XFA
 void CPDFSDK_Widget::ResetAppearance(bool bValueChanged) {
   switch (GetFieldType()) {
-    case FIELDTYPE_TEXTFIELD:
-    case FIELDTYPE_COMBOBOX: {
+    case FormFieldType::kTextField:
+    case FormFieldType::kComboBox: {
       bool bFormatted = false;
       WideString sValue = OnFormat(bFormatted);
       ResetAppearance(bFormatted ? &sValue : nullptr, true);
@@ -757,24 +764,26 @@
 
   CPWL_AppStream appStream(this, GetAPDict());
   switch (GetFieldType()) {
-    case FIELDTYPE_PUSHBUTTON:
+    case FormFieldType::kPushButton:
       appStream.SetAsPushButton();
       break;
-    case FIELDTYPE_CHECKBOX:
+    case FormFieldType::kCheckBox:
       appStream.SetAsCheckBox();
       break;
-    case FIELDTYPE_RADIOBUTTON:
+    case FormFieldType::kRadioButton:
       appStream.SetAsRadioButton();
       break;
-    case FIELDTYPE_COMBOBOX:
+    case FormFieldType::kComboBox:
       appStream.SetAsComboBox(sValue);
       break;
-    case FIELDTYPE_LISTBOX:
+    case FormFieldType::kListBox:
       appStream.SetAsListBox();
       break;
-    case FIELDTYPE_TEXTFIELD:
+    case FormFieldType::kTextField:
       appStream.SetAsTextField(sValue);
       break;
+    default:
+      break;
   }
 
   m_pAnnot->ClearCachedAP();
@@ -796,10 +805,10 @@
                                     const CFX_Matrix& mtUser2Device,
                                     CPDF_Annot::AppearanceMode mode,
                                     const CPDF_RenderOptions* pOptions) {
-  int nFieldType = GetFieldType();
+  FormFieldType fieldType = GetFieldType();
 
-  if ((nFieldType == FIELDTYPE_CHECKBOX ||
-       nFieldType == FIELDTYPE_RADIOBUTTON) &&
+  if ((fieldType == FormFieldType::kCheckBox ||
+       fieldType == FormFieldType::kRadioButton) &&
       mode == CPDF_Annot::Normal &&
       !IsWidgetAppearanceValid(CPDF_Annot::Normal)) {
     CFX_PathData pathData;
@@ -827,8 +836,8 @@
 
 void CPDFSDK_Widget::DrawShadow(CFX_RenderDevice* pDevice,
                                 CPDFSDK_PageView* pPageView) {
-  int nFieldType = GetFieldType();
-  if (!m_pInterForm->IsNeedHighLight(nFieldType))
+  FormFieldType fieldType = GetFieldType();
+  if (!m_pInterForm->IsNeedHighLight(fieldType))
     return;
 
   CFX_Matrix page2device;
@@ -848,7 +857,7 @@
   FX_RECT rcDev = rcDevice.ToFxRect();
   pDevice->FillRect(
       &rcDev, ArgbEncode(static_cast<int>(m_pInterForm->GetHighlightAlpha()),
-                         m_pInterForm->GetHighlightColor(nFieldType)));
+                         m_pInterForm->GetHighlightColor(fieldType)));
 }
 
 CFX_FloatRect CPDFSDK_Widget::GetClientRect() const {
diff --git a/fpdfsdk/cpdfsdk_widget.h b/fpdfsdk/cpdfsdk_widget.h
index f57e08d..4b11150 100644
--- a/fpdfsdk/cpdfsdk_widget.h
+++ b/fpdfsdk/cpdfsdk_widget.h
@@ -71,7 +71,7 @@
 
   int GetLayoutOrder() const override;
 
-  int GetFieldType() const;
+  FormFieldType GetFieldType() const;
   int GetFieldFlags() const;
   int GetRotate() const;
 
diff --git a/fpdfsdk/cpdfsdk_widgethandler.cpp b/fpdfsdk/cpdfsdk_widgethandler.cpp
index 3eb8e5d..dcce7b6 100644
--- a/fpdfsdk/cpdfsdk_widgethandler.cpp
+++ b/fpdfsdk/cpdfsdk_widgethandler.cpp
@@ -43,7 +43,7 @@
   if ((nFieldFlags & FIELDFLAG_READONLY) == FIELDFLAG_READONLY)
     return false;
 
-  if (pWidget->GetFieldType() == FIELDTYPE_PUSHBUTTON)
+  if (pWidget->GetFieldType() == FormFieldType::kPushButton)
     return true;
 
   CPDF_Page* pPage = pWidget->GetPDFPage();
@@ -227,15 +227,16 @@
   if (!pWidget->IsAppearanceValid())
     pWidget->ResetAppearance(nullptr, false);
 
-  int nFieldType = pWidget->GetFieldType();
-  if (nFieldType == FIELDTYPE_TEXTFIELD || nFieldType == FIELDTYPE_COMBOBOX) {
+  FormFieldType fieldType = pWidget->GetFieldType();
+  if (fieldType == FormFieldType::kTextField ||
+      fieldType == FormFieldType::kComboBox) {
     bool bFormatted = false;
     CPDFSDK_Annot::ObservedPtr pObserved(pWidget);
     WideString sValue = pWidget->OnFormat(bFormatted);
     if (!pObserved)
       return;
 
-    if (bFormatted && nFieldType == FIELDTYPE_COMBOBOX)
+    if (bFormatted && fieldType == FormFieldType::kComboBox)
       pWidget->ResetAppearance(&sValue, false);
   }
 
diff --git a/fpdfsdk/formfiller/cffl_formfiller.cpp b/fpdfsdk/formfiller/cffl_formfiller.cpp
index f86cb68..d3aa37e 100644
--- a/fpdfsdk/formfiller/cffl_formfiller.cpp
+++ b/fpdfsdk/formfiller/cffl_formfiller.cpp
@@ -268,9 +268,9 @@
 
   bool bDestroyPDFWindow;
   switch (m_pWidget->GetFieldType()) {
-    case FIELDTYPE_PUSHBUTTON:
-    case FIELDTYPE_CHECKBOX:
-    case FIELDTYPE_RADIOBUTTON:
+    case FormFieldType::kPushButton:
+    case FormFieldType::kCheckBox:
+    case FormFieldType::kRadioButton:
       bDestroyPDFWindow = true;
       break;
     default:
diff --git a/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp b/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp
index 703fc47..e74f902 100644
--- a/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp
+++ b/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp
@@ -228,9 +228,9 @@
 
   bool bSetFocus;
   switch (pWidget->GetFieldType()) {
-    case FIELDTYPE_PUSHBUTTON:
-    case FIELDTYPE_CHECKBOX:
-    case FIELDTYPE_RADIOBUTTON: {
+    case FormFieldType::kPushButton:
+    case FormFieldType::kCheckBox:
+    case FormFieldType::kRadioButton: {
       FX_RECT bbox = GetViewBBox(pPageView, pAnnot->Get());
       bSetFocus =
           bbox.Contains(static_cast<int>(point.x), static_cast<int>(point.y));
@@ -455,7 +455,7 @@
 }
 
 bool CFFL_InteractiveFormFiller::IsFillingAllowed(CPDFSDK_Widget* pWidget) {
-  if (pWidget->GetFieldType() == FIELDTYPE_PUSHBUTTON)
+  if (pWidget->GetFieldType() == FormFieldType::kPushButton)
     return false;
 
   CPDF_Page* pPage = pWidget->GetPDFPage();
@@ -477,28 +477,28 @@
 
   // TODO(thestig): How do we know |pAnnot| is a CPDFSDK_Widget?
   CPDFSDK_Widget* pWidget = static_cast<CPDFSDK_Widget*>(pAnnot);
-  int nFieldType = pWidget->GetFieldType();
+  FormFieldType fieldType = pWidget->GetFieldType();
   CFFL_FormFiller* pFormFiller;
-  switch (nFieldType) {
-    case FIELDTYPE_PUSHBUTTON:
+  switch (fieldType) {
+    case FormFieldType::kPushButton:
       pFormFiller = new CFFL_PushButton(m_pFormFillEnv.Get(), pWidget);
       break;
-    case FIELDTYPE_CHECKBOX:
+    case FormFieldType::kCheckBox:
       pFormFiller = new CFFL_CheckBox(m_pFormFillEnv.Get(), pWidget);
       break;
-    case FIELDTYPE_RADIOBUTTON:
+    case FormFieldType::kRadioButton:
       pFormFiller = new CFFL_RadioButton(m_pFormFillEnv.Get(), pWidget);
       break;
-    case FIELDTYPE_TEXTFIELD:
+    case FormFieldType::kTextField:
       pFormFiller = new CFFL_TextField(m_pFormFillEnv.Get(), pWidget);
       break;
-    case FIELDTYPE_LISTBOX:
+    case FormFieldType::kListBox:
       pFormFiller = new CFFL_ListBox(m_pFormFillEnv.Get(), pWidget);
       break;
-    case FIELDTYPE_COMBOBOX:
+    case FormFieldType::kComboBox:
       pFormFiller = new CFFL_ComboBox(m_pFormFillEnv.Get(), pWidget);
       break;
-    case FIELDTYPE_UNKNOWN:
+    case FormFieldType::kUnknown:
     default:
       pFormFiller = nullptr;
       break;
diff --git a/fpdfsdk/fpdfformfill.cpp b/fpdfsdk/fpdfformfill.cpp
index 3d61336..cc2861f 100644
--- a/fpdfsdk/fpdfformfill.cpp
+++ b/fpdfsdk/fpdfformfill.cpp
@@ -44,6 +44,37 @@
               "XFA foreground form types must match");
 #endif  // PDF_ENABLE_XFA
 
+static_assert(static_cast<int>(FormFieldType::kUnknown) ==
+                  FPDF_FORMFIELD_UNKNOWN,
+              "Unknown form field types must match");
+static_assert(static_cast<int>(FormFieldType::kPushButton) ==
+                  FPDF_FORMFIELD_PUSHBUTTON,
+              "PushButton form field types must match");
+static_assert(static_cast<int>(FormFieldType::kCheckBox) ==
+                  FPDF_FORMFIELD_CHECKBOX,
+              "CheckBox form field types must match");
+static_assert(static_cast<int>(FormFieldType::kRadioButton) ==
+                  FPDF_FORMFIELD_RADIOBUTTON,
+              "RadioButton form field types must match");
+static_assert(static_cast<int>(FormFieldType::kComboBox) ==
+                  FPDF_FORMFIELD_COMBOBOX,
+              "ComboBox form field types must match");
+static_assert(static_cast<int>(FormFieldType::kListBox) ==
+                  FPDF_FORMFIELD_LISTBOX,
+              "ListBox form field types must match");
+static_assert(static_cast<int>(FormFieldType::kTextField) ==
+                  FPDF_FORMFIELD_TEXTFIELD,
+              "TextField form field types must match");
+static_assert(static_cast<int>(FormFieldType::kSignature) ==
+                  FPDF_FORMFIELD_SIGNATURE,
+              "Signature form field types must match");
+#ifdef PDF_ENABLE_XFA
+static_assert(static_cast<int>(FormFieldType::kXFA) == FPDF_FORMFIELD_XFA,
+              "XFA form field types must match");
+#endif  // PDF_ENABLE_XFA
+static_assert(kFormFieldTypeCount == FPDF_FORMFIELD_COUNT,
+              "Number of form field types must match");
+
 namespace {
 
 CPDFSDK_FormFillEnvironment* HandleToCPDFSDKEnvironment(
@@ -173,7 +204,7 @@
     if (!pFormCtrl)
       return -1;
     CPDF_FormField* pFormField = pFormCtrl->GetField();
-    return pFormField ? pFormField->GetFieldType() : -1;
+    return pFormField ? static_cast<int>(pFormField->GetFieldType()) : -1;
   }
 
 #ifdef PDF_ENABLE_XFA
@@ -199,17 +230,16 @@
   if (!pWidgetIterator)
     return -1;
 
-  CXFA_FFWidget* pXFAAnnot = pWidgetIterator->MoveToNext();
-  while (pXFAAnnot) {
+  CXFA_FFWidget* pXFAAnnot;
+  while ((pXFAAnnot = pWidgetIterator->MoveToNext()) != nullptr) {
     CFX_RectF rcBBox = pXFAAnnot->GetBBox(0);
     CFX_FloatRect rcWidget(rcBBox.left, rcBBox.top, rcBBox.left + rcBBox.width,
                            rcBBox.top + rcBBox.height);
     rcWidget.Inflate(1.0f, 1.0f);
     if (rcWidget.Contains(CFX_PointF(static_cast<float>(page_x),
                                      static_cast<float>(page_y)))) {
-      return FPDF_FORMFIELD_XFA;
+      return static_cast<int>(FormFieldType::kXFA);
     }
-    pXFAAnnot = pWidgetIterator->MoveToNext();
   }
 #endif  // PDF_ENABLE_XFA
   return -1;
@@ -663,8 +693,19 @@
 FPDF_SetFormFieldHighlightColor(FPDF_FORMHANDLE hHandle,
                                 int fieldType,
                                 unsigned long color) {
-  if (CPDFSDK_InterForm* pInterForm = FormHandleToInterForm(hHandle))
-    pInterForm->SetHighlightColor(color, fieldType);
+  CPDFSDK_InterForm* interForm = FormHandleToInterForm(hHandle);
+  if (!interForm)
+    return;
+
+  Optional<FormFieldType> cast_input = IntToFormFieldType(fieldType);
+  if (!cast_input.has_value())
+    return;
+
+  if (cast_input.value() == FormFieldType::kUnknown) {
+    interForm->SetAllHighlightColors(color);
+  } else {
+    interForm->SetHighlightColor(color, cast_input.value());
+  }
 }
 
 FPDF_EXPORT void FPDF_CALLCONV
@@ -676,7 +717,7 @@
 FPDF_EXPORT void FPDF_CALLCONV
 FPDF_RemoveFormFieldHighlight(FPDF_FORMHANDLE hHandle) {
   if (CPDFSDK_InterForm* pInterForm = FormHandleToInterForm(hHandle))
-    pInterForm->RemoveAllHighLight();
+    pInterForm->RemoveAllHighLights();
 }
 
 FPDF_EXPORT void FPDF_CALLCONV FORM_OnAfterLoadPage(FPDF_PAGE page,
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
index 93f5912..4ebe8f9 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
@@ -598,7 +598,7 @@
     return 0;
 
   return ArgbEncode(pInterForm->GetHighlightAlpha(),
-                    pInterForm->GetHighlightColor(FPDF_FORMFIELD_XFA));
+                    pInterForm->GetHighlightColor(FormFieldType::kXFA));
 }
 
 bool CPDFXFA_DocEnvironment::NotifySubmit(bool bPrevOrPost) {
diff --git a/fxjs/cjs_field.cpp b/fxjs/cjs_field.cpp
index f2e27f2..0f06be0 100644
--- a/fxjs/cjs_field.cpp
+++ b/fxjs/cjs_field.cpp
@@ -268,8 +268,9 @@
     std::vector<CPDFSDK_Annot::ObservedPtr> widgets;
     pInterForm->GetWidgets(pFormField, &widgets);
 
-    int nFieldType = pFormField->GetFieldType();
-    if (nFieldType == FIELDTYPE_COMBOBOX || nFieldType == FIELDTYPE_TEXTFIELD) {
+    FormFieldType fieldType = pFormField->GetFieldType();
+    if (fieldType == FormFieldType::kComboBox ||
+        fieldType == FormFieldType::kTextField) {
       for (auto& pObserved : widgets) {
         if (pObserved) {
           bool bFormatted = false;
@@ -327,9 +328,9 @@
   if (pWidget) {
     CPDFSDK_Widget::ObservedPtr observed_widget(pWidget);
     if (bResetAP) {
-      int nFieldType = pWidget->GetFieldType();
-      if (nFieldType == FIELDTYPE_COMBOBOX ||
-          nFieldType == FIELDTYPE_TEXTFIELD) {
+      FormFieldType fieldType = pWidget->GetFieldType();
+      if (fieldType == FormFieldType::kComboBox ||
+          fieldType == FormFieldType::kTextField) {
         bool bFormatted = false;
         WideString sValue = pWidget->OnFormat(bFormatted);
         if (!observed_widget)
@@ -385,7 +386,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -517,7 +518,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -547,7 +548,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -577,7 +578,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -602,7 +603,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -626,7 +627,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -651,7 +652,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -691,8 +692,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_COMBOBOX &&
-      pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD) {
+  if (pFormField->GetFieldType() != FormFieldType::kComboBox &&
+      pFormField->GetFieldType() != FormFieldType::kTextField) {
     return CJS_Return(false);
   }
 
@@ -716,7 +717,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
   return CJS_Return(
       pRuntime->NewNumber(static_cast<int32_t>(pFormField->GetMaxLen())));
@@ -736,7 +737,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
 
   return CJS_Return(
@@ -756,8 +757,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_COMBOBOX &&
-      pFormField->GetFieldType() != FIELDTYPE_LISTBOX) {
+  if (pFormField->GetFieldType() != FormFieldType::kComboBox &&
+      pFormField->GetFieldType() != FormFieldType::kListBox) {
     return CJS_Return(false);
   }
 
@@ -777,8 +778,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_COMBOBOX &&
-      pFormField->GetFieldType() != FIELDTYPE_LISTBOX) {
+  if (pFormField->GetFieldType() != FormFieldType::kComboBox &&
+      pFormField->GetFieldType() != FormFieldType::kListBox) {
     return CJS_Return(false);
   }
 
@@ -832,8 +833,9 @@
       GetFormFields(pFormFillEnv, swFieldName);
 
   for (CPDF_FormField* pFormField : FieldArray) {
-    int nFieldType = pFormField->GetFieldType();
-    if (nFieldType == FIELDTYPE_COMBOBOX || nFieldType == FIELDTYPE_LISTBOX) {
+    FormFieldType fieldType = pFormField->GetFieldType();
+    if (fieldType == FormFieldType::kComboBox ||
+        fieldType == FormFieldType::kListBox) {
       uint32_t dwFieldFlags = pFormField->GetFieldFlags();
       pFormField->ClearSelection(true);
       for (size_t i = 0; i < array.size(); ++i) {
@@ -866,8 +868,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() == FIELDTYPE_PUSHBUTTON ||
-      pFormField->GetFieldType() == FIELDTYPE_SIGNATURE) {
+  if (pFormField->GetFieldType() == FormFieldType::kPushButton ||
+      pFormField->GetFieldType() == FormFieldType::kSignature) {
     return CJS_Return(false);
   }
 
@@ -888,7 +890,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
@@ -909,8 +911,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD &&
-      pFormField->GetFieldType() != FIELDTYPE_COMBOBOX) {
+  if (pFormField->GetFieldType() != FormFieldType::kTextField &&
+      pFormField->GetFieldType() != FormFieldType::kComboBox) {
     return CJS_Return(false);
   }
 
@@ -1034,7 +1036,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_COMBOBOX)
+  if (pFormField->GetFieldType() != FormFieldType::kComboBox)
     return CJS_Return(false);
 
   return CJS_Return(
@@ -1051,8 +1053,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_CHECKBOX &&
-      pFormField->GetFieldType() != FIELDTYPE_RADIOBUTTON) {
+  if (pFormField->GetFieldType() != FormFieldType::kCheckBox &&
+      pFormField->GetFieldType() != FormFieldType::kRadioButton) {
     return CJS_Return(false);
   }
 
@@ -1087,8 +1089,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_CHECKBOX &&
-      pFormField->GetFieldType() != FIELDTYPE_RADIOBUTTON) {
+  if (pFormField->GetFieldType() != FormFieldType::kCheckBox &&
+      pFormField->GetFieldType() != FormFieldType::kRadioButton) {
     return CJS_Return(false);
   }
 
@@ -1101,7 +1103,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
@@ -1115,7 +1117,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
   return CJS_Return(m_bCanSet);
 }
@@ -1221,7 +1223,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -1334,7 +1336,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
@@ -1354,7 +1356,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_LISTBOX)
+  if (pFormField->GetFieldType() != FormFieldType::kListBox)
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
@@ -1385,8 +1387,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_COMBOBOX &&
-      pFormField->GetFieldType() != FIELDTYPE_LISTBOX) {
+  if (pFormField->GetFieldType() != FormFieldType::kComboBox &&
+      pFormField->GetFieldType() != FormFieldType::kListBox) {
     return CJS_Return(false);
   }
 
@@ -1443,7 +1445,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
@@ -1535,7 +1537,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_RADIOBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kRadioButton)
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
@@ -1688,7 +1690,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() == FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() == FormFieldType::kPushButton)
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
@@ -1710,7 +1712,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_TEXTFIELD)
+  if (pFormField->GetFieldType() != FormFieldType::kTextField)
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
@@ -1807,8 +1809,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_RADIOBUTTON &&
-      pFormField->GetFieldType() != FIELDTYPE_CHECKBOX) {
+  if (pFormField->GetFieldType() != FormFieldType::kRadioButton &&
+      pFormField->GetFieldType() != FormFieldType::kCheckBox) {
     return CJS_Return(false);
   }
 
@@ -1912,9 +1914,11 @@
   if (!pFormControl)
     return CJS_Return(false);
 
-  int nFieldType = pFormField->GetFieldType();
-  if (nFieldType != FIELDTYPE_PUSHBUTTON && nFieldType != FIELDTYPE_COMBOBOX &&
-      nFieldType != FIELDTYPE_LISTBOX && nFieldType != FIELDTYPE_TEXTFIELD) {
+  FormFieldType fieldType = pFormField->GetFieldType();
+  if (fieldType != FormFieldType::kPushButton &&
+      fieldType != FormFieldType::kComboBox &&
+      fieldType != FormFieldType::kListBox &&
+      fieldType != FormFieldType::kTextField) {
     return CJS_Return(false);
   }
 
@@ -1968,24 +1972,25 @@
 
   CPDF_FormField* pFormField = FieldArray[0];
   switch (pFormField->GetFieldType()) {
-    case FIELDTYPE_UNKNOWN:
+    case FormFieldType::kUnknown:
       return CJS_Return(pRuntime->NewString(L"unknown"));
-    case FIELDTYPE_PUSHBUTTON:
+    case FormFieldType::kPushButton:
       return CJS_Return(pRuntime->NewString(L"button"));
-    case FIELDTYPE_CHECKBOX:
+    case FormFieldType::kCheckBox:
       return CJS_Return(pRuntime->NewString(L"checkbox"));
-    case FIELDTYPE_RADIOBUTTON:
+    case FormFieldType::kRadioButton:
       return CJS_Return(pRuntime->NewString(L"radiobutton"));
-    case FIELDTYPE_COMBOBOX:
+    case FormFieldType::kComboBox:
       return CJS_Return(pRuntime->NewString(L"combobox"));
-    case FIELDTYPE_LISTBOX:
+    case FormFieldType::kListBox:
       return CJS_Return(pRuntime->NewString(L"listbox"));
-    case FIELDTYPE_TEXTFIELD:
+    case FormFieldType::kTextField:
       return CJS_Return(pRuntime->NewString(L"text"));
-    case FIELDTYPE_SIGNATURE:
+    case FormFieldType::kSignature:
       return CJS_Return(pRuntime->NewString(L"signature"));
+    default:
+      return CJS_Return(pRuntime->NewString(L"unknown"));
   }
-  return CJS_Return(pRuntime->NewString(L"unknown"));
 }
 
 CJS_Return Field::set_type(CJS_Runtime* pRuntime, v8::Local<v8::Value> vp) {
@@ -2018,13 +2023,13 @@
 
   CPDF_FormField* pFormField = FieldArray[0];
   switch (pFormField->GetFieldType()) {
-    case FIELDTYPE_PUSHBUTTON:
+    case FormFieldType::kPushButton:
       return CJS_Return(false);
-    case FIELDTYPE_COMBOBOX:
-    case FIELDTYPE_TEXTFIELD:
+    case FormFieldType::kComboBox:
+    case FormFieldType::kTextField:
       ret = pRuntime->NewString(pFormField->GetValue().c_str());
       break;
-    case FIELDTYPE_LISTBOX: {
+    case FormFieldType::kListBox: {
       if (pFormField->CountSelectedItems() > 1) {
         v8::Local<v8::Array> ValueArray = pRuntime->NewArray();
         v8::Local<v8::Value> ElementValue;
@@ -2045,8 +2050,8 @@
       }
       break;
     }
-    case FIELDTYPE_CHECKBOX:
-    case FIELDTYPE_RADIOBUTTON: {
+    case FormFieldType::kCheckBox:
+    case FormFieldType::kRadioButton: {
       bool bFind = false;
       for (int i = 0, sz = pFormField->CountControls(); i < sz; i++) {
         if (pFormField->GetControl(i)->IsChecked()) {
@@ -2108,21 +2113,21 @@
       continue;
 
     switch (pFormField->GetFieldType()) {
-      case FIELDTYPE_TEXTFIELD:
-      case FIELDTYPE_COMBOBOX:
+      case FormFieldType::kTextField:
+      case FormFieldType::kComboBox:
         if (pFormField->GetValue() != strArray[0]) {
           pFormField->SetValue(strArray[0], true);
           UpdateFormField(pFormFillEnv, pFormField, true, false, true);
         }
         break;
-      case FIELDTYPE_CHECKBOX:
-      case FIELDTYPE_RADIOBUTTON:
+      case FormFieldType::kCheckBox:
+      case FormFieldType::kRadioButton:
         if (pFormField->GetValue() != strArray[0]) {
           pFormField->SetValue(strArray[0], true);
           UpdateFormField(pFormFillEnv, pFormField, true, false, true);
         }
         break;
-      case FIELDTYPE_LISTBOX: {
+      case FormFieldType::kListBox: {
         bool bModified = false;
         for (const auto& str : strArray) {
           if (!pFormField->IsItemSelected(pFormField->FindOption(str))) {
@@ -2153,17 +2158,17 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() == FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() == FormFieldType::kPushButton)
     return CJS_Return(false);
 
-  if (pFormField->GetFieldType() == FIELDTYPE_CHECKBOX) {
+  if (pFormField->GetFieldType() == FormFieldType::kCheckBox) {
     if (!pFormField->CountControls())
       return CJS_Return(false);
     return CJS_Return(pRuntime->NewString(
         pFormField->GetControl(0)->IsChecked() ? L"Yes" : L"Off"));
   }
 
-  if (pFormField->GetFieldType() == FIELDTYPE_RADIOBUTTON &&
+  if (pFormField->GetFieldType() == FormFieldType::kRadioButton &&
       !(pFormField->GetFieldFlags() & FIELDFLAG_RADIOSINUNISON)) {
     for (int i = 0, sz = pFormField->CountControls(); i < sz; i++) {
       if (pFormField->GetControl(i)->IsChecked()) {
@@ -2174,7 +2179,7 @@
     return CJS_Return(pRuntime->NewString(L"Off"));
   }
 
-  if (pFormField->GetFieldType() == FIELDTYPE_LISTBOX &&
+  if (pFormField->GetFieldType() == FormFieldType::kListBox &&
       (pFormField->CountSelectedItems() > 1)) {
     return CJS_Return(pRuntime->NewString(L""));
   }
@@ -2195,7 +2200,7 @@
 
   CPDF_FormField* pFormField = FieldArray[0];
   if ((pFormField->GetFieldFlags() & FIELDFLAG_FILESELECT) &&
-      (pFormField->GetFieldType() == FIELDTYPE_TEXTFIELD)) {
+      (pFormField->GetFieldType() == FormFieldType::kTextField)) {
     WideString wsFileName = m_pFormFillEnv->JS_fieldBrowse();
     if (!wsFileName.IsEmpty()) {
       pFormField->SetValue(wsFileName);
@@ -2219,7 +2224,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -2253,7 +2258,7 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
+  if (pFormField->GetFieldType() != FormFieldType::kPushButton)
     return CJS_Return(false);
 
   CPDF_FormControl* pFormControl = GetSmartFieldControl(pFormField);
@@ -2309,15 +2314,15 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if (pFormField->GetFieldType() != FIELDTYPE_CHECKBOX &&
-      pFormField->GetFieldType() != FIELDTYPE_RADIOBUTTON) {
+  if (pFormField->GetFieldType() != FormFieldType::kCheckBox &&
+      pFormField->GetFieldType() != FormFieldType::kRadioButton) {
     return CJS_Return(false);
   }
   if (nWidget < 0 || nWidget >= pFormField->CountControls())
     return CJS_Return(false);
   // TODO(weili): Check whether anything special needed for radio button,
   // otherwise merge these branches.
-  if (pFormField->GetFieldType() == FIELDTYPE_RADIOBUTTON)
+  if (pFormField->GetFieldType() == FormFieldType::kRadioButton)
     pFormField->CheckControl(nWidget, bCheckit, true);
   else
     pFormField->CheckControl(nWidget, bCheckit, true);
@@ -2351,8 +2356,8 @@
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
-      pFormField->GetFieldType() == FIELDTYPE_CHECKBOX ||
-      pFormField->GetFieldType() == FIELDTYPE_RADIOBUTTON));
+      pFormField->GetFieldType() == FormFieldType::kCheckBox ||
+      pFormField->GetFieldType() == FormFieldType::kRadioButton));
 }
 
 CJS_Return Field::deleteItemAt(
@@ -2413,8 +2418,8 @@
     return CJS_Return(false);
 
   CPDF_FormField* pFormField = FieldArray[0];
-  if ((pFormField->GetFieldType() == FIELDTYPE_LISTBOX) ||
-      (pFormField->GetFieldType() == FIELDTYPE_COMBOBOX)) {
+  if ((pFormField->GetFieldType() == FormFieldType::kListBox) ||
+      (pFormField->GetFieldType() == FormFieldType::kComboBox)) {
     if (nIdx == -1 || nIdx > pFormField->CountOptions())
       nIdx = pFormField->CountOptions() - 1;
     if (bExport) {
@@ -2458,8 +2463,8 @@
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
-      ((pFormField->GetFieldType() == FIELDTYPE_CHECKBOX ||
-        pFormField->GetFieldType() == FIELDTYPE_RADIOBUTTON) &&
+      ((pFormField->GetFieldType() == FormFieldType::kCheckBox ||
+        pFormField->GetFieldType() == FormFieldType::kRadioButton) &&
        pFormField->GetControl(nIndex)->IsChecked() != 0)));
 }
 
@@ -2479,8 +2484,8 @@
     return CJS_Return(false);
 
   return CJS_Return(pRuntime->NewBoolean(
-      ((pFormField->GetFieldType() == FIELDTYPE_CHECKBOX ||
-        pFormField->GetFieldType() == FIELDTYPE_RADIOBUTTON) &&
+      ((pFormField->GetFieldType() == FormFieldType::kCheckBox ||
+        pFormField->GetFieldType() == FormFieldType::kRadioButton) &&
        pFormField->GetControl(nIndex)->IsDefaultChecked() != 0)));
 }
 
diff --git a/fxjs/cjs_publicmethods.cpp b/fxjs/cjs_publicmethods.cpp
index eaa16c9..45eae7f 100644
--- a/fxjs/cjs_publicmethods.cpp
+++ b/fxjs/cjs_publicmethods.cpp
@@ -1599,18 +1599,18 @@
 
       double dTemp = 0.0;
       switch (pFormField->GetFieldType()) {
-        case FIELDTYPE_TEXTFIELD:
-        case FIELDTYPE_COMBOBOX: {
+        case FormFieldType::kTextField:
+        case FormFieldType::kComboBox: {
           WideString trimmed = pFormField->GetValue();
           trimmed.TrimRight();
           trimmed.TrimLeft();
           dTemp = FX_atof(trimmed.AsStringView());
           break;
         }
-        case FIELDTYPE_PUSHBUTTON:
+        case FormFieldType::kPushButton:
           break;
-        case FIELDTYPE_CHECKBOX:
-        case FIELDTYPE_RADIOBUTTON:
+        case FormFieldType::kCheckBox:
+        case FormFieldType::kRadioButton:
           for (int c = 0; c < pFormField->CountControls(); ++c) {
             CPDF_FormControl* pFormCtrl = pFormField->GetControl(c);
             if (!pFormField || !pFormCtrl->IsChecked())
@@ -1623,7 +1623,7 @@
             break;
           }
           break;
-        case FIELDTYPE_LISTBOX:
+        case FormFieldType::kListBox:
           if (pFormField->CountSelectedItems() <= 1) {
             WideString trimmed = pFormField->GetValue();
             trimmed.TrimRight();
diff --git a/public/fpdf_formfill.h b/public/fpdf_formfill.h
index 5bc3cf3..e4cdaee 100644
--- a/public/fpdf_formfill.h
+++ b/public/fpdf_formfill.h
@@ -1441,7 +1441,9 @@
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
 FORM_ForceToKillFocus(FPDF_FORMHANDLE hHandle);
 
-// Field Types
+// Form Field Types
+// The names of the defines are stable, but the specific values associated with
+// them are not, so do not hardcode their values.
 #define FPDF_FORMFIELD_UNKNOWN 0      // Unknown.
 #define FPDF_FORMFIELD_PUSHBUTTON 1   // push button type.
 #define FPDF_FORMFIELD_CHECKBOX 2     // check box type.
@@ -1449,8 +1451,15 @@
 #define FPDF_FORMFIELD_COMBOBOX 4     // combo box type.
 #define FPDF_FORMFIELD_LISTBOX 5      // list box type.
 #define FPDF_FORMFIELD_TEXTFIELD 6    // text field type.
+#define FPDF_FORMFIELD_SIGNATURE 7    // text field type.
 #ifdef PDF_ENABLE_XFA
-#define FPDF_FORMFIELD_XFA 7          // text field type.
+#define FPDF_FORMFIELD_XFA 8  // Generic XFA type.
+#endif                        // PDF_ENABLE_XFA
+
+#ifndef PDF_ENABLE_XFA
+#define FPDF_FORMFIELD_COUNT 8
+#else
+#define FPDF_FORMFIELD_COUNT 9
 #endif  // PDF_ENABLE_XFA
 
 /**
@@ -1507,11 +1516,11 @@
  * Return Value:
  *          NONE.
  * Comments:
- *          When the parameter fieldType is set to zero, the highlight color
- *will be applied to all the form fields in the
+ *          When the parameter fieldType is set to FPDF_FORMFIELD_UNKNOWN, the
+ *          highlight color will be applied to all the form fields in the
  *          document.
  *          Please refresh the client window to show the highlight immediately
- *if necessary.
+ *          if necessary.
  **/
 FPDF_EXPORT void FPDF_CALLCONV
 FPDF_SetFormFieldHighlightColor(FPDF_FORMHANDLE hHandle,
diff --git a/samples/pdfium_test.cc b/samples/pdfium_test.cc
index 97090cf..1549bd7 100644
--- a/samples/pdfium_test.cc
+++ b/samples/pdfium_test.cc
@@ -1437,7 +1437,7 @@
   }
 #endif  // PDF_ENABLE_XFA
 
-  FPDF_SetFormFieldHighlightColor(form.get(), 0, 0xFFE4DD);
+  FPDF_SetFormFieldHighlightColor(form.get(), FPDF_FORMFIELD_UNKNOWN, 0xFFE4DD);
   FPDF_SetFormFieldHighlightAlpha(form.get(), 100);
   FORM_DoDocumentJSAction(form.get());
   FORM_DoDocumentOpenAction(form.get());
diff --git a/testing/embedder_test.cpp b/testing/embedder_test.cpp
index baedeb3..de72513 100644
--- a/testing/embedder_test.cpp
+++ b/testing/embedder_test.cpp
@@ -219,7 +219,8 @@
   formfillinfo->m_pJsPlatform = platform;
   FPDF_FORMHANDLE form_handle =
       FPDFDOC_InitFormFillEnvironment(doc, formfillinfo);
-  FPDF_SetFormFieldHighlightColor(form_handle, 0, 0xFFE4DD);
+  FPDF_SetFormFieldHighlightColor(form_handle, FPDF_FORMFIELD_UNKNOWN,
+                                  0xFFE4DD);
   FPDF_SetFormFieldHighlightAlpha(form_handle, 100);
   return form_handle;
 }