Add "Underlying types" to master.

Change some master code to line up better with XFA, so
that the XFA changes are additive when possible, rather
than replacements.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1468253005 .

12 files changed, 141 insertions, 118 deletions

diff --git a/fpdfsdk/include/fsdk_baseannot.h b/fpdfsdk/include/fsdk_baseannot.h
index 2e54096c76..f747f8576b 100644
--- a/fpdfsdk/include/fsdk_baseannot.h
+++ b/fpdfsdk/include/fsdk_baseannot.h
@@ -15,6 +15,7 @@
 
 #include "core/include/fpdfdoc/fpdf_doc.h"
 #include "core/include/fxcrt/fx_basic.h"
+#include "fpdfsdk/include/fsdk_define.h"
 #include "fx_systemhandler.h"
 
 class CPDFSDK_PageView;
@@ -88,6 +89,7 @@ class CPDFSDK_Annot {
                             CPDF_Matrix* pUser2Device,
                             CPDF_RenderOptions* pOptions) {}
 
+  UnderlyingPageType* GetUnderlyingPage();
   CPDF_Page* GetPDFPage();
 
   void SetPage(CPDFSDK_PageView* pPageView) { m_pPageView = pPageView; }
diff --git a/fpdfsdk/include/fsdk_define.h b/fpdfsdk/include/fsdk_define.h
index bca7805226..980411c27b 100644
--- a/fpdfsdk/include/fsdk_define.h
+++ b/fpdfsdk/include/fsdk_define.h
@@ -52,6 +52,18 @@ class CPDF_CustomAccess final : public IFX_FileRead {
   FPDF_FILEACCESS m_FileAccess;
 };
 
+// Object types for public FPDF_ types; these correspond to next layer down
+// from fpdfsdk. For master, these are CPDF_ types, but for XFA, these are
+// CPDFXFA_ types.
+using UnderlyingDocumentType = CPDF_Document;
+using UnderlyingPageType = CPDF_Page;
+
+// Conversions to/from underlying types.
+UnderlyingDocumentType* UnderlyingFromFPDFDocument(FPDF_DOCUMENT doc);
+FPDF_DOCUMENT FPDFDocumentFromUnderlying(UnderlyingDocumentType* doc);
+
+UnderlyingPageType* UnderlyingFromFPDFPage(FPDF_PAGE page);
+
 // Conversions to/from FPDF_ types.
 CPDF_Document* CPDFDocumentFromFPDFDocument(FPDF_DOCUMENT doc);
 FPDF_DOCUMENT FPDFDocumentFromCPDFDocument(CPDF_Document* doc);
diff --git a/fpdfsdk/include/fsdk_mgr.h b/fpdfsdk/include/fsdk_mgr.h
index b7b349197a..a4385be318 100644
--- a/fpdfsdk/include/fsdk_mgr.h
+++ b/fpdfsdk/include/fsdk_mgr.h
@@ -33,7 +33,7 @@ class IFX_SystemHandler;
 
 class CPDFDoc_Environment final {
  public:
-  CPDFDoc_Environment(CPDF_Document* pDoc, FPDF_FORMFILLINFO* pFFinfo);
+  CPDFDoc_Environment(UnderlyingDocumentType* pDoc, FPDF_FORMFILLINFO* pFFinfo);
   ~CPDFDoc_Environment();
 
   void FFI_Invalidate(FPDF_PAGE page,
@@ -203,7 +203,9 @@ class CPDFDoc_Environment final {
   FX_BOOL IsJSInitiated() const { return m_pInfo && m_pInfo->m_pJsPlatform; }
   void SetSDKDocument(CPDFSDK_Document* pFXDoc) { m_pSDKDoc = pFXDoc; }
   CPDFSDK_Document* GetSDKDocument() const { return m_pSDKDoc; }
-  CPDF_Document* GetPDFDocument() const { return m_pPDFDoc; }
+  UnderlyingDocumentType* GetUnderlyingDocument() const {
+    return m_pUnderlyingDoc;
+  }
   CFX_ByteString GetAppName() const { return ""; }
   IFX_SystemHandler* GetSysHandler() const { return m_pSysHandler.get(); }
   FPDF_FORMFILLINFO* GetFormFillInfo() const { return m_pInfo; }
@@ -219,30 +221,33 @@ class CPDFDoc_Environment final {
   nonstd::unique_ptr<IJS_Runtime> m_pJSRuntime;
   FPDF_FORMFILLINFO* const m_pInfo;
   CPDFSDK_Document* m_pSDKDoc;
-  CPDF_Document* const m_pPDFDoc;
+  UnderlyingDocumentType* const m_pUnderlyingDoc;
   nonstd::unique_ptr<CFFL_IFormFiller> m_pIFormFiller;
   nonstd::unique_ptr<IFX_SystemHandler> m_pSysHandler;
 };
 
 class CPDFSDK_Document {
  public:
-  CPDFSDK_Document(CPDF_Document* pDoc, CPDFDoc_Environment* pEnv);
+  CPDFSDK_Document(UnderlyingDocumentType* pDoc, CPDFDoc_Environment* pEnv);
   ~CPDFSDK_Document();
 
   CPDFSDK_InterForm* GetInterForm();
 
   // Gets the document object for the next layer down; for master this is
   // a CPDF_Document, but for XFA it is a CPDFXFA_Document.
-  CPDF_Document* GetDocument() const { return m_pDoc; }
+  UnderlyingDocumentType* GetUnderlyingDocument() const {
+    return GetPDFDocument();
+  }
 
   // Gets the CPDF_Document, either directly in master, or from the
   // CPDFXFA_Document for XFA.
   CPDF_Document* GetPDFDocument() const { return m_pDoc; }
 
-  CPDFSDK_PageView* GetPageView(CPDF_Page* pPDFPage, FX_BOOL ReNew = TRUE);
+  CPDFSDK_PageView* GetPageView(UnderlyingPageType* pPage,
+                                FX_BOOL ReNew = TRUE);
   CPDFSDK_PageView* GetPageView(int nIndex);
   CPDFSDK_PageView* GetCurrentView();
-  void ReMovePageView(CPDF_Page* pPDFPage);
+  void RemovePageView(UnderlyingPageType* pPage);
   void UpdateAllViews(CPDFSDK_PageView* pSender, CPDFSDK_Annot* pAnnot);
 
   CPDFSDK_Annot* GetFocusAnnot();
@@ -269,15 +274,15 @@ class CPDFSDK_Document {
   void SetChangeMark() { m_bChangeMask = TRUE; }
   void ClearChangeMark() { m_bChangeMask = FALSE; }
   CFX_WideString GetPath();
-  CPDF_Page* GetPage(int nIndex);
+  UnderlyingPageType* GetPage(int nIndex);
   CPDFDoc_Environment* GetEnv() { return m_pEnv; }
   void ProcJavascriptFun();
   FX_BOOL ProcOpenAction();
   CPDF_OCContext* GetOCContext();
 
  private:
-  std::map<CPDF_Page*, CPDFSDK_PageView*> m_pageMap;
-  CPDF_Document* m_pDoc;
+  std::map<UnderlyingPageType*, CPDFSDK_PageView*> m_pageMap;
+  UnderlyingDocumentType* m_pDoc;
   nonstd::unique_ptr<CPDFSDK_InterForm> m_pInterForm;
   CPDFSDK_Annot* m_pFocusAnnot;
   CPDFDoc_Environment* m_pEnv;
@@ -287,7 +292,7 @@ class CPDFSDK_Document {
 };
 class CPDFSDK_PageView final {
  public:
-  CPDFSDK_PageView(CPDFSDK_Document* pSDKDoc, CPDF_Page* page);
+  CPDFSDK_PageView(CPDFSDK_Document* pSDKDoc, UnderlyingPageType* page);
   ~CPDFSDK_PageView();
   void PageView_OnDraw(CFX_RenderDevice* pDevice,
                        CPDF_Matrix* pUser2Device,
@@ -348,7 +353,7 @@ class CPDFSDK_PageView final {
                                       CPDFSDK_Widget* pWidget);
 
   CPDF_Matrix m_curMatrix;
-  CPDF_Page* m_page;
+  UnderlyingPageType* m_page;
   nonstd::unique_ptr<CPDF_AnnotList> m_pAnnotList;
   std::vector<CPDFSDK_Annot*> m_fxAnnotArray;
   CPDFSDK_Document* m_pSDKDoc;
diff --git a/fpdfsdk/src/fpdfformfill.cpp b/fpdfsdk/src/fpdfformfill.cpp
index 06ea2ce755..525cb152b1 100644
--- a/fpdfsdk/src/fpdfformfill.cpp
+++ b/fpdfsdk/src/fpdfformfill.cpp
@@ -25,7 +25,7 @@ CPDFSDK_InterForm* FormHandleToInterForm(FPDF_FORMHANDLE hHandle) {
 
 CPDFSDK_PageView* FormHandleToPageView(FPDF_FORMHANDLE hHandle,
                                        FPDF_PAGE page) {
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
+  UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   if (!pPage)
     return nullptr;
 
@@ -80,12 +80,14 @@ DLLEXPORT int STDCALL FPDFPage_FormFieldZOrderAtPoint(FPDF_FORMHANDLE hHandle,
 DLLEXPORT FPDF_FORMHANDLE STDCALL
 FPDFDOC_InitFormFillEnvironment(FPDF_DOCUMENT document,
                                 FPDF_FORMFILLINFO* formInfo) {
-  if (!formInfo || formInfo->version != 1)
+  const int kRequiredVersion = 1;
+  if (!formInfo || formInfo->version != kRequiredVersion)
     return nullptr;
 
-  CPDF_Document* pDocument = CPDFDocumentFromFPDFDocument(document);
+  UnderlyingDocumentType* pDocument = UnderlyingFromFPDFDocument(document);
   if (!pDocument)
     return nullptr;
+
   CPDFDoc_Environment* pEnv = new CPDFDoc_Environment(pDocument, formInfo);
   pEnv->SetSDKDocument(new CPDFSDK_Document(pDocument, pEnv));
   return pEnv;
@@ -274,15 +276,15 @@ DLLEXPORT void STDCALL FORM_OnBeforeClosePage(FPDF_PAGE page,
   if (!pSDKDoc)
     return;
 
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
+  UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   if (!pPage)
     return;
 
   CPDFSDK_PageView* pPageView = pSDKDoc->GetPageView(pPage, FALSE);
   if (pPageView) {
     pPageView->SetValid(FALSE);
-    // ReMovePageView() takes care of the delete for us.
-    pSDKDoc->ReMovePageView(pPage);
+    // RemovePageView() takes care of the delete for us.
+    pSDKDoc->RemovePageView(pPage);
   }
 }
 
@@ -304,7 +306,7 @@ DLLEXPORT void STDCALL FORM_DoDocumentAAction(FPDF_FORMHANDLE hHandle,
   if (!pSDKDoc)
     return;
 
-  CPDF_Document* pDoc = pSDKDoc->GetDocument();
+  CPDF_Document* pDoc = pSDKDoc->GetPDFDocument();
   CPDF_Dictionary* pDic = pDoc->GetRoot();
   if (!pDic)
     return;
@@ -326,13 +328,14 @@ DLLEXPORT void STDCALL FORM_DoPageAAction(FPDF_PAGE page,
   if (!hHandle)
     return;
   CPDFSDK_Document* pSDKDoc = ((CPDFDoc_Environment*)hHandle)->GetSDKDocument();
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
-  if (!pPage)
+  UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
+  CPDF_Page* pPDFPage = CPDFPageFromFPDFPage(page);
+  if (!pPDFPage)
     return;
   if (pSDKDoc->GetPageView(pPage, FALSE)) {
     CPDFDoc_Environment* pEnv = pSDKDoc->GetEnv();
     CPDFSDK_ActionHandler* pActionHandler = pEnv->GetActionHander();
-    CPDF_Dictionary* pPageDict = pPage->m_pFormDict;
+    CPDF_Dictionary* pPageDict = pPDFPage->m_pFormDict;
     CPDF_AAction aa = pPageDict->GetDict(FX_BSTRC("AA"));
     if (FPDFPAGE_AACTION_OPEN == aaType) {
       if (aa.ActionExist(CPDF_AAction::OpenPage)) {
diff --git a/fpdfsdk/src/fpdfview.cpp b/fpdfsdk/src/fpdfview.cpp
index 6ffb523468..fcb6731563 100644
--- a/fpdfsdk/src/fpdfview.cpp
+++ b/fpdfsdk/src/fpdfview.cpp
@@ -17,21 +17,32 @@
 #include "third_party/base/nonstd_unique_ptr.h"
 #include "third_party/base/numerics/safe_conversions_impl.h"
 
+UnderlyingDocumentType* UnderlyingFromFPDFDocument(FPDF_DOCUMENT doc) {
+  return static_cast<UnderlyingDocumentType*>(doc);
+}
+
+FPDF_DOCUMENT FPDFDocumentFromUnderlying(UnderlyingDocumentType* doc) {
+  return static_cast<FPDF_DOCUMENT>(doc);
+}
+
+UnderlyingPageType* UnderlyingFromFPDFPage(FPDF_PAGE page) {
+  return static_cast<UnderlyingPageType*>(page);
+}
+
 CPDF_Document* CPDFDocumentFromFPDFDocument(FPDF_DOCUMENT doc) {
-  return static_cast<CPDF_Document*>(doc);
+  return UnderlyingFromFPDFDocument(doc);
 }
 
 FPDF_DOCUMENT FPDFDocumentFromCPDFDocument(CPDF_Document* doc) {
-  return static_cast<FPDF_DOCUMENT>(doc);
+  return FPDFDocumentFromUnderlying(doc);
 }
 
 CPDF_Page* CPDFPageFromFPDFPage(FPDF_PAGE page) {
-  return static_cast<CPDF_Page*>(page);
+  return UnderlyingFromFPDFPage(page);
 }
 
 CPDF_CustomAccess::CPDF_CustomAccess(FPDF_FILEACCESS* pFileAccess) {
-  if (pFileAccess)
-    m_FileAccess = *pFileAccess;
+  m_FileAccess = *pFileAccess;
 }
 
 FX_BOOL CPDF_CustomAccess::ReadBlock(void* buffer,
@@ -240,7 +251,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDF_GetFileVersion(FPDF_DOCUMENT doc,
   if (!pDoc)
     return FALSE;
 
-  CPDF_Parser* pParser = (CPDF_Parser*)pDoc->GetParser();
+  CPDF_Parser* pParser = pDoc->GetParser();
   if (!pParser)
     return FALSE;
 
@@ -269,17 +280,17 @@ DLLEXPORT int STDCALL FPDF_GetSecurityHandlerRevision(FPDF_DOCUMENT document) {
 }
 
 DLLEXPORT int STDCALL FPDF_GetPageCount(FPDF_DOCUMENT document) {
-  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
+  UnderlyingDocumentType* pDoc = UnderlyingFromFPDFDocument(document);
   return pDoc ? pDoc->GetPageCount() : 0;
 }
 
 DLLEXPORT FPDF_PAGE STDCALL FPDF_LoadPage(FPDF_DOCUMENT document,
                                           int page_index) {
-  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
+  UnderlyingDocumentType* pDoc = UnderlyingFromFPDFDocument(document);
   if (!pDoc)
     return nullptr;
 
-  if (page_index < 0 || page_index >= FPDF_GetPageCount(document))
+  if (page_index < 0 || page_index >= pDoc->GetPageCount())
     return nullptr;
 
   CPDF_Dictionary* pDict = pDoc->GetPage(page_index);
@@ -292,12 +303,12 @@ DLLEXPORT FPDF_PAGE STDCALL FPDF_LoadPage(FPDF_DOCUMENT document,
 }
 
 DLLEXPORT double STDCALL FPDF_GetPageWidth(FPDF_PAGE page) {
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
+  UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   return pPage ? pPage->GetPageWidth() : 0.0;
 }
 
 DLLEXPORT double STDCALL FPDF_GetPageHeight(FPDF_PAGE page) {
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
+  UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   return pPage ? pPage->GetPageHeight() : 0.0;
 }
 
@@ -551,7 +562,7 @@ DLLEXPORT void STDCALL FPDF_DeviceToPage(FPDF_PAGE page,
                                          double* page_y) {
   if (page == NULL || page_x == NULL || page_y == NULL)
     return;
-  CPDF_Page* pPage = (CPDF_Page*)page;
+  UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
 
   CPDF_Matrix page2device;
   pPage->GetDisplayMatrix(page2device, start_x, start_y, size_x, size_y,
@@ -579,7 +590,7 @@ DLLEXPORT void STDCALL FPDF_PageToDevice(FPDF_PAGE page,
                                          int* device_y) {
   if (!device_x || !device_y)
     return;
-  CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
+  UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   if (!pPage)
     return;
   CPDF_Matrix page2device;
@@ -757,7 +768,7 @@ DLLEXPORT int STDCALL FPDF_GetPageSizeByIndex(FPDF_DOCUMENT document,
                                               int page_index,
                                               double* width,
                                               double* height) {
-  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
+  UnderlyingDocumentType* pDoc = UnderlyingFromFPDFDocument(document);
   if (!pDoc)
     return FALSE;
 
@@ -851,13 +862,17 @@ DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDest(FPDF_DOCUMENT document,
                                               long* buflen) {
   if (!buffer)
     *buflen = 0;
-  if (!document || index < 0)
-    return NULL;
-  CPDF_Document* pDoc = (CPDF_Document*)document;
+
+  if (index < 0)
+    return nullptr;
+
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
+  if (!pDoc)
+    return nullptr;
 
   CPDF_Dictionary* pRoot = pDoc->GetRoot();
   if (!pRoot)
-    return NULL;
+    return nullptr;
 
   CPDF_Object* pDestObj = NULL;
   CFX_ByteString bsName;
diff --git a/fpdfsdk/src/fsdk_actionhandler.cpp b/fpdfsdk/src/fsdk_actionhandler.cpp
index 736b4074f4..0043bc7787 100644
--- a/fpdfsdk/src/fsdk_actionhandler.cpp
+++ b/fpdfsdk/src/fsdk_actionhandler.cpp
@@ -433,7 +433,7 @@ void CPDFSDK_ActionHandler::DoAction_GoTo(CPDFSDK_Document* pDocument,
                                           const CPDF_Action& action) {
   ASSERT(action);
 
-  CPDF_Document* pPDFDocument = pDocument->GetDocument();
+  CPDF_Document* pPDFDocument = pDocument->GetPDFDocument();
   ASSERT(pPDFDocument);
 
   CPDF_Dest MyDest = action.GetDest(pPDFDocument);
@@ -469,7 +469,7 @@ void CPDFSDK_ActionHandler::DoAction_URI(CPDFSDK_Document* pDocument,
   CPDFDoc_Environment* pApp = pDocument->GetEnv();
   ASSERT(pApp != NULL);
 
-  CFX_ByteString sURI = action.GetURI(pDocument->GetDocument());
+  CFX_ByteString sURI = action.GetURI(pDocument->GetPDFDocument());
   pApp->FFI_DoURIAction(sURI.c_str());
 }
 
diff --git a/fpdfsdk/src/fsdk_annothandler.cpp b/fpdfsdk/src/fsdk_annothandler.cpp
index 9209a46f49..ee06091bff 100644
--- a/fpdfsdk/src/fsdk_annothandler.cpp
+++ b/fpdfsdk/src/fsdk_annothandler.cpp
@@ -577,28 +577,24 @@ void CPDFSDK_BFAnnotHandler::OnCreate(CPDFSDK_Annot* pAnnot) {
 }
 
 void CPDFSDK_BFAnnotHandler::OnLoad(CPDFSDK_Annot* pAnnot) {
-  ASSERT(pAnnot != NULL);
-
-  CFX_ByteString sSubType = pAnnot->GetSubType();
+  if (pAnnot->GetSubType() == BFFT_SIGNATURE)
+    return;
 
-  if (sSubType == BFFT_SIGNATURE) {
-  } else {
-    CPDFSDK_Widget* pWidget = (CPDFSDK_Widget*)pAnnot;
-    if (!pWidget->IsAppearanceValid())
-      pWidget->ResetAppearance(NULL, FALSE);
-
-    int nFieldType = pWidget->GetFieldType();
-    if (nFieldType == FIELDTYPE_TEXTFIELD || nFieldType == FIELDTYPE_COMBOBOX) {
-      FX_BOOL bFormated = FALSE;
-      CFX_WideString sValue = pWidget->OnFormat(bFormated);
-      if (bFormated && nFieldType == FIELDTYPE_COMBOBOX) {
-        pWidget->ResetAppearance(sValue.c_str(), FALSE);
-      }
+  CPDFSDK_Widget* pWidget = (CPDFSDK_Widget*)pAnnot;
+  if (!pWidget->IsAppearanceValid())
+    pWidget->ResetAppearance(NULL, FALSE);
+
+  int nFieldType = pWidget->GetFieldType();
+  if (nFieldType == FIELDTYPE_TEXTFIELD || nFieldType == FIELDTYPE_COMBOBOX) {
+    FX_BOOL bFormated = FALSE;
+    CFX_WideString sValue = pWidget->OnFormat(bFormated);
+    if (bFormated && nFieldType == FIELDTYPE_COMBOBOX) {
+      pWidget->ResetAppearance(sValue.c_str(), FALSE);
     }
-
-    if (m_pFormFiller)
-      m_pFormFiller->OnLoad(pAnnot);
   }
+
+  if (m_pFormFiller)
+    m_pFormFiller->OnLoad(pAnnot);
 }
 
 FX_BOOL CPDFSDK_BFAnnotHandler::OnSetFocus(CPDFSDK_Annot* pAnnot,
diff --git a/fpdfsdk/src/fsdk_baseannot.cpp b/fpdfsdk/src/fsdk_baseannot.cpp
index 8cd3df97c0..e124ace2a3 100644
--- a/fpdfsdk/src/fsdk_baseannot.cpp
+++ b/fpdfsdk/src/fsdk_baseannot.cpp
@@ -976,6 +976,10 @@ void CPDFSDK_BAAnnot::Annot_OnDraw(CFX_RenderDevice* pDevice,
   return;
 }
 
+UnderlyingPageType* CPDFSDK_Annot::GetUnderlyingPage() {
+  return GetPDFPage();
+}
+
 CPDF_Page* CPDFSDK_Annot::GetPDFPage() {
   if (m_pPageView)
     return m_pPageView->GetPDFPage();
diff --git a/fpdfsdk/src/fsdk_baseform.cpp b/fpdfsdk/src/fsdk_baseform.cpp
index 3a304986d4..98836e9465 100644
--- a/fpdfsdk/src/fsdk_baseform.cpp
+++ b/fpdfsdk/src/fsdk_baseform.cpp
@@ -76,8 +76,6 @@ int CPDFSDK_Widget::GetFieldType() const {
 }
 
 FX_BOOL CPDFSDK_Widget::IsAppearanceValid() {
-  ASSERT(m_pPageView != NULL);
-
   return CPDFSDK_BAAnnot::IsAppearanceValid();
 }
 
@@ -1435,11 +1433,11 @@ void CPDFSDK_Widget::RemoveAppearance(const CFX_ByteString& sAPType) {
 FX_BOOL CPDFSDK_Widget::OnAAction(CPDF_AAction::AActionType type,
                                   PDFSDK_FieldAction& data,
                                   CPDFSDK_PageView* pPageView) {
+  CPDFSDK_Document* pDocument = pPageView->GetSDKDocument();
+  CPDFDoc_Environment* pEnv = pDocument->GetEnv();
   CPDF_Action action = GetAAction(type);
 
   if (action && action.GetType() != CPDF_Action::Unknown) {
-    CPDFSDK_Document* pDocument = pPageView->GetSDKDocument();
-    CPDFDoc_Environment* pEnv = pDocument->GetEnv();
     CPDFSDK_ActionHandler* pActionHandler = pEnv->GetActionHander();
     return pActionHandler->DoAction_Field(action, type, pDocument,
                                           GetFormField(), data);
@@ -1514,9 +1512,7 @@ CPDFSDK_InterForm::CPDFSDK_InterForm(CPDFSDK_Document* pDocument)
       m_pInterForm(NULL),
       m_bCalculate(TRUE),
       m_bBusy(FALSE) {
-  ASSERT(m_pDocument != NULL);
-  m_pInterForm = new CPDF_InterForm(m_pDocument->GetDocument(), FALSE);
-  ASSERT(m_pInterForm != NULL);
+  m_pInterForm = new CPDF_InterForm(m_pDocument->GetPDFDocument(), FALSE);
   m_pInterForm->SetFormNotify(this);
 
   for (int i = 0; i < kNumFieldTypes; ++i)
@@ -1558,7 +1554,7 @@ CPDFSDK_Widget* CPDFSDK_InterForm::GetWidget(CPDF_FormControl* pControl) const {
     return pWidget;
 
   CPDF_Dictionary* pControlDict = pControl->GetWidget();
-  CPDF_Document* pDocument = m_pDocument->GetDocument();
+  CPDF_Document* pDocument = m_pDocument->GetPDFDocument();
   CPDFSDK_PageView* pPage = nullptr;
 
   if (CPDF_Dictionary* pPageDict = pControlDict->GetDict("P")) {
@@ -1643,10 +1639,7 @@ FX_BOOL CPDFSDK_InterForm::IsCalculateEnabled() const {
 
 #ifdef _WIN32
 CPDF_Stream* CPDFSDK_InterForm::LoadImageFromFile(const CFX_WideString& sFile) {
-  ASSERT(m_pDocument != NULL);
-  CPDF_Document* pDocument = m_pDocument->GetDocument();
-  ASSERT(pDocument != NULL);
-
+  CPDF_Document* pDocument = m_pDocument->GetPDFDocument();
   CPDF_Stream* pRetStream = NULL;
 
   if (CFX_DIBitmap* pBmp = CFX_WindowsDIB::LoadFromFile(sFile.c_str())) {
@@ -1835,8 +1828,6 @@ void CPDFSDK_InterForm::ResetFieldAppearance(CPDF_FormField* pFormField,
 }
 
 void CPDFSDK_InterForm::UpdateField(CPDF_FormField* pFormField) {
-  ASSERT(pFormField != NULL);
-
   for (int i = 0, sz = pFormField->CountControls(); i < sz; i++) {
     CPDF_FormControl* pFormCtrl = pFormField->GetControl(i);
     ASSERT(pFormCtrl != NULL);
@@ -1844,10 +1835,8 @@ void CPDFSDK_InterForm::UpdateField(CPDF_FormField* pFormField) {
     if (CPDFSDK_Widget* pWidget = GetWidget(pFormCtrl)) {
       CPDFDoc_Environment* pEnv = m_pDocument->GetEnv();
       CFFL_IFormFiller* pIFormFiller = pEnv->GetIFormFiller();
-
-      CPDF_Page* pPage = pWidget->GetPDFPage();
+      UnderlyingPageType* pPage = pWidget->GetUnderlyingPage();
       CPDFSDK_PageView* pPageView = m_pDocument->GetPageView(pPage, FALSE);
-
       FX_RECT rcBBox = pIFormFiller->GetViewBBox(pPageView, pWidget);
 
       pEnv->FFI_Invalidate(pPage, rcBBox.left, rcBBox.top, rcBBox.right,
diff --git a/fpdfsdk/src/fsdk_mgr.cpp b/fpdfsdk/src/fsdk_mgr.cpp
index 09b0e0aa20..480dc4a51f 100644
--- a/fpdfsdk/src/fsdk_mgr.cpp
+++ b/fpdfsdk/src/fsdk_mgr.cpp
@@ -90,12 +90,9 @@ void CFX_SystemHandler::SetCursor(int32_t nCursorType) {
 }
 
 void CFX_SystemHandler::InvalidateRect(FX_HWND hWnd, FX_RECT rect) {
-  // g_pFormFillApp->FFI_Invalidate();
   CPDFSDK_Annot* pSDKAnnot = (CPDFSDK_Annot*)hWnd;
-  CPDF_Page* pPage = NULL;
-  CPDFSDK_PageView* pPageView = NULL;
-  pPageView = pSDKAnnot->GetPageView();
-  pPage = pSDKAnnot->GetPDFPage();
+  CPDFSDK_PageView* pPageView = pSDKAnnot->GetPageView();
+  UnderlyingPageType* pPage = pSDKAnnot->GetUnderlyingPage();
   if (!pPage || !pPageView)
     return;
   CPDF_Matrix page2device;
@@ -119,10 +116,8 @@ void CFX_SystemHandler::OutputSelectedRect(void* pFormFiller, CPDF_Rect& rect) {
     CPDF_Point righttop = CPDF_Point(rect.right, rect.top);
     CPDF_Point ptA = pFFL->PWLtoFFL(leftbottom);
     CPDF_Point ptB = pFFL->PWLtoFFL(righttop);
-
     CPDFSDK_Annot* pAnnot = pFFL->GetSDKAnnot();
-    ASSERT(pAnnot);
-    CPDF_Page* pPage = pAnnot->GetPDFPage();
+    UnderlyingPageType* pPage = pAnnot->GetUnderlyingPage();
     ASSERT(pPage);
     m_pEnv->FFI_OutputSelectedRect(pPage, ptA.x, ptB.y, ptB.x, ptA.y);
   }
@@ -205,9 +200,9 @@ FX_SYSTEMTIME CFX_SystemHandler::GetLocalTime() {
   return m_pEnv->FFI_GetLocalTime();
 }
 
-CPDFDoc_Environment::CPDFDoc_Environment(CPDF_Document* pDoc,
+CPDFDoc_Environment::CPDFDoc_Environment(UnderlyingDocumentType* pDoc,
                                          FPDF_FORMFILLINFO* pFFinfo)
-    : m_pInfo(pFFinfo), m_pSDKDoc(NULL), m_pPDFDoc(pDoc) {
+    : m_pInfo(pFFinfo), m_pSDKDoc(NULL), m_pUnderlyingDoc(pDoc) {
   m_pSysHandler.reset(new CFX_SystemHandler(this));
 }
 
@@ -382,14 +377,13 @@ CFFL_IFormFiller* CPDFDoc_Environment::GetIFormFiller() {
   return m_pIFormFiller.get();
 }
 
-CPDFSDK_Document::CPDFSDK_Document(CPDF_Document* pDoc,
+CPDFSDK_Document::CPDFSDK_Document(UnderlyingDocumentType* pDoc,
                                    CPDFDoc_Environment* pEnv)
     : m_pDoc(pDoc),
       m_pFocusAnnot(nullptr),
       m_pEnv(pEnv),
       m_bChangeMask(FALSE),
-      m_bBeingDestroyed(FALSE) {
-}
+      m_bBeingDestroyed(FALSE) {}
 
 CPDFSDK_Document::~CPDFSDK_Document() {
   m_bBeingDestroyed = TRUE;
@@ -402,29 +396,32 @@ CPDFSDK_Document::~CPDFSDK_Document() {
   m_pageMap.clear();
 }
 
-CPDFSDK_PageView* CPDFSDK_Document::GetPageView(CPDF_Page* pPDFPage,
-                                                FX_BOOL ReNew) {
-  auto it = m_pageMap.find(pPDFPage);
+CPDFSDK_PageView* CPDFSDK_Document::GetPageView(
+    UnderlyingPageType* pUnderlyingPage,
+    FX_BOOL ReNew) {
+  auto it = m_pageMap.find(pUnderlyingPage);
   if (it != m_pageMap.end())
     return it->second;
 
   if (!ReNew)
     return nullptr;
 
-  CPDFSDK_PageView* pPageView = new CPDFSDK_PageView(this, pPDFPage);
-  m_pageMap[pPDFPage] = pPageView;
+  CPDFSDK_PageView* pPageView = new CPDFSDK_PageView(this, pUnderlyingPage);
+  m_pageMap[pUnderlyingPage] = pPageView;
   // Delay to load all the annotations, to avoid endless loop.
   pPageView->LoadFXAnnots();
   return pPageView;
 }
 
 CPDFSDK_PageView* CPDFSDK_Document::GetCurrentView() {
-  CPDF_Page* pPage = (CPDF_Page*)m_pEnv->FFI_GetCurrentPage(m_pDoc);
+  UnderlyingPageType* pPage =
+      UnderlyingFromFPDFPage(m_pEnv->FFI_GetCurrentPage(m_pDoc));
   return pPage ? GetPageView(pPage, TRUE) : nullptr;
 }
 
 CPDFSDK_PageView* CPDFSDK_Document::GetPageView(int nIndex) {
-  CPDF_Page* pTempPage = (CPDF_Page*)m_pEnv->FFI_GetPage(m_pDoc, nIndex);
+  UnderlyingPageType* pTempPage =
+      UnderlyingFromFPDFPage(m_pEnv->FFI_GetPage(m_pDoc, nIndex));
   if (!pTempPage)
     return nullptr;
 
@@ -433,7 +430,7 @@ CPDFSDK_PageView* CPDFSDK_Document::GetPageView(int nIndex) {
 }
 
 void CPDFSDK_Document::ProcJavascriptFun() {
-  CPDF_Document* pPDFDoc = GetDocument();
+  CPDF_Document* pPDFDoc = GetPDFDocument();
   CPDF_DocJSActions docJS(pPDFDoc);
   int iCount = docJS.CountJSActions();
   if (iCount < 1)
@@ -451,7 +448,7 @@ FX_BOOL CPDFSDK_Document::ProcOpenAction() {
   if (!m_pDoc)
     return FALSE;
 
-  CPDF_Dictionary* pRoot = m_pDoc->GetRoot();
+  CPDF_Dictionary* pRoot = GetPDFDocument()->GetRoot();
   if (!pRoot)
     return FALSE;
 
@@ -476,12 +473,12 @@ FX_BOOL CPDFSDK_Document::ProcOpenAction() {
 
 CPDF_OCContext* CPDFSDK_Document::GetOCContext() {
   if (!m_pOccontent)
-    m_pOccontent.reset(new CPDF_OCContext(m_pDoc));
+    m_pOccontent.reset(new CPDF_OCContext(GetPDFDocument()));
   return m_pOccontent.get();
 }
 
-void CPDFSDK_Document::ReMovePageView(CPDF_Page* pPDFPage) {
-  auto it = m_pageMap.find(pPDFPage);
+void CPDFSDK_Document::RemovePageView(UnderlyingPageType* pUnderlyingPage) {
+  auto it = m_pageMap.find(pUnderlyingPage);
   if (it == m_pageMap.end())
     return;
 
@@ -494,11 +491,8 @@ void CPDFSDK_Document::ReMovePageView(CPDF_Page* pPDFPage) {
   m_pageMap.erase(it);
 }
 
-CPDF_Page* CPDFSDK_Document::GetPage(int nIndex) {
-  CPDF_Page* pTempPage = (CPDF_Page*)m_pEnv->FFI_GetPage(m_pDoc, nIndex);
-  if (!pTempPage)
-    return NULL;
-  return pTempPage;
+UnderlyingPageType* CPDFSDK_Document::GetPage(int nIndex) {
+  return UnderlyingFromFPDFPage(m_pEnv->FFI_GetPage(m_pDoc, nIndex));
 }
 
 CPDFSDK_InterForm* CPDFSDK_Document::GetInterForm() {
@@ -532,8 +526,12 @@ FX_BOOL CPDFSDK_Document::SetFocusAnnot(CPDFSDK_Annot* pAnnot, FX_UINT nFlag) {
     if (!KillFocusAnnot(nFlag))
       return FALSE;
   }
+
+  if (!pAnnot)
+    return FALSE;
+
   CPDFSDK_PageView* pPageView = pAnnot->GetPageView();
-  if (pAnnot && pPageView->IsValid()) {
+  if (pPageView && pPageView->IsValid()) {
     CPDFSDK_AnnotHandlerMgr* pAnnotHandler = m_pEnv->GetAnnotHandlerMgr();
     if (!m_pFocusAnnot) {
       if (!pAnnotHandler->Annot_OnSetFocus(pAnnot, nFlag))
@@ -576,8 +574,7 @@ void CPDFSDK_Document::OnCloseDocument() {
 }
 
 FX_BOOL CPDFSDK_Document::GetPermissions(int nFlag) {
-  FX_DWORD dwPermissions = m_pDoc->GetUserPermissions();
-  return dwPermissions & nFlag;
+  return GetPDFDocument()->GetUserPermissions() & nFlag;
 }
 
 IJS_Runtime* CPDFSDK_Document::GetJsRuntime() {
@@ -590,7 +587,8 @@ CFX_WideString CPDFSDK_Document::GetPath() {
   return m_pEnv->JS_docGetFilePath();
 }
 
-CPDFSDK_PageView::CPDFSDK_PageView(CPDFSDK_Document* pSDKDoc, CPDF_Page* page)
+CPDFSDK_PageView::CPDFSDK_PageView(CPDFSDK_Document* pSDKDoc,
+                                   UnderlyingPageType* page)
     : m_page(page),
       m_pSDKDoc(pSDKDoc),
       m_CaptureWidget(nullptr),
@@ -903,7 +901,7 @@ void CPDFSDK_PageView::UpdateView(CPDFSDK_Annot* pAnnot) {
 int CPDFSDK_PageView::GetPageIndex() {
   if (m_page) {
     CPDF_Dictionary* pDic = m_page->m_pFormDict;
-    CPDF_Document* pDoc = m_pSDKDoc->GetDocument();
+    CPDF_Document* pDoc = m_pSDKDoc->GetPDFDocument();
     if (pDoc && pDic) {
       return pDoc->GetPageIndex(pDic->GetObjNum());
     }
diff --git a/fpdfsdk/src/javascript/Document.cpp b/fpdfsdk/src/javascript/Document.cpp
index 9e352a1ab6..1fa88f9b12 100644
--- a/fpdfsdk/src/javascript/Document.cpp
+++ b/fpdfsdk/src/javascript/Document.cpp
@@ -536,7 +536,7 @@ FX_BOOL Document::removeField(IJS_Context* cc,
     CFX_RectArray aRefresh;
     aRefresh.Add(rcAnnot);
 
-    CPDF_Page* pPage = pWidget->GetPDFPage();
+    UnderlyingPageType* pPage = pWidget->GetUnderlyingPage();
     ASSERT(pPage);
 
     CPDFSDK_PageView* pPageView = m_pDocument->GetPageView(pPage);
@@ -1019,7 +1019,7 @@ FX_BOOL Document::subject(IJS_Context* cc,
 FX_BOOL Document::title(IJS_Context* cc,
                         CJS_PropValue& vp,
                         CFX_WideString& sError) {
-  if (m_pDocument == NULL || m_pDocument->GetPDFDocument() == NULL)
+  if (!m_pDocument || !m_pDocument->GetUnderlyingDocument())
     return FALSE;
 
   CPDF_Dictionary* pDictionary = m_pDocument->GetPDFDocument()->GetInfo();
diff --git a/fpdfsdk/src/javascript/Field.cpp b/fpdfsdk/src/javascript/Field.cpp
index 39d67d00dc..39e15e9868 100644
--- a/fpdfsdk/src/javascript/Field.cpp
+++ b/fpdfsdk/src/javascript/Field.cpp
@@ -3397,9 +3397,8 @@ FX_BOOL Field::setFocus(IJS_Context* cc,
     pWidget = pInterForm->GetWidget(pFormField->GetControl(0));
   } else {
     CPDFDoc_Environment* pEnv = m_pDocument->GetEnv();
-    ASSERT(pEnv);
-    CPDF_Page* pPage =
-        (CPDF_Page*)pEnv->FFI_GetCurrentPage(m_pDocument->GetDocument());
+    UnderlyingPageType* pPage = UnderlyingFromFPDFPage(
+        pEnv->FFI_GetCurrentPage(m_pDocument->GetUnderlyingDocument()));
     if (!pPage)
       return FALSE;
     if (CPDFSDK_PageView* pCurPageView = m_pDocument->GetPageView(pPage)) {