fpdfsdk/ differences with XFA (for didactic purposes only).

fpdfsdk/src/fpdfview.cpp

Index: fpdfsdk/src/fpdfview.cpp
diff --git a/fpdfsdk/src/fpdfview.cpp b/fpdfsdk/src/fpdfview.cpp
index 99a3d90246df0ffdd04a8b029cecfb23f8dca470..d47e2b02da539ebbf00800c74d4ca3fad2dd3958 100644
--- a/fpdfsdk/src/fpdfview.cpp
+++ b/fpdfsdk/src/fpdfview.cpp
@@ -6,6 +6,13 @@
 
 #include "public/fpdfview.h"
 
+#ifdef PDF_ENABLE_XFA
+#include "../include/fpdfxfa/fpdfxfa_app.h"
+#include "../include/fpdfxfa/fpdfxfa_doc.h"
+#include "../include/fpdfxfa/fpdfxfa_page.h"
+#include "../include/fpdfxfa/fpdfxfa_util.h"
+#include "core/include/fpdfapi/fpdf_module.h"
+#endif
 #include "core/include/fxcodec/fx_codec.h"
 #include "core/include/fxcrt/fx_safe_types.h"
 #include "fpdfsdk/include/fsdk_define.h"
@@ -13,6 +20,9 @@
 #include "fpdfsdk/include/fsdk_rendercontext.h"
 #include "fpdfsdk/include/javascript/IJavaScript.h"
 #include "public/fpdf_ext.h"
+#ifdef PDF_ENABLE_XFA
+#include "public/fpdf_formfill.h"
+#endif
 #include "public/fpdf_progressive.h"
 #include "third_party/base/nonstd_unique_ptr.h"
 #include "third_party/base/numerics/safe_conversions_impl.h"
@@ -30,19 +40,141 @@ UnderlyingPageType* UnderlyingFromFPDFPage(FPDF_PAGE page) {
 }
 
 CPDF_Document* CPDFDocumentFromFPDFDocument(FPDF_DOCUMENT doc) {
+#ifndef PDF_ENABLE_XFA
   return UnderlyingFromFPDFDocument(doc);
+#else
+  return doc ? UnderlyingFromFPDFDocument(doc)->GetPDFDoc() : nullptr;
+#endif
 }
 
 FPDF_DOCUMENT FPDFDocumentFromCPDFDocument(CPDF_Document* doc) {
+#ifndef PDF_ENABLE_XFA
   return FPDFDocumentFromUnderlying(doc);
+#else
+  return doc ? FPDFDocumentFromUnderlying(
+                   new CPDFXFA_Document(doc, CPDFXFA_App::GetInstance()))
+             : nullptr;
+#endif
 }
 
 CPDF_Page* CPDFPageFromFPDFPage(FPDF_PAGE page) {
+#ifndef PDF_ENABLE_XFA
   return UnderlyingFromFPDFPage(page);
+#else
+  return page ? UnderlyingFromFPDFPage(page)->GetPDFPage() : nullptr;
+}
+
+CFPDF_FileStream::CFPDF_FileStream(FPDF_FILEHANDLER* pFS) {
+  m_pFS = pFS;
+  m_nCurPos = 0;
+}
+
+IFX_FileStream* CFPDF_FileStream::Retain() {
+  return this;
+}
+
+void CFPDF_FileStream::Release() {
+  if (m_pFS && m_pFS->Release)
+    m_pFS->Release(m_pFS->clientData);
+  delete this;
+}
+
+FX_FILESIZE CFPDF_FileStream::GetSize() {
+  if (m_pFS && m_pFS->GetSize)
+    return (FX_FILESIZE)m_pFS->GetSize(m_pFS->clientData);
+  return 0;
+}
+
+FX_BOOL CFPDF_FileStream::IsEOF() {
+  return m_nCurPos >= GetSize();
+}
+
+FX_BOOL CFPDF_FileStream::ReadBlock(void* buffer,
+                                    FX_FILESIZE offset,
+                                    size_t size) {
+  if (!buffer || !size || !m_pFS->ReadBlock)
+    return FALSE;
+
+  if (m_pFS->ReadBlock(m_pFS->clientData, (FPDF_DWORD)offset, buffer,
+                       (FPDF_DWORD)size) == 0) {
+    m_nCurPos = offset + size;
+    return TRUE;
+  }
+  return FALSE;
+}
+
+size_t CFPDF_FileStream::ReadBlock(void* buffer, size_t size) {
+  if (!buffer || !size || !m_pFS->ReadBlock)
+    return 0;
+
+  FX_FILESIZE nSize = GetSize();
+  if (m_nCurPos >= nSize)
+    return 0;
+  FX_FILESIZE dwAvail = nSize - m_nCurPos;
+  if (dwAvail < (FX_FILESIZE)size)
+    size = (size_t)dwAvail;
+  if (m_pFS->ReadBlock(m_pFS->clientData, (FPDF_DWORD)m_nCurPos, buffer,
+                       (FPDF_DWORD)size) == 0) {
+    m_nCurPos += size;
+    return size;
+  }
+
+  return 0;
+}
+
+FX_BOOL CFPDF_FileStream::WriteBlock(const void* buffer,
+                                     FX_FILESIZE offset,
+                                     size_t size) {
+  if (!m_pFS || !m_pFS->WriteBlock)
+    return FALSE;
+
+  if (m_pFS->WriteBlock(m_pFS->clientData, (FPDF_DWORD)offset, buffer,
+                        (FPDF_DWORD)size) == 0) {
+    m_nCurPos = offset + size;
+    return TRUE;
+  }
+  return FALSE;
+}
+
+FX_BOOL CFPDF_FileStream::Flush() {
+  if (!m_pFS || !m_pFS->Flush)
+    return TRUE;
+
+  return m_pFS->Flush(m_pFS->clientData) == 0;
+#endif
 }
 
 CPDF_CustomAccess::CPDF_CustomAccess(FPDF_FILEACCESS* pFileAccess) {
   m_FileAccess = *pFileAccess;
+#ifdef PDF_ENABLE_XFA
+  m_BufferOffset = (FX_DWORD)-1;
+}
+
+FX_BOOL CPDF_CustomAccess::GetByte(FX_DWORD pos, uint8_t& ch) {
+  if (pos >= m_FileAccess.m_FileLen)
+    return FALSE;
+  if (m_BufferOffset == (FX_DWORD)-1 || pos < m_BufferOffset ||
+      pos >= m_BufferOffset + 512) {
+    // Need to read from file access
+    m_BufferOffset = pos;
+    int size = 512;
+    if (pos + 512 > m_FileAccess.m_FileLen)
+      size = m_FileAccess.m_FileLen - pos;
+    if (!m_FileAccess.m_GetBlock(m_FileAccess.m_Param, m_BufferOffset, m_Buffer,
+                                 size))
+      return FALSE;
+  }
+  ch = m_Buffer[pos - m_BufferOffset];
+  return TRUE;
+}
+
+FX_BOOL CPDF_CustomAccess::GetBlock(FX_DWORD pos,
+                                    uint8_t* pBuf,
+                                    FX_DWORD size) {
+  if (pos + size > m_FileAccess.m_FileLen)
+    return FALSE;
+  return m_FileAccess.m_GetBlock(m_FileAccess.m_Param, pos, pBuf, size);
+#endif
 }
 
 FX_BOOL CPDF_CustomAccess::ReadBlock(void* buffer,
@@ -104,15 +236,22 @@ DLLEXPORT void STDCALL FPDF_InitLibraryWithConfig(
   pModuleMgr->SetCodecModule(g_pCodecModule);
   pModuleMgr->InitPageModule();
   pModuleMgr->InitRenderModule();
+#ifndef PDF_ENABLE_XFA
   pModuleMgr->LoadEmbeddedGB1CMaps();
   pModuleMgr->LoadEmbeddedJapan1CMaps();
   pModuleMgr->LoadEmbeddedCNS1CMaps();
   pModuleMgr->LoadEmbeddedKorea1CMaps();
+#else
+  CPDFXFA_App::GetInstance()->Initialize();
+#endif
   if (cfg && cfg->version >= 2)
     IJS_Runtime::Initialize(cfg->m_v8EmbedderSlot, cfg->m_pIsolate);
 }
 
 DLLEXPORT void STDCALL FPDF_DestroyLibrary() {
+#ifdef PDF_ENABLE_XFA
+  CPDFXFA_App::ReleaseInstance();
+#endif
   CPDF_ModuleMgr::Destroy();
   CFX_GEModule::Destroy();
 
@@ -173,7 +312,52 @@ DLLEXPORT FPDF_DOCUMENT STDCALL FPDF_LoadDocument(FPDF_STRING file_path,
     ProcessParseError(err_code);
     return NULL;
   }
+#ifndef PDF_ENABLE_XFA
   return pParser->GetDocument();
+#else
+  CPDF_Document* pPDFDoc = pParser->GetDocument();
+  if (!pPDFDoc)
+    return NULL;
+
+  CPDFXFA_App* pProvider = CPDFXFA_App::GetInstance();
+  return new CPDFXFA_Document(pPDFDoc, pProvider);
+}
+
+DLLEXPORT FPDF_BOOL STDCALL FPDF_HasXFAField(FPDF_DOCUMENT document,
+                                             int* docType) {
+  if (!document)
+    return FALSE;
+
+  CPDF_Document* pdfDoc =
+      (static_cast<CPDFXFA_Document*>(document))->GetPDFDoc();
+  if (!pdfDoc)
+    return FALSE;
+
+  CPDF_Dictionary* pRoot = pdfDoc->GetRoot();
+  if (!pRoot)
+    return FALSE;
+
+  CPDF_Dictionary* pAcroForm = pRoot->GetDict("AcroForm");
+  if (!pAcroForm)
+    return FALSE;
+
+  CPDF_Object* pXFA = pAcroForm->GetElement("XFA");
+  if (!pXFA)
+    return FALSE;
+
+  FX_BOOL bDynamicXFA = pRoot->GetBoolean("NeedsRendering", FALSE);
+
+  if (bDynamicXFA)
+    *docType = DOCTYPE_DYNAMIC_XFA;
+  else
+    *docType = DOCTYPE_STATIC_XFA;
+
+  return TRUE;
+}
+
+DLLEXPORT FPDF_BOOL STDCALL FPDF_LoadXFA(FPDF_DOCUMENT document) {
+  return document && (static_cast<CPDFXFA_Document*>(document))->LoadXFADoc();
+#endif
 }
 
 class CMemFile final : public IFX_FileRead {
@@ -262,7 +446,11 @@ DLLEXPORT FPDF_BOOL STDCALL FPDF_GetFileVersion(FPDF_DOCUMENT doc,
 DLLEXPORT unsigned long STDCALL FPDF_GetDocPermissions(FPDF_DOCUMENT document) {
   CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
+#ifndef PDF_ENABLE_XFA
     return 0;
+#else
+    return (FX_DWORD)-1;
+#endif
 
   CPDF_Dictionary* pDict = pDoc->GetParser()->GetEncryptDict();
   return pDict ? pDict->GetInteger("P") : (FX_DWORD)-1;
@@ -291,6 +479,7 @@ DLLEXPORT FPDF_PAGE STDCALL FPDF_LoadPage(FPDF_DOCUMENT document,
   if (page_index < 0 || page_index >= pDoc->GetPageCount())
     return nullptr;
 
+#ifndef PDF_ENABLE_XFA
   CPDF_Dictionary* pDict = pDoc->GetPage(page_index);
   if (pDict == NULL)
     return NULL;
@@ -298,6 +487,9 @@ DLLEXPORT FPDF_PAGE STDCALL FPDF_LoadPage(FPDF_DOCUMENT document,
   pPage->Load(pDoc, pDict);
   pPage->ParseContent();
   return pPage;
+#else
+  return pDoc->GetPage(page_index);
+#endif
 }
 
 DLLEXPORT double STDCALL FPDF_GetPageWidth(FPDF_PAGE page) {
@@ -522,6 +714,7 @@ DLLEXPORT void STDCALL FPDF_RenderPageBitmap(FPDF_BITMAP bitmap,
 DLLEXPORT void STDCALL FPDF_ClosePage(FPDF_PAGE page) {
   if (!page)
     return;
+#ifndef PDF_ENABLE_XFA
   CPDFSDK_PageView* pPageView =
       (CPDFSDK_PageView*)(((CPDF_Page*)page))->GetPrivateData((void*)page);
   if (pPageView && pPageView->IsLocked()) {
@@ -529,9 +722,15 @@ DLLEXPORT void STDCALL FPDF_ClosePage(FPDF_PAGE page) {
     return;
   }
   delete (CPDF_Page*)page;
+#else
+
+  CPDFXFA_Page* pPage = (CPDFXFA_Page*)page;
+  pPage->Release();
+#endif
 }
 
 DLLEXPORT void STDCALL FPDF_CloseDocument(FPDF_DOCUMENT document) {
+#ifndef PDF_ENABLE_XFA
   CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return;
@@ -542,6 +741,9 @@ DLLEXPORT void STDCALL FPDF_CloseDocument(FPDF_DOCUMENT document) {
     return;
   }
   delete pParser;
+#else
+  delete CPDFDocumentFromFPDFDocument(document);
+#endif
 }
 
 DLLEXPORT unsigned long STDCALL FPDF_GetLastError() {
@@ -561,6 +763,7 @@ DLLEXPORT void STDCALL FPDF_DeviceToPage(FPDF_PAGE page,
   if (page == NULL || page_x == NULL || page_y == NULL)
     return;
   UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
+#ifndef PDF_ENABLE_XFA
 
   CPDF_Matrix page2device;
   pPage->GetDisplayMatrix(page2device, start_x, start_y, size_x, size_y,
@@ -574,6 +777,10 @@ DLLEXPORT void STDCALL FPDF_DeviceToPage(FPDF_PAGE page,
 
   *page_x = (page_x_f);
   *page_y = (page_y_f);
+#else
+  pPage->DeviceToPage(start_x, start_y, size_x, size_y, rotate, device_x,
+                      device_y, page_x, page_y);
+#endif
 }
 
 DLLEXPORT void STDCALL FPDF_PageToDevice(FPDF_PAGE page,
@@ -591,6 +798,7 @@ DLLEXPORT void STDCALL FPDF_PageToDevice(FPDF_PAGE page,
   UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   if (!pPage)
     return;
+#ifndef PDF_ENABLE_XFA
   CPDF_Matrix page2device;
   pPage->GetDisplayMatrix(page2device, start_x, start_y, size_x, size_y,
                           rotate);
@@ -601,6 +809,10 @@ DLLEXPORT void STDCALL FPDF_PageToDevice(FPDF_PAGE page,
 
   *device_x = FXSYS_round(device_x_f);
   *device_y = FXSYS_round(device_y_f);
+#else
+  pPage->PageToDevice(start_x, start_y, size_x, size_y, rotate, page_x, page_y,
+                      device_x, device_y);
+#endif
 }
 
 DLLEXPORT FPDF_BITMAP STDCALL FPDFBitmap_Create(int width,
@@ -715,12 +927,14 @@ void FPDF_RenderPage_Retail(CRenderContext* pContext,
     pContext->m_pOptions->m_Flags |= RENDER_LIMITEDIMAGECACHE;
   if (flags & FPDF_RENDER_FORCEHALFTONE)
     pContext->m_pOptions->m_Flags |= RENDER_FORCE_HALFTONE;
+#ifndef PDF_ENABLE_XFA
   if (flags & FPDF_RENDER_NO_SMOOTHTEXT)
     pContext->m_pOptions->m_Flags |= RENDER_NOTEXTSMOOTH;
   if (flags & FPDF_RENDER_NO_SMOOTHIMAGE)
     pContext->m_pOptions->m_Flags |= RENDER_NOIMAGESMOOTH;
   if (flags & FPDF_RENDER_NO_SMOOTHPATH)
     pContext->m_pOptions->m_Flags |= RENDER_NOPATHSMOOTH;
+#endif
   // Grayscale output
   if (flags & FPDF_GRAYSCALE) {
     pContext->m_pOptions->m_ColorMode = RENDER_COLOR_GRAY;
@@ -770,14 +984,28 @@ DLLEXPORT int STDCALL FPDF_GetPageSizeByIndex(FPDF_DOCUMENT document,
   if (!pDoc)
     return FALSE;
 
+#ifndef PDF_ENABLE_XFA
   CPDF_Dictionary* pDict = pDoc->GetPage(page_index);
   if (!pDict)
+#else
+  int count = pDoc->GetPageCount();
+  if (page_index < 0 || page_index >= count)
+    return FALSE;
+
+  CPDFXFA_Page* pPage = pDoc->GetPage(page_index);
+  if (!pPage)
+#endif
     return FALSE;
 
+#ifndef PDF_ENABLE_XFA
   CPDF_Page page;
   page.Load(pDoc, pDict);
   *width = page.GetPageWidth();
   *height = page.GetPageHeight();
+#else
+  *width = pPage->GetPageWidth();
+  *height = pPage->GetPageHeight();
+#endif
 
   return TRUE;
 }
@@ -854,6 +1082,60 @@ DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDestByName(FPDF_DOCUMENT document,
   return name_tree.LookupNamedDest(pDoc, name);
 }
 
+#ifdef PDF_ENABLE_XFA
+FPDF_RESULT FPDF_BStr_Init(FPDF_BSTR* str) {
+  if (!str)
+    return -1;
+
+  FXSYS_memset(str, 0, sizeof(FPDF_BSTR));
+  return 0;
+}
+
+FPDF_RESULT FPDF_BStr_Set(FPDF_BSTR* str, FPDF_LPCSTR bstr, int length) {
+  if (!str)
+    return -1;
+  if (!bstr || !length)
+    return -1;
+  if (length == -1)
+    length = FXSYS_strlen(bstr);
+
+  if (length == 0) {
+    if (str->str) {
+      FX_Free(str->str);
+      str->str = NULL;
+    }
+    str->len = 0;
+    return 0;
+  }
+
+  if (str->str && str->len < length)
+    str->str = FX_Realloc(char, str->str, length + 1);
+  else if (!str->str)
+    str->str = FX_Alloc(char, length + 1);
+
+  str->str[length] = 0;
+  if (str->str == NULL)
+    return -1;
+
+  FXSYS_memcpy(str->str, bstr, length);
+  str->len = length;
+
+  return 0;
+}
+
+FPDF_RESULT FPDF_BStr_Clear(FPDF_BSTR* str) {
+  if (!str)
+    return -1;
+
+  if (str->str) {
+    FX_Free(str->str);
+    str->str = NULL;
+  }
+  str->len = 0;
+  return 0;
+}
+
+#endif
 DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDest(FPDF_DOCUMENT document,
                                               int index,
                                               void* buffer,