Merge to XFA: Add type cast definitions for CPDF_Array.

This Cl adds ToArray, CPDF_Object::AsArray and CPDF_Object::IsArray and
updates the src to use them as needed.

BUG=pdfium:201
R=thestig@chromium.org, tsepez@chromium.org

Review URL: https://codereview.chromium.org/1417893003 .

(cherry picked from commit c2bfc000e502c42c9a3017038fd9104c7997d126)

Review URL: https://codereview.chromium.org/1419643005 .

7 files changed, 53 insertions, 67 deletions

diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page.cpp
index f6f03336a0..162acfa898 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page.cpp
@@ -814,8 +814,7 @@ void CPDF_Page::Load(CPDF_Document* pDocument,
   if (rotate < 0) {
     rotate += 4;
   }
-  CPDF_Array *pMediaBox, *pCropBox;
-  pMediaBox = (CPDF_Array*)GetPageAttr(FX_BSTRC("MediaBox"));
+  CPDF_Array* pMediaBox = ToArray(GetPageAttr(FX_BSTRC("MediaBox")));
   CFX_FloatRect mediabox;
   if (pMediaBox) {
     mediabox = pMediaBox->GetRect();
@@ -824,7 +823,8 @@ void CPDF_Page::Load(CPDF_Document* pDocument,
   if (mediabox.IsEmpty()) {
     mediabox = CFX_FloatRect(0, 0, 612, 792);
   }
-  pCropBox = (CPDF_Array*)GetPageAttr(FX_BSTRC("CropBox"));
+
+  CPDF_Array* pCropBox = ToArray(GetPageAttr(FX_BSTRC("CropBox")));
   if (pCropBox) {
     m_BBox = pCropBox->GetRect();
     m_BBox.Normalize();
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_colors.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_colors.cpp
index 73b1091856..4f54c01ce7 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_colors.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_colors.cpp
@@ -1139,14 +1139,11 @@ void CPDF_DeviceNCS::GetDefaultValue(int iComponent,
   max = 1.0f;
 }
 FX_BOOL CPDF_DeviceNCS::v_Load(CPDF_Document* pDoc, CPDF_Array* pArray) {
-  CPDF_Object* pObj = pArray->GetElementValue(1);
-  if (!pObj) {
-    return FALSE;
-  }
-  if (pObj->GetType() != PDFOBJ_ARRAY) {
+  CPDF_Array* pObj = ToArray(pArray->GetElementValue(1));
+  if (!pObj)
     return FALSE;
-  }
-  m_nComponents = ((CPDF_Array*)pObj)->GetCount();
+
+  m_nComponents = pObj->GetCount();
   CPDF_Object* pAltCS = pArray->GetElementValue(2);
   if (!pAltCS || pAltCS == m_pArray) {
     return FALSE;
@@ -1224,21 +1221,19 @@ CPDF_ColorSpace* CPDF_ColorSpace::Load(CPDF_Document* pDoc, CPDF_Object* pObj) {
     }
     return nullptr;
   }
-  if (pObj->GetType() != PDFOBJ_ARRAY) {
-    return NULL;
-  }
-  CPDF_Array* pArray = (CPDF_Array*)pObj;
-  if (pArray->GetCount() == 0) {
-    return NULL;
-  }
+
+  CPDF_Array* pArray = pObj->AsArray();
+  if (!pArray || pArray->GetCount() == 0)
+    return nullptr;
+
   CPDF_Object* pFamilyObj = pArray->GetElementValue(0);
-  if (!pFamilyObj) {
-    return NULL;
-  }
+  if (!pFamilyObj)
+    return nullptr;
+
   CFX_ByteString familyname = pFamilyObj->GetString();
-  if (pArray->GetCount() == 1) {
+  if (pArray->GetCount() == 1)
     return _CSFromName(familyname);
-  }
+
   CPDF_ColorSpace* pCS = NULL;
   FX_DWORD id = familyname.GetID();
   if (id == FXBSTR_ID('C', 'a', 'l', 'G')) {
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
index 9a1d48a416..436cca6d99 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
@@ -343,10 +343,8 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpace(CPDF_Object* pCSObj,
     return pDefaultCS ? GetColorSpace(pDefaultCS, nullptr) : pCS;
   }
 
-  if (pCSObj->GetType() != PDFOBJ_ARRAY)
-    return nullptr;
-  CPDF_Array* pArray = (CPDF_Array*)pCSObj;
-  if (pArray->GetCount() == 0)
+  CPDF_Array* pArray = pCSObj->AsArray();
+  if (!pArray || pArray->GetCount() == 0)
     return nullptr;
   if (pArray->GetCount() == 1)
     return GetColorSpace(pArray->GetElementValue(0), pResources);
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp
index 62a3c67996..78d3d26188 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp
@@ -461,10 +461,10 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
   while (pos) {
     CFX_ByteString key_str;
     CPDF_Object* pElement = pGS->GetNextElement(pos, key_str);
-    CPDF_Object* pObject = pElement ? pElement->GetDirect() : NULL;
-    if (pObject == NULL) {
+    CPDF_Object* pObject = pElement ? pElement->GetDirect() : nullptr;
+    if (!pObject)
       continue;
-    }
+
     FX_DWORD key = key_str.GetID();
     switch (key) {
       case FXBSTR_ID('L', 'W', 0, 0):
@@ -482,14 +482,14 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
         m_GraphState.GetModify()->m_MiterLimit = pObject->GetNumber();
         break;
       case FXBSTR_ID('D', 0, 0, 0): {
-        if (pObject->GetType() != PDFOBJ_ARRAY) {
+        CPDF_Array* pDash = pObject->AsArray();
+        if (!pDash)
           break;
-        }
-        CPDF_Array* pDash = (CPDF_Array*)pObject;
+
         CPDF_Array* pArray = pDash->GetArray(0);
-        if (pArray == NULL) {
+        if (!pArray)
           break;
-        }
+
         SetLineDash(pArray, pDash->GetNumber(1), 1.0f);
         break;
       }
@@ -497,10 +497,10 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
         m_GeneralState.SetRenderIntent(pObject->GetString());
         break;
       case FXBSTR_ID('F', 'o', 'n', 't'): {
-        if (pObject->GetType() != PDFOBJ_ARRAY) {
+        CPDF_Array* pFont = pObject->AsArray();
+        if (!pFont)
           break;
-        }
-        CPDF_Array* pFont = (CPDF_Array*)pObject;
+
         m_TextState.GetModify()->m_FontSize = pFont->GetNumber(1);
         m_TextState.SetFont(pParser->FindFont(pFont->GetString(0)));
         break;
@@ -514,12 +514,10 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
             (pObject && !pObject->IsName()) ? pObject : nullptr;
         break;
       case FXBSTR_ID('B', 'M', 0, 0): {
-        CFX_ByteString mode;
-        if (pObject->GetType() == PDFOBJ_ARRAY) {
-          mode = ((CPDF_Array*)pObject)->GetString(0);
-        } else {
-          mode = pObject->GetString();
-        }
+        CPDF_Array* pArray = pObject->AsArray();
+        CFX_ByteString mode =
+            pArray ? pArray->GetString(0) : pObject->GetString();
+
         pGeneralState->SetBlendMode(mode);
         if (pGeneralState->m_BlendType > FXDIB_BLEND_MULTIPLY) {
           pParser->GetObjectList()->m_bBackgroundAlphaNeeded = TRUE;
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
index 6f186e6c3b..7aa2cf8aa3 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
@@ -514,7 +514,7 @@ void _PDF_ReplaceAbbr(CPDF_Object* pObj) {
       break;
     }
     case PDFOBJ_ARRAY: {
-      CPDF_Array* pArray = (CPDF_Array*)pObj;
+      CPDF_Array* pArray = pObj->AsArray();
       for (FX_DWORD i = 0; i < pArray->GetCount(); i++) {
         CPDF_Object* pElement = pArray->GetElement(i);
         if (pElement->IsName()) {
@@ -577,7 +577,7 @@ void _PDF_ReplaceFull(CPDF_Object* pObj) {
       break;
     }
     case PDFOBJ_ARRAY: {
-      CPDF_Array* pArray = (CPDF_Array*)pObj;
+      CPDF_Array* pArray = pObj->AsArray();
       for (FX_DWORD i = 0; i < pArray->GetCount(); i++) {
         CPDF_Object* pElement = pArray->GetElement(i);
         if (pElement->IsName()) {
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
index f051d0db5a..c27ede44cb 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
@@ -332,16 +332,16 @@ CPDF_Stream* CPDF_StreamParser::ReadInlineStream(CPDF_Document* pDoc,
   CFX_ByteString Decoder;
   CPDF_Dictionary* pParam = NULL;
   CPDF_Object* pFilter = pDict->GetElementValue(FX_BSTRC("Filter"));
-  if (pFilter == NULL) {
-  } else if (pFilter->GetType() == PDFOBJ_ARRAY) {
-    Decoder = ((CPDF_Array*)pFilter)->GetString(0);
-    CPDF_Array* pParams = pDict->GetArray(FX_BSTRC("DecodeParms"));
-    if (pParams) {
-      pParam = pParams->GetDict(0);
+  if (pFilter) {
+    if (CPDF_Array* pArray = pFilter->AsArray()) {
+      Decoder = pArray->GetString(0);
+      CPDF_Array* pParams = pDict->GetArray(FX_BSTRC("DecodeParms"));
+      if (pParams)
+        pParam = pParams->GetDict(0);
+    } else {
+      Decoder = pFilter->GetString();
+      pParam = pDict->GetDict(FX_BSTRC("DecodeParms"));
     }
-  } else {
-    Decoder = pFilter->GetString();
-    pParam = pDict->GetDict(FX_BSTRC("DecodeParms"));
   }
   FX_DWORD width = pDict->GetInteger(FX_BSTRC("Width"));
   FX_DWORD height = pDict->GetInteger(FX_BSTRC("Height"));
@@ -403,12 +403,11 @@ CPDF_Stream* CPDF_StreamParser::ReadInlineStream(CPDF_Document* pDoc,
     if (bDecode) {
       m_Pos += dwStreamSize;
       dwStreamSize = dwDestSize;
-      if (pFilter->GetType() == PDFOBJ_ARRAY) {
-        ((CPDF_Array*)pFilter)->RemoveAt(0);
+      if (CPDF_Array* pArray = pFilter->AsArray()) {
+        pArray->RemoveAt(0);
         CPDF_Array* pParams = pDict->GetArray(FX_BSTRC("DecodeParms"));
-        if (pParams) {
+        if (pParams)
           pParams->RemoveAt(0);
-        }
       } else {
         pDict->RemoveAt(FX_BSTRC("Filter"));
         pDict->RemoveAt(FX_BSTRC("DecodeParms"));
@@ -965,8 +964,7 @@ void CPDF_ContentParser::Start(CPDF_Page* pPage, CPDF_ParseOptions* pOptions) {
     m_nStreams = 0;
     m_pSingleStream = new CPDF_StreamAcc;
     m_pSingleStream->LoadAllData((CPDF_Stream*)pContent, FALSE);
-  } else if (pContent->GetType() == PDFOBJ_ARRAY) {
-    CPDF_Array* pArray = (CPDF_Array*)pContent;
+  } else if (CPDF_Array* pArray = pContent->AsArray()) {
     m_nStreams = pArray->GetCount();
     if (m_nStreams == 0) {
       m_Status = Done;
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_pattern.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_pattern.cpp
index 3f915a7b79..a73bdc9e8e 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_pattern.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_pattern.cpp
@@ -118,14 +118,11 @@ FX_BOOL CPDF_ShadingPattern::Load() {
   }
   CPDF_Object* pFunc = pShadingDict->GetElementValue(FX_BSTRC("Function"));
   if (pFunc) {
-    if (pFunc->GetType() == PDFOBJ_ARRAY) {
-      m_nFuncs = ((CPDF_Array*)pFunc)->GetCount();
-      if (m_nFuncs > 4) {
-        m_nFuncs = 4;
-      }
+    if (CPDF_Array* pArray = pFunc->AsArray()) {
+      m_nFuncs = std::min<int>(pArray->GetCount(), 4);
+
       for (int i = 0; i < m_nFuncs; i++) {
-        m_pFunctions[i] =
-            CPDF_Function::Load(((CPDF_Array*)pFunc)->GetElementValue(i));
+        m_pFunctions[i] = CPDF_Function::Load(pArray->GetElementValue(i));
       }
     } else {
       m_pFunctions[0] = CPDF_Function::Load(pFunc);