Add type cast definitions for CPDF_String.

This Cl adds ToString, CPDF_Object::AsString and CPDF_Object::IsString and
updates the src to use them as needed.

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

Review URL: https://codereview.chromium.org/1417933002 .

6 files changed, 37 insertions, 60 deletions

diff --git a/core/src/fpdfdoc/doc_action.cpp b/core/src/fpdfdoc/doc_action.cpp
index 409d050484..c55c20cb1d 100644
--- a/core/src/fpdfdoc/doc_action.cpp
+++ b/core/src/fpdfdoc/doc_action.cpp
@@ -17,7 +17,7 @@ CPDF_Dest CPDF_Action::GetDest(CPDF_Document* pDoc) const {
   if (!pDest) {
     return CPDF_Dest();
   }
-  if (pDest->GetType() == PDFOBJ_STRING || pDest->GetType() == PDFOBJ_NAME) {
+  if (pDest->IsString() || pDest->GetType() == PDFOBJ_NAME) {
     CPDF_NameTree name_tree(pDoc, FX_BSTRC("Dests"));
     CFX_ByteStringC name = pDest->GetString();
     return CPDF_Dest(name_tree.LookupNamedDest(pDoc, name));
@@ -102,19 +102,14 @@ FX_DWORD CPDF_ActionFields::GetFieldsCount() const {
   } else {
     pFields = pDict->GetArray("Fields");
   }
-  if (pFields == NULL) {
+  if (!pFields)
     return 0;
-  }
-  int iType = pFields->GetType();
-  if (iType == PDFOBJ_DICTIONARY) {
+  if (pFields->IsDictionary())
     return 1;
-  }
-  if (iType == PDFOBJ_STRING) {
+  if (pFields->IsString())
     return 1;
-  }
-  if (iType == PDFOBJ_ARRAY) {
+  if (pFields->GetType() == PDFOBJ_ARRAY)
     return ((CPDF_Array*)pFields)->GetCount();
-  }
   return 0;
 }
 void CPDF_ActionFields::GetAllFields(CFX_PtrArray& fieldObjects) const {
@@ -133,13 +128,12 @@ void CPDF_ActionFields::GetAllFields(CFX_PtrArray& fieldObjects) const {
   } else {
     pFields = pDict->GetArray("Fields");
   }
-  if (pFields == NULL) {
+  if (!pFields)
     return;
-  }
-  int iType = pFields->GetType();
-  if (iType == PDFOBJ_DICTIONARY || iType == PDFOBJ_STRING) {
+
+  if (pFields->IsDictionary() || pFields->IsString()) {
     fieldObjects.Add(pFields);
-  } else if (iType == PDFOBJ_ARRAY) {
+  } else if (pFields->GetType() == PDFOBJ_ARRAY) {
     CPDF_Array* pArray = (CPDF_Array*)pFields;
     FX_DWORD iCount = pArray->GetCount();
     for (FX_DWORD i = 0; i < iCount; i++) {
@@ -169,12 +163,10 @@ CPDF_Object* CPDF_ActionFields::GetField(FX_DWORD iIndex) const {
     return NULL;
   }
   CPDF_Object* pFindObj = NULL;
-  int iType = pFields->GetType();
-  if (iType == PDFOBJ_DICTIONARY || iType == PDFOBJ_STRING) {
-    if (iIndex == 0) {
+  if (pFields->IsDictionary() || pFields->IsString()) {
+    if (iIndex == 0)
       pFindObj = pFields;
-    }
-  } else if (iType == PDFOBJ_ARRAY) {
+  } else if (pFields->GetType() == PDFOBJ_ARRAY) {
     pFindObj = ((CPDF_Array*)pFields)->GetElementValue(iIndex);
   }
   return pFindObj;
diff --git a/core/src/fpdfdoc/doc_ap.cpp b/core/src/fpdfdoc/doc_ap.cpp
index 2367d0e7e9..71025ec532 100644
--- a/core/src/fpdfdoc/doc_ap.cpp
+++ b/core/src/fpdfdoc/doc_ap.cpp
@@ -618,7 +618,7 @@ static FX_BOOL GenerateWidgetAP(CPDF_Document* pDoc,
           }
           if (CPDF_Object* pOpt = pOpts->GetElementValue(i)) {
             CFX_WideString swItem;
-            if (pOpt->GetType() == PDFOBJ_STRING) {
+            if (pOpt->IsString()) {
               swItem = pOpt->GetUnicodeText();
             } else if (pOpt->GetType() == PDFOBJ_ARRAY) {
               swItem =
diff --git a/core/src/fpdfdoc/doc_basic.cpp b/core/src/fpdfdoc/doc_basic.cpp
index bbf51139ad..cbf956bd9b 100644
--- a/core/src/fpdfdoc/doc_basic.cpp
+++ b/core/src/fpdfdoc/doc_basic.cpp
@@ -406,8 +406,7 @@ static void FPDFDOC_FILESPEC_SetFileName(CPDF_Object* pObj,
   } else {
     wsStr = FILESPEC_EncodeFileName(wsFileName);
   }
-  int32_t iType = pObj->GetType();
-  if (iType == PDFOBJ_STRING) {
+  if (pObj->IsString()) {
     pObj->SetString(CFX_ByteString::FromUnicode(wsStr));
   } else if (CPDF_Dictionary* pDict = pObj->AsDictionary()) {
     pDict->SetAtString(FX_BSTRC("F"), CFX_ByteString::FromUnicode(wsStr));
diff --git a/core/src/fpdfdoc/doc_bookmark.cpp b/core/src/fpdfdoc/doc_bookmark.cpp
index 2fea810ecc..9d2a9f61ea 100644
--- a/core/src/fpdfdoc/doc_bookmark.cpp
+++ b/core/src/fpdfdoc/doc_bookmark.cpp
@@ -51,10 +51,10 @@ CFX_WideString CPDF_Bookmark::GetTitle() const {
   if (!m_pDict) {
     return CFX_WideString();
   }
-  CPDF_String* pString = (CPDF_String*)m_pDict->GetElementValue("Title");
-  if (!pString || pString->GetType() != PDFOBJ_STRING) {
+  CPDF_String* pString = ToString(m_pDict->GetElementValue("Title"));
+  if (!pString)
     return CFX_WideString();
-  }
+
   CFX_WideString title = pString->GetUnicodeText();
   int len = title.GetLength();
   if (!len) {
@@ -75,7 +75,7 @@ CPDF_Dest CPDF_Bookmark::GetDest(CPDF_Document* pDocument) const {
   if (!pDest) {
     return CPDF_Dest();
   }
-  if (pDest->GetType() == PDFOBJ_STRING || pDest->GetType() == PDFOBJ_NAME) {
+  if (pDest->IsString() || pDest->GetType() == PDFOBJ_NAME) {
     CPDF_NameTree name_tree(pDocument, FX_BSTRC("Dests"));
     CFX_ByteStringC name = pDest->GetString();
     return CPDF_Dest(name_tree.LookupNamedDest(pDocument, name));
diff --git a/core/src/fpdfdoc/doc_formfield.cpp b/core/src/fpdfdoc/doc_formfield.cpp
index 9ef28836a1..25f5490a72 100644
--- a/core/src/fpdfdoc/doc_formfield.cpp
+++ b/core/src/fpdfdoc/doc_formfield.cpp
@@ -425,18 +425,10 @@ int CPDF_FormField::CountSelectedItems() {
       return 0;
     }
   }
-  if (pValue->GetType() == PDFOBJ_STRING) {
-    if (pValue->GetString().IsEmpty()) {
-      return 0;
-    }
-    return 1;
-  }
-  if (pValue->IsNumber()) {
-    if (pValue->GetString().IsEmpty()) {
-      return 0;
-    }
-    return 1;
-  }
+
+  if (pValue->IsString() || pValue->IsNumber())
+    return pValue->GetString().IsEmpty() ? 0 : 1;
+
   if (pValue->GetType() != PDFOBJ_ARRAY) {
     return 0;
   }
@@ -454,10 +446,10 @@ int CPDF_FormField::GetSelectedIndex(int index) {
     return pValue->GetInteger();
 
   CFX_WideString sel_value;
-  if (pValue->GetType() == PDFOBJ_STRING) {
-    if (index != 0) {
+  if (pValue->IsString()) {
+    if (index != 0)
       return -1;
-    }
+
     sel_value = pValue->GetUnicodeText();
   } else {
     if (pValue->GetType() != PDFOBJ_ARRAY) {
@@ -535,21 +527,16 @@ FX_BOOL CPDF_FormField::IsItemSelected(int index) {
       return FALSE;
     }
   }
-  if (pValue->GetType() == PDFOBJ_STRING) {
-    if (pValue->GetUnicodeText() == opt_value) {
-      return TRUE;
-    }
-    return FALSE;
-  }
+
+  if (pValue->IsString())
+    return (pValue->GetUnicodeText() == opt_value);
+
   if (pValue->IsNumber()) {
-    if (pValue->GetString().IsEmpty()) {
+    if (pValue->GetString().IsEmpty())
       return FALSE;
-    }
-    if (pValue->GetInteger() == index) {
-      return TRUE;
-    }
-    return FALSE;
+    return (pValue->GetInteger() == index);
   }
+
   if (pValue->GetType() != PDFOBJ_ARRAY) {
     return FALSE;
   }
@@ -593,7 +580,7 @@ FX_BOOL CPDF_FormField::SetItemSelection(int index,
     if (pValue != NULL) {
       if (m_Type == ListBox) {
         SelectOption(index, FALSE);
-        if (pValue->GetType() == PDFOBJ_STRING) {
+        if (pValue->IsString()) {
           if (pValue->GetUnicodeText() == opt_value) {
             m_pDict->RemoveAt("V");
           }
@@ -734,10 +721,9 @@ CFX_WideString CPDF_FormField::GetOptionText(int index, int sub_index) {
   if (pOption->GetType() == PDFOBJ_ARRAY) {
     pOption = ((CPDF_Array*)pOption)->GetElementValue(sub_index);
   }
-  if (pOption == NULL || pOption->GetType() != PDFOBJ_STRING) {
-    return CFX_WideString();
-  }
-  return ((CPDF_String*)pOption)->GetUnicodeText();
+
+  CPDF_String* pString = ToString(pOption);
+  return pString ? pString->GetUnicodeText() : CFX_WideString();
 }
 CFX_WideString CPDF_FormField::GetOptionLabel(int index) {
   return GetOptionText(index, 1);
diff --git a/core/src/fpdfdoc/doc_link.cpp b/core/src/fpdfdoc/doc_link.cpp
index fbf18f99e5..95411013b4 100644
--- a/core/src/fpdfdoc/doc_link.cpp
+++ b/core/src/fpdfdoc/doc_link.cpp
@@ -76,7 +76,7 @@ CPDF_Dest CPDF_Link::GetDest(CPDF_Document* pDoc) {
   if (pDest == NULL) {
     return CPDF_Dest();
   }
-  if (pDest->GetType() == PDFOBJ_STRING || pDest->GetType() == PDFOBJ_NAME) {
+  if (pDest->IsString() || pDest->GetType() == PDFOBJ_NAME) {
     CPDF_NameTree name_tree(pDoc, FX_BSTRC("Dests"));
     CFX_ByteStringC name = pDest->GetString();
     return CPDF_Dest(name_tree.LookupNamedDest(pDoc, name));