Move CXFA_ThisProxy helper to CXFA_Object.

Because the other helpers are declared here.
Rename VariablesThis to ThisProxy in a few places; VariablesThis is
a slightly different concept (see GetVariablesThis()).
Then introduce helper for CXFA_List subclass as well.
Remove unused const version of some helpers.

Change-Id: Ia328d8cd170a8b97015e98c1c770fa8a44810455
Reviewed-on: https://pdfium-review.googlesource.com/38670
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

9 files changed, 41 insertions, 42 deletions

diff --git a/fxjs/cfxjse_engine.cpp b/fxjs/cfxjse_engine.cpp
index e297ed16e2..cc584a3fa3 100644
--- a/fxjs/cfxjse_engine.cpp
+++ b/fxjs/cfxjse_engine.cpp
@@ -67,9 +67,7 @@ const char kFormCalcRuntime[] = "pfm_rt";
 
 CXFA_ThisProxy* ToThisProxy(CFXJSE_Value* pValue) {
   CFXJSE_HostObject* pHostObject = pValue->ToHostObject();
-  if (!pHostObject)
-    return nullptr;
-  return CXFA_ThisProxy::FromCXFAObject(pHostObject->AsCXFAObject());
+  return pHostObject ? ToThisProxy(pHostObject->AsCXFAObject()) : nullptr;
 }
 
 }  // namespace
@@ -181,7 +179,7 @@ void CFXJSE_Engine::GlobalPropertySetter(CFXJSE_Value* pObject,
   CXFA_Document* pDoc = lpOrginalNode->GetDocument();
   CFXJSE_Engine* lpScriptContext = pDoc->GetScriptContext();
   CXFA_Node* pRefNode = ToNode(lpScriptContext->GetThisObject());
-  if (lpOrginalNode->IsVariablesThis())
+  if (lpOrginalNode->IsThisProxy())
     pRefNode = ToNode(lpScriptContext->GetVariablesThis(lpOrginalNode));
 
   WideString wsPropName = WideString::FromUTF8(szPropName);
@@ -193,7 +191,7 @@ void CFXJSE_Engine::GlobalPropertySetter(CFXJSE_Value* pObject,
           true)) {
     return;
   }
-  if (lpOrginalNode->IsVariablesThis()) {
+  if (lpOrginalNode->IsThisProxy()) {
     if (pValue && pValue->IsUndefined()) {
       pObject->SetObjectOwnProperty(szPropName, pValue);
       return;
@@ -234,7 +232,7 @@ void CFXJSE_Engine::GlobalPropertyGetter(CFXJSE_Value* pObject,
   }
 
   CXFA_Node* pRefNode = ToNode(lpScriptContext->GetThisObject());
-  if (pOriginalObject->IsVariablesThis())
+  if (pOriginalObject->IsThisProxy())
     pRefNode = ToNode(lpScriptContext->GetVariablesThis(pOriginalObject));
 
   if (lpScriptContext->QueryNodeByFlag(
@@ -473,7 +471,7 @@ CFXJSE_Context* CFXJSE_Engine::CreateVariablesContext(CXFA_Node* pScriptNode,
 
 CXFA_Object* CFXJSE_Engine::GetVariablesThis(CXFA_Object* pObject,
                                              bool bScriptNode) {
-  CXFA_ThisProxy* pProxy = CXFA_ThisProxy::FromCXFAObject(pObject);
+  CXFA_ThisProxy* pProxy = ToThisProxy(pObject);
   if (!pProxy)
     return pObject;
 
diff --git a/fxjs/xfa/cjx_list.cpp b/fxjs/xfa/cjx_list.cpp
index fcac45f58c..e56515d0b1 100644
--- a/fxjs/xfa/cjx_list.cpp
+++ b/fxjs/xfa/cjx_list.cpp
@@ -28,7 +28,7 @@ CJX_List::CJX_List(CXFA_List* list) : CJX_Object(list) {
 CJX_List::~CJX_List() {}
 
 CXFA_List* CJX_List::GetXFAList() {
-  return static_cast<CXFA_List*>(GetXFAObject());
+  return ToList(GetXFAObject());
 }
 
 CJS_Return CJX_List::append(CFX_V8* runtime,
diff --git a/fxjs/xfa/cjx_node.cpp b/fxjs/xfa/cjx_node.cpp
index 856fea5267..efef5af87b 100644
--- a/fxjs/xfa/cjx_node.cpp
+++ b/fxjs/xfa/cjx_node.cpp
@@ -103,12 +103,8 @@ CJX_Node::CJX_Node(CXFA_Node* node) : CJX_Tree(node) {
 
 CJX_Node::~CJX_Node() = default;
 
-CXFA_Node* CJX_Node::GetXFANode() {
-  return static_cast<CXFA_Node*>(GetXFAObject());
-}
-
-const CXFA_Node* CJX_Node::GetXFANode() const {
-  return static_cast<const CXFA_Node*>(GetXFAObject());
+CXFA_Node* CJX_Node::GetXFANode() const {
+  return ToNode(GetXFAObject());
 }
 
 CJS_Return CJX_Node::applyXSL(CFX_V8* runtime,
diff --git a/fxjs/xfa/cjx_node.h b/fxjs/xfa/cjx_node.h
index 8d266424ab..af6800b5e5 100644
--- a/fxjs/xfa/cjx_node.h
+++ b/fxjs/xfa/cjx_node.h
@@ -38,8 +38,7 @@ class CJX_Node : public CJX_Tree {
   JSE_PROP(ns);
   JSE_PROP(oneOfChild);
 
-  CXFA_Node* GetXFANode();
-  const CXFA_Node* GetXFANode() const;
+  CXFA_Node* GetXFANode() const;
 
  protected:
   int32_t execSingleEventByName(const WideStringView& wsEventName,
diff --git a/fxjs/xfa/cjx_treelist.cpp b/fxjs/xfa/cjx_treelist.cpp
index b79b9e16b4..53c3ec1b54 100644
--- a/fxjs/xfa/cjx_treelist.cpp
+++ b/fxjs/xfa/cjx_treelist.cpp
@@ -25,7 +25,7 @@ CJX_TreeList::CJX_TreeList(CXFA_TreeList* list) : CJX_List(list) {
 CJX_TreeList::~CJX_TreeList() {}
 
 CXFA_TreeList* CJX_TreeList::GetXFATreeList() {
-  return static_cast<CXFA_TreeList*>(GetXFAObject());
+  return ToTreeList(GetXFAObject());
 }
 
 CJS_Return CJX_TreeList::namedItem(
diff --git a/xfa/fxfa/parser/cxfa_object.cpp b/xfa/fxfa/parser/cxfa_object.cpp
index 920e33860e..6daf3aa7b4 100644
--- a/xfa/fxfa/parser/cxfa_object.cpp
+++ b/xfa/fxfa/parser/cxfa_object.cpp
@@ -15,6 +15,7 @@
 #include "xfa/fxfa/cxfa_ffnotify.h"
 #include "xfa/fxfa/parser/cxfa_document.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
+#include "xfa/fxfa/parser/cxfa_thisproxy.h"
 #include "xfa/fxfa/parser/cxfa_treelist.h"
 
 CXFA_Object::CXFA_Object(CXFA_Document* pDocument,
@@ -43,6 +44,10 @@ WideString CXFA_Object::GetSOMExpression() {
   return pScriptContext->GetSomExpression(ToNode(this));
 }
 
+CXFA_List* CXFA_Object::AsList() {
+  return IsList() ? static_cast<CXFA_List*>(this) : nullptr;
+}
+
 CXFA_Node* CXFA_Object::AsNode() {
   return IsNode() ? static_cast<CXFA_Node*>(this) : nullptr;
 }
@@ -51,18 +56,22 @@ CXFA_TreeList* CXFA_Object::AsTreeList() {
   return IsTreeList() ? static_cast<CXFA_TreeList*>(this) : nullptr;
 }
 
-const CXFA_Node* CXFA_Object::AsNode() const {
-  return IsNode() ? static_cast<const CXFA_Node*>(this) : nullptr;
+CXFA_ThisProxy* CXFA_Object::AsThisProxy() {
+  return IsThisProxy() ? static_cast<CXFA_ThisProxy*>(this) : nullptr;
 }
 
-const CXFA_TreeList* CXFA_Object::AsTreeList() const {
-  return IsTreeList() ? static_cast<const CXFA_TreeList*>(this) : nullptr;
+CXFA_List* ToList(CXFA_Object* pObj) {
+  return pObj ? pObj->AsList() : nullptr;
 }
 
 CXFA_Node* ToNode(CXFA_Object* pObj) {
   return pObj ? pObj->AsNode() : nullptr;
 }
 
-const CXFA_Node* ToNode(const CXFA_Object* pObj) {
-  return pObj ? pObj->AsNode() : nullptr;
+CXFA_TreeList* ToTreeList(CXFA_Object* pObj) {
+  return pObj ? pObj->AsTreeList() : nullptr;
+}
+
+CXFA_ThisProxy* ToThisProxy(CXFA_Object* pObj) {
+  return pObj ? pObj->AsThisProxy() : nullptr;
 }
diff --git a/xfa/fxfa/parser/cxfa_object.h b/xfa/fxfa/parser/cxfa_object.h
index 023516a05e..173bf23f25 100644
--- a/xfa/fxfa/parser/cxfa_object.h
+++ b/xfa/fxfa/parser/cxfa_object.h
@@ -24,12 +24,14 @@ enum class XFA_ObjectType {
   TreeList,
   ContainerNode,
   ContentNode,
-  VariablesThis
+  ThisProxy,
 };
 
 class CJX_Object;
 class CXFA_Document;
+class CXFA_List;
 class CXFA_Node;
+class CXFA_ThisProxy;
 class CXFA_TreeList;
 
 class CXFA_Object : public CFXJSE_HostObject {
@@ -42,6 +44,10 @@ class CXFA_Object : public CFXJSE_HostObject {
   CXFA_Document* GetDocument() const { return m_pDocument.Get(); }
   XFA_ObjectType GetObjectType() const { return m_objectType; }
 
+  bool IsList() const {
+    return m_objectType == XFA_ObjectType::List ||
+           m_objectType == XFA_ObjectType::TreeList;
+  }
   bool IsNode() const {
     return m_objectType == XFA_ObjectType::Node ||
            m_objectType == XFA_ObjectType::NodeC ||
@@ -50,7 +56,7 @@ class CXFA_Object : public CFXJSE_HostObject {
            m_objectType == XFA_ObjectType::TextNode ||
            m_objectType == XFA_ObjectType::ContainerNode ||
            m_objectType == XFA_ObjectType::ContentNode ||
-           m_objectType == XFA_ObjectType::VariablesThis;
+           m_objectType == XFA_ObjectType::ThisProxy;
   }
   bool IsTreeList() const { return m_objectType == XFA_ObjectType::TreeList; }
   bool IsContentNode() const {
@@ -61,15 +67,12 @@ class CXFA_Object : public CFXJSE_HostObject {
   }
   bool IsModelNode() const { return m_objectType == XFA_ObjectType::ModelNode; }
   bool IsNodeV() const { return m_objectType == XFA_ObjectType::NodeV; }
-  bool IsVariablesThis() const {
-    return m_objectType == XFA_ObjectType::VariablesThis;
-  }
+  bool IsThisProxy() const { return m_objectType == XFA_ObjectType::ThisProxy; }
 
+  CXFA_List* AsList();
   CXFA_Node* AsNode();
   CXFA_TreeList* AsTreeList();
-
-  const CXFA_Node* AsNode() const;
-  const CXFA_TreeList* AsTreeList() const;
+  CXFA_ThisProxy* AsThisProxy();
 
   CJX_Object* JSObject() { return m_pJSObject.get(); }
   const CJX_Object* JSObject() const { return m_pJSObject.get(); }
@@ -99,11 +102,13 @@ class CXFA_Object : public CFXJSE_HostObject {
   const XFA_Element m_elementType;
   const uint32_t m_elementNameHash;
   const WideStringView m_elementName;
-
   std::unique_ptr<CJX_Object> m_pJSObject;
 };
 
+// Helper functions that permit nullptr arguments.
+CXFA_List* ToList(CXFA_Object* pObj);
 CXFA_Node* ToNode(CXFA_Object* pObj);
-const CXFA_Node* ToNode(const CXFA_Object* pObj);
+CXFA_TreeList* ToTreeList(CXFA_Object* pObj);
+CXFA_ThisProxy* ToThisProxy(CXFA_Object* pObj);
 
 #endif  // XFA_FXFA_PARSER_CXFA_OBJECT_H_
diff --git a/xfa/fxfa/parser/cxfa_thisproxy.cpp b/xfa/fxfa/parser/cxfa_thisproxy.cpp
index a3593e99b5..60a90b0931 100644
--- a/xfa/fxfa/parser/cxfa_thisproxy.cpp
+++ b/xfa/fxfa/parser/cxfa_thisproxy.cpp
@@ -10,15 +10,9 @@
 #include "third_party/base/ptr_util.h"
 #include "xfa/fxfa/parser/cxfa_node.h"
 
-// static
-CXFA_ThisProxy* CXFA_ThisProxy::FromCXFAObject(CXFA_Object* that) {
-  return that && that->IsVariablesThis() ? static_cast<CXFA_ThisProxy*>(that)
-                                         : nullptr;
-}
-
 CXFA_ThisProxy::CXFA_ThisProxy(CXFA_Node* pThisNode, CXFA_Node* pScriptNode)
     : CXFA_Object(pThisNode->GetDocument(),
-                  XFA_ObjectType::VariablesThis,
+                  XFA_ObjectType::ThisProxy,
                   XFA_Element::Unknown,
                   WideStringView(),
                   pdfium::MakeUnique<CJX_Object>(this)),
diff --git a/xfa/fxfa/parser/cxfa_thisproxy.h b/xfa/fxfa/parser/cxfa_thisproxy.h
index e86a6b5534..197a97da67 100644
--- a/xfa/fxfa/parser/cxfa_thisproxy.h
+++ b/xfa/fxfa/parser/cxfa_thisproxy.h
@@ -13,8 +13,6 @@
 
 class CXFA_ThisProxy : public CXFA_Object {
  public:
-  static CXFA_ThisProxy* FromCXFAObject(CXFA_Object* that);
-
   CXFA_ThisProxy(CXFA_Node* pThisNode, CXFA_Node* pScriptNode);
   ~CXFA_ThisProxy() override;