Make conversions for CPDF_Link explicit.

Precursor to taking a second shot at cleaning up the FPDF_*
APIs.  A FPDF_LINK is a CPDF_Dictionary, and a CPDF_Link
is a structure holding a FPDF_LINK.  This goes against the
convention that FPDF_ types get cast to CPDF_* types, so we
want to make it clear where objects are getting constructed.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/985503005

3 files changed, 17 insertions, 28 deletions

diff --git a/core/include/fpdfdoc/fpdf_doc.h b/core/include/fpdfdoc/fpdf_doc.h
index dac215e711..002f7ea1f4 100644
--- a/core/include/fpdfdoc/fpdf_doc.h
+++ b/core/include/fpdfdoc/fpdf_doc.h
@@ -545,26 +545,16 @@ protected:
 class CPDF_Link : public CFX_Object
 {
 public:
+    CPDF_Link() : m_pDict(nullptr) { }
+    explicit CPDF_Link(CPDF_Dictionary* pDict) : m_pDict(pDict) { }
 
-    CPDF_Link(CPDF_Dictionary* pDict = NULL)
-    {
-        m_pDict = pDict;
-    }
-
-    operator CPDF_Dictionary*() const
-    {
-        return m_pDict;
-    }
+    CPDF_Dictionary* GetDict() const { return m_pDict; }
 
     CFX_FloatRect		GetRect();
-
-
-
     CPDF_Dest			GetDest(CPDF_Document* pDoc);
-
     CPDF_Action			GetAction();
 
-
+protected:
     CPDF_Dictionary*	m_pDict;
 };
 #define ANNOTFLAG_INVISIBLE			1
diff --git a/core/src/fpdfdoc/doc_link.cpp b/core/src/fpdfdoc/doc_link.cpp
index b7c640af5e..4a42e21388 100644
--- a/core/src/fpdfdoc/doc_link.cpp
+++ b/core/src/fpdfdoc/doc_link.cpp
@@ -44,26 +44,26 @@ int CPDF_LinkList::CountLinks(CPDF_Page* pPage)
 CPDF_Link CPDF_LinkList::GetLink(CPDF_Page* pPage, int index)
 {
     CFX_PtrArray* pPageLinkList = GetPageLinks(pPage);
-    if (pPageLinkList == NULL) {
-        return NULL;
+    if (!pPageLinkList) {
+        return CPDF_Link();
     }
-    return (CPDF_Dictionary*)pPageLinkList->GetAt(index);
+    return CPDF_Link((CPDF_Dictionary*)pPageLinkList->GetAt(index));
 }
 CPDF_Link CPDF_LinkList::GetLinkAtPoint(CPDF_Page* pPage, FX_FLOAT pdf_x, FX_FLOAT pdf_y)
 {
     CFX_PtrArray* pPageLinkList = GetPageLinks(pPage);
-    if (pPageLinkList == NULL) {
-        return NULL;
+    if (!pPageLinkList) {
+        return CPDF_Link();
     }
     int size = pPageLinkList->GetSize();
     for (int i = size - 1; i >= 0; --i) {
-        CPDF_Link Link = (CPDF_Dictionary*)pPageLinkList->GetAt(i);
-        CPDF_Rect rect = Link.GetRect();
+        CPDF_Link link((CPDF_Dictionary*)pPageLinkList->GetAt(i));
+        CPDF_Rect rect = link.GetRect();
         if (rect.Contains(pdf_x, pdf_y)) {
-            return Link;
+            return link;
         }
     }
-    return NULL;
+    return CPDF_Link();
 }
 void CPDF_LinkList::LoadPageLinks(CPDF_Page* pPage, CFX_PtrArray* pList)
 {
diff --git a/fpdfsdk/src/fpdfdoc.cpp b/fpdfsdk/src/fpdfdoc.cpp
index ab3dd2c5b8..d1f741bca9 100644
--- a/fpdfsdk/src/fpdfdoc.cpp
+++ b/fpdfsdk/src/fpdfdoc.cpp
@@ -176,18 +176,17 @@ DLLEXPORT FPDF_LINK STDCALL FPDFLink_GetLinkAtPoint(FPDF_PAGE page, double x, do
 		pLinkList = FX_NEW CPDF_LinkList(pDoc);
 		pDoc->SetPrivateData(&THISMODULE, pLinkList, ReleaseLinkList);
 	}
-	return pLinkList->GetLinkAtPoint(pPage, (FX_FLOAT)x, (FX_FLOAT)y);
+	return pLinkList->GetLinkAtPoint(pPage, (FX_FLOAT)x, (FX_FLOAT)y).GetDict();
 }
 
 DLLEXPORT FPDF_DEST STDCALL FPDFLink_GetDest(FPDF_DOCUMENT document, FPDF_LINK pDict)
 {
 	if (!document)
 		return NULL;
-	CPDF_Document* pDoc = (CPDF_Document*)document;
 	if (!pDict)
 		return NULL;
-	CPDF_Link link = (CPDF_Dictionary*)pDict;
-
+	CPDF_Document* pDoc = (CPDF_Document*)document;
+	CPDF_Link link((CPDF_Dictionary*)pDict);
 	FPDF_DEST dest = link.GetDest(pDoc).GetObject();
 	if (dest)
 		return dest;
@@ -202,7 +201,7 @@ DLLEXPORT FPDF_ACTION STDCALL FPDFLink_GetAction(FPDF_LINK pDict)
 {
 	if (!pDict)
 		return NULL;
-	CPDF_Link link = (CPDF_Dictionary*)pDict;
+	CPDF_Link link((CPDF_Dictionary*)pDict);
 	return link.GetAction().GetDict();
 }