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

2 files changed, 13 insertions, 23 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)
 {