Rename CPDF_CountedObject to CFX_WeakPtr::Handlechromium/2869

This better describes its purpose, and reduces confusion
with the CFX_CountRef class, which is unrelated.

The WeakPtr class itself that manipulates handles is NYI.

Review-Url: https://codereview.chromium.org/2366673003

1 files changed, 48 insertions, 0 deletions

diff --git a/core/fxcrt/include/cfx_weak_ptr.h b/core/fxcrt/include/cfx_weak_ptr.h
new file mode 100644
index 0000000000..ea71cd01fd
--- /dev/null
+++ b/core/fxcrt/include/cfx_weak_ptr.h
@@ -0,0 +1,48 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FXCRT_INCLUDE_CFX_WEAK_PTR_H_
+#define CORE_FXCRT_INCLUDE_CFX_WEAK_PTR_H_
+
+#include "core/fxcrt/include/fx_system.h"
+
+template <class T>
+class CFX_WeakPtr {
+ public:
+  class Handle {
+   public:
+    explicit Handle(T* ptr) : m_nCount(1), m_pObj(ptr) {}
+    void reset(T* ptr) {  // CAUTION: tosses prior ref counts.
+      m_nCount = 1;
+      m_pObj = ptr;
+    }
+    void clear() {  // Now you're all weak ptrs ...
+      // Guard against accidental re-entry.
+      T* pObj = m_pObj;
+      m_pObj = nullptr;
+      delete pObj;
+    }
+    T* get() const { return m_pObj; }
+    T* AddRef() {
+      ASSERT(m_pObj);
+      ++m_nCount;
+      return m_pObj;
+    }
+    void RemoveRef() {
+      if (m_nCount)
+        --m_nCount;
+    }
+    size_t use_count() const { return m_nCount; }
+
+   protected:
+    size_t m_nCount;
+    T* m_pObj;
+  };
+
+  // TODO(tsepez): implement weak pointer operations themselves.
+};
+
+#endif  // CORE_FXCRT_INCLUDE_CFX_WEAK_PTR_H_