palemoon-dev/platform/xpcom/glue/AppData.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_AppData_h
#define mozilla_AppData_h

#include "nsXREAppData.h"
#include "nscore.h"
#include "nsStringGlue.h"
#include "nsISupportsUtils.h"

namespace mozilla {

// Like nsXREAppData, but releases all strong refs/allocated memory
// in the destructor.
class ScopedAppData : public nsXREAppData
{
public:
  ScopedAppData()
  {
    Zero();
    this->size = sizeof(*this);
  }

  explicit ScopedAppData(const nsXREAppData* aAppData);

  void Zero() { memset(this, 0, sizeof(*this)); }

  ~ScopedAppData();
};

/**
 * Given |aStr| is holding a string allocated with NS_Alloc, or null:
 * replace the value in |aStr| with a new value.
 *
 * @param aNewValue Null is permitted. The string is cloned with NS_strdup.
 */
void SetAllocatedString(const char*& aStr, const char* aNewValue);

/**
 * Given "str" is holding a string allocated with NS_Alloc, or null:
 * replace the value in "str" with a new value.
 *
 * @param aNewValue If |aNewValue| is the empty string, |aStr| will be set
 *                  to null.
 */
void SetAllocatedString(const char*& aStr, const nsACString& aNewValue);

template<class T>
void
SetStrongPtr(T*& aPtr, T* aNewValue)
{
  NS_IF_RELEASE(aPtr);
  aPtr = aNewValue;
  NS_IF_ADDREF(aPtr);
}

} // namespace mozilla

#endif