gecko-dev/layout/base/nsFrameTraversal.h
Gerald Squelart b099eab802 Bug 1488684 - Made nsIFrame-derived classes and some others 'final' where possible - r=dbaron
All classes deriving from nsIFrame that did not have any subclasses themselves
(at the time of writing this patch) have been marked with `final`.
Some other Layout classes have also been made final, but this was opportunistic
while working on nsIFrame subclasses, and is definitely not exhaustive, further
patches welcome; refer to bug 1332680.

Advantages of marking a class final include:
- Allowing the compiler to devirtualize some method calls (i.e., calling
  virtual functions directly instead of going through the vtable),
- Indicating that the class is not currently subclassed,
- Preventing subclassing without being aware that this would remove the
  finalization benefits of the parent class.
`final` does not signify that these classes should *never* be subclassed, this
is left for developers to decide.

Differential Revision: https://phabricator.services.mozilla.com/D5020

--HG--
extra : moz-landing-system : lando
2018-09-06 01:23:14 +00:00

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1.5 KiB
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 NSFRAMETRAVERSAL_H
#define NSFRAMETRAVERSAL_H
#include "mozilla/Attributes.h"
#include "nsIFrameTraversal.h"
class nsIFrame;
nsresult NS_NewFrameTraversal(nsIFrameEnumerator **aEnumerator,
nsPresContext* aPresContext,
nsIFrame *aStart,
nsIteratorType aType,
bool aVisual,
bool aLockInScrollView,
bool aFollowOOFs,
bool aSkipPopupChecks);
nsresult NS_CreateFrameTraversal(nsIFrameTraversal** aResult);
class nsFrameTraversal final : public nsIFrameTraversal
{
public:
nsFrameTraversal();
NS_DECL_ISUPPORTS
NS_IMETHOD NewFrameTraversal(nsIFrameEnumerator **aEnumerator,
nsPresContext* aPresContext,
nsIFrame *aStart,
int32_t aType,
bool aVisual,
bool aLockInScrollView,
bool aFollowOOFs,
bool aSkipPopupChecks) override;
protected:
virtual ~nsFrameTraversal();
};
#endif //NSFRAMETRAVERSAL_H