gecko-dev/dom/base/GroupedSHistory.h

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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 GroupedSHistory_h
#define GroupedSHistory_h
#include "nsIFrameLoader.h"
#include "nsIGroupedSHistory.h"
#include "nsIPartialSHistory.h"
#include "nsTArray.h"
#include "nsWeakReference.h"
namespace mozilla {
namespace dom {
/**
* GroupedSHistory connects session histories across multiple frameloaders.
* Each frameloader has a PartialSHistory, and GroupedSHistory has an array
* refering to all participating PartialSHistory(s).
*
* The following figure illustrates the idea. In this case, the GroupedSHistory
* is composed of 3 frameloaders, and the active one is frameloader 1.
* GroupedSHistory is always attached to the active frameloader.
*
* +----------------------------------------------------+
* | |
* | v
* +------------------+ +-------------------+ +-----------------+
* | FrameLoader 1 | | PartialSHistory 1 | | GroupedSHistory |
* | (active) |----->| (active) |<--+---| |
* +------------------+ +-------------------+ | +-----------------+
* |
* +------------------+ +-------------------+ |
* | FrameLoader 2 | | PartialSHistory 2 | |
* | (inactive) |----->| (inactive) |<--+
* +------------------+ +-------------------+ |
* |
* +------------------+ +-------------------+ |
* | FrameLoader 3 | | PartialSHistory 3 | |
* | (inactive) |----->| (inactive) |<--+
* +------------------+ +-------------------+
*
* If a history navigation leads to frameloader 3, it becomes the active one,
* and GroupedSHistory is re-attached to frameloader 3.
*
* +------------------+ +-------------------+
* | FrameLoader 1 | | PartialSHistory 1 |
* | (inactive) |----->| (inactive) |<--+
* +------------------+ +-------------------+ |
* |
* +------------------+ +-------------------+ |
* | FrameLoader 2 | | PartialSHistory 2 | |
* | (inactive) |----->| (inactive) |<--+
* +------------------+ +-------------------+ |
* |
* +------------------+ +-------------------+ | +-----------------+
* | FrameLoader 3 | | PartialSHistory 3 | | | GroupedSHistory |
* | (active) |----->| (active) |<--+---| |
* +------------------+ +-------------------+ +-----------------+
* | ^
* | |
* +----------------------------------------------------+
*/
class GroupedSHistory final : public nsIGroupedSHistory
{
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS(GroupedSHistory)
NS_DECL_NSIGROUPEDSHISTORY
GroupedSHistory();
/**
* Get the value of preference "browser.groupedhistory.enabled" to determine
* if grouped session history should be enabled.
*/
static bool GroupedHistoryEnabled();
private:
~GroupedSHistory() {}
/**
* Remove all partial histories and close tabs after the given index (of
* mPartialHistories, not the index of session history entries).
*/
void PurgePartialHistories(uint32_t aLastPartialIndexToKeep);
// The total number of entries in all partial histories.
uint32_t mCount;
// The index of currently active partial history in mPartialHistories.
// Use int32_t as we have invalid index and nsCOMArray also uses int32_t.
int32_t mIndexOfActivePartialHistory;
// All participating nsIPartialSHistory objects.
nsCOMArray<nsIPartialSHistory> mPartialHistories;
};
} // namespace dom
} // namespace mozilla
#endif /* GroupedSHistory_h */