gecko-dev/layout/generic/nsIntervalSet.h

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2.3 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
// vim:cindent:ts=8:et:sw=4:
/* 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/. */
/* a set of ranges on a number-line */
#ifndef nsIntervalSet_h___
#define nsIntervalSet_h___
#include "nsCoord.h"
#include "nsDebug.h"
typedef void *
(* IntervalSetAlloc)(size_t aBytes, void *aClosure);
typedef void
(* IntervalSetFree) (size_t aBytes, void *aPtr, void *aClosure);
/*
* A list-based class (hopefully tree-based when I get around to it)
* for representing a set of ranges on a number-line.
*/
class nsIntervalSet {
public:
typedef nscoord coord_type;
nsIntervalSet(IntervalSetAlloc aAlloc, IntervalSetFree aFree,
void* aAllocatorClosure);
~nsIntervalSet();
/*
* Include the interval [aBegin, aEnd] in the set.
*
* Removal of intervals added is not supported because that would
* require keeping track of the individual intervals that were
* added (nsIntervalMap should do that). It would be simple to
* implement ExcludeInterval if anyone wants it, though.
*/
void IncludeInterval(coord_type aBegin, coord_type aEnd);
/*
* Are _some_ points in [aBegin, aEnd] contained within the set
* of intervals?
*/
bool Intersects(coord_type aBegin, coord_type aEnd) const;
/*
* Are _all_ points in [aBegin, aEnd] contained within the set
* of intervals?
*/
bool Contains(coord_type aBegin, coord_type aEnd) const;
bool IsEmpty() const
{
return !mList;
}
private:
class Interval {
public:
Interval(coord_type aBegin, coord_type aEnd)
: mBegin(aBegin),
mEnd(aEnd),
mPrev(nullptr),
mNext(nullptr)
{
}
coord_type mBegin;
coord_type mEnd;
Interval *mPrev;
Interval *mNext;
};
void FreeInterval(Interval *aInterval);
Interval *mList;
IntervalSetAlloc mAlloc;
IntervalSetFree mFree;
void *mAllocatorClosure;
};
#endif // !defined(nsIntervalSet_h___)