1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsIntervalSet.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,89 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +// vim:cindent:ts=8:et:sw=4:
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/* a set of ranges on a number-line */
1.11 +
1.12 +#ifndef nsIntervalSet_h___
1.13 +#define nsIntervalSet_h___
1.14 +
1.15 +#include "nsCoord.h"
1.16 +
1.17 +typedef void *
1.18 +(* IntervalSetAlloc)(size_t aBytes, void *aClosure);
1.19 +
1.20 +typedef void
1.21 +(* IntervalSetFree) (size_t aBytes, void *aPtr, void *aClosure);
1.22 +
1.23 +/*
1.24 + * A list-based class (hopefully tree-based when I get around to it)
1.25 + * for representing a set of ranges on a number-line.
1.26 + */
1.27 +class nsIntervalSet {
1.28 +
1.29 +public:
1.30 +
1.31 + typedef nscoord coord_type;
1.32 +
1.33 + nsIntervalSet(IntervalSetAlloc aAlloc, IntervalSetFree aFree,
1.34 + void* aAllocatorClosure);
1.35 + ~nsIntervalSet();
1.36 +
1.37 + /*
1.38 + * Include the interval [aBegin, aEnd] in the set.
1.39 + *
1.40 + * Removal of intervals added is not supported because that would
1.41 + * require keeping track of the individual intervals that were
1.42 + * added (nsIntervalMap should do that). It would be simple to
1.43 + * implement ExcludeInterval if anyone wants it, though.
1.44 + */
1.45 + void IncludeInterval(coord_type aBegin, coord_type aEnd);
1.46 +
1.47 + /*
1.48 + * Are _some_ points in [aBegin, aEnd] contained within the set
1.49 + * of intervals?
1.50 + */
1.51 + bool Intersects(coord_type aBegin, coord_type aEnd) const;
1.52 +
1.53 + /*
1.54 + * Are _all_ points in [aBegin, aEnd] contained within the set
1.55 + * of intervals?
1.56 + */
1.57 + bool Contains(coord_type aBegin, coord_type aEnd) const;
1.58 +
1.59 + bool IsEmpty() const
1.60 + {
1.61 + return !mList;
1.62 + }
1.63 +
1.64 +private:
1.65 +
1.66 + class Interval {
1.67 +
1.68 + public:
1.69 + Interval(coord_type aBegin, coord_type aEnd)
1.70 + : mBegin(aBegin),
1.71 + mEnd(aEnd),
1.72 + mPrev(nullptr),
1.73 + mNext(nullptr)
1.74 + {
1.75 + }
1.76 +
1.77 + coord_type mBegin;
1.78 + coord_type mEnd;
1.79 + Interval *mPrev;
1.80 + Interval *mNext;
1.81 + };
1.82 +
1.83 + void FreeInterval(Interval *aInterval);
1.84 +
1.85 + Interval *mList;
1.86 + IntervalSetAlloc mAlloc;
1.87 + IntervalSetFree mFree;
1.88 + void *mAllocatorClosure;
1.89 +
1.90 +};
1.91 +
1.92 +#endif // !defined(nsIntervalSet_h___)
