layout/generic/nsIntervalSet.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 // vim:cindent:ts=8:et:sw=4:
   3 /* ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is nsIntervalSet.
  17  *
  18  * The Initial Developer of the Original Code is Netscape Communications
  19  * Corporation.  Portions created by the Initial Developer are Copyright
  20  * (C) 2001 the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   L. David Baron <dbaron@dbaron.org> (original author)
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
  29  * of those above. If you wish to allow use of your version of this file only
  30  * under the terms of either the GPL or the LGPL, and not to allow others to
  31  * use your version of this file under the terms of the MPL, indicate your
  32  * decision by deleting the provisions above and replace them with the notice
  33  * and other provisions required by the GPL or the LGPL. If you do not delete
  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 /* a set of ranges on a number-line */
  40
  41 #ifndef nsIntervalSet_h___
  42 #define nsIntervalSet_h___
  43
  44 #include "prtypes.h"
  45 #include "nsCoord.h"
  46 #include "nsDebug.h"
  47
  48 typedef void *
  49 (* IntervalSetAlloc)(size_t aBytes, void *aClosure);
  50
  51 typedef void
  52 (* IntervalSetFree) (size_t aBytes, void *aPtr, void *aClosure);
  53
  54 /*
  55  * A list-based class (hopefully tree-based when I get around to it)
  56  * for representing a set of ranges on a number-line.
  57  */
  58 class nsIntervalSet {
  59
  60 public:
  61
  62     typedef nscoord coord_type;
  63
  64     nsIntervalSet(IntervalSetAlloc aAlloc, IntervalSetFree aFree,
  65                   void* aAllocatorClosure);
  66     ~nsIntervalSet();
  67
  68     /*
  69      * Include the interval [aBegin, aEnd] in the set.
  70      *
  71      * Removal of intervals added is not supported because that would
  72      * require keeping track of the individual intervals that were
  73      * added (nsIntervalMap should do that).  It would be simple to
  74      * implement ExcludeInterval if anyone wants it, though.
  75      */
  76     void IncludeInterval(coord_type aBegin, coord_type aEnd);
  77
  78     /*
  79      * Is the point aPoint contained within the set of intervals?
  80      */
  81     PRBool HasPoint(coord_type aPoint) const;
  82
  83     /*
  84      * Are _some_ points in [aBegin, aEnd] contained within the set
  85      * of intervals?
  86      */
  87     PRBool Intersects(coord_type aBegin, coord_type aEnd) const;
  88
  89     /*
  90      * Are _all_ points in [aBegin, aEnd] contained within the set
  91      * of intervals?
  92      */
  93     PRBool Contains(coord_type aBegin, coord_type aEnd) const;
  94
  95     PRBool IsEmpty() const
  96     {
  97         return !mList;
  98     }
  99
 100 private:
 101
 102     class Interval {
 103
 104     public:
 105         Interval(coord_type aBegin, coord_type aEnd)
 106             : mBegin(aBegin),
 107               mEnd(aEnd),
 108               mPrev(nsnull),
 109               mNext(nsnull)
 110         {
 111         }
 112
 113         coord_type mBegin;
 114         coord_type mEnd;
 115         Interval *mPrev;
 116         Interval *mNext;
 117     };
 118
 119     void FreeInterval(Interval *aInterval);
 120
 121     Interval           *mList;
 122     IntervalSetAlloc    mAlloc;
 123     IntervalSetFree     mFree;
 124     void               *mAllocatorClosure;
 125
 126 };
 127
 128 #endif // !defined(nsIntervalSet_h___)