src/kitemviews/kitemrange.h

   1 /*
   2  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
   3  * SPDX-FileCopyrightText: 2013 Frank Reininghaus <frank78ac@googlemail.com>
   4  *
   5  * Based on the Itemviews NG project from Trolltech Labs
   6  *
   7  * SPDX-License-Identifier: GPL-2.0-or-later
   8  */
   9
  10 #ifndef KITEMRANGE_H
  11 #define KITEMRANGE_H
  12
  13 #include <QList>
  14
  15 struct KItemRange {
  16     KItemRange(int index = 0, int count = 0);
  17     int index;
  18     int count;
  19
  20     bool operator==(const KItemRange &other) const;
  21 };
  22
  23 inline KItemRange::KItemRange(int index, int count)
  24     : index(index)
  25     , count(count)
  26 {
  27 }
  28
  29 inline bool KItemRange::operator==(const KItemRange &other) const
  30 {
  31     return index == other.index && count == other.count;
  32 }
  33
  34 class KItemRangeList : public QList<KItemRange>
  35 {
  36 public:
  37     KItemRangeList()
  38         : QList<KItemRange>()
  39     {
  40     }
  41     explicit KItemRangeList(const QList<KItemRange> &list)
  42         : QList<KItemRange>(list)
  43     {
  44     }
  45
  46     template<class Container>
  47     static KItemRangeList fromSortedContainer(const Container &container);
  48
  49     KItemRangeList &operator<<(const KItemRange &range)
  50     {
  51         append(range);
  52         return *this;
  53     }
  54 };
  55
  56 template<class Container>
  57 KItemRangeList KItemRangeList::fromSortedContainer(const Container &container)
  58 {
  59     typename Container::const_iterator it = container.constBegin();
  60     const typename Container::const_iterator end = container.constEnd();
  61
  62     if (it == end) {
  63         return KItemRangeList();
  64     }
  65
  66     KItemRangeList result;
  67
  68     int index = *it;
  69     int count = 1;
  70
  71     // Remove duplicates, see https://bugs.kde.org/show_bug.cgi?id=335672
  72     while (it != end && *it == index) {
  73         ++it;
  74     }
  75
  76     while (it != end) {
  77         if (*it == index + count) {
  78             ++count;
  79         } else {
  80             result << KItemRange(index, count);
  81             index = *it;
  82             count = 1;
  83         }
  84         ++it;
  85
  86         // Remove duplicates, see https://bugs.kde.org/show_bug.cgi?id=335672
  87         while (it != end && *it == *(it - 1)) {
  88             ++it;
  89         }
  90     }
  91
  92     result << KItemRange(index, count);
  93     return result;
  94 }
  95
  96 #endif