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 {
  17     KItemRange(int index = 0, int count = 0);
  18     int index;
  19     int count;
  20
  21     bool operator == (const KItemRange& other) const;
  22 };
  23
  24 inline KItemRange::KItemRange(int index, int count) :
  25     index(index),
  26     count(count)
  27 {
  28 }
  29
  30 inline bool KItemRange::operator == (const KItemRange& other) const
  31 {
  32     return index == other.index && count == other.count;
  33 }
  34
  35
  36 class KItemRangeList : public QList<KItemRange>
  37 {
  38 public:
  39     KItemRangeList() : QList<KItemRange>() {}
  40     explicit KItemRangeList(const QList<KItemRange>& list) : QList<KItemRange>(list) {}
  41
  42     template<class Container>
  43     static KItemRangeList fromSortedContainer(const Container& container);
  44
  45     KItemRangeList& operator<<(const KItemRange& range)
  46     {
  47         append(range);
  48         return *this;
  49     }
  50 };
  51
  52 template<class Container>
  53 KItemRangeList KItemRangeList::fromSortedContainer(const Container& container)
  54 {
  55     typename Container::const_iterator it = container.constBegin();
  56     const typename Container::const_iterator end = container.constEnd();
  57
  58     if (it == end) {
  59         return KItemRangeList();
  60     }
  61
  62     KItemRangeList result;
  63
  64     int index = *it;
  65     int count = 1;
  66
  67     // Remove duplicates, see https://bugs.kde.org/show_bug.cgi?id=335672
  68     while (it != end && *it == index) {
  69         ++it;
  70     }
  71
  72     while (it != end) {
  73         if (*it == index + count) {
  74             ++count;
  75         } else {
  76             result << KItemRange(index, count);
  77             index = *it;
  78             count = 1;
  79         }
  80         ++it;
  81
  82         // Remove duplicates, see https://bugs.kde.org/show_bug.cgi?id=335672
  83         while (it != end && *it == *(it - 1)) {
  84             ++it;
  85         }
  86     }
  87
  88     result << KItemRange(index, count);
  89     return result;
  90 }
  91
  92 #endif