pv/view/rowitemiterator.h

   1 /*
   2  * This file is part of the PulseView project.
   3  *
   4  * Copyright (C) 2014 Joel Holdsworth <joel@airwebreathe.org.uk>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #ifndef PULSEVIEW_PV_VIEW_ROWITEMITERATOR_H
  22 #define PULSEVIEW_PV_VIEW_ROWITEMITERATOR_H
  23
  24 #include <algorithm>
  25 #include <cassert>
  26 #include <iterator>
  27 #include <memory>
  28 #include <stack>
  29 #include <type_traits>
  30 #include <vector>
  31
  32 #include <boost/thread.hpp>
  33
  34 #include <pv/sigsession.h>
  35
  36 namespace pv {
  37 namespace view {
  38
  39 template<class Owner, class Item> class RowItemIterator
  40 {
  41 public:
  42         typedef typename std::conditional<std::is_const<Owner>::value,
  43                 typename Owner::item_list::const_iterator,
  44                 typename Owner::item_list::iterator>::type child_iterator;
  45
  46         typedef std::shared_ptr<Item> value_type;
  47         typedef ptrdiff_t difference_type;
  48         typedef value_type pointer;
  49         typedef value_type& reference;
  50         typedef std::forward_iterator_tag iterator_category;
  51
  52 public:
  53         RowItemIterator(Owner *owner) :
  54                 _owner(owner),
  55                 _lock(owner->session().signals_mutex()) {}
  56
  57         RowItemIterator(Owner *owner, child_iterator iter) :
  58                 _owner(owner),
  59                 _lock(owner->session().signals_mutex()) {
  60                 assert(owner);
  61                 if (iter != owner->child_items().end())
  62                         _iter_stack.push(iter);
  63         }
  64
  65         RowItemIterator(const RowItemIterator<Owner, Item> &o) :
  66                 _owner(o._owner),
  67                 _lock(*o._lock.mutex()),
  68                 _iter_stack(o._iter_stack) {}
  69
  70         reference operator*() const {
  71                 return *_iter_stack.top();
  72         }
  73
  74         reference operator->() const {
  75                 return *this;
  76         }
  77
  78         RowItemIterator<Owner, Item>& operator++() {
  79                 using std::dynamic_pointer_cast;
  80                 using std::shared_ptr;
  81
  82                 assert(_owner);
  83                 assert(!_iter_stack.empty());
  84
  85                 shared_ptr<Owner> owner(dynamic_pointer_cast<Owner>(
  86                         *_iter_stack.top()));
  87                 if (owner && !owner->child_items().empty()) {
  88                         _owner = owner.get();
  89                         _iter_stack.push(owner->child_items().begin());
  90                 } else {
  91                         ++_iter_stack.top();
  92                         while (_owner && _iter_stack.top() ==
  93                                 _owner->child_items().end()) {
  94                                 _iter_stack.pop();
  95                                 _owner = _iter_stack.empty() ? nullptr :
  96                                         (*_iter_stack.top()++)->owner();
  97                         }
  98                 }
  99
 100                 return *this;
 101         }
 102
 103         RowItemIterator<Owner, Item> operator++(int) {
 104                 RowItemIterator<Owner, Item> pre = *this;
 105                 ++*this;
 106                 return pre;
 107         }
 108
 109         bool operator==(const RowItemIterator &o) const {
 110                 return (_iter_stack.empty() && o._iter_stack.empty()) ||
 111                         (_owner == o._owner &&
 112                         _iter_stack.size() == o._iter_stack.size() &&
 113                         std::equal(
 114                                 _owner->child_items().cbegin(),
 115                                 _owner->child_items().cend(),
 116                                 o._owner->child_items().cbegin()));
 117         }
 118
 119         bool operator!=(const RowItemIterator &o) const {
 120                 return !((const RowItemIterator&)*this == o);
 121         }
 122
 123         void swap(RowItemIterator<Owner, Item>& other) {
 124                 swap(_owner, other._owner);
 125                 swap(_iter_stack, other._iter_stack);
 126         }
 127
 128 private:
 129         Owner *_owner;
 130         boost::shared_lock<boost::shared_mutex> _lock;
 131         std::stack<child_iterator> _iter_stack;
 132 };
 133
 134 template<class Owner, class Item>
 135 void swap(RowItemIterator<Owner, Item>& a, RowItemIterator<Owner, Item>& b)
 136 {
 137         a.swap(b);
 138 }
 139
 140 } // namespace view
 141 } // namespace pv
 142
 143 #endif // PULSEVIEW_PV_VIEW_ROWITEMITERATOR_H