TreeModelIterator.cpp

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// SPDX-FileCopyrightText: Copyright (c) OpenGeoSys Community (opengeosys.org)
// SPDX-License-Identifier: BSD-3-Clause
 
// ** INCLUDES **
#include "TreeModelIterator.h"
 
#include "Base/TreeItem.h"
#include "Base/TreeModel.h"
 
TreeModelIterator::TreeModelIterator(TreeModel* model)
    : _current(nullptr), _model(model)
{
    if (_model->rootItem()->childCount() > 0)
    {
        _current = _model->rootItem();
    }
}
 
TreeItem* TreeModelIterator::operator*() const
{
    return _current;
}
 
TreeModelIterator& TreeModelIterator::operator++()
{
    if (_current)
    {
        _current = next(_current);
    }
 
    return *this;
}
 
TreeItem* TreeModelIterator::next(const TreeItem* current)
{
    if (!current)
    {
        return nullptr;
    }
 
    TreeItem* next = nullptr;
    if (current->childCount())
    {
        // walk the child
        _parentIndex.push(_currentIndex);
        _currentIndex = 0;
        next = current->child(0);
    }
    else
    {
        // walk the sibling
        TreeItem* parent = current->parentItem();
        next = parent ? parent->child(_currentIndex + 1)
                      : _model->rootItem()->child(_currentIndex + 1);
        while (!next && parent)
        {
            // if we had no sibling walk up the parent
            // and try the sibling of that
            parent = parent->parentItem();
            _currentIndex = _parentIndex.pop();
            next = parent ? parent->child(_currentIndex + 1)
                          : _model->rootItem()->child(_currentIndex + 1);
        }
        if (next)
        {
            ++(_currentIndex);
        }
    }
    return next;
}