TreeModelIterator Class Reference

Detailed Description

TreeModelIterator provides a way to iterate over TreeItems in a TreeModel. Usage:

TreeModelIterator it(model);
while(*it)
{
       QVariant var = (*it)->data(0);
       std::cout << var.toString().toStdString() << std::endl;
       ++it;
} 

Definition at line 34 of file TreeModelIterator.h.

#include <TreeModelIterator.h>

Collaboration diagram for TreeModelIterator:

Public Member Functions
	TreeModelIterator (TreeModel *model)
	Constructor. Provide a tree model to iterate over.
TreeItem *	operator* () const
	Dereferencing the iterator to retrieve the current TreeItem. Returns nullptr if the iterator is at the end.
TreeModelIterator &	operator++ ()
	Advance the iterator to the next TreeItem.

Private Member Functions
TreeItem *	next (const TreeItem *current)
	The traversal implementation.

Private Attributes
TreeItem *	_current
	The current TreeItem.
int	_currentIndex
	The current child index.
QStack< int >	_parentIndex
	Stack to save the child indices of the parent TreeItems.
TreeModel *	_model
	The model to iterate over.

Constructor & Destructor Documentation

TreeModelIterator()

TreeModelIterator::TreeModelIterator ( TreeModel * model )

explicit

Constructor. Provide a tree model to iterate over.

Definition at line 21 of file TreeModelIterator.cpp.

    : _current(nullptr), _model(model)
{
    if (_model->rootItem()->childCount() > 0)
    {
        _current = _model->rootItem();
    }
}

References _model, TreeItem::childCount(), and TreeModel::rootItem().

Member Function Documentation

next()

TreeItem * TreeModelIterator::next ( const TreeItem * current )

private

The traversal implementation.

Definition at line 45 of file TreeModelIterator.cpp.

{
    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;
}

References _currentIndex, _model, _parentIndex, TreeItem::child(), TreeItem::childCount(), next(), TreeItem::parentItem(), and TreeModel::rootItem().

Referenced by next(), and operator++().

operator*()

TreeItem * TreeModelIterator::operator*

(

)

const

Dereferencing the iterator to retrieve the current TreeItem. Returns nullptr if the iterator is at the end.

Definition at line 30 of file TreeModelIterator.cpp.

{
    return _current;
}

References _current.

operator++()

TreeModelIterator & TreeModelIterator::operator++

(

)

Advance the iterator to the next TreeItem.

Definition at line 35 of file TreeModelIterator.cpp.

{
    if (_current)
    {
        _current = next(_current);
    }
 
    return *this;
}

References _current, and next().

Member Data Documentation

_current

TreeItem* TreeModelIterator::_current

private

The current TreeItem.

Definition at line 49 of file TreeModelIterator.h.

Referenced by operator*(), and operator++().

_currentIndex

int TreeModelIterator::_currentIndex

private

The current child index.

Definition at line 52 of file TreeModelIterator.h.

Referenced by next().

_model

TreeModel* TreeModelIterator::_model

private

The model to iterate over.

Definition at line 58 of file TreeModelIterator.h.

Referenced by TreeModelIterator(), and next().

_parentIndex

QStack<int> TreeModelIterator::_parentIndex

private

Stack to save the child indices of the parent TreeItems.

Definition at line 55 of file TreeModelIterator.h.

Referenced by next().

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The documentation for this class was generated from the following files:

• Applications/DataExplorer/Base/TreeModelIterator.h
• Applications/DataExplorer/Base/TreeModelIterator.cpp