Gtk::TreeIter< T > Class Template Reference

Typedefed as TreeModel::iterator and TreeModel::const_iterator. More...

#include <gtkmm/treeiter.h>

Inheritance diagram for Gtk::TreeIter< T >:

Public Types
using	iterator_category = std::bidirectional_iterator_tag
	TreeIter instances can be incremented and decremented. More...
using	value_type = T
	The TreeRow or TreeConstRow type to which the iterator refers. More...
using	difference_type = int
	This is not used. More...
using	reference = T &
	A reference to the TreeRow or TreeConstRow type, as yielded by operator*() More...
using	pointer = T *
	A pointer to the TreeRow or TreeConstRow type, as yielded by operator->() More...

Public Member Functions
	TreeIter ()
	Default constructor creates an invalid iterator, not referring to a model. More...
template<typename T2 , typename = typename std::enable_if< std::is_same<T, TreeConstRow>::value && std::is_same<T2, TreeRow>::value, T2>::type>
	TreeIter (const TreeIter< T2 > & src)
	iterator to const_iterator conversion. More...
template<typename T2 , typename = typename std::enable_if< std::is_same<T, TreeConstRow>::value && std::is_same<T2, TreeRow>::value, T2>::type>
TreeIter &	operator= (const TreeIter< T2 > & src)
	iterator to const_iterator assignment. More...
TreeIter &	operator++ ()
	Increment the iterator to refer to the next position in the model, and return a reference to the iterator as it is after the increment. More...
TreeIter	operator++ (int)
	Increment the iterator to refer to the next position in the model, but return a copy of the iterator as it was before the increment. More...
TreeIter &	operator-- ()
	Note that this is very slow compared to operator++(). More...
TreeIter	operator-- (int)
	Note that this is very slow compared to operator++(int). More...
reference	operator* () const
	Dereference the iterator to get a TreeRow or TreeConstRow, as appropriate. More...
pointer	operator-> () const
	Dereference the iterator to get a TreeRow or TreeConstRow, as appropriate. More...
	operator bool () const
	Discover whether the iterator is valid, and not equal to end(). More...
Public Member Functions inherited from Gtk::TreeIterBase3
bool	equal (const TreeIterBase3 & other) const
int	get_stamp () const
	This is only useful when implementing a custom Gtk::TreeModel class. More...
void	set_stamp (int stamp)
	This is only useful when implementing a custom Gtk::TreeModel class. More...
Public Member Functions inherited from Gtk::TreeIterBase
	TreeIterBase (const TreeIterBase & other) noexcept
TreeIterBase &	operator= (const TreeIterBase & other) noexcept
	TreeIterBase (TreeIterBase && other) noexcept
TreeIterBase &	operator= (TreeIterBase && other) noexcept
	TreeIterBase ()
	TreeIterBase (const GtkTreeIter * gobject)
GtkTreeIter *	gobj ()
	Provides access to the underlying C instance. More...
const GtkTreeIter *	gobj () const
	Provides access to the underlying C instance. More...

Related Functions
(Note that these are not member functions.)
bool	operator== (const TreeIterBase3 & lhs, const TreeIterBase3 & rhs)
bool	operator!= (const TreeIterBase3 & lhs, const TreeIterBase3 & rhs)

Additional Inherited Members
Static Public Member Functions inherited from Gtk::TreeIterBase
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system. More...
Protected Attributes inherited from Gtk::TreeIterBase
GtkTreeIter	gobject_

Detailed Description

template<typename T>
class Gtk::TreeIter< T >

Typedefed as TreeModel::iterator and TreeModel::const_iterator.

A Gtk::TreeModel::iterator is a reference to a specific node on a specific model. It is a generic structure with an integer and three generic pointers. These are filled in by the model in a model-specific way.

One can convert a path to an iterator by calling Gtk::TreeModel::get_iter().

These iterators are the primary way of accessing a model and are similar to the iterators used by Gtk::TextBuffer. The model interface defines a set of operations using them for navigating the model.

The lifecycle of an iterator can be a little confusing at first. Iterators are expected to always be valid for as long as the model is unchanged (and doesn't emit a signal). Additionally, some models guarantee that an iterator is valid for as long as the node it refers to is valid (most notably the Gtk::TreeStore and Gtk::ListStore).

One can convert an iterator to a TreeRow or TreeConstRow, as appropriate, by dereferencing it via TreeIter::operator*() or TreeIter::operator->(). The row classes can give nicer syntax by avoiding repeatedly dereferencing iterators. But see the warning re: reference safety in the doc of TreeIter::operator*().

Although generally uninteresting, as one always has to allow for the case where iterators do not persist beyond a signal, some very important performance enhancements were made in the sort model. As a result, the Gtk::TreeModel::Flags::ITERS_PERSIST flag was added to indicate this behaviour - see Gtk::TreeModel::get_flags().

Template Parameters

T	TreeRow for an iterator, TreeConstRow for a const_iterator.

Deprecated:

4.10: Use Gio::ListModel instead.

Member Typedef Documentation

difference_type

template <typename T >

using Gtk::TreeIter< T >::difference_type = int

This is not used.

iterator_category

template <typename T >

using Gtk::TreeIter< T >::iterator_category = std::bidirectional_iterator_tag

TreeIter instances can be incremented and decremented.

pointer

template <typename T >

using Gtk::TreeIter< T >::pointer = T*

A pointer to the TreeRow or TreeConstRow type, as yielded by operator->()

reference

template <typename T >

using Gtk::TreeIter< T >::reference = T&

A reference to the TreeRow or TreeConstRow type, as yielded by operator*()

value_type

template <typename T >

using Gtk::TreeIter< T >::value_type = T

The TreeRow or TreeConstRow type to which the iterator refers.

Constructor & Destructor Documentation

TreeIter() [1/2]

template <typename T >

Gtk::TreeIter< T >::TreeIter

(

)

Default constructor creates an invalid iterator, not referring to a model.

TreeIter() [2/2]

template <typename T >

template <typename T2 , typename = typename std::enable_if< std::is_same<T, TreeConstRow>::value && std::is_same<T2, TreeRow>::value, T2>::type>

Gtk::TreeIter< T >::TreeIter

(

const TreeIter< T2 > &

src

)

iterator to const_iterator conversion.

Member Function Documentation

operator bool()

template <typename T >

Gtk::TreeIter< T >::operator bool ( ) const

inlineexplicit

Discover whether the iterator is valid, and not equal to end().

For instance,

if (treeiter)
  do_something();

Since gtkmm 3.22:

operator*()

template <typename T >

reference Gtk::TreeIter< T >::operator* ( ) const

inline

Dereference the iterator to get a TreeRow or TreeConstRow, as appropriate.

Warning: The returned reference is implemented by casting from *this, and so the returned reference is only valid while this iter is. Thus, if you do something like auto& row = *model->append(), you get a dangling reference to the returned temporary and undefined behaviour. Thus for such cases, you must copy the returned row via auto row = *model->append() or equivalent. This risk cannot be mitigated in gtkmm v4, and the class will not be in v5.

operator++() [1/2]

template <typename T >

TreeIter & Gtk::TreeIter< T >::operator++

(

)

Increment the iterator to refer to the next position in the model, and return a reference to the iterator as it is after the increment.

operator++() [2/2]

template <typename T >

TreeIter Gtk::TreeIter< T >::operator++

(

int

)

Increment the iterator to refer to the next position in the model, but return a copy of the iterator as it was before the increment.

operator--() [1/2]

template <typename T >

TreeIter & Gtk::TreeIter< T >::operator--

(

)

Note that this is very slow compared to operator++().

Decrement the iterator to refer to the previous position in the model, and return a reference to the iterator as it is after the decrement.

operator--() [2/2]

template <typename T >

TreeIter Gtk::TreeIter< T >::operator--

(

int

)

Note that this is very slow compared to operator++(int).

Decrement the iterator to refer to the previous position in the model, but return a copy of the iterator as it was before the decrement.

operator->()

template <typename T >

pointer Gtk::TreeIter< T >::operator-> ( ) const

inline

Dereference the iterator to get a TreeRow or TreeConstRow, as appropriate.

operator=()

template <typename T >

template <typename T2 , typename = typename std::enable_if< std::is_same<T, TreeConstRow>::value && std::is_same<T2, TreeRow>::value, T2>::type>

TreeIter & Gtk::TreeIter< T >::operator=

(

const TreeIter< T2 > &

src

)

iterator to const_iterator assignment.

Friends And Related Function Documentation

operator!=()

template <typename T >

bool operator!= ( const TreeIterBase3 &  lhs, const TreeIterBase3 &  rhs  )

related

operator==()

template <typename T >

bool operator== ( const TreeIterBase3 &  lhs, const TreeIterBase3 &  rhs  )

related