:right-sidebar: True

GlyphItemIter
===================================================================

.. currentmodule:: gi.repository.Pango


.. versionadded:: 1.22




.. class:: GlyphItemIter(*args, **kwargs)
   :no-contents-entry:






A ``PangoGlyphItemIter`` is an iterator over the clusters in a
``PangoGlyphItem``\.

The *forward direction* of the iterator is the logical direction of text.
That is, with increasing ``start_index`` and ``start_char`` values. If ``glyph_item``
is right-to-left (that is, if ``glyph_item->item->analysis.level`` is odd),
then ``start_glyph`` decreases as the iterator moves forward.  Moreover,
in right-to-left cases, ``start_glyph`` is greater than ``end_glyph``\.

An iterator should be initialized using either
:func:`~gi.repository.Pango.GlyphItemIter.init_start` or
:func:`~gi.repository.Pango.GlyphItemIter.init_end`, for forward and backward iteration
respectively, and walked over using any desired mixture of
:func:`~gi.repository.Pango.GlyphItemIter.next_cluster` and
:func:`~gi.repository.Pango.GlyphItemIter.prev_cluster`.

A common idiom for doing a forward iteration over the clusters is:


.. code-block::
    :dedent:

    PangoGlyphItemIter cluster_iter;
    gboolean have_cluster;

    for (have_cluster = pango_glyph_item_iter_init_start (&cluster_iter,
                                                          glyph_item, text);
         have_cluster;
         have_cluster = pango_glyph_item_iter_next_cluster (&cluster_iter))
    {
      ...
    }

Note that ``text`` is the start of the text for layout, which is then
indexed by ``glyph_item->item->offset`` to get to the text of ``glyph_item``\.
The ``start_index`` and ``end_index`` values can directly index into ``text``\. The
``start_glyph``\, ``end_glyph``\, ``start_char``\, and ``end_char`` values however are
zero-based for the ``glyph_item``\.  For each cluster, the item pointed at by
the start variables is included in the cluster while the one pointed at by
end variables is not.

None of the members of a ``PangoGlyphItemIter`` should be modified manually.




Methods
-------

.. rst-class:: interim-class

.. class:: GlyphItemIter
   :no-index:


   .. method:: free() -> None

      Frees a ``PangoGlyphItem``\Iter.


      .. versionadded:: 1.22








   .. method:: init_end(glyph_item: ~gi.repository.Pango.GlyphItem, text: str) -> bool

      Initializes a ``PangoGlyphItemIter`` structure to point to the
      last cluster in a glyph item.

      See ``PangoGlyphItemIter`` for details of cluster orders.


      .. versionadded:: 1.22





      :param glyph_item: the glyph item to iterate over

      :param text: text corresponding to the glyph item




   .. method:: init_start(glyph_item: ~gi.repository.Pango.GlyphItem, text: str) -> bool

      Initializes a ``PangoGlyphItemIter`` structure to point to the
      first cluster in a glyph item.

      See ``PangoGlyphItemIter`` for details of cluster orders.


      .. versionadded:: 1.22





      :param glyph_item: the glyph item to iterate over

      :param text: text corresponding to the glyph item




   .. method:: next_cluster() -> bool

      Advances the iterator to the next cluster in the glyph item.

      See ``PangoGlyphItemIter`` for details of cluster orders.


      .. versionadded:: 1.22








   .. method:: prev_cluster() -> bool

      Moves the iterator to the preceding cluster in the glyph item.
      See ``PangoGlyphItemIter`` for details of cluster orders.


      .. versionadded:: 1.22


















Fields
------

.. rst-class:: interim-class

.. class:: GlyphItemIter
   :no-index:
   

   .. attribute:: end_char

      






   .. attribute:: end_glyph

      






   .. attribute:: end_index

      






   .. attribute:: glyph_item

      






   .. attribute:: start_char

      






   .. attribute:: start_glyph

      






   .. attribute:: start_index

      






   .. attribute:: text