Pango.GlyphItemIter¶
record (struct)
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
GlyphItemIter.init_start or
GlyphItemIter.init_end, for forward and backward iteration
respectively, and walked over using any desired mixture of
GlyphItemIter.next_cluster and
GlyphItemIter.prev_cluster.
A common idiom for doing a forward iteration over the clusters is:
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¶
copy¶
Make a shallow copy of an existing PangoGlyphItemIter structure.
free¶
Frees a PangoGlyphItemIter.
init_end¶
Initializes a PangoGlyphItemIter structure to point to the
last cluster in a glyph item.
See PangoGlyphItemIter for details of cluster orders.
Parameters:
glyph_item— the glyph item to iterate overtext— text corresponding to the glyph item
init_start¶
Initializes a PangoGlyphItemIter structure to point to the
first cluster in a glyph item.
See PangoGlyphItemIter for details of cluster orders.
Parameters:
glyph_item— the glyph item to iterate overtext— text corresponding to the glyph item
next_cluster¶
Advances the iterator to the next cluster in the glyph item.
See PangoGlyphItemIter for details of cluster orders.
prev_cluster¶
Moves the iterator to the preceding cluster in the glyph item.
See PangoGlyphItemIter for details of cluster orders.