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/*
* Copyright (C) 2002 Red Hat Software
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <pango/pango-glyph-item-private.h>
G_BEGIN_DECLS
/**
* Pango2GlyphItemIter:
*
* A `Pango2GlyphItemIter` is an iterator over the clusters in a
* `Pango2GlyphItem`.
*
* 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
* [method@Pango2.GlyphItemIter.init_start] or
* [method@Pango2.GlyphItemIter.init_end], for forward and backward iteration
* respectively, and walked over using any desired mixture of
* [method@Pango2.GlyphItemIter.next_cluster] and
* [method@Pango2.GlyphItemIter.prev_cluster].
*
* A common idiom for doing a forward iteration over the clusters is:
*
* ```
* Pango2GlyphItemIter cluster_iter;
* gboolean have_cluster;
*
* for (have_cluster = pango2_glyph_item_iter_init_start (&cluster_iter,
* glyph_item, text);
* have_cluster;
* have_cluster = pango2_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 `Pango2GlyphItemIter` should be modified manually.
*/
typedef struct _Pango2GlyphItemIter Pango2GlyphItemIter;
struct _Pango2GlyphItemIter
{
Pango2GlyphItem *glyph_item;
const char *text;
int start_glyph;
int start_index;
int start_char;
int end_glyph;
int end_index;
int end_char;
};
#define PANGO2_TYPE_GLYPH_ITEM_ITER (pango2_glyph_item_iter_get_type ())
PANGO2_AVAILABLE_IN_ALL
GType pango2_glyph_item_iter_get_type (void) G_GNUC_CONST;
PANGO2_AVAILABLE_IN_ALL
Pango2GlyphItemIter * pango2_glyph_item_iter_copy (Pango2GlyphItemIter *orig);
PANGO2_AVAILABLE_IN_ALL
void pango2_glyph_item_iter_free (Pango2GlyphItemIter *iter);
PANGO2_AVAILABLE_IN_ALL
gboolean pango2_glyph_item_iter_init_start (Pango2GlyphItemIter *iter,
Pango2GlyphItem *glyph_item,
const char *text);
PANGO2_AVAILABLE_IN_ALL
gboolean pango2_glyph_item_iter_init_end (Pango2GlyphItemIter *iter,
Pango2GlyphItem *glyph_item,
const char *text);
PANGO2_AVAILABLE_IN_ALL
gboolean pango2_glyph_item_iter_next_cluster (Pango2GlyphItemIter *iter);
PANGO2_AVAILABLE_IN_ALL
gboolean pango2_glyph_item_iter_prev_cluster (Pango2GlyphItemIter *iter);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(Pango2GlyphItemIter, pango2_glyph_item_iter_free)
G_END_DECLS
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