Struct pango::GlyphItemIter

source ·
pub struct GlyphItemIter<'item> { /* private fields */ }
Expand description

A GlyphItemIter is an iterator over the clusters in a GlyphItem.

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 pango_glyph_item_iter_init_start() or pango_glyph_item_iter_init_end(), for forward and backward iteration respectively, and walked over using any desired mixture of pango_glyph_item_iter_next_cluster() and pango_glyph_item_iter_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 GlyphItemIter should be modified manually.

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Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
The type of the elements being iterated over.
Which kind of iterator are we turning this into?
Creates an iterator from a value. Read more
Returns the type identifier of Self.

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Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Ensures that the type has been registered with the type system.
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
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The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.