Struct pango::GlyphItemIter

pub struct GlyphItemIter(_);

A GlyphItemIter is an iterator over the clusters in a GlyphItem. The <firstterm>forward direction</firstterm> 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 <literal>``glyph_item->item->analysis.level</literal> 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 of init_start() and init_end(), for forward and backward iteration respectively, and walked over using any desired mixture of next_cluster() and prev_cluster(). A common idiom for doing a forward iteration over the clusters is: <programlisting> 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)) { … } </programlisting>

Note that text is the start of the text for layout, which is then indexed by <literal>``glyph_item->item->offset</literal> 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.

Implementations

impl GlyphItemIter

pub fn init_end(&mut self, glyph_item: &mut GlyphItem, text: &str) -> bool

Initializes a GlyphItemIter structure to point to the last cluster in a glyph item. See GlyphItemIter for details of cluster orders.

glyph_item

the glyph item to iterate over

text

text corresponding to the glyph item

Returns

false if there are no clusters in the glyph item

pub fn init_start(&mut self, glyph_item: &mut GlyphItem, text: &str) -> bool

Initializes a GlyphItemIter structure to point to the first cluster in a glyph item. See GlyphItemIter for details of cluster orders.

glyph_item

the glyph item to iterate over

text

text corresponding to the glyph item

Returns

false if there are no clusters in the glyph item

pub fn next_cluster(&mut self) -> bool

Advances the iterator to the next cluster in the glyph item. See GlyphItemIter for details of cluster orders.

Returns

true if the iterator was advanced, false if we were already on the last cluster.

pub fn prev_cluster(&mut self) -> bool

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

Returns

true if the iterator was moved, false if we were already on the first cluster.

Trait Implementations

impl Clone for GlyphItemIter

fn clone(&self) -> GlyphItemIter

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for GlyphItemIter

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for GlyphItemIter

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl Ord for GlyphItemIter

fn cmp(&self, other: &GlyphItemIter) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<GlyphItemIter> for GlyphItemIter

fn eq(&self, other: &GlyphItemIter) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &GlyphItemIter) -> bool

This method tests for !=.

impl PartialOrd<GlyphItemIter> for GlyphItemIter

fn partial_cmp(&self, other: &GlyphItemIter) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for GlyphItemIter

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for GlyphItemIter

impl StructuralEq for GlyphItemIter

impl StructuralPartialEq for GlyphItemIter