class Pango::GlyphItemIter


A Pango::GlyphItemIter is an iterator over the clusters in a Pango::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:

Pango::GlyphItemIter cluster_iter;
gboolean have_cluster;

for (have_cluster = pango_glyph_item_iter_init_start (&cluster_iter,
                                                      glyph_item, text);
     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 Pango::GlyphItemIter should be modified manually.

Defined in:



Class Method Summary

Instance Method Summary

Constructor Detail

def : Pointer(Void), transfer : GICrystal::Transfer) #

def : LibPango::GlyphItemIter, transfer : GICrystal::Transfer) #

def : Int32? = nil, start_index : Int32? = nil, start_char : Int32? = nil, end_glyph : Int32? = nil, end_index : Int32? = nil, end_char : Int32? = nil) #

Class Method Detail

def self.g_type : UInt64 #

Returns the type id (GType) registered in GLib type system.

Instance Method Detail

def ==(other : self) : Bool #
Description copied from class Reference

Returns true if this reference is the same as other. Invokes same?.

def copy : Pango::GlyphItemIter? #

def end_char : Int32 #

def end_char=(value : Int32) #

def end_glyph : Int32 #

def end_glyph=(value : Int32) #

def end_index : Int32 #

def end_index=(value : Int32) #

def free : Nil #

def glyph_item : Pango::GlyphItem? #

def glyph_item! #

def init_end(glyph_item : Pango::GlyphItem, text : String) : Bool #

def init_start(glyph_item : Pango::GlyphItem, text : String) : Bool #

def next_cluster : Bool #

def prev_cluster : Bool #

def start_char : Int32 #

def start_char=(value : Int32) #

def start_glyph : Int32 #

def start_glyph=(value : Int32) #

def start_index : Int32 #

def start_index=(value : Int32) #

def text : String? #

def text! #

def to_unsafe #