void pango_attr_list_update ( PangoAttrList* list, int pos, int remove, int add )
Update indices of attributes in
list for a change in the
text they refer to.
The change that this function applies is removing
bytes at position
pos and inserting
add bytes instead.
Attributes that fall entirely in the (
range are removed.
Attributes that start or end inside the (
range are shortened to reflect the removal.
Attributes start and end positions are updated if they are