Applies a partial of the font/character-run override interface to the current
text selection. When there is no selection, applies it to every character run of
the story — the library has no element-level setter for these. Used by the
decoration (underline/strikethrough) and super/subscript toolbar controls.
Applies a partial of the font/character-run override interface to the current text selection. When there is no selection, applies it to every character run of the story — the library has no element-level setter for these. Used by the decoration (underline/strikethrough) and super/subscript toolbar controls.