Hi @haphantran, Slicer already has a media control widget for playing sequences that is currently used in the Sequence browser module. Sequences — 3D Slicer documentation
Did you not like that design of the sequence control widget? Could you provide feedback to how you might change it so it could be improved for all Slicer users?
I’ve not attempted Unicode symbols before but have used the Slicer sequence playback widget. Here is where the icons are defined for the Slicer playback widget. Slicer/Modules/Loadable/Sequences/Widgets/Resources/Icons at v5.2.1 · Slicer/Slicer · GitHub