The orientation of a slider, or of radio buttons in a radio set.
Data type: LOGICAL
Access: Readable/Writeable
Applies to: RADIO-SET widget, SLIDER widget
If HORIZONTAL is TRUE, the orientation is horizontal; if it is FALSE, the orientation is VERTICAL. By default, the orientation of sliders is horizontal and the orientation of radio sets is vertical.
You can set this attribute only before the widget is realized.