Set to double.nan if value is less than travellength, or the ratio between
Called shen the scrollbar's value is changed
Returns the slider position.
Sets the slider position, and redraws the slider. Returns the new slider position.
Returns the maximum value of the slider.
Sets the new maximum value and bar lenght of the slider. Position is kept or lowered if maximum is reached.
Returns the length of the scrollbar in pixels.
Horizontal scrollbar.