3.2 Barmenus

A barmenu displays a bar graph whose size can be adjusted using the mouse.

(barmenu-create maxval initval barwidth
&optional title horizontal subtrackfn subtrackparms
parentw x y perm flat color)

A value is selected by: (barmenu-select m:barmenu &optional inside)
If the barmenu is not flat, its window should be destroyed following the selection using menu-destroy.

The user must first click the mouse in the bar area; then the size of the displayed bar is adjusted as the user moves the mouse pointer. In addition, the subtrackfn is called with arguments of the size of the bar followed by the subtrackparms; this can be used, for example, to display a numeric value in addition to the bar size.