7.2.6 Range gadgets

7.2.6.3 Sliders

Sliders can be created in much the same way as scroll bars. By default, the gadget value is displayed alongside the slider itself.

Figure 7.21 A slider

You can display tick marks along the slider using the tick-marks: init-keyword, which is either #f (no tick marks are displayed) or an integer, which specifies the number of tick marks to display. The default is not to show tick marks.

If tick marks are used, they are distributed evenly along the length of the slider. You can use as many or as few tick marks as you wish, and you are advised to use a number that is natural to the user, such as 3, 5, or 10. While it is possible to use oddball numbers such as 29, this could confuse the user of your application, unless there is a compelling reason to do so.

define variable *my-slider* 
   := make(<slider>, 
           value-range: range(from: 0, to: 50)
           tick-marks: 10);