Scale Widgets

Gtk::Scale widgets (or "sliders") allow the user to visually select and manipulate a value within a specific range. You might use one, for instance, to adjust the magnification level on a zoomed preview of a picture, or to control the brightness of a colour, or to specify the number of minutes of inactivity before a screensaver takes over the screen.

As with Scrollbars, the orientation can be either horizontal or vertical. The default constructor creates an Adjustment with all of its values set to 0.0. This isn't useful so you will need to set some Adjustment details to get meaningful behaviour.

7.2.1. Useful methods

Scale widgets can display their current value as a number next to the trough. By default they show the value, but you can change this with the set_draw_value() method.

The value displayed by a scale widget is rounded to one decimal point by default, as is the value field in its Gtk::Adjustment. You can change this with the set_digits() method.

Also, the value can be drawn in different positions relative to the trough, specified by the set_value_pos() method.

Reference