|
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, there are separate widget types for horizontal and vertical widgets - Gtk::HScale and Gtk::VScale. The default constructors create 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. 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. |