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.