# Scale (Vala)

Tiffany Antopolski
tiffany.antopolski@gmail.com 2012
A slider widget for selecting a value from a range

# Scale

Slide the scales!

/* This is the application. */ public class MyApplication : Gtk.Application { Gtk.Scale h_scale; Gtk.Scale v_scale; Gtk.Label label;

/* Override the 'activate' signal of GLib.Application. */ protected override void activate () { var window = new Gtk.ApplicationWindow (this); window.title = "Scale Example"; window.set_default_size (400, 300); window.set_border_width (5);

h_scale = new Gtk.Scale.with_range (Gtk.Orientation.HORIZONTAL, 0.0, 100.0, 5.0); h_scale.set_digits (0); //number of decimal places displayed h_scale.set_valign (Gtk.Align.START); //horizontal alignment

var adjustment = new Gtk.Adjustment (42.0, 0.0, 100.0, 5.0, 10.0, 0.0); v_scale = new Gtk.Scale (Gtk.Orientation.VERTICAL, adjustment); v_scale.set_vexpand(true);

label = new Gtk.Label ("Move the scale handles...");

var grid = new Gtk.Grid (); grid.set_column_spacing (10); //amount of space between columns grid.set_column_homogeneous (true); //all columns same width grid.attach (h_scale, 0, 0, 1, 1); grid.attach_next_to (v_scale, h_scale, Gtk.PositionType.RIGHT, 1, 1); grid.attach (label, 0, 1, 2, 1);

h_scale.value_changed.connect (scale_moved); v_scale.value_changed.connect (scale_moved);

window.add (grid); window.show_all (); }

/* Callback function for "value-changed" signal. * The parameter refers to the scale which emitted the signal. * Since we are accessing the values of not one, but two scales, * we made the ranges instance variables, and ignore the * parameter. */ void scale_moved (Gtk.Range range) { label.set_text ("Horizontal scale is %.1f; vertical scale is %.1f.".printf (h_scale.get_value (), v_scale.get_value ())); } }

/* main creates and runs the application. */ public int main (string[] args) { return new MyApplication ().run (args); }

In this sample we used the following:

Gtk.Scale

Gtk.Adjustment

Gtk.PositionType

Gtk.Orientation