Example: ColorChooserWidget

public class Application : Gtk.Window {

public Application () {
// Prepare Gtk.Window:
this.title = "My Gtk.ColorChooserWidget";
this.window_position = Gtk.WindowPosition.CENTER;
this.destroy.connect (Gtk.main_quit);

// The Box:
Gtk.Box box = new Gtk.Box (Gtk.Orientation.VERTICAL, 0);
this.add (box);

// The ColorChooserWidget:
Gtk.ColorChooserWidget widget = new Gtk.ColorChooserWidget ();
box.add (widget);

// A ToggleButton:
Gtk.Button toggle = new Gtk.Button.with_label ("Toggle Single/Multi Color Mode");
box.add (toggle);

toggle.clicked.connect (() => {
widget.show_editor = !widget.show_editor;
});

// A Button:
Gtk.Button button = new Gtk.Button.with_label ("Print Color");
box.add (button);

button.clicked.connect (() => {
string alpha = widget.use_alpha.to_string ();
string col = widget.rgba.to_string ();
print ("Color: %s, Alpha: %s\n", col, alpha);
});
}

public static int main (string[] args) {
Gtk.init (ref args);

Application app = new Application ();
app.show_all ();
Gtk.main ();
return 0;
}
}

 valac --pkg gtk+-3.0 Gtk.ColorChooserWidget.vala

See: