Vala support for the Libgweather

The recent version of libgweather library from git master comes with the Vala bindings support. At least the Clocks App (gnome-clocks) will heavily rely on this bindings support and therefore we are very thankful to Giovanni Campagna for his fruitful cooperation and good and friendly support.

Please note additionally, that the new version of libgweather will deprecate some function calls. To obtain a new instance of the Location object the function “gweather_location_get_world” should be used instead of “gweather_location_new_world”. “gweather_location_new_world” is deprecated and should be omitted in the newly written code. There are many more, so for more details please refer to the official documentation.

In favour of this good announcement I would like to share with you a small sample code written in Vala, in which some capabilities of the libgweather library are briefly demonstrated: This example reveals how to obtain a timezone name for almost all corresponding major cities.

Sample app:

public class LocationInfo {
    private Gtk.Window window;
    private Gtk.Box box;
    private GWeather.LocationEntry location_entry;
    private Gtk.Label city_label;
    private Gtk.Label timezone_label;

    public LocationInfo () {
        Gtk.Builder builder = new Gtk.Builder ();

        try {
            builder.add_from_file ("window.ui");
        } catch (Error e) {}

        this.window = builder.get_object ("window") as Gtk.Window;

        this.window.title = "libgweather testing";
        this.window.border_width = 10;
        this.window.window_position = Gtk.WindowPosition.CENTER;
        this.window.destroy.connect (Gtk.main_quit);

        this.box = builder.get_object ("box") as Gtk.Box;
        this.location_entry =
          new GWeather.LocationEntry (GWeather.Location.get_world ());
        this.location_entry.set_activates_default (true);
        this.location_entry.changed.connect (this.location_defined);
        this.box.pack_start (location_entry);

        this.city_label = builder.get_object ("city") as Gtk.Label;
        this.timezone_label = builder.get_object ("time_zone") as Gtk.Label;
    }

    public void show () {
        this.window.show_all ();
    }

    private void location_defined () {
        GWeather.Location? l = null;
        GWeather.Timezone? t = null;

        if (this.location_entry.get_text () != "") {
            l = this.location_entry.get_location ();
        }

		if (l != null) {
			t = l.get_timezone ();

			this.city_label.set_text (l.get_city_name ());

			if (t != null)
				this.timezone_label.set_text (t.get_tzid ());
			else
				this.timezone_label.set_text ("Unknown");
		}
		else {
			this.city_label.set_text ("");
			this.timezone_label.set_text ("");
		}
	}

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

        var location_info = new LocationInfo ();
        location_info.show ();
	
		Gtk.main ();
	}
}

The code can be compiled with the following Makefile:

all:
	valac --pkg gtk+-3.0 --target-glib=2.38 gweather-sample.vala \
		--pkg gweather-3.0 -X -DGWEATHER_I_KNOW_THIS_IS_UNSTABLE

The source code can be found here: libgweather-vala.tar.gz.