First steps [Vala + Gtk 3]: Hello World !!

We are going to see in this little tutorial how to take our first steps with Vala and GTK3. Let's get started:

Installing the necessary tools

sudo apt-get install valac libgtk-3-dev

The IDE:

We can find a great variety of editors which we can use / configure as IDE. Example of them are Scratch, SublimeText, geany … In my case I'm going to use Scratch (which we can find in elementary os).

Let's see the typical example of Hello World!, Which would be as follows:

And the code would look like this:

Now let's see the details of the code. We have a class which is a Gtk window.

# We initialize Gtk with arguments Gtk.init (ref args); # We create the application. Application app = new Application (); # We put the application in the center of the screen. app.window_position = Gtk.WindowPosition.CENTER; # When closing we destroy the app. app.destroy.connect (Gtk.main_quit); # We measure the window app.set_default_size (100, 50); # We create a button and connect the button click event and print a hello! var button = new Gtk.Button.with_label ("Say Hello"); button.clicked.connect (() => {print ("Hello! \ n");}); # Add the button to the app app.add (button); # We show the App / Window app.show_all ();

By clicking on the button we will get as output:

We compile and execute:

$ valac -v lol.vala --pkg gtk + -3.0 $ ./lol

Now I leave you some links of interest:

http://elementaryos.org/docs/code/the-basic-setup