Setting up a Vala development environment

Here is what I believe is the easiest way to setup a Vala development environment. If you don’t know what Vala is, you can find out here. Vala is the easiest way I found to create programs with a GUI. Some other beginner-friendly ways are PyGObject (Python language binding for GTK) and Qt for Python.

This setup uses flatpak, VSCodium, and my distro of choice, Debian.

The following commands will install:

• flatpak
• VSCodium
• the Vala SDK (which importantly contains the Vala language server)
• and the Vala VSCodium extension:

sudo apt install flatpak
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
#
flatpak install flathub com.vscodium.codium
#
flatpak install flathub org.freedesktop.Sdk.Extension.vala
#
flatpak run com.vscodium.codium --install-extension prince781.vala

Flatpak override

Now we need to instruct VSCodium to include the Vala SDK when it launches. We can do that using an override:

flatpak override --user --env FLATPAK_ENABLE_SDK_EXT=vala com.vscodium.codium

This command will add the following block to $XDG_DATA_HOME/flatpak/overrides/com.vscodium.codium:

[Environment]
FLATPAK_ENABLE_SDK_EXT=vala

Host system

Finally, let’s install the Vala compiler and GTK4 dependencies on the host system (so not in the flatpak):

sudo apt install libgtk-4-dev valac

In addition, don’t forget to include this shebang line at the top of the .vala file! (IntelliSense won’t work otherwise):

#!/usr/bin/env -S vala --pkg gtk4

Putting it all together

Let’s use the first example from the Vala docs. Create the file ExampleApp.vala and add:

#!/usr/bin/env -S vala --pkg gtk4
// ExampleApp.vala

public class ExampleApp : Gtk.Application {
  public ExampleApp () {
    Object (application_id: "com.example.App");
  }

  public override void activate () {
    var win = new Gtk.ApplicationWindow (this);

    var btn = new Gtk.Button.with_label ("Hello World");
    btn.clicked.connect (win.close);

    win.child = btn;
    win.present ();
  }

  public static int main (string[] args) {
    var app = new ExampleApp ();
    return app.run (args);
  }
}

Compile it:

valac --pkg gtk4 ExampleApp.vala

Run it:

./ExampleApp