How to create a multi-process webkitgtk application (Vala) ?

Question

Hello, I want to make a web browser in Vala using webkit.

But, I don't know how to make it multi-process.

I want each tab to have its own process.

How can I do that using Vala and Gtk+.

Thanks for your answer.

Answer 1

You may want to use GtkPlug see this discussion in Vala-list (and gtk forum).

Answer 2

Check out Gtk.Plug and Gtk.Socket. You'll need to put a Gtk.Socket in each tab you open. Then spawn a process using one of the GLib.Process functions, and in that process construct a Gtk.Plug containing your WebView. Then you'll need some way of inter-process communication, for one thing to connect your plug to your socket, and to pass commands from your user-interface to the webview (such as "make the font larger").

It looks like the Vala documentation doesn't contain very much explanation, you might want to check out the C documentation for more information on how plugs and sockets work.

EDIT:

You asked for more information on inter-process communication. There are several ways, and I'm not sure which one is the most appropriate for you. Perhaps you can try GLib.Process.spawn_async_with_pipes() to start your child process and get file descriptors for the child's standard input and output. You can then pass these file descriptors to GLib.IOChannel.unix_new() to pass messages back and forth between your processes.

Another way is to use DBus, but that's more complicated and less documented.

Answer 3

Edit : I forgot a "null" parameter before "out numEntree" ; now it’s working. Thanks.

Hello ! I tried to make something working, but I failed. I tried with a chess software (gnuchess).

Here is my code :

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

    Gtk.Window window = new Gtk.Window(Gtk.WindowType.TOPLEVEL);
    window.set_default_size(300, 200);
    window.destroy.connect(Gtk.main_quit);

    int numEntree = 0;
    int numSortie = 0;

    string[] commande = {"gnuchess"};

    GLib.Process.spawn_async_with_pipes("/usr/games/", commande, null,
    GLib.SpawnFlags.FILE_AND_ARGV_ZERO, null, out numEntree, out numSortie);

    GLib.IOChannel sortie = new GLib.IOChannel.unix_new(numSortie);
    GLib.IOChannel entree = new GLib.IOChannel.unix_new(numEntree);

    string ligne = "";

    if(sortie.read_line(out ligne, null, null) != GLib.IOStatus.ERROR) {
      window.add(new Gtk.Label(ligne));
    }

    window.show_all();
    Gtk.main();
    return 0;
  }
}

I got these errors at the execution :

(Commande2:18155): GLib-WARNING **: /build/buildd/glib2.0-2.24.1/glib/giounix.c:406Error while getting flags for FD: Mauvais descripteur de fichier (9)

(Commande2:18155): GLib-CRITICAL **: g_io_channel_read_line: assertion `channel->is_readable' failed

The terminal show the lines I want my program to read :

GNU Chess 5.07 Adjusting HashSize to 1024 slots Transposition table: Entries=1K Size=40K Pawn hash table: Entries=0K Size=28K

And I got a lot of :

White (1) : Illegal move:

but I am not supposed to.

What is wrong in that code ?

Thanks for your help.