Sending XKeyEvent to gtk3 applications

Question

I used following documentation to write a method in Vala to send key press events (e.g. <Ctrl>V) to the application which has the focus.

Here is the code:

public void press(string accelerator)
{
    X.KeyEvent key_event;
    if(create_key_event(accelerator, X.EventType.KeyPress, out key_event)) {
        X.Event event = (X.Event)key_event;
        key_event.display.send_event(key_event.window, false,
            X.EventMask.KeyPressMask, ref event);
    }
}

private bool create_key_event(string accelerator,
    int event_type, out X.KeyEvent key_event)
{
    // convert accelerator
    uint keysym;
    Gdk.ModifierType modifiers;
    Gtk.accelerator_parse(accelerator, out keysym, out modifiers);
    unowned X.Display display = Gdk.x11_get_default_xdisplay();
    key_event = X.KeyEvent();

    int keycode = display.keysym_to_keycode(keysym);

    if(keycode != 0) {
        X.Window root_window = Gdk.x11_get_default_root_xwindow();

        // get window with focus
        X.Window focus;
        int revert_to_return;
        display.get_input_focus(out focus, out revert_to_return);

        key_event.display = display;
        key_event.root = root_window;
        key_event.window = focus;
        key_event.subwindow = X.None;
        key_event.time = X.CURRENT_TIME;
        key_event.keycode = keycode;
        key_event.state = modifiers;
        key_event.type = event_type;
        key_event.x = 1;
        key_event.y = 1;
        key_event.x_root = 1;
        key_event.y_root = 1;
        return true;
    }

    return false;
}

This just works fine on gtk2 applications. However gtk3 applications seem to ignore such events altogether. Is there a way to send such events to gtk3 applications as well?

Answer 1

I have done some more investigation on this. It seems that such events will be received by gtk3 application when sent with the XTest extension also mention on the stated documentation.

Here is a sample in vala and you will need to bind it against xtst.vapi to be able to build it:

public void press(string accelerator)
{
  if(perform_key_event(accelerator, true)) {
    debug("Successfully pressed key " + accelerator);
  }
}

private bool perform_key_event(string accelerator, bool press)
{
    // convert accelerator
    uint keysym;
    Gdk.ModifierType modifiers;
    Gtk.accelerator_parse(accelerator, out keysym, out modifiers);
    unowned X.Display display = Gdk.x11_get_default_xdisplay();
    int keycode = display.keysym_to_keycode(keysym);

    if(keycode != 0) {

      if(Gdk.ModifierType.CONTROL_MASK in modifiers) {
        int modcode = display.keysym_to_keycode(Gdk.Key.Control_L);
        XTest.fake_key_event(display, modcode, press, delay);  
      }
      if(Gdk.ModifierType.SHIFT_MASK in modifiers) {
        int modcode = display.keysym_to_keycode(Gdk.Key.Shift_L);
        XTest.fake_key_event(display, modcode, press, delay);
      }

      X.Test.fake_key_event(display, keycode, press, 0);                
      return true;
    }

    return false;
}