Missing dissconnect

[gavr123456789]

Here my app example when all good:

Peek.2021-06-17.17-59.mp4

Im using ListView with factory from this good known tutorial: https://github.com/ToshioCP/Gtk4-tutorial/blob/main/gfm/sec25.md

proc unbind_cb(factory: gtk4.SignalListItemFactory, listitem: gtk4.ListItem) =  
# There's nothing to do here.   
# If you does something like setting a signal in bind_cb,  
# then disconnecting the signal is necessary in unbind_cb.   echo "unbind"

But now I have connect in my bind_cb so i need disconnect func, and im missing it.
Here what happening:

Peek.2021-06-18.00-40.mp4

How you can see nothing bad happend with open/close empty folder test, but there are crash with others.
Absolutelly nothing in console throw(no error messages)
Im not 100% sure, but I think its because there no disconnect in my unbind_cb and when the factory starts reusing the same widgets without disconnecting the previous signals there is a problem

[gavr123456789]

Here how i dissconnected signals in my previous GTK 3 vala app 11, 12, 16, 17 lines: https://github.com/gavr123456789/FileBrowser/blob/master/src/Views/RowWidget.vala#L16
Here my current nim version GTK 4: https://github.com/gavr123456789/Katana/blob/master/createListView.nim

[gavr123456789]

May be this some how related to #118

[StefanSalewski]

May be this some how related to #118

No, should be not related. I think what demotohiro reported is a tiny well know leak for a connect() macro call. That leak is a few bytes in the macro -- unfortunately I am not good in macro writing and there is no support from core devs. And I have always the fear that I may break it, so whenever I modify macros I would have to do extended testing. That is more a task for long dark winter.

[StefanSalewski]

What exactly do you need? Is it g-signal-handler-disconnect

https://developer.gnome.org/gobject/stable/gobject-Signals.html#g-signal-handler-disconnect

That may be hard, I just try to remember when I started with gintro in 2015, I think that time I had the impression that providing a g-signal-handler-disconnect() would be very difficult. Maybe we would have to consult an expert like Arne Doehring or Disruptec for that :-(

A link to a tiny working C code example which uses that disconect would help.

[gavr123456789]

I was never interested in how Vala does this on the C side of the code, the first Googling gave out that there are several types of discount in C.
disconnect-by-func
disconnect-matched
https://stackoverflow.com/questions/8037345/how-to-disconnect-a-signal-of-gtk
I will try to create minimac example in Vala, and send to you C code that generated from it.

[gavr123456789]

Looks like Vala using disconnect-matched, here line 16 in C code:
Vala Line 16: direction_btn.toggled.disconnect(direction_toggled_handler);
Vala direction_toggled_handler: void direction_toggled_handler (ToggleButton src){...}
Vala direction_btn.toggled is a signal "toggled" of ToggleButton, Vala has strong typed signals.
C:

	RowWidget * self;
	GtkToggleButton* _tmp0_;
	guint _tmp1_;
	GtkToggleButton* _tmp2_;
	guint _tmp3_;

	self = G_TYPE_CHECK_INSTANCE_CAST (obj, TYPE_ROW_WIDGET, RowWidget);
#line 16 "../src/Views/RowWidget.vala"
	_tmp0_ = self->priv->direction_btn;
#line 16 "../src/Views/RowWidget.vala"
	g_signal_parse_name ("toggled", gtk_toggle_button_get_type (), &_tmp1_, NULL, FALSE);
#line 16 "../src/Views/RowWidget.vala"
	g_signal_handlers_disconnect_matched (_tmp0_, G_SIGNAL_MATCH_ID | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA, _tmp1_, 0, NULL, (GCallback) _row_widget_direction_toggled_handler_gtk_toggle_button_toggled, self);

So looks like first what we doing is getting signal handler in to &tmp1, by signal name + GType with g_signal_parse_name, than with this signal id we disconnecting signal by call g_signal_handlers_disconnect_matched, _row_widget_direction_toggled_handler_gtk_toggle_button_toggled here is call back that was connected:
Vala:

direction_btn.toggled.connect(direction_toggled_handler);

C:

self = (RowWidget*) g_object_new (object_type, NULL);
...
_tmp9_ = self->priv->direction_btn;
g_signal_connect_object (_tmp9_, "toggled", (GCallback) _row_widget_direction_toggled_handler_gtk_toggle_button_toggled, self, 0);

[gavr123456789]

Just done simplest example: 2 buttons, second btn is counter that increase its label, first disconnecting signal of second.

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

int counter = 0;

void button2_clicked_cb (Gtk.Button button){
  counter++;
  button.label = @"$counter";
}

int main (string[] argv) {
  var app = new Gtk.Application ("com.example.GtkApplication", GLib.ApplicationFlags.FLAGS_NONE);

  app.activate.connect (() => {
      var window = new Gtk.ApplicationWindow (app);

      var button = new Gtk.Button.with_label ("disconnect btn 2");
      var button2 = new Gtk.Button.with_label ("connected");
      button2.clicked.connect (button2_clicked_cb);
      
      button.clicked.connect (() => {
          print("disconnect");
          button2.clicked.disconnect (button2_clicked_cb);
      });


      var box = new Gtk.Box(Gtk.Orientation.HORIZONTAL, 0);
      box.append(button);
      box.append(button2);
      window.set_child (box);
      window.present ();
  });

  return app.run (argv);
}

To run make it executable and run file.
To get C code valac -C filename --pkg gtk4

[StefanSalewski]

Well, actually the function signalHandlerDisconnect() is available, so we can rewrite your last vala example as

# nim c --gc:arc t.nim
import gintro/[gtk4, gobject, gio]

var counter: int
var id: uint64

proc button2ClickedCb(button: Button) =
  inc(counter)
  button.label = $counter
  
proc buttonClickedCb(button: Button; arg: Button) =
  echo("disconnect")
  arg.signalHandlerDisconnect(id)

proc activate(app: gtk4.Application) =
  let window = newApplicationWindow(app)
  let button = newButton("disconnect btn 2")
  let button2 = newButton("connected")
  id = button2.connect("clicked", button2ClickedCb)
  button.connect("clicked", buttonClickedCb, button2)  
  let box = newBox(Orientation.horizontal, 0)
  box.append(button)
  box.append(button2)
  window.setChild(box)
  window.present()

proc main =
  let app = newApplication("org.gtk.example", {})
  app.connect("activate", activate)
  let status = app.run
  quit(status)

main()

Maybe not that nice due to the global id variable, but you can subclass a Button as described in the gintro README and add a field id, or you can create a ref object with field button and id and pass that as arg.

I am not sure if this will solve your initial issue. The link to your nim program was not working.

If this is not enough, maybe you can create your own g_signal_handlers_disconnect_matched() in pure Nim, which then calls signalHandlerDisconnect(). Note that disconnecting more than one time may give an error, you may catch that somehow.

[gavr123456789]

@StefanSalewski Thank you very much! Now everything works and does not crash.

Peek.2021-06-19.05-34.mp4

The link to your nim program was not working.

https://github.com/gavr123456789/Katana/blob/master/list_view.nim#L33
https://github.com/gavr123456789/Katana/blob/master/row_widget.nim#L11