Is there way to get GType from GObject / Widget

[gavr123456789]

Im remaking this example, and cant find a method for get type from Widget, like was donw on this line:
https://github.com/aeldemery/simple-drag-n-drop/blob/main/sources/MainWindow.vala#L84

https://valadoc.org/gobject-2.0/GLib.Object.get_type.html
Looks like this bind vala to C G_TYPE_FROM_INSTANCE

[StefanSalewski]

From the Vala docs we learn that get_type() is related to

https://developer.gnome.org/gobject/stable/gobject-Type-Information.html#G-TYPE-FROM-INSTANCE:CAPS

which should only be used in type implementations.

But we have

grep "g_type_check_instance_is_a\*" ~/.nimble/pkgs/gintro-#head/gintro/*
/home/salewski/.nimble/pkgs/gintro-#head/gintro/gobject.nim:proc g_type_check_instance_is_a*(instance: ptr TypeInstance00; ifaceType: GType): gboolean {.

what may do what you need.

Generally we should be a bit careful porting Vala examples, as Vala code may be not of highest quality. May be fine for tiny examples, but for larger ones we may get code which is not 100% correct. The aeldemery examples may be nice, but he told me that he is a german doctor, not a professional programmer. Personally I use mostly C examples from gtk4-demo and from gtk/tests.

Have you seen the ugly GIR file bugs from https://gitlab.gnome.org/GNOME/gtk/-/issues/4097

That is really ugly as it may takes years until all people have the fixed version. I may have to fix that manually somehow.

[gavr123456789]

The aeldemery examples may be nice, but he told me that he is a german doctor, not a professional programmer

He translates C examples from gtk4 demo to Vala, so I think they correct.
As you can see with DnD example https://github.com/aeldemery/gtk4_dnd/

Screen from C demo:

https://gitlab.gnome.org/GNOME/gtk/-/blob/master/demos/gtk-demo/dnd.c

[gavr123456789]

@StefanSalewski

g_type_check_instance_is_a what may do what you need

I need GType to create Gtk. Expression #144
Which I need to sort files in my file browser app.

Here Vala example
https://github.com/aeldemery/gtk4_list_colors/blob/master/sources/ColorGridWidget.vala#L66

Here my start code of doing this, but I need to get GType of FileInfo to create expression.

import gintro/[gio, glib, gtk4, gobject]

let
    file = gio.newGFileForPath(".")
    dl = gtk4.newDirectoryList("standard::name", file)
    sortListModel = newSortListModel(listModel(dl))
    listModel = sortListModel.listModel()
    expression = newPropertyExpression()
    strSorter = newStringSorter(expression)

sortListModel.sorter = strSorter

let x = cast[gio.FileInfo](listModel.getItem(0))
echo x.name

[gavr123456789]

So far, I can use the typeFromName function