I made a small story on the whim of the New Year, so I will keep a record
I made a GUI JSON viewer using Ruby/GTK3. You can see how to use Ruby/GTK3 by looking in the sample directory of ruby-gnome.
This time, I referred to the following sample.
The point is one point, first create a model in TreeStore, then create Gtk :: TreeView. The rest is the reuse of the Yard code below according to the template. Somehow it is transparent in the Glade settings.