You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: initialize_gui.rs
    path of file: ./repos/szyszka/src
    
    the code of the file until where you have to start completion: use glib::Type;
use gtk4::prelude::*;
use gtk4::{GestureClick, ListStore, ScrolledWindow, SelectionMode, TreeView};

use crate::create_tree_view::{create_tree_view_results, create_tree_view_rules};
use crate::example_fields::update_examples;
use crate::gui_data_things::gui_data::GuiData;
use crate::help_function::{ColumnsResults, CHARACTER};
use crate::language_functions::LANGUAGES_ALL;
use crate::notebook_enum::EXAMPLE_NAME;

pub fn initialize_gui(gui_data: &GuiData) {
    setup_languages(gui_data);
    create_tree_view_in_scrolled_window(gui_data);
    create_tree_view_in_rules_window(gui_data);
    set_example_name(gui_data);
}

#[derive(Copy, Clone)]
pub enum OpenMode {
    OnlyPath,
    PathAndName,
}

fn setup_languages(gui_data: &GuiData) {
    let combo_box_settings_language = gui_data.settings.combo_box_settings_language.clone();
    for lang in LANGUAGES_ALL {
        combo_box_settings_language.append_text(lang.combo_box_text);
    }
    combo_box_settings_language.set_active(Some(0));
}

fn create_tree_view_in_scrolled_window(gui_data: &GuiData) {
    let scrolled_window_results: ScrolledWindow = gui_data.results.scrolled_window_results.clone();

    let col_types: [Type; 8] = [Type::STRING, Type::U8, Type::STRING, Type::STRING, Type::STRING, Typ
    
fn create_tree_view_in_scrolled_window(gui_data: &GuiData) {
    let scrolled_window_results: ScrolledWindow = gui_data.results.scrolled_window_results.clone();

    let col_types: [Type; 8] = [Type::STRING, Type::U8, Type::STRING, Type::STRING, Type::STRING, Type::U64, Type::U64, Type::U64];

    let list_store: ListStore = ListStore::new(&col_types);

    let tree_view: TreeView = gui_data.results.tree_view_results.clone();
    let gc_tree_view: GestureClick = gui_data.results.gc_tree_view_results.clone();
    tree_view.set_model(Some(&list_store));

    tree_view.selection().set_mode(SelectionMode::Multiple);

    gc_tree_view.set_button(0);
    gc_tree_view.connect_pressed(|gesture_click: &GestureClick, number_of_clicks: i32, _b: f64, _c: f64| {
        let tree_view = gesture_click.widget().downcast::<TreeView>().unwrap();

        if number_of_clicks == 2 {
            if gesture_click.current_button() == 1 {
                common_open_function(&tree_view, ColumnsResults::CurrentName as i32, ColumnsResults::Path as i32, &OpenMode::PathAndName);
            } else if gesture_click.current_button() == 3 {
                common_open_function(&tree_view, ColumnsResults::CurrentName as i32, ColumnsResults::Path as i32, &OpenMode::OnlyPath);
            }
        }
    });

    create_tree_view_results(&tree_view);

    scrolled_window_results.set_child(Some(&tree_view));
    scrolled_window_results.show();
}