main.rs

use gtk::prelude::*;
use gtk::{
    ApplicationWindow, CellRendererText, Label, ListStore, Orientation, TreeView, TreeViewColumn,
    WindowPosition,
};

fn create_and_fill_model() -> ListStore {
    // Creation of a model with two rows.
    let model = ListStore::new(&[u32::static_type(), String::static_type()]);

    // Filling up the tree view.
    let entries = &["Michel", "Sara", "Liam", "Zelda", "Neo", "Octopus master"];
    for (i, entry) in entries.iter().enumerate() {
        model.insert_with_values(None, &[(0, &(i as u32 + 1)), (1, &entry)]);
    }
    model
}

fn append_column(tree: &TreeView, id: i32) {
    let column = TreeViewColumn::new();
    let cell = CellRendererText::new();

    TreeViewColumnExt::pack_start(&column, &cell, true);
    // Association of the view's column with the model's `id` column.
    TreeViewColumnExt::add_attribute(&column, &cell, "text", id);
    tree.append_column(&column);
}

fn create_and_setup_view() -> TreeView {
    // Creating the tree view.
    let tree = TreeView::new();

    tree.set_headers_visible(false);
    // Creating the two columns inside the view.
    append_column(&tree, 0);
    append_column(&tree, 1);
    tree
}

fn build_ui(application: &gtk::Application) {
    let window = ApplicationWindow::new(application);

    window.set_title("Simple TreeView example");
    window.set_position(WindowPosition::Center);

    // Creating a vertical layout to place both tree view and label in the window.
    let vertical_layout = gtk::Box::new(Orientation::Vertical, 0);

    // Creation of the label.
    let label = Label::new(None);

    let tree = create_and_setup_view();

    let model = create_and_fill_model();
    // Setting the model into the view.
    tree.set_model(Some(&model));
    // Adding the view to the layout.
    vertical_layout.add(&tree);
    // Same goes for the label.
    vertical_layout.add(&label);

    // The closure responds to selection changes by connection to "::cursor-changed" signal,
    // that gets emitted when the cursor moves (focus changes).
    tree.connect_cursor_changed(move |tree_view| {
        let selection = tree_view.selection();
        if let Some((model, iter)) = selection.selected() {
            // Now getting back the values from the row corresponding to the
            // iterator `iter`.
            //
            // The `get_value` method do the conversion between the gtk type and Rust.
            label.set_text(&format!(
                "Hello '{}' from row {}",
                model
                    .value(&iter, 1)
                    .get::<String>()
                    .expect("Treeview selection, column 1"),
                model
                    .value(&iter, 0)
                    .get::<u32>()
                    .expect("Treeview selection, column 0"),
            ));
        }
    });

    // Adding the layout to the window.
    window.add(&vertical_layout);

    window.show_all();
}

fn main() {
    let application = gtk::Application::new(
        Some("com.github.gtk-rs.examples.simple_treeview"),
        Default::default(),
    );

    application.connect_activate(build_ui);

    application.run();
}