GTK-rs getting input from GTK::Entry - rust

Question

I have a small gtk-rs application where I am trying to display an input field and get the input from the user. At the moment I can't get the input from the input field when the user clicks the button. I know button.connect_clicked is where I need to do this but I don't know how?
My build_ui method:
use gtk::prelude::*;
use gtk::{Application, ApplicationWindow, Button, Orientation};
pub fn build_ui(app: &Application) {
let button = Button::builder()
.label("Submit")
.margin_top(12)
.margin_bottom(12)
.margin_start(12)
.margin_end(12)
.build();
let input = gtk::Entry::builder()
.placeholder_text("input")
.margin_top(12)
.margin_bottom(12)
.margin_start(12)
.margin_end(12)
.build();
let gtk_box = gtk::Box::builder()
.orientation(Orientation::Vertical)
.build();
gtk_box.append(&input);
gtk_box.append(&button);
button.connect_clicked(move | _button| {
println!("{}", input.display());
});
let window = ApplicationWindow::builder()
.application(app)
.title("gtk-app")
.child(&gtk_box)
.default_height(720)
.default_width(360)
.build();
window.present();
}
main.rs:
const APP_ID: &str = "org.my-gtk-app";
fn main() {
// Create a new application
let app = Application::builder().application_id(APP_ID).build();
// Connect to "activate" signal of `app`
app.connect_activate(home::build_ui);
// Run the application
app.run();
}
I have found this question which is almost exactly the same however when I try and implement the solution all of the .add methods throw an error stating:
the following trait bounds were not satisfied: `ApplicationWindow: IsA<CellArea>` which is required by `ApplicationWindow: gtk4::prelude::CellAreaExt`
EDIT:
Also Gtk::Entry does not have a .get_text() method according to the compiler. After doing a bit more googling around this it seems that GTK3 had a get_text method for Gtk::Entry however Gtk4 does not.
So does anyone know how to get the text from a Gtk::Entry object when using Gtk4?
EDIT 2:
I think I needed to use the .display() method however when I run the code now I don't get the text input from the user. input.display() just returns an empty string. I have updated the code samples to reflect these changes.

Answer 1

The Entry does have a text() method which gives you a GString (because Entry implements Editable), that can be converted to a rust str using as_str().
So in order to get the current text from an entry, you can do the following:
let my_input_value = my_input.text().as_str();
For completeness, here is the updated build_ui function:
pub fn build_ui(app: &Application) {
let button = Button::builder()
.label("Submit")
.margin_top(12)
.margin_bottom(12)
.margin_start(12)
.margin_end(12)
.build();
let input = gtk::Entry::builder()
.placeholder_text("input")
.margin_top(12)
.margin_bottom(12)
.margin_start(12)
.margin_end(12)
.build();
let gtk_box = gtk::Box::builder()
.orientation(Orientation::Vertical)
.build();
gtk_box.append(&input);
gtk_box.append(&button);
button.connect_clicked(move | _button| {
println!("{}", input.text().as_str());
});
let window = ApplicationWindow::builder()
.application(app)
.title("gtk-app")
.child(&gtk_box)
.default_height(720)
.default_width(360)
.build();
window.present();
}
Edit
Because GString implements Display the following works as well:
println!("{}", input.text());