chore: Adds hello world.

gui/Cargo.toml

@@ -6,3 +6,5 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+eframe = "0.27.2"
+egui = "0.27.2"

gui/src/main.rs

@@ -1,3 +1,28 @@
-fn main() {
-    println!("Hello, world!");
-}
+use eframe::egui;
+
+fn main() -> Result<(), eframe::Error> {
+    let options = eframe::NativeOptions {
+        viewport: egui::ViewportBuilder::default().with_inner_size([320.0, 240.0]),
+        ..Default::default()
+    };
+
+    // Our application state:
+    let mut name = "Arthur".to_owned();
+    let mut age = 42;
+
+    eframe::run_simple_native("My egui App", options, move |ctx, _frame| {
+        egui::CentralPanel::default().show(ctx, |ui| {
+            ui.heading("My egui Application");
+            ui.horizontal(|ui| {
+                let name_label = ui.label("Your name: ");
+                ui.text_edit_singleline(&mut name)
+                    .labelled_by(name_label.id);
+            });
+            ui.add(egui::Slider::new(&mut age, 0..=120).text("age"));
+            if ui.button("Increment").clicked() {
+                age += 1;
+            }
+            ui.label(format!("Hello '{name}', age {age}"));
+        });
+    })
+}