new: initial implementation

src/main.rs

@@ -1,16 +1,67 @@
-use bevy::prelude::*;
-use bevy_egui::{egui, EguiContexts, EguiPlugin};
+use bevy::{prelude::*, winit::WinitSettings};
+use bevy_egui::{
+    egui::{self},
+    EguiContexts, EguiPlugin,
+};
+
+#[cfg(windows)]
+const LINE_ENDING: &str = "\r\n";
+#[cfg(not(windows))]
+const LINE_ENDING: &str = "\n";
+
+#[derive(Resource)]
+struct InputText {
+    value: String,
+}
+
+#[derive(Resource)]
+struct OutputText {
+    value: String,
+}
 
 fn main() {
     App::new()
+        .insert_resource(WinitSettings::desktop_app())
+        .insert_resource(InputText {
+            value: "".to_string(),
+        })
+        .insert_resource(OutputText {
+            value: "".to_string(),
+        })
         .add_plugins(DefaultPlugins)
         .add_plugins(EguiPlugin)
-        .add_systems(Update, ui_example_system)
+        .add_systems(Update, ui_system)
+        .add_systems(Update, process_text)
         .run();
 }
 
-fn ui_example_system(mut contexts: EguiContexts) {
-    egui::Window::new("Hello").show(contexts.ctx_mut(), |ui| {
-        ui.label("world");
+fn process_text(input_text: Res<InputText>, mut output_text: ResMut<OutputText>) {
+    let mut arr = input_text.value.lines().collect::<Vec<_>>();
+    arr.sort_by(|&a, &b| vsort::compare(a, b));
+    output_text.value = arr.join(LINE_ENDING);
+}
+
+fn ui_system(
+    mut contexts: EguiContexts,
+    mut input_text: ResMut<InputText>,
+    mut output_text: ResMut<OutputText>,
+) {
+    egui::CentralPanel::default().show(contexts.ctx_mut(), |ui| {
+        ui.horizontal(|ui| {
+            ui.vertical(|ui| {
+                ui.label("input: ");
+                ui.add_sized(
+                    [ui.available_width() / 2.0, ui.available_height()],
+                    egui::TextEdit::multiline(&mut input_text.value),
+                );
+            });
+            ui.vertical(|ui| {
+                ui.label("output: ");
+                ui.add_sized(
+                    [ui.available_width() / 2.0, ui.available_height()],
+                    egui::TextEdit::multiline(&mut output_text.value),
+                );
+            });
+        });
     });
 }