Fix multi_window example

examples/multi_window/src/main.rs

@@ -0,0 +1,58 @@
+use iced::multi_window::Application;
+use iced::pure::{button, column, text, Element};
+use iced::{window, Alignment, Command, Settings};
+
+pub fn main() -> iced::Result {
+    Counter::run(Settings::default())
+}
+
+struct Counter {
+    value: i32,
+}
+
+#[derive(Debug, Clone, Copy)]
+enum Message {
+    IncrementPressed,
+    DecrementPressed,
+}
+
+impl Application for Counter {
+    type Flags = ();
+    type Executor = iced::executor::Default;
+    type Message = Message;
+
+    fn new(_flags: ()) -> (Self, Command<Message>) {
+        (Self { value: 0 }, Command::none())
+    }
+
+    fn title(&self) -> String {
+        String::from("MultiWindow - Iced")
+    }
+
+    fn windows(&self) -> Vec<(window::Id, iced::window::Settings)> {
+        todo!()
+    }
+
+    fn update(&mut self, message: Message) -> Command<Message> {
+        match message {
+            Message::IncrementPressed => {
+                self.value += 1;
+            }
+            Message::DecrementPressed => {
+                self.value -= 1;
+            }
+        }
+
+        Command::none()
+    }
+
+    fn view(&self) -> Element<Message> {
+        column()
+            .padding(20)
+            .align_items(Alignment::Center)
+            .push(button("Increment").on_press(Message::IncrementPressed))
+            .push(text(self.value.to_string()).size(50))
+            .push(button("Decrement").on_press(Message::DecrementPressed))
+            .into()
+    }
+}