feat: display image dimensions in title

pure(er) functions are so much easier to work with
(see the bug fix in the pior commit)

there's a bit of duplicate code introduced but it's worth it

src/main.rs

@@ -79,9 +79,13 @@ impl State {
                     }
                 }
 
-                Key::Character("o") => {
-                    return self.pick_and_load_image();
+                Key::Character("o") => match self.pick_and_load_image() {
+                    Ok(task) => {
+                        self.error = None;
+                        return task;
                     }
+                    Err(e) => self.error = Some(e),
+                },
 
                 Key::Character("r") => {
                     match self.image.as_ref() {
@@ -115,9 +119,13 @@ impl State {
             },
 
             Message::Event(iced::Event::Window(window_event)) => match window_event {
-                window::Event::FileDropped(file) => {
-                    return self.load_image(file);
+                window::Event::FileDropped(file) => match self.load_image(file) {
+                    Ok(task) => {
+                        self.error = None;
+                        return task;
                     }
+                    Err(e) => self.error = Some(e),
+                },
 
                 // ignore unused window events
                 _ => {}
@@ -130,28 +138,14 @@ impl State {
         Task::none()
     }
 
-    #[must_use]
-    fn load_image(&mut self, path: impl AsRef<Path>) -> Task<Message> {
-        let task;
-        (self.error, task) = match utils::load_image(path) {
-            Ok(image) => {
+    fn load_image(&mut self, path: impl AsRef<Path>) -> Result<Task<Message>, String> {
+        utils::load_image(path).and_then(|image| {
             self.image = Some(image);
-                (None, self.allocate_image())
+            Ok(self.allocate_image())
+        })
     }
-            Err(e) => (Some(e), Task::none()),
-        };
-
-        task
-    }
-    #[must_use]
-    fn pick_and_load_image(&mut self) -> Task<Message> {
-        let task;
-        (self.error, task) = match utils::pick_image() {
-            Ok(path) => (None, self.load_image(path)),
-            Err(e) => (Some(e), Task::none()),
-        };
-
-        task
+    fn pick_and_load_image(&mut self) -> Result<Task<Message>, String> {
+        utils::pick_image().and_then(|path| self.load_image(path))
     }
 
     fn save_image(&mut self) {
@@ -176,11 +170,18 @@ impl State {
     fn subscription(&self) -> Subscription<Message> {
         event::listen().map(Message::Event)
     }
+    fn title(&self) -> String {
+        match self.image.as_ref() {
+            Some(image) => format!("imagey {}x{}", image.width(), image.height()),
+            None => format!("imagey"),
+        }
+    }
 }
 
 fn main() -> Result<(), iced::Error> {
     iced::application(State::new, State::update, State::view)
         .subscription(State::subscription)
+        .title(State::title)
         .theme(Theme::custom(
             "custom",
             theme::Palette {