feat: make pickers async

cargo clippy --no-deps -- --deny clippy::nursery --deny clippy::pedantic
(does not quite pass due to unused `&self` in State::subscription)
I am considering ignoring events when the file picker is opened,
but that isn't a very nice solution (should just make it async atp)

flake.nix

@@ -19,22 +19,25 @@
         cargoToml = fromTOML (builtins.readFile ./Cargo.toml);
         name = cargoToml.package.name;
 
-        dlDeps = with pkgs; [
-          # libdbus, for rfd
-          dbus.lib
+        dlDeps =
+          with pkgs;
+          [
+            # needed for both x11 and wayland
+            libxkbcommon
+            libGL
 
-          # needed for both x11 and wayland
-          libxkbcommon
-          libGL
-          vulkan-loader
+            libx11
+            libxcursor
+            libxi
+            libxcb
+          ]
+          ++ lib.optionals stdenv.hostPlatform.isLinux [
+            # libdbus, for rfd
+            dbus.lib
 
-          wayland
-
-          libx11
-          libxcursor
-          libxi
-          libxcb
-        ];
+            vulkan-loader
+            wayland
+          ];
 
         commonArgs = {
           # all that's needed for artifacts and checks

src/main.rs

@@ -1,4 +1,9 @@
-use std::{borrow::Cow, env, ffi::OsStr, path::Path};
+use std::{
+    borrow::Cow,
+    env,
+    ffi::OsStr,
+    path::{Path, PathBuf},
+};
 
 use iced::{
     Alignment, Color, Element, Length, Renderer, Subscription, Task, Theme, event,
@@ -12,7 +17,9 @@ mod utils;
 
 #[derive(Clone, Debug)]
 enum Message {
+    ImagePicked(Result<PathBuf, String>),
     ImageDisplayReady(Result<widget::image::Allocation, widget::image::Error>),
+    SavePathPicked(Result<PathBuf, String>),
 
     Event(iced::Event),
 }
@@ -29,7 +36,7 @@ struct State {
 }
 impl State {
     fn new() -> (Self, Task<Message>) {
-        let mut state = State::default();
+        let mut state = Self::default();
 
         if let Some(path) = env::args().nth(1) {
             match state.load_image(path) {
@@ -43,22 +50,25 @@ impl State {
     fn view(&self) -> Element<'_, Message, Theme, Renderer> {
         let mut main = Vec::new();
 
-        main.push(if let Some(allocation) = self.image_display.as_ref() {
-            widget::image::viewer(allocation.handle().clone())
-                .filter_method(self.image_filter)
-                .max_scale(50.)
-                .min_scale(1.)
-                .width(Length::Fill)
-                .height(Length::Fill)
-                .into()
-        } else {
-            widget::container(widget::text(include_str!("usage.txt")))
-                .height(Length::Fill)
-                .width(Length::Fill)
-                .align_x(Alignment::Center)
-                .align_y(Alignment::Center)
-                .into()
-        });
+        main.push(self.image_display.as_ref().map_or_else(
+            || {
+                widget::container(widget::text(include_str!("usage.txt")))
+                    .height(Length::Fill)
+                    .width(Length::Fill)
+                    .align_x(Alignment::Center)
+                    .align_y(Alignment::Center)
+                    .into()
+            },
+            |allocation| {
+                widget::image::viewer(allocation.handle().clone())
+                    .filter_method(self.image_filter)
+                    .max_scale(50.)
+                    .min_scale(1.)
+                    .width(Length::Fill)
+                    .height(Length::Fill)
+                    .into()
+            },
+        ));
 
         if let Some(error) = self.error.as_ref() {
             main.push(widget::text(error).style(widget::text::danger).into());
@@ -71,9 +81,26 @@ impl State {
     }
     fn update(&mut self, message: Message) -> Task<Message> {
         match message {
+            Message::ImagePicked(result) => match result.and_then(|path| self.load_image(path)) {
+                Err(e) => self.error = Some(e),
+                Ok(task) => {
+                    self.error = None;
+                    return task;
+                }
+            },
             Message::ImageDisplayReady(result) => {
                 self.image_display = Some(result.unwrap());
             }
+            Message::SavePathPicked(result) => {
+                self.error = result
+                    .and_then(|path| {
+                        self.image.as_ref().map_or_else(
+                            || Err("no image to save".into()),
+                            |image| image.save(path).map_err(|e| e.to_string()),
+                        )
+                    })
+                    .err();
+            }
 
             Message::Event(iced::Event::Keyboard(keyboard::Event::KeyPressed {
                 key,
@@ -84,39 +111,30 @@ impl State {
                 Key::Named(key::Named::Tab) => {
                     if modifiers.shift() {
                         return widget::operation::focus_previous();
-                    } else {
-                        return widget::operation::focus_next();
                     }
+                    return widget::operation::focus_next();
                 }
 
-                Key::Character("o") => match self.pick_and_load_image() {
-                    Ok(task) => {
+                Key::Character("o") => {
+                    return Task::perform(utils::pick_image(), Message::ImagePicked);
+                }
+
+                Key::Character("r") => match self.image.as_ref() {
+                    None => self.error = Some("no image to rotate".into()),
+                    Some(image) => {
                         self.error = None;
-                        return task;
+                        self.image = Some(imageops::rotate90(image));
+                        return self.allocate_image();
+                    }
+                },
+                Key::Character("i") => match self.image.as_mut() {
+                    None => self.error = Some("no image to invert".into()),
+                    Some(image) => {
+                        self.error = None;
+                        imageops::invert(image);
+                        return self.allocate_image();
                     }
-                    Err(e) => self.error = Some(e),
                 },
-
-                Key::Character("r") => {
-                    match self.image.as_ref() {
-                        None => self.error = Some("no image to rotate".into()),
-                        Some(image) => {
-                            self.error = None;
-                            self.image = Some(imageops::rotate90(image));
-                            return self.allocate_image();
-                        }
-                    };
-                }
-                Key::Character("i") => {
-                    match self.image.as_mut() {
-                        None => self.error = Some("no image to invert".into()),
-                        Some(image) => {
-                            self.error = None;
-                            imageops::invert(image);
-                            return self.allocate_image();
-                        }
-                    };
-                }
                 Key::Character("f") => {
                     self.image_filter = match self.image_filter {
                         widget::image::FilterMethod::Linear => widget::image::FilterMethod::Nearest,
@@ -128,7 +146,12 @@ impl State {
                 }
 
                 Key::Character("s") => {
-                    self.save_image();
+                    if self.image.is_some() {
+                        self.error = None;
+                        return Task::perform(utils::pick_save_path(), Message::SavePathPicked);
+                    } else {
+                        self.error = Some("no image to save".into())
+                    }
                 }
 
                 Key::Character("q") => return window::latest().and_then(window::close),
@@ -160,8 +183,7 @@ impl State {
                 "{} {}x{}",
                 path.as_ref()
                     .file_name()
-                    .map(OsStr::to_string_lossy)
-                    .unwrap_or(Cow::Borrowed("[no file]")),
+                    .map_or(Cow::Borrowed("[no file]"), OsStr::to_string_lossy),
                 image.width(),
                 image.height(),
             ));
@@ -172,13 +194,6 @@ impl State {
             self.allocate_image()
         })
     }
-    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) {
-        self.error = utils::save_image(self.image.as_ref()).err();
-    }
 
     fn allocate_image(&self) -> Task<Message> {
         let Some(image) = self.image.as_ref() else {
@@ -210,13 +225,15 @@ impl State {
         event::listen().map(Message::Event)
     }
     fn title(&self) -> String {
-        match self.info.as_ref() {
-            Some(info) => format!(
-                "imagey {info} {}",
-                utils::string_from_filter_type(self.image_filter),
-            ),
-            None => "imagey".into(),
-        }
+        self.info.as_ref().map_or_else(
+            || "imagey".into(),
+            |info| {
+                format!(
+                    "imagey {info} {}",
+                    utils::string_from_filter_type(self.image_filter),
+                )
+            },
+        )
     }
 }
 

src/utils.rs

@@ -2,12 +2,12 @@ use std::path::{Path, PathBuf};
 
 use iced::widget;
 use image::{DynamicImage, ImageDecoder, ImageReader, ImageResult, RgbaImage};
-use rfd::FileDialog;
+use rfd::AsyncFileDialog;
 
 pub fn load_image(path: impl AsRef<Path>) -> Result<RgbaImage, String> {
-    _load_image(path).map_err(|e| e.to_string())
+    load_image_impl(path).map_err(|e| e.to_string())
 }
-fn _load_image(path: impl AsRef<Path>) -> ImageResult<RgbaImage> {
+fn load_image_impl(path: impl AsRef<Path>) -> ImageResult<RgbaImage> {
     let mut decoder = ImageReader::open(path)?
         .with_guessed_format()?
         .into_decoder()?;
@@ -20,8 +20,8 @@ fn _load_image(path: impl AsRef<Path>) -> ImageResult<RgbaImage> {
 
     Ok(decoded_image.into_rgba8())
 }
-pub fn pick_image() -> Result<PathBuf, String> {
-    let Some(path) = FileDialog::new()
+pub async fn pick_image() -> Result<PathBuf, String> {
+    let Some(filehandle) = AsyncFileDialog::new()
         .add_filter(
             "image",
             &[
@@ -30,30 +30,23 @@ pub fn pick_image() -> Result<PathBuf, String> {
             ],
         )
         .pick_file()
+        .await
     else {
         return Err("no path to open provided".into());
     };
 
-    Ok(path)
+    Ok(filehandle.path().to_owned())
 }
 
-pub fn save_image(image: Option<&RgbaImage>) -> Result<(), String> {
-    let Some(image) = image else {
-        return Err("no image to save".into());
-    };
-
-    let Some(path) = FileDialog::new().save_file() else {
+pub async fn pick_save_path() -> Result<PathBuf, String> {
+    let Some(filehandle) = AsyncFileDialog::new().save_file().await else {
         return Err("no path to save provided".into());
     };
 
-    if let Err(e) = image.save(&path) {
-        return Err(e.to_string());
-    };
-
-    Ok(())
+    Ok(filehandle.path().to_owned())
 }
 
-pub fn string_from_filter_type(f: widget::image::FilterMethod) -> &'static str {
+pub const fn string_from_filter_type(f: widget::image::FilterMethod) -> &'static str {
     match f {
         widget::image::FilterMethod::Linear => "bilinear",
         widget::image::FilterMethod::Nearest => "nearest neighbor",