fix: pull oreintation workaround from imagey

it also made sense to create the thumnail in the function,
since it is easier to rotate a smaller image.
(this is fine because max_width == max_height)

flake.nix

@@ -32,6 +32,8 @@
             libxcb
           ]
           ++ lib.optionals stdenv.hostPlatform.isLinux [
+            dbus.lib
+
             vulkan-loader
             wayland
           ];

src/app/maybe_image.rs

@@ -0,0 +1,28 @@
+use iced::{task, widget};
+use image::DynamicImage;
+
+#[derive(Clone, Debug, Default)]
+pub enum MaybeImage {
+    #[default]
+    Unloaded,
+
+    #[allow(dead_code)]
+    /// should be abort_on_drop,
+    /// so that it will abort, for instance,
+    /// when it's set back to `Self::Unloaded`
+    Loading(task::Handle),
+
+    Loaded(widget::image::Handle),
+}
+impl MaybeImage {
+    pub fn handle(&self) -> Option<&widget::image::Handle> {
+        match self {
+            Self::Loaded(h) => Some(&h),
+            _ => None,
+        }
+    }
+}
+
+pub fn handle_from_image(image: DynamicImage) -> widget::image::Handle {
+    widget::image::Handle::from_rgba(image.width(), image.height(), image.into_rgba8().into_raw())
+}

src/app/mod.rs

@@ -1,27 +1,46 @@
-use std::{borrow::Cow, collections::HashMap, env, path::PathBuf, process};
+use std::{
+    borrow::Cow,
+    collections::BTreeMap,
+    env,
+    path::{Path, PathBuf},
+    process,
+    sync::Arc,
+};
 
 use iced::{
     Color, Element, Event, Length, Renderer, Subscription, Task, Theme, application, event,
     keyboard, theme, widget, window,
 };
 use ignore::{WalkBuilder, types::TypesBuilder};
+use image::ImageError;
 use rayon::iter::{ParallelBridge, ParallelIterator};
+use rfd::AsyncFileDialog;
 
-use crate::SUPPORTED_TYPES;
+use crate::{
+    SUPPORTED_TYPES,
+    app::maybe_image::{MaybeImage, handle_from_image},
+    utils,
+};
+
+mod maybe_image;
 
 #[derive(Clone, Debug)]
 enum Message {
     LoadImage(PathBuf),
+    ImageLoaded(Result<(PathBuf, widget::image::Handle), Arc<ImageError>>),
+
     UnloadImage(PathBuf),
 
     OpenImage(PathBuf),
 
+    OpenPath(Option<PathBuf>),
+
     KeyPressed(keyboard::Key, keyboard::Modifiers),
 }
 
 #[derive(Default)]
 struct State {
-    images: HashMap<PathBuf, Option<widget::image::Handle>>,
+    images: BTreeMap<PathBuf, MaybeImage>,
 
     columns: usize,
 
@@ -29,47 +48,58 @@ struct State {
 }
 
 impl State {
-    fn new() -> Self {
-        let mut builder = TypesBuilder::new();
-        builder.add_defaults();
-        for ext in SUPPORTED_TYPES {
-            builder.add("supportedImages", ext).unwrap();
-        }
-        builder.select("supportedImages");
-
+    fn new() -> (Self, Task<Message>) {
+        (
             Self {
                 columns: 3,
                 error: None,
-            images: WalkBuilder::new(
+                images: BTreeMap::new(),
+            },
+            Task::done(Message::OpenPath(Some(
                 env::args()
                     .nth(1)
-                    .map(Cow::Owned)
-                    .unwrap_or(Cow::Borrowed("./"))
-                    .as_ref(),
+                    .unwrap_or_else(|| String::from("./"))
+                    .into(),
+            ))),
         )
-            .types(builder.build().unwrap())
-            .max_depth(Some(1))
-            .build()
-            .par_bridge()
-            .filter_map(|r| {
-                r.inspect_err(|e| eprintln!("{e}"))
-                    .ok()
-                    .map(|entry| entry.into_path())
-            })
-            .filter(|path| path.is_file())
-            .map(|path| (path, None))
-            .collect(),
-        }
     }
     fn update(&mut self, message: Message) -> Task<Message> {
         match message {
             Message::LoadImage(path) => {
-                self.images
-                    .entry(path.clone())
-                    .and_modify(|e| *e = Some(widget::image::Handle::from_path(path)));
+                let entry = self.images.entry(path.clone()).or_default();
+
+                if matches!(entry, MaybeImage::Unloaded) {
+                    let size = 1000 / self.columns as u32;
+                    let (task, handle) = Task::perform(
+                        async move {
+                            utils::load_thumbnail(&path, size)
+                                .map(|img| (path, handle_from_image(img)))
+                                .map_err(Arc::new)
+                        },
+                        Message::ImageLoaded,
+                    )
+                    .abortable();
+
+                    *entry = MaybeImage::Loading(handle.abort_on_drop());
+                    return task;
                 }
+            }
+            Message::ImageLoaded(result) => {
+                self.error = result.as_ref().err().map(|e| e.to_string());
+
+                if let Ok((path, handle)) = result {
+                    let entry = self.images.entry(path).or_default();
+
+                    if matches!(entry, MaybeImage::Loaded(_)) {
+                        self.error = Some("tried to load already-loaded image!".into())
+                    } else {
+                        *entry = MaybeImage::Loaded(handle)
+                    }
+                }
+            }
+
             Message::UnloadImage(path) => {
-                self.images.entry(path).and_modify(|e| *e = None);
+                self.images.entry(path).insert_entry(MaybeImage::Unloaded);
             }
 
             Message::OpenImage(path) => {
@@ -80,6 +110,17 @@ impl State {
                     .err()
             }
 
+            Message::OpenPath(opt_path) => {
+                self.error = match opt_path {
+                    Some(_) => None,
+                    None => Some("no path to open given".into()),
+                };
+
+                if let Some(path) = opt_path {
+                    self.open_path(path);
+                }
+            }
+
             Message::KeyPressed(key, modifiers) => match key.as_ref() {
                 // input field cycling
                 keyboard::Key::Named(keyboard::key::Named::Tab) => {
@@ -90,6 +131,13 @@ impl State {
                     };
                 }
 
+                keyboard::Key::Character("o") => {
+                    return Task::perform(
+                        async { AsyncFileDialog::new().pick_folder().await.map(Into::into) },
+                        Message::OpenPath,
+                    );
+                }
+
                 keyboard::Key::Character("=" | "+") => {
                     self.columns = (self.columns + 1).clamp(1, 10)
                 }
@@ -109,18 +157,28 @@ impl State {
     fn view(&self) -> Element<'_, Message, Theme, Renderer> {
         widget::column([
             widget::scrollable(
-                widget::grid(self.images.iter().map(|(path, opt_handle)| {
-                    widget::button(
+                widget::grid(self.images.iter().map(|(path, maybe_image)| {
+                    widget::button(widget::column([
                         widget::container(
-                            widget::sensor(opt_handle.as_ref().map_or_else(
+                            widget::sensor(maybe_image.handle().map_or_else(
                                 || Element::from(widget::space()),
                                 |handle| widget::image(handle).into(),
                             ))
+                            .anticipate(2000)
                             .on_show(|_size| Message::LoadImage(path.clone()))
                             .on_hide(Message::UnloadImage(path.clone())),
                         )
-                        .center(Length::Fill),
+                        .center(Length::Fill)
+                        .into(),
+                        widget::text(
+                            path.file_name()
+                                .map_or(Cow::Borrowed("[no file]"), |extension| {
+                                    extension.to_string_lossy()
+                                }),
                         )
+                        .center()
+                        .into(),
+                    ]))
                     .style(widget::button::subtle)
                     .on_press(Message::OpenImage(path.clone()))
                     .into()
@@ -129,13 +187,10 @@ impl State {
             )
             .height(Length::Fill)
             .into(),
-            self.error
-                .as_ref()
-                .map_or_else(
+            self.error.as_ref().map_or_else(
                 || Element::from(widget::space()),
                 |error| widget::text(error).style(widget::text::danger).into(),
-                )
-                .into(),
+            ),
         ])
         .into()
     }
@@ -148,6 +203,29 @@ impl State {
             _ => None,
         })
     }
+
+    fn open_path(&mut self, path: impl AsRef<Path>) {
+        let mut builder = TypesBuilder::new();
+        builder.add_defaults();
+        for ext in SUPPORTED_TYPES {
+            builder.add("supportedImages", ext).unwrap();
+        }
+        builder.select("supportedImages");
+
+        self.images = WalkBuilder::new(path)
+            .types(builder.build().unwrap())
+            .max_depth(Some(1))
+            .build()
+            .par_bridge()
+            .filter_map(|r| {
+                r.inspect_err(|e| eprintln!("{e}"))
+                    .ok()
+                    .map(|entry| entry.into_path())
+            })
+            .filter(|path| path.is_file())
+            .map(|path| (path, MaybeImage::Unloaded))
+            .collect();
+    }
 }
 
 pub fn run() -> Result<(), impl std::error::Error> {

src/main.rs

@@ -1,4 +1,5 @@
 mod app;
+mod utils;
 
 const SUPPORTED_TYPES: &[&str; 20] = &[
     "*.png", "*.PNG", "*.jpg", "*.JPG", "*.jpeg", "*.JPEG", "*.avif", "*.jxl", "*.bmp", "*.exr",

src/utils.rs

@@ -0,0 +1,27 @@
+use std::{ffi::OsStr, path::Path};
+
+use image::{DynamicImage, ImageDecoder, ImageReader, ImageResult};
+
+pub fn load_thumbnail(path: impl AsRef<Path>, max_size: u32) -> ImageResult<DynamicImage> {
+    let mut decoder = ImageReader::open(&path)?
+        .with_guessed_format()?
+        .into_decoder()?;
+
+    let oreintation = decoder.orientation()?;
+
+    let mut decoded_image = DynamicImage::from_decoder(decoder)?.thumbnail(max_size, max_size);
+
+    // the condition is a workaround to not rotate JXL images twice;
+    // since they are already rotated by the decoder
+    // (while jpegs for instance aren't)
+    if !path
+        .as_ref()
+        .extension()
+        .map(OsStr::to_string_lossy)
+        .is_some_and(|s| s == "jxl")
+    {
+        decoded_image.apply_orientation(oreintation);
+    }
+
+    Ok(decoded_image)
+}