init basic image viewer

src/main.rs

@@ -0,0 +1,89 @@
+use std::env;
+
+use iced::{
+    Color, Element, Renderer, Subscription, Task, Theme, color, event,
+    keyboard::{self, Key, key},
+    theme, widget,
+};
+use image::{EncodableLayout, ImageReader, RgbaImage};
+
+#[derive(Clone, Debug)]
+enum Message {
+    Event(iced::Event),
+}
+
+#[derive(Clone, Debug)]
+struct State {
+    image: RgbaImage,
+    image_handle: widget::image::Handle,
+}
+impl State {
+    fn new() -> Self {
+        let image = if let Some(path) = env::args().nth(1) {
+            ImageReader::open(path)
+                .unwrap()
+                .decode()
+                .unwrap()
+                .into_rgba8()
+        } else {
+            RgbaImage::new(100, 100)
+        };
+
+        State {
+            image_handle: widget::image::Handle::from_rgba(image.width(), image.height(), unsafe {
+                std::mem::transmute::<_, &'static [u8]>(image.as_bytes())
+            }),
+            image,
+        }
+    }
+    fn view(&self) -> Element<'_, Message, Theme, Renderer> {
+        widget::image(&self.image_handle).into()
+    }
+    fn update(&mut self, message: Message) -> Task<Message> {
+        match message {
+            Message::Event(iced::Event::Keyboard(keyboard::Event::KeyPressed {
+                key,
+                modifiers,
+                ..
+            })) => match key.as_ref() {
+                // input field cycling
+                Key::Named(key::Named::Tab) => {
+                    if modifiers.shift() {
+                        return widget::operation::focus_previous();
+                    } else {
+                        return widget::operation::focus_next();
+                    }
+                }
+
+                // ignore unused keys
+                _ => {}
+            },
+
+            // ignore unused events
+            Message::Event(_) => {}
+        }
+
+        Task::none()
+    }
+
+    fn subscription(&self) -> Subscription<Message> {
+        event::listen().map(Message::Event)
+    }
+}
+
+fn main() -> Result<(), iced::Error> {
+    iced::application(State::new, State::update, State::view)
+        .subscription(State::subscription)
+        .theme(Theme::custom(
+            "custom",
+            theme::Palette {
+                background: color!(0x080808),
+                text: Color::WHITE,
+                primary: color!(0xff00ff),
+                success: color!(0x00ff00),
+                warning: color!(0x880000),
+                danger: color!(0xff0000),
+            },
+        ))
+        .run()
+}