Use Program API in todos example

core/src/size.rs

@@ -53,20 +53,20 @@ impl Size {
     }
 }
 
-impl From<[f32; 2]> for Size {
-    fn from([width, height]: [f32; 2]) -> Self {
+impl<T> From<[T; 2]> for Size<T> {
+    fn from([width, height]: [T; 2]) -> Self {
         Size { width, height }
     }
 }
 
-impl From<[u16; 2]> for Size {
-    fn from([width, height]: [u16; 2]) -> Self {
-        Size::new(width.into(), height.into())
+impl<T> From<(T, T)> for Size<T> {
+    fn from((width, height): (T, T)) -> Self {
+        Self { width, height }
     }
 }
 
-impl From<Vector<f32>> for Size {
-    fn from(vector: Vector<f32>) -> Self {
+impl<T> From<Vector<T>> for Size<T> {
+    fn from(vector: Vector<T>) -> Self {
         Size {
             width: vector.x,
             height: vector.y,
@@ -74,20 +74,23 @@ impl From<Vector<f32>> for Size {
     }
 }
 
-impl From<Size> for [f32; 2] {
-    fn from(size: Size) -> [f32; 2] {
+impl<T> From<Size<T>> for [T; 2] {
+    fn from(size: Size<T>) -> Self {
         [size.width, size.height]
     }
 }
 
-impl From<Size> for Vector<f32> {
-    fn from(size: Size) -> Self {
+impl<T> From<Size<T>> for Vector<T> {
+    fn from(size: Size<T>) -> Self {
         Vector::new(size.width, size.height)
     }
 }
 
-impl std::ops::Sub for Size {
-    type Output = Size;
+impl<T> std::ops::Sub for Size<T>
+where
+    T: std::ops::Sub<Output = T>,
+{
+    type Output = Size<T>;
 
     fn sub(self, rhs: Self) -> Self::Output {
         Size {

examples/todos/src/main.rs

@@ -1,14 +1,11 @@
 use iced::alignment::{self, Alignment};
-use iced::font::{self, Font};
 use iced::keyboard;
 use iced::widget::{
     self, button, checkbox, column, container, keyed_column, row, scrollable,
     text, text_input, Text,
 };
 use iced::window;
-use iced::{
-    Application, Command, Element, Length, Settings, Size, Subscription, Theme,
-};
+use iced::{Command, Element, Font, Length, Subscription};
 
 use once_cell::sync::Lazy;
 use serde::{Deserialize, Serialize};
@@ -20,17 +17,17 @@ pub fn main() -> iced::Result {
     #[cfg(not(target_arch = "wasm32"))]
     tracing_subscriber::fmt::init();
 
-    Todos::run(Settings {
-        window: window::Settings {
-            size: Size::new(500.0, 800.0),
-            ..window::Settings::default()
-        },
-        ..Settings::default()
-    })
+    iced::program(Todos::title, Todos::update, Todos::view)
+        .load(Todos::load)
+        .subscription(Todos::subscription)
+        .font(include_bytes!("../fonts/icons.ttf").as_slice())
+        .window_size((500.0, 800.0))
+        .run()
 }
 
-#[derive(Debug)]
+#[derive(Default, Debug)]
 enum Todos {
+    #[default]
     Loading,
     Loaded(State),
 }
@@ -47,7 +44,6 @@ struct State {
 #[derive(Debug, Clone)]
 enum Message {
     Loaded(Result<SavedState, LoadError>),
-    FontLoaded(Result<(), font::Error>),
     Saved(Result<(), SaveError>),
     InputChanged(String),
     CreateTask,
@@ -57,21 +53,12 @@ enum Message {
     ToggleFullscreen(window::Mode),
 }
 
-impl Application for Todos {
-    type Message = Message;
-    type Theme = Theme;
-    type Executor = iced::executor::Default;
-    type Flags = ();
-
-    fn new(_flags: ()) -> (Todos, Command<Message>) {
-        (
-            Todos::Loading,
-            Command::batch(vec![
-                font::load(include_bytes!("../fonts/icons.ttf").as_slice())
-                    .map(Message::FontLoaded),
-                Command::perform(SavedState::load(), Message::Loaded),
-            ]),
-        )
+impl Todos {
+    fn load() -> Command<Message> {
+        Command::batch(vec![Command::perform(
+            SavedState::load(),
+            Message::Loaded,
+        )])
     }
 
     fn title(&self) -> String {

src/application/program.rs

@@ -32,7 +32,7 @@
 use crate::application::{self, Application};
 use crate::executor::{self, Executor};
 use crate::window;
-use crate::{Command, Element, Font, Result, Settings, Subscription};
+use crate::{Command, Element, Font, Result, Settings, Size, Subscription};
 
 use std::borrow::Cow;
 
@@ -277,6 +277,20 @@ impl<P: Definition> Program<P> {
         }
     }
 
+    /// Sets the [`window::Settings::size`] of the [`Program`].
+    pub fn window_size(self, size: impl Into<Size>) -> Self {
+        Self {
+            settings: Settings {
+                window: window::Settings {
+                    size: size.into(),
+                    ..self.settings.window
+                },
+                ..self.settings
+            },
+            ..self
+        }
+    }
+
     /// Sets the [`window::Settings::transparent`] of the [`Program`].
     pub fn transparent(self, transparent: bool) -> Self {
         Self {