Infinite List widget from upstream feature/list-widget-reloaded branch

examples/list/src/main.rs

@@ -0,0 +1,107 @@
+use iced::widget::{
+    button, center, column, container, list, row, scrollable,
+    space::horizontal, text,
+};
+use iced::{Alignment, Element, Length, Task, Theme};
+
+pub fn main() -> iced::Result {
+    iced::application(List::new, List::update, List::view)
+        .title(List::title)
+        .window_size((500.0, 800.0))
+        .theme(List::theme)
+        .run()
+}
+
+struct List {
+    content: list::Content<(usize, State)>,
+}
+
+#[derive(Debug, Clone, Copy)]
+enum Message {
+    Update(usize),
+    Remove(usize),
+}
+
+impl List {
+    fn new() -> (Self, Task<Message>) {
+        (Self::default(), Task::none())
+    }
+
+    fn title(&self) -> String {
+        "List - Iced".to_string()
+    }
+
+    fn theme(&self) -> Theme {
+        Theme::TokyoNight
+    }
+
+    fn update(&mut self, message: Message) -> Task<Message> {
+        match message {
+            Message::Update(index) => {
+                if let Some((_id, state)) = self.content.get_mut(index) {
+                    *state = State::Updated;
+                }
+            }
+            Message::Remove(index) => {
+                let _ = self.content.remove(index);
+            }
+        }
+        Task::none()
+    }
+
+    fn view(&self) -> Element<'_, Message> {
+        center(
+            scrollable(
+                container(list(&self.content, |index, (id, state)| {
+                    row![
+                        match state {
+                            State::Idle =>
+                                Element::from(text(format!("I am item {id}!"))),
+                            State::Updated => center(
+                                column![
+                                    text(format!("I am item {id}!")),
+                                    text("... but different!")
+                                ]
+                                .spacing(20)
+                            )
+                            .height(300)
+                            .into(),
+                        },
+                        horizontal(),
+                        button("Update").on_press_maybe(
+                            matches!(state, State::Idle)
+                                .then_some(Message::Update(index))
+                        ),
+                        button("Remove")
+                            .on_press(Message::Remove(index))
+                            .style(button::danger)
+                    ]
+                    .spacing(10)
+                    .padding(5)
+                    .align_y(Alignment::Center)
+                    .into()
+                }))
+                .padding(10),
+            )
+            .width(Length::Fill),
+        )
+        .padding(10)
+        .into()
+    }
+}
+
+impl Default for List {
+    fn default() -> Self {
+        Self {
+            content: list::Content::from_iter(
+                (0..1_000).map(|id| (id, State::Idle)),
+            ),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum State {
+    Idle,
+    Updated,
+}