Tutorial 1 - Basic Window and Button

This tutorial matches the architecture used in ref/examples/counter: typed messages, a small state struct, and a view that emits events.

# Use this when...

• You want your first complete message-flow app.
• You need a concrete pattern for button interactions.
• You are learning where state updates belong.

# Minimal example

#[derive(Default)]
struct Counter {
    value: i64,
}

#[derive(Debug, Clone, Copy)]
enum Message {
    Increment,
    Decrement,
}

# How it works

Each button maps a click to a message. update handles those messages and mutates state. view is called again and renders the new value.

# Common patterns

use iced::widget::{button, column, text};

fn view(state: &Counter) -> iced::widget::Column<'_, Message> {
    column![
        button("Increment").on_press(Message::Increment),
        text(state.value),
        button("Decrement").on_press(Message::Decrement),
    ]
}

pub fn main() -> iced::Result {
    iced::run(Counter::update, Counter::view)
}

# Gotchas / tips

• Keep button message handlers explicit; avoid generic catch-all variants.
• Let view read from state only; do not mutate in rendering code.
• Start simple (run) before introducing builder/runtime complexity.

# Next

• Tutorial 2 - Layout and Input
• Runtime API