Project Structure

Project Structure

Recommended Layout

For a typical Blinc application:

my-app/
├── Cargo.toml
├── src/
│   ├── main.rs           # Application entry point
│   ├── app.rs            # Main UI builder
│   ├── components/       # Reusable UI components
│   │   ├── mod.rs
│   │   ├── header.rs
│   │   ├── sidebar.rs
│   │   └── card.rs
│   ├── screens/          # Full-page views
│   │   ├── mod.rs
│   │   ├── home.rs
│   │   └── settings.rs
│   └── state/            # Application state
│       ├── mod.rs
│       └── app_state.rs
└── assets/               # Static assets
    ├── fonts/
    ├── images/
    └── icons/

Entry Point Pattern

// src/main.rs
use blinc_app::prelude::*;
use blinc_app::windowed::{WindowedApp, WindowedContext};

mod app;
mod components;
mod screens;
mod state;

fn main() -> Result<()> {
    tracing_subscriber::fmt()
        .with_env_filter(
            tracing_subscriber::EnvFilter::from_default_env()
                .add_directive(tracing::Level::INFO.into()),
        )
        .init();

    let config = WindowConfig {
        title: "My App".to_string(),
        width: 1200,
        height: 800,
        resizable: true,
        ..Default::default()
    };

    WindowedApp::run(config, |ctx| app::build(ctx))
}

Component Organization

Simple Component

// src/components/card.rs
use blinc_app::prelude::*;

pub fn card(title: &str) -> Div {
    div()
        .p(16.0)
        .rounded(12.0)
        .bg(Color::rgba(0.15, 0.15, 0.2, 1.0))
        .flex_col()
        .gap(8.0)
        .child(
            text(title)
                .size(18.0)
                .weight(FontWeight::SemiBold)
                .color(Color::WHITE)
        )
}

Component with Children

// src/components/card.rs
pub fn card_with_content<E: ElementBuilder>(title: &str, content: E) -> Div {
    div()
        .p(16.0)
        .rounded(12.0)
        .bg(Color::rgba(0.15, 0.15, 0.2, 1.0))
        .flex_col()
        .gap(8.0)
        .child(
            text(title)
                .size(18.0)
                .weight(FontWeight::SemiBold)
                .color(Color::WHITE)
        )
        .child(content)
}

Stateful Component with BlincComponent

// src/components/animated_card.rs
use blinc_app::prelude::*;
use blinc_app::windowed::WindowedContext;
use blinc_animation::SpringConfig;
use std::sync::Arc;

#[derive(BlincComponent)]
pub struct AnimatedCard {
    #[animation]
    scale: f32,
    #[animation]
    opacity: f32,
}

pub fn animated_card(ctx: &WindowedContext, title: &str) -> Div {
    let scale = AnimatedCard::use_scale(ctx, 1.0, SpringConfig::snappy());
    let opacity = AnimatedCard::use_opacity(ctx, 1.0, SpringConfig::gentle());

    let hover_scale = Arc::clone(&scale);
    let leave_scale = Arc::clone(&scale);

    div()
        .p(16.0)
        .rounded(12.0)
        .bg(Color::rgba(0.15, 0.15, 0.2, 1.0))
        .transform(Transform::scale(scale.lock().unwrap().get()))
        .opacity(opacity.lock().unwrap().get())
        .on_hover_enter(move |_| {
            hover_scale.lock().unwrap().set_target(1.05);
        })
        .on_hover_leave(move |_| {
            leave_scale.lock().unwrap().set_target(1.0);
        })
        .child(text(title).size(18.0).color(Color::WHITE))
}

Screen Organization

// src/screens/home.rs
use blinc_app::prelude::*;
use blinc_app::windowed::WindowedContext;
use crate::components::{header, card};

pub fn home_screen(ctx: &WindowedContext) -> impl ElementBuilder {
    div()
        .w(ctx.width)
        .h(ctx.height)
        .bg(Color::rgba(0.08, 0.08, 0.12, 1.0))
        .flex_col()
        .child(header::header(ctx))
        .child(
            div()
                .flex_1()
                .p(24.0)
                .flex_col()
                .gap(16.0)
                .child(card("Welcome"))
                .child(card("Getting Started"))
        )
}

State Management Patterns

Global App State

App-wide state lives in State<T> slots keyed by string (so every call site resolves to the same slot across rebuilds). State<T> clones are cheap — pass them around by value or reference.

// src/state/app_state.rs
use blinc_core::{State, use_state_keyed};

#[derive(Clone, Copy, PartialEq)]
pub enum Theme {
    Light,
    Dark,
}

#[derive(Clone)]
pub struct AppState {
    pub user_name:    State<String>,
    pub theme:        State<Theme>,
    pub sidebar_open: State<bool>,
}

impl AppState {
    /// Resolve every slot by string key — calling this from anywhere
    /// in the app returns the same shared handles.
    pub fn get() -> Self {
        Self {
            user_name:    use_state_keyed("app.user_name",    || String::new()),
            theme:        use_state_keyed("app.theme",        || Theme::Dark),
            sidebar_open: use_state_keyed("app.sidebar_open", || true),
        }
    }
}

Using App State

Two integration routes for reading the state:

1. Reactive property bindings (cheapest) — pass the State<T> straight to a reactive setter. Only the bound property re-evaluates when the signal changes; no subtree rebuild.

// src/app.rs
use blinc_app::prelude::*;
use blinc_app::windowed::WindowedContext;
use blinc_core::context_state::use_computed;
use crate::state::AppState;

pub fn build(ctx: &WindowedContext) -> impl ElementBuilder {
    let state = AppState::get();

    // Derived: theme → background colour. Auto-tracks `state.theme`.
    let bg_color = {
        let theme = state.theme.clone();
        use_computed(move |_g| match theme.get() {
            Theme::Light => Color::rgba(0.95, 0.95, 0.97, 1.0),
            Theme::Dark  => Color::rgba(0.08, 0.08, 0.12, 1.0),
        })
    };

    div()
        .w(ctx.width)
        .h(ctx.height)
        .flex_row()
        .bg(&bg_color)                     // re-paints on theme change
        .child(sidebar(&state))
        .child(main_content(&state))
}

2. Stateful + .deps([…]) (for subtree restructuring) — use when a signal change must swap children or branch the tree shape.

use blinc_layout::prelude::*;
use blinc_layout::stateful::{NoState, stateful};

fn sidebar(state: &AppState) -> impl ElementBuilder {
    // Derived: collapse width to 0 when closed. Reactive setter on
    // `.w()` is enough — no rebuild required.
    let width = {
        let open = state.sidebar_open.clone();
        use_computed(move |_g| if open.get() { 250.0 } else { 0.0 })
    };

    div()
        .w(&width)
        .h_full()
        .bg(Color::rgba(0.1, 0.1, 0.15, 1.0))
    // … sidebar content
}

/// Header that swaps content based on the user_name signal —
/// structural change, so it goes through `on_state`.
fn header(state: &AppState) -> impl ElementBuilder {
    let user = state.user_name.clone();
    stateful::<NoState>()
        .deps([user.signal_id()])
        .on_state(move |_ctx| {
            let name = user.get();
            if name.is_empty() {
                div().child(text("Welcome, guest"))
            } else {
                div().child(text(&format!("Welcome, {name}")))
            }
        })
}

Toggling state from anywhere:

// Inside an event handler — no ctx needed.
let state = AppState::get();
let open = state.sidebar_open.clone();
button("Toggle sidebar").on_click(move |_| {
    open.update(|v| !v);
});

Tip — keep state slots granular. A separate State<Theme> and State<bool> re-render less than a single State<AppConfig> carrying both, because each property binding only fires for the signal that actually changed.

Module Re-exports

// src/components/mod.rs
mod card;
mod header;
mod sidebar;
mod animated_card;

pub use card::*;
pub use header::*;
pub use sidebar::*;
pub use animated_card::*;

// src/screens/mod.rs
mod home;
mod settings;

pub use home::*;
pub use settings::*;

Asset Loading

For images and other assets, use relative paths from your project root:

// Load an image
image("assets/images/logo.png")
    .w(100.0)
    .h(100.0)
    .contain()

// Load an SVG icon
svg("assets/icons/menu.svg")
    .w(24.0)
    .h(24.0)
    .tint(Color::WHITE)

Tips

1. Keep components small - Each component should do one thing well
2. Use BlincComponent - For any component with animations or complex state
3. Separate concerns - UI building, state management, and business logic
4. Use the prelude - use blinc_app::prelude::* imports common items
5. Consistent naming - Use _screen suffix for full-page views, no suffix for components