GPUI Navigator

A declarative navigation library for GPUI with smooth transitions, nested routing, and beautiful default error pages.

Features

• 🎨 Smooth Transitions - Fade, slide animations with dual enter/exit support
• 🔀 Nested Routing - Parent/child route hierarchies with RouterOutlet
• 🎯 Simple API - Intuitive route definition with closures
• 🖼️ Beautiful Defaults - Pre-styled 404 and error pages out of the box
• 🔗 RouterLink Widget - Navigation links with active state styling
• 🛡️ Route Guards - Authentication and authorization (optional)
• 🔌 Middleware - Before/after navigation hooks (optional)
• 📝 Named Routes - Navigate by name instead of path

Why GPUI Navigator?

Unlike other GPUI routers:

• Zero Boilerplate - Define routes with simple closures, no complex builders
• Smooth Animations - Dual-animation system for professional transitions
• Production Ready - Beautiful error pages included, not placeholder text
• Developer Experience - Clean API inspired by modern web frameworks

Installation

[dependencies]
gpui-navigator = "0.1"
gpui = "0.2"

Quick Start

use gpui::prelude::*;
use gpui::*;
use gpui_navigator::*;

fn main() {
    Application::new().run(|cx: &mut App| {
        // Initialize router
        init_router(cx, |router| {
            // Define routes - simple and ergonomic!
            router.add_route(
                Route::view("/", || home_page().into_any_element())
                    .transition(Transition::fade(300))
            );
            
            router.add_route(
                Route::view("/about", || about_page().into_any_element())
                    .transition(Transition::slide_left(400))
            );
        });

        // Open window with RouterOutlet
        cx.open_window(WindowOptions::default(), |_, cx| {
            cx.new(|cx| AppView::new(cx))
        }).unwrap();
    });
}

fn home_page() -> impl IntoElement {
    div().child("Home Page")
}

fn about_page() -> impl IntoElement {
    div().child("About Page")
}

struct AppView {
    outlet: Entity<RouterOutlet>,
}

impl AppView {
    fn new(cx: &mut Context<'_, Self>) -> Self {
        Self {
            outlet: cx.new(|_| RouterOutlet::new()),
        }
    }
}

impl Render for AppView {
    fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
        div()
            .flex()
            .flex_col()
            .size_full()
            .child(self.outlet.clone())
    }
}

Route Builders

GPUI Navigator provides three ergonomic methods for defining routes:

Route::view() - Stateless Pages

For simple pages that don't need state or parameters:

Route::view("/about", || {
    div().child("About Page").into_any_element()
})

Route::component() - Stateful Pages

For pages with internal state that persists across navigation. The component is automatically cached using window.use_keyed_state():

use gpui::*;
use gpui_navigator::*;

struct CounterPage {
    count: i32,
}

impl CounterPage {
    fn new() -> Self {
        Self { count: 0 }
    }
}

impl Render for CounterPage {
    fn render(&mut self, _: &mut Window, cx: &mut Context<'_, Self>) -> impl IntoElement {
        div()
            .child(format!("Count: {}", self.count))
            .child(
                div()
                    .on_mouse_down(MouseButton::Left, cx.listener(|page, _, _, cx| {
                        page.count += 1;
                        cx.notify();
                    }))
                    .child("Increment")
            )
    }
}

// Route definition - component state persists across navigation!
Route::component("/counter", CounterPage::new)

Benefits:

• ✅ State persists when navigating away and back
• ✅ Automatic Entity caching
• ✅ Clean, concise API

Route::component_with_params() - Stateful Pages with Route Params

For pages that need route parameters and maintain state:

struct UserPage {
    user_id: String,
}

impl UserPage {
    fn new(user_id: String) -> Self {
        Self { user_id }
    }
}

impl Render for UserPage {
    fn render(&mut self, _: &mut Window, _: &mut Context<'_, Self>) -> impl IntoElement {
        div().child(format!("User: {}", self.user_id))
    }
}

// Each unique user_id gets its own cached component instance
Route::component_with_params("/user/:id", |params| {
    let id = params.get("id").unwrap().to_string();
    UserPage::new(id)
})

Route::new() - Full Control

For advanced use cases when you need full control over the builder function:

Route::new("/advanced", |window, cx, params| {
    // Full access to Window, App context, and route params
    custom_page(window, cx, params).into_any_element()
})

Navigation

Programmatic Navigation

use gpui_navigator::Navigator;

// Push new route
Navigator::push(cx, "/about");

// Replace current route
Navigator::replace(cx, "/login");

// Go back
Navigator::pop(cx);

// Go forward  
Navigator::forward(cx);

// Get current path
let path = Navigator::current_path(cx);

// Check if can go back
if Navigator::can_pop(cx) {
    Navigator::pop(cx);
}

RouterLink Widget

Create clickable navigation links with automatic active state:

use gpui_navigator::*;

fn navbar(cx: &mut Context<'_, AppView>) -> impl IntoElement {
    div()
        .flex()
        .gap_4()
        // Basic link
        .child(
            RouterLink::new("/".to_string())
                .child(div().child("Home"))
                .build(cx)
        )
        // Link with active styling
        .child(
            RouterLink::new("/about".to_string())
                .child(div().px_4().py_2().child("About"))
                .active_class(|div| {
                    div.bg(rgb(0x2196f3))
                       .text_color(white())
                })
                .build(cx)
        )
}

RouterLink features:

• ✅ Instant navigation with immediate UI updates
• ✅ Automatic active state detection
• ✅ Customizable active styling
• ✅ Works with nested routes

Route Transitions

Add smooth animations between pages:

use gpui_navigator::*;

// Fade transition
Route::new("/fade", |_, _| page().into_any_element())
    .transition(Transition::fade(300))

// Slide transitions
Route::new("/slide-left", |_, _| page().into_any_element())
    .transition(Transition::slide_left(400))

Route::new("/slide-right", |_, _| page().into_any_element())
    .transition(Transition::slide_right(400))

Route::new("/slide-up", |_, _| page().into_any_element())
    .transition(Transition::slide_up(400))

Route::new("/slide-down", |_, _| page().into_any_element())
    .transition(Transition::slide_down(400))

// No transition
Route::new("/instant", |_, _| page().into_any_element())
    .transition(Transition::None)

Dual Animation System: GPUI Navigator uses the new route's transition for both exit and enter animations, creating smooth, professional transitions.

Route Parameters

Extract dynamic values from URLs:

use gpui_navigator::*;

// Define route with parameter
router.add_route(
    Route::new("/users/:id", |_, params| {
        user_page(params).into_any_element()
    })
);

fn user_page(params: &RouteParams) -> impl IntoElement {
    let user_id = params.get("id").unwrap_or(&"unknown".to_string());
    div().child(format!("User: {}", user_id))
}

// Navigate with parameter
Navigator::push(cx, "/users/123");

Nested Routes

Create layouts with child routes:

use gpui_navigator::*;

router.add_route(
    Route::new("/dashboard", |_, _| dashboard_layout().into_any_element())
        .children(vec![
            Route::new("overview", |_, _| overview_page().into_any_element()).into(),
            Route::new("settings", |_, _| settings_page().into_any_element()).into(),
        ])
);

fn dashboard_layout() -> impl IntoElement {
    div()
        .flex()
        .flex_col()
        .child("Dashboard Header")
        .child(RouterOutlet::new())  // Child routes render here
}

Access nested routes:

• /dashboard - Shows dashboard layout
• /dashboard/overview - Shows overview inside layout
• /dashboard/settings - Shows settings inside layout

Error Handling

Default Error Pages

GPUI Navigator includes beautiful, pre-styled error pages:

• 404 Page - Shown when no route matches (styled with red badge)
• Loading Page - Optional loading state
• Error Page - Generic error display

These work automatically - no configuration needed!

Custom Error Pages

Override defaults if desired:

use gpui_navigator::*;

let default_pages = DefaultPages::new()
    .with_not_found(|| {
        div()
            .child("Custom 404")
            .child("Page not found")
            .into_any_element()
    });

Named Routes

Navigate by name instead of hardcoded paths:

// Define named route
router.add_route(
    Route::new("/users/:id", |_, params| user_page(params).into_any_element())
        .name("user-profile")
);

// Navigate by name
let mut params = RouteParams::new();
params.set("id".to_string(), "123".to_string());
Navigator::push_named(cx, "user-profile", &params);

Optional Features

Enable advanced features in Cargo.toml:

[dependencies]
gpui-navigator = { version = "0.1", features = ["guard", "middleware", "cache"] }

Route Guards

Protect routes with authentication:

#[cfg(feature = "guard")]
use gpui_navigator::*;

fn is_logged_in(cx: &App) -> bool {
    // Check auth state
    true
}

Route::new("/profile", |_, _| profile_page().into_any_element())
    .guard(AuthGuard::new(is_logged_in, "/login"))

Middleware

Add hooks before/after navigation:

#[cfg(feature = "middleware")]
use gpui_navigator::*;

struct LoggingMiddleware;

impl RouteMiddleware for LoggingMiddleware {
    // Implement before_navigation and after_navigation
}

Route::new("/", |_, _| home().into_any_element())
    .middleware(LoggingMiddleware)

Examples

Run the included examples:

# Transition animations demo
cargo run --example transition_demo

# RouterLink and error handling demo
cargo run --example error_demo

API Summary

Architecture

GPUI Navigator is built with a clean, modular architecture:

• Core: Route matching, state management, navigation
• Widgets: RouterOutlet (route renderer), RouterLink (nav links)
• Optional: Guards, middleware, caching (feature-gated)
• Defaults: Beautiful error pages included

Minimum Supported Rust Version

Rust 1.75 or later.

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE)
• MIT license (LICENSE-MIT)

at your option.

Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create your feature branch
3. Add tests for new features
4. Ensure all tests pass: cargo test
5. Submit a Pull Request

Acknowledgments

• Built for GPUI by Zed Industries
• Inspired by modern web routing libraries