mobiler_web/
lib.rs

1//! `mobiler-web` — Mobiler's web shell.
2//!
3//! Renders **any** Mobiler app's `Widget` tree to the DOM (Leptos / WASM), driving
4//! the Rust core via crux's `Core` and fulfilling capabilities (HTTP) with the
5//! browser's `fetch`. The web twin of the generic Android/SwiftUI shells: write
6//! your app once as a `MobilerApp`, then
7//!
8//! ```ignore
9//! fn main() { mobiler_web::run::<my_app::App>(); }
10//! ```
11//!
12//! renders it on the web — fully styled, no CSS required: the shell ships its own
13//! theme (`mobiler.css`) and injects it on mount, and `Scaffold.dark_mode` flips
14//! the whole theme. Your crate only supplies a minimal `index.html` with the Trunk
15//! entry point; an app may add its own stylesheet to override any widget class.
16
17use std::cell::RefCell;
18use std::sync::Arc;
19
20use crux_core::{App, Core};
21use leptos::prelude::*;
22use mobiler_core::{
23    Action, BoxAlign, ButtonStyle, CardStyle, Effect, Icon, ImageRatio, ImageShape, InputValue,
24    PluginCall, PluginNotify, PluginResponse, ProjectColor, Spacing, TextStyle, Tone, Widget,
25};
26use wasm_bindgen_futures::spawn_local;
27
28/// The shell's own stylesheet — the web twin of the look the Android/SwiftUI shells
29/// decide in code. Shipped with the crate and injected on mount, so `run::<App>()`
30/// renders a fully styled, themeable app with no CSS required from the consuming
31/// app (it can still override any class). Uses CSS variables so `Scaffold.dark_mode`
32/// flips the whole theme by toggling one class.
33const STYLE: &str = include_str!("mobiler.css");
34
35/// Cloneable handle for sending an `Action` into the core. Leptos 0.7 view closures
36/// require `Send`, so this is `Arc` + `Send + Sync` (the crux `Core` is both).
37type Dispatch = Arc<dyn Fn(Action) + Send + Sync>;
38
39/// What a Mobiler app must be to render on the web: a crux `App` speaking the fixed
40/// ABI (`Action` in, `Widget` out, `Effect` for capabilities). `MobilerShell<_>`
41/// satisfies this automatically.
42pub trait WebApp:
43    App<Event = Action, ViewModel = Widget, Effect = Effect> + Default + Send + Sync + 'static
44where
45    Self::Model: Default + Send + Sync,
46{
47}
48impl<T> WebApp for T
49where
50    T: App<Event = Action, ViewModel = Widget, Effect = Effect> + Default + Send + Sync + 'static,
51    T::Model: Default + Send + Sync,
52{
53}
54
55/// Mount a Mobiler app into the document body. Call from your wasm `main`.
56pub fn run<A: WebApp>()
57where
58    A::Model: Default + Send + Sync,
59{
60    console_error_panic_hook::set_once();
61    inject_default_style();
62    leptos::mount::mount_to_body(shell::<A>);
63}
64
65/// Inject the shell's default stylesheet at the **front** of `<head>` so it's the
66/// lowest-precedence baseline: an app that ships its own CSS (later in the document)
67/// overrides any of these classes, while an app with no CSS still gets a full theme.
68fn inject_default_style() {
69    let document = leptos::prelude::document();
70    let Some(head) = document.head() else { return };
71    let Ok(style) = document.create_element("style") else { return };
72    let _ = style.set_attribute("data-mobiler", "shell");
73    style.set_text_content(Some(STYLE));
74    let _ = head.insert_before(&style, head.first_child().as_ref());
75}
76
77fn shell<A: WebApp>() -> impl IntoView
78where
79    A::Model: Default + Send + Sync,
80{
81    let core = Arc::new(Core::<A>::new());
82    let (view, set_view) = signal(core.view());
83
84    let send: Dispatch = {
85        let core = core.clone();
86        Arc::new(move |action: Action| {
87            let effects = core.process_event(action);
88            drive(&core, set_view, effects);
89        })
90    };
91
92    // Restore persisted state (localStorage), then fire Start — mirrors the native
93    // shells (which restore before Start so the app sees its saved Model on launch).
94    let saved = local_storage().and_then(|s| s.get_item(STORAGE_KEY).ok().flatten()).unwrap_or_default();
95    if !saved.is_empty() {
96        send(Action::Restore { data: saved });
97    }
98    send(Action::Start);
99
100    let send_for_view = send.clone();
101    view! {
102        <div class="app">
103            {move || render(&view.get(), &send_for_view)}
104        </div>
105    }
106}
107
108/// Process effects: re-read the view on Render; fulfil HTTP via fetch and resolve.
109fn drive<A: WebApp>(core: &Arc<Core<A>>, set_view: WriteSignal<Widget>, effects: Vec<Effect>)
110where
111    A::Model: Default + Send + Sync,
112{
113    for effect in effects {
114        match effect {
115            Effect::Render(_) => set_view.set(core.view()),
116            Effect::PluginNotify(notify) => perform_notify(&notify.operation),
117            Effect::Plugin(mut request) => {
118                let core = core.clone();
119                spawn_local(async move {
120                    let response = perform(&request.operation).await;
121                    if let Ok(next) = core.resolve(&mut request, response) {
122                        drive(&core, set_view, next);
123                    }
124                });
125            }
126        }
127    }
128}
129
130/// Fulfil a request/response capability. `http` via `fetch`; `device` via the
131/// browser's user-agent string (the web analogue of a device model).
132async fn perform(call: &PluginCall) -> PluginResponse {
133    if call.plugin == "device" {
134        let ua = web_sys::window()
135            .and_then(|w| w.navigator().user_agent().ok())
136            .unwrap_or_default();
137        return PluginResponse { ok: true, output: ua };
138    }
139    if call.plugin == "dialog" && call.op == "confirm" {
140        let v: serde_json::Value = serde_json::from_str(&call.input).unwrap_or(serde_json::Value::Null);
141        let title = v.get("title").and_then(serde_json::Value::as_str).unwrap_or("");
142        let message = v.get("message").and_then(serde_json::Value::as_str).unwrap_or("");
143        let prompt = if title.is_empty() { message.to_string() } else { format!("{title}\n\n{message}") };
144        let ok = web_sys::window()
145            .and_then(|w| w.confirm_with_message(&prompt).ok())
146            .unwrap_or(false);
147        return PluginResponse { ok, output: if ok { "ok".into() } else { "cancel".into() } };
148    }
149    if call.plugin != "http" {
150        return PluginResponse { ok: false, output: format!("plugin '{}' not available", call.plugin) };
151    }
152    let v: serde_json::Value = serde_json::from_str(&call.input).unwrap_or(serde_json::Value::Null);
153    let url = v.get("url").and_then(serde_json::Value::as_str).unwrap_or("");
154    let body = v.get("body").and_then(serde_json::Value::as_str);
155
156    use gloo_net::http::Request;
157    let builder = match call.op.as_str() {
158        "POST" => Request::post(url),
159        "PATCH" => Request::patch(url),
160        "DELETE" => Request::delete(url),
161        _ => Request::get(url),
162    };
163    let request = match body {
164        Some(b) => builder.header("Content-Type", "application/json").body(b),
165        None => builder.build(),
166    };
167    let request = match request {
168        Ok(r) => r,
169        Err(e) => return PluginResponse { ok: false, output: e.to_string() },
170    };
171    match request.send().await {
172        Ok(resp) => PluginResponse { ok: resp.ok(), output: resp.text().await.unwrap_or_default() },
173        Err(e) => PluginResponse { ok: false, output: e.to_string() },
174    }
175}
176
177const STORAGE_KEY: &str = "mobiler.state";
178
179/// `window.localStorage`, if available.
180fn local_storage() -> Option<web_sys::Storage> {
181    web_sys::window()?.local_storage().ok().flatten()
182}
183
184/// Fulfil a fire-and-forget capability in the browser — the web twin of the native
185/// shells' notify handlers (storage/clipboard/share/browser). None block; an unknown
186/// capability is a graceful no-op.
187fn perform_notify(notify: &PluginNotify) {
188    let win = match web_sys::window() {
189        Some(w) => w,
190        None => return,
191    };
192    match (notify.plugin.as_str(), notify.op.as_str()) {
193        // Persist the state blob (paired with cx.save + restore-on-startup above).
194        ("storage", "save") => {
195            if let Some(s) = local_storage() {
196                let _ = s.set_item(STORAGE_KEY, &notify.input);
197            }
198        }
199        // Copy to the clipboard (write_text returns a Promise we let run).
200        ("clipboard", "copy") => {
201            let _ = win.navigator().clipboard().write_text(&notify.input);
202        }
203        // Open a URL in a new tab.
204        ("browser", "open") => {
205            let _ = win.open_with_url_and_target(&notify.input, "_blank");
206        }
207        // No reliable cross-browser share sheet (navigator.share is mobile-only and
208        // gesture-gated), so degrade to copying — a sane universal fallback.
209        ("share", _) => {
210            let _ = win.navigator().clipboard().write_text(&notify.input);
211        }
212        // Transient toast: a styled div appended to <body>, auto-removed after a beat.
213        ("toast", _) => show_toast(&notify.input),
214        // Haptic tap. navigator.vibrate is unsupported on iOS Safari (a graceful no-op).
215        ("haptics", style) => {
216            let ms = match style {
217                "light" => 15,
218                "heavy" => 50,
219                _ => 30, // medium / unknown
220            };
221            let _ = win.navigator().vibrate_with_duration(ms);
222        }
223        _ => {} // unknown capability: ignore
224    }
225}
226
227/// Append a transient toast to `<body>` (styled by `.toast` in mobiler.css) and
228/// remove it after ~2.6 s — the web twin of the native toast/snackbar.
229fn show_toast(text: &str) {
230    let Some(doc) = web_sys::window().and_then(|w| w.document()) else { return };
231    let (Ok(el), Some(body)) = (doc.create_element("div"), doc.body()) else { return };
232    el.set_class_name("toast");
233    el.set_text_content(Some(text));
234    let _ = body.append_child(&el);
235    gloo_timers::callback::Timeout::new(2600, move || el.remove()).forget();
236}
237
238// ---------------- Widget → DOM ----------------
239
240/// `Widget` → DOM. **Exhaustive** by construction — the `match` has no catch-all,
241/// so (like the Compose/SwiftUI shells) it won't compile until every `Widget`
242/// variant is handled. Style *intent* (TextStyle, Tone, …) becomes a CSS class;
243/// the concrete look lives in `mobiler.css`.
244fn render(widget: &Widget, send: &Dispatch) -> AnyView {
245    match widget {
246        // ---- content ----
247        Widget::Text { content, style } => {
248            let (class, content) = (text_class(*style), content.clone());
249            view! { <p class=class>{content}</p> }.into_any()
250        }
251        Widget::Image { source, shape, ratio } => {
252            let (class, source) = (image_class(*shape, *ratio), source.clone());
253            view! { <img class=class src=source /> }.into_any()
254        }
255        Widget::Badge { label, tone } => {
256            let (class, label) = (format!("badge {}", tone_class(*tone)), label.clone());
257            view! { <span class=class>{label}</span> }.into_any()
258        }
259        Widget::ColorDot { color } => {
260            view! { <span class=format!("dot {}", dot_class(*color))></span> }.into_any()
261        }
262        Widget::Divider => view! { <hr class="divider" /> }.into_any(),
263        Widget::Spacer { size } => {
264            view! { <div class=format!("spacer {}", spacer_class(*size))></div> }.into_any()
265        }
266
267        // ---- layout ----
268        Widget::Row { children } => {
269            let kids = render_all(children, send);
270            view! { <div class="row">{kids}</div> }.into_any()
271        }
272        Widget::Column { children } => {
273            let kids = render_all(children, send);
274            view! { <div class="col">{kids}</div> }.into_any()
275        }
276        Widget::Card { child, style, on_press } => {
277            let class = format!("card {}", card_class(*style));
278            let body = render(child, send);
279            match on_press {
280                Some(token) => {
281                    let (send, token) = (send.clone(), token.clone());
282                    view! {
283                        <button
284                            class=format!("{class} card-tappable")
285                            on:click=move |_| send(Action::Fired { token: token.clone() })
286                        >
287                            {body}
288                        </button>
289                    }
290                    .into_any()
291                }
292                None => view! { <div class=class>{body}</div> }.into_any(),
293            }
294        }
295        // Z-stack. With `scrim`, the first child is a background image, darkened
296        // by an overlay, and the rest layer on top in light content — the DOM twin
297        // of the Compose `matchParentSize` scrim / SwiftUI `.overlay` on the image.
298        Widget::Box { children, align, scrim } => {
299            let acls = align_class(*align);
300            if *scrim && children.len() > 1 {
301                let bg = render(&children[0], send);
302                let content = render_all(&children[1..], send);
303                view! {
304                    <div class=format!("box box-scrim {acls}")>
305                        {bg}
306                        <div class="scrim"></div>
307                        <div class="box-content">{content}</div>
308                    </div>
309                }
310                .into_any()
311            } else {
312                let kids = render_all(children, send);
313                view! { <div class=format!("box {acls}")>{kids}</div> }.into_any()
314            }
315        }
316        Widget::Grid { children } => {
317            let kids = render_all(children, send);
318            view! { <div class="grid">{kids}</div> }.into_any()
319        }
320
321        // ---- input / actions ----
322        Widget::Button { label, style, on_press } => {
323            let (send, token, label) = (send.clone(), on_press.clone(), label.clone());
324            let class = format!("btn {}", button_class(*style));
325            view! {
326                <button class=class on:click=move |_| send(Action::Fired { token: token.clone() })>
327                    {label}
328                </button>
329            }
330            .into_any()
331        }
332        Widget::IconButton { icon, on_press } => {
333            let (send, token) = (send.clone(), on_press.clone());
334            let glyph = icon_glyph(*icon);
335            view! {
336                <button class="iconbtn" on:click=move |_| send(Action::Fired { token: token.clone() })>
337                    {glyph}
338                </button>
339            }
340            .into_any()
341        }
342        Widget::Chip { label, selected, on_press } => {
343            let (send, token, label) = (send.clone(), on_press.clone(), label.clone());
344            let class = if *selected { "chip selected" } else { "chip" };
345            view! {
346                <button class=class on:click=move |_| send(Action::Fired { token: token.clone() })>
347                    {label}
348                </button>
349            }
350            .into_any()
351        }
352        Widget::TextField { id, placeholder, value } => {
353            let (send, id) = (send.clone(), id.clone());
354            let (placeholder, value) = (placeholder.clone(), value.clone());
355            view! {
356                <input
357                    class="field"
358                    placeholder=placeholder
359                    prop:value=value
360                    on:input=move |ev| send(Action::Input {
361                        id: id.clone(),
362                        value: InputValue::Text(event_target_value(&ev)),
363                    })
364                />
365            }
366            .into_any()
367        }
368        Widget::Toggle { id, label, value } => {
369            let (send, id, label, checked) = (send.clone(), id.clone(), label.clone(), *value);
370            view! {
371                <label class="toggle">
372                    {label}
373                    <input
374                        type="checkbox"
375                        role="switch"
376                        prop:checked=checked
377                        on:change=move |ev| send(Action::Input {
378                            id: id.clone(),
379                            value: InputValue::Bool(event_target_checked(&ev)),
380                        })
381                    />
382                </label>
383            }
384            .into_any()
385        }
386        Widget::Checkbox { id, label, value } => {
387            let (send, id, label, checked) = (send.clone(), id.clone(), label.clone(), *value);
388            view! {
389                <label class="check">
390                    <input
391                        type="checkbox"
392                        prop:checked=checked
393                        on:change=move |ev| send(Action::Input {
394                            id: id.clone(),
395                            value: InputValue::Bool(event_target_checked(&ev)),
396                        })
397                    />
398                    {label}
399                </label>
400            }
401            .into_any()
402        }
403        Widget::Slider { id, value, max } => {
404            let (send, id, value, max) = (send.clone(), id.clone(), *value, *max);
405            view! {
406                <input
407                    class="slider"
408                    type="range"
409                    min="0"
410                    max=max
411                    prop:value=value
412                    on:input=move |ev| send(Action::Input {
413                        id: id.clone(),
414                        value: InputValue::Int(event_target_value(&ev).parse().unwrap_or(0)),
415                    })
416                />
417            }
418            .into_any()
419        }
420        Widget::Stepper { value, on_decrement, on_increment } => {
421            let send_dec = send.clone();
422            let send_inc = send.clone();
423            let (dec, inc) = (on_decrement.clone(), on_increment.clone());
424            view! {
425                <div class="stepper">
426                    <button on:click=move |_| send_dec(Action::Fired { token: dec.clone() })>"−"</button>
427                    <span class="stepper-value">{*value}</span>
428                    <button on:click=move |_| send_inc(Action::Fired { token: inc.clone() })>"+"</button>
429                </div>
430            }
431            .into_any()
432        }
433
434        // ---- shell ----
435        Widget::Scaffold { title, body, tabs, back, dark_mode, route, depth } => {
436            let back_btn = back.clone().map(|token| {
437                let send = send.clone();
438                view! {
439                    <button class="back" on:click=move |_| send(Action::Fired { token: token.clone() })>
440                        "‹"
441                    </button>
442                }
443            });
444            let tabbar = (!tabs.is_empty()).then(|| {
445                let tabs: Vec<AnyView> = tabs
446                    .iter()
447                    .map(|tab| {
448                        let (send, token) = (send.clone(), tab.on_select.clone());
449                        let class = if tab.selected { "tab selected" } else { "tab" };
450                        let label = tab.label.clone();
451                        view! {
452                            <button class=class on:click=move |_| send(Action::Fired { token: token.clone() })>
453                                {label}
454                            </button>
455                        }
456                        .into_any()
457                    })
458                    .collect();
459                view! { <div class="tabbar">{tabs}</div> }
460            });
461            // `theme-dark` flips the CSS variables for the whole shell — theme-as-data,
462            // the web twin of the native shells' `preferredColorScheme`/Material theme.
463            let class = if *dark_mode { "scaffold theme-dark" } else { "scaffold" };
464            let body_class = format!("scaffold-body {}", nav_class(route, *depth));
465            let (title, body) = (title.clone(), render(body, send));
466            view! {
467                <div class=class>
468                    <div class="topbar">
469                        {back_btn}
470                        <span class="title">{title}</span>
471                    </div>
472                    <div class=body_class data-route=route.clone()>{body}</div>
473                    {tabbar}
474                </div>
475            }
476            .into_any()
477        }
478    }
479}
480
481/// Render a slice of children as sibling views.
482fn render_all(children: &[Widget], send: &Dispatch) -> Vec<AnyView> {
483    children.iter().map(|c| render(c, send)).collect()
484}
485
486thread_local! {
487    /// (previous route key, previous depth, alternating toggle). The render is a
488    /// stateless whole-tree rebuild, so nav state lives here (wasm is single-
489    /// threaded). Lets the Scaffold body animate on navigation — the web twin of
490    /// the native shells keying their body on `route`.
491    static NAV: RefCell<(String, u32, bool)> = const { RefCell::new((String::new(), 0, false)) };
492}
493
494/// Pick the Scaffold body's transition class for this render. Returns `""` for a
495/// same-route data update (re-render in place, no transition). On a route change it
496/// returns a directional class — slide-in from the right when `depth` grew (push),
497/// from the left when it shrank (pop), a crossfade for a lateral move — and *alternates*
498/// the `-a`/`-b` suffix each navigation so the CSS animation restarts even though
499/// Leptos reuses the same DOM node.
500fn nav_class(route: &str, depth: u32) -> &'static str {
501    NAV.with_borrow_mut(|(prev_route, prev_depth, toggle)| {
502        if route == prev_route {
503            return "";
504        }
505        let dir = if depth > *prev_depth {
506            ["nav-push-a", "nav-push-b"]
507        } else if depth < *prev_depth {
508            ["nav-pop-a", "nav-pop-b"]
509        } else {
510            ["nav-fade-a", "nav-fade-b"]
511        };
512        *toggle = !*toggle;
513        *prev_route = route.to_string();
514        *prev_depth = depth;
515        dir[usize::from(*toggle)]
516    })
517}
518
519// ---- style intent → CSS class / glyph (the only place that names the look) ----
520
521fn text_class(s: TextStyle) -> &'static str {
522    match s {
523        TextStyle::Title => "t-title",
524        TextStyle::Subtitle => "t-subtitle",
525        TextStyle::Caption => "t-caption",
526        TextStyle::Emphasis => "t-emphasis",
527        TextStyle::Body => "t-body",
528    }
529}
530
531fn button_class(s: ButtonStyle) -> &'static str {
532    match s {
533        ButtonStyle::Filled => "btn-filled",
534        ButtonStyle::Outlined => "btn-outlined",
535        ButtonStyle::Text => "btn-text",
536    }
537}
538
539fn card_class(s: CardStyle) -> &'static str {
540    match s {
541        CardStyle::Elevated => "card-elevated",
542        CardStyle::Outlined => "card-outlined",
543        CardStyle::Filled => "card-filled",
544    }
545}
546
547fn tone_class(t: Tone) -> &'static str {
548    match t {
549        Tone::Neutral => "tone-neutral",
550        Tone::Success => "tone-success",
551        Tone::Warning => "tone-warning",
552        Tone::Danger => "tone-danger",
553        Tone::Info => "tone-info",
554    }
555}
556
557fn spacer_class(s: Spacing) -> &'static str {
558    match s {
559        Spacing::Xs => "sp-xs",
560        Spacing::Sm => "sp-sm",
561        Spacing::Md => "sp-md",
562        Spacing::Lg => "sp-lg",
563        Spacing::Xl => "sp-xl",
564    }
565}
566
567fn icon_glyph(i: Icon) -> &'static str {
568    match i {
569        Icon::Delete => "🗑",
570        Icon::Add => "＋",
571        Icon::Edit => "✏️",
572        Icon::Close => "✕",
573        Icon::Settings => "⚙",
574        Icon::Check => "✓",
575        Icon::Star => "★",
576    }
577}
578
579fn image_class(shape: ImageShape, ratio: ImageRatio) -> String {
580    let shape = match shape {
581        ImageShape::Square => "img-square",
582        ImageShape::Rounded => "img-rounded",
583        ImageShape::Circle => "img-circle",
584    };
585    let ratio = match ratio {
586        ImageRatio::Wide => "ratio-wide",
587        ImageRatio::Square => "ratio-square",
588        ImageRatio::Tall => "ratio-tall",
589    };
590    format!("img {shape} {ratio}")
591}
592
593fn dot_class(c: ProjectColor) -> &'static str {
594    match c {
595        ProjectColor::Indigo => "dot-indigo",
596        ProjectColor::Teal => "dot-teal",
597        ProjectColor::Coral => "dot-coral",
598        ProjectColor::Amber => "dot-amber",
599        ProjectColor::Lime => "dot-lime",
600        ProjectColor::Pink => "dot-pink",
601    }
602}
603
604fn align_class(a: BoxAlign) -> &'static str {
605    match a {
606        BoxAlign::TopStart => "align-top-start",
607        BoxAlign::TopEnd => "align-top-end",
608        BoxAlign::Center => "align-center",
609        BoxAlign::BottomStart => "align-bottom-start",
610        BoxAlign::BottomCenter => "align-bottom-center",
611        BoxAlign::BottomEnd => "align-bottom-end",
612    }
613}
mobiler_web/lib.rs

mobiler_web/
lib.rs
