crates/laymesh-wasm/src/lib.rs

1//! Browser bindings use the same parser, layout, fonts, and SVG renderer as native.2use laymesh_core::{3    engine::compile_source,4    model::{Host, Scene},5};6use laymesh_language::{LanguageService, byte_offset, utf16_offset};7use serde_json::{Value as J, json};8use std::cell::RefCell;9use std::collections::BTreeMap;10use wasm_bindgen::prelude::*;11thread_local! {12    static PREVIEW_FONTS: RefCell<BTreeMap<String, Vec<u8>>> = RefCell::new(BTreeMap::new());13}14 15/// Register Page-only body fonts as bytes, avoiding a large JSON byte array on every render.16#[wasm_bindgen]17pub fn register_preview_font(filename: &str, bytes: &[u8]) {18    PREVIEW_FONTS.with(|fonts| {19        fonts20            .borrow_mut()21            .insert(filename.to_owned(), bytes.to_vec());22    });23}24/// A scene remains in WASM memory between layout and SVG generation, avoiding25/// serialization of embedded fonts just to measure the two stages separately.26#[wasm_bindgen]27pub struct RenderJob {28    scene: Scene,29}30#[wasm_bindgen]31impl RenderJob {32    pub fn svg(&self) -> Result<String, JsValue> {33        laymesh_render::render_svg(&self.scene).map_err(|e| JsValue::from_str(&e.to_string()))34    }35    pub fn inspection(&self) -> String {36        json!({"inspection":laymesh_language::inspect::inspect_scene(&self.scene),"warnings":self.scene.warnings}).to_string()37    }38}39#[wasm_bindgen]40pub fn prepare_render(41    source: &str,42    filename: &str,43    files_json: &str,44) -> Result<RenderJob, JsValue> {45    let files: J =46        serde_json::from_str(files_json).map_err(|e| JsValue::from_str(&e.to_string()))?;47    let mut host = Host {48        native: false,49        ..Host::default()50    };51    if let Some(files) = files.as_object() {52        for (name, value) in files {53            let data = if let Some(s) = value.as_str() {54                s.as_bytes().to_vec()55            } else if let Some(a) = value.as_array() {56                a.iter().map(|v| v.as_u64().unwrap_or(0) as u8).collect()57            } else {58                continue;59            };60            host.files.insert(name.clone(), data);61        }62    }63    PREVIEW_FONTS.with(|fonts| {64        host.files.extend(65            fonts66                .borrow()67                .iter()68                .map(|(name, data)| (name.clone(), data.clone())),69        );70    });71    let scene = compile_source(source, filename, host).map_err(|e| {72        let mut diagnostic = serde_json::to_value(&e).unwrap();73        // Native errors remain unchanged. This extra field is a browser resource74        // request; the worker only honors paths in its local resource manifest.75        if e.code == "E_ASSET" {76            if let Some(path) = e.message.strip_prefix("无法读取资源：") {77                diagnostic["resource"] = json!(path);78            }79        }80        JsValue::from_str(&diagnostic.to_string())81    })?;82    Ok(RenderJob { scene })83}84#[wasm_bindgen]85pub fn render(source: &str, filename: &str, files_json: &str) -> Result<String, JsValue> {86    let job = prepare_render(source, filename, files_json)?;87    let mut result: J = serde_json::from_str(&job.inspection()).unwrap();88    result["svg"] = json!(job.svg()?);89    Ok(result.to_string())90}91#[wasm_bindgen]92pub fn color_convert(input: &str) -> Result<String, JsValue> {93    let v: J = serde_json::from_str(input).map_err(|e| JsValue::from_str(&e.to_string()))?;94    let c = laymesh_core::color::Color::new(95        v["space"].as_str().unwrap_or("rgb"),96        [97            v["channels"][0].as_f64().unwrap_or(f64::NAN),98            v["channels"][1].as_f64().unwrap_or(f64::NAN),99            v["channels"][2].as_f64().unwrap_or(f64::NAN),100        ],101        v["alpha"].as_f64().unwrap_or(1.),102    )103    .map_err(|e| JsValue::from_str(&e))?;104    Ok(json!({"rgba":c.rgba,"mapped":c.mapped,"hex":c.hex(),"rgb":c.channels_in("rgb"),"hsv":c.channels_in("hsv"),"oklch":c.channels_in("oklch")}).to_string())105}106#[wasm_bindgen]107pub fn color_presentations(108    files: &str,109    filename: &str,110    from: usize,111    to: usize,112    rgba: &str,113) -> Result<String, JsValue> {114    let files: BTreeMap<String, String> =115        serde_json::from_str(files).map_err(|e| JsValue::from_str(&e.to_string()))?;116    let values: [f64; 4] =117        serde_json::from_str(rgba).map_err(|e| JsValue::from_str(&e.to_string()))?;118    let mut service = LanguageService::new("en");119    service.documents = files;120    let source = service121        .documents122        .get(filename)123        .map(String::as_str)124        .unwrap_or("");125    let mut result = service.color_presentations(126        filename,127        byte_offset(source, from),128        byte_offset(source, to),129        values,130    );131    for v in result.as_array_mut().unwrap() {132        v["from"] = json!(from);133        v["to"] = json!(to);134    }135    Ok(result.to_string())136}137#[wasm_bindgen]138pub fn language_query(139    files_json: &str,140    filename: &str,141    method: &str,142    utf16: usize,143    locale: &str,144) -> Result<String, JsValue> {145    let files: BTreeMap<String, String> =146        serde_json::from_str(files_json).map_err(|e| JsValue::from_str(&e.to_string()))?;147    let mut service = LanguageService::new(locale);148    service.documents = files;149    let source = service150        .documents151        .get(filename)152        .map(String::as_str)153        .unwrap_or("");154    let mut result = service.query(method, filename, byte_offset(source, utf16));155    fn convert(v: &mut J, source: &str, files: &BTreeMap<String, String>) {156        match v {157            J::Array(a) => {158                for x in a {159                    convert(x, source, files)160                }161            }162            J::Object(m) => {163                let own = m164                    .get("uri")165                    .and_then(J::as_str)166                    .and_then(|u| files.get(u))167                    .map(String::as_str)168                    .unwrap_or(source);169                for key in ["from", "to"] {170                    if let Some(n) = m.get(key).and_then(J::as_u64) {171                        m.insert(key.into(), json!(utf16_offset(own, n as usize)));172                    }173                }174                for (key, value) in m.iter_mut() {175                    if key != "from" && key != "to" {176                        convert(value, own, files);177                    }178                }179            }180            _ => {}181        }182    }183    convert(&mut result, source, &service.documents);184    Ok(result.to_string())185}