attempt to integrate liblouis into pyodide environment

prefig/core/label.py

@@ -24,10 +24,11 @@ def init(format, environment):
 
     if environment == "pyodide":
         text_measurements = label_tools.PyodideTextMeasurements()
+        braille_translator = label_tools.PyodideBrailleTranslator()
     else:
         text_measurements = label_tools.CairoTextMeasurements()
+        braille_translator = label_tools.LocalLouisBrailleTranslator()
 
-    braille_translator = label_tools.LocalLouisBrailleTranslator()
 
 def add_macros(macros):
     math_labels.add_macros(macros)

prefig/core/label_tools.py

@@ -201,8 +201,28 @@ def translate(self, text, typeform):
             text,
             typeform=typeform
         )
-
-
+
+
+class PyodideBrailleTranslator(AbstractBrailleTranslator):
+    def __init__(self):
+        global prefigBrowserApi
+        import prefigBrowserApi
+
+    def initialized(self):
+        return True
+
+    def translate(self, text, typeform):
+        log.info('Called translate text')
+        try:
+            # `prefigBrowserApi` will return a JsProxy. We want a native python object,
+            # so we convert it to a list.
+            braille_string = prefigBrowserApi.translate_text(text, typeform).to_py()
+            return braille_string
+        except Exception as e:
+            log.error(str(e))
+            log.error("Error in translating text")
+
+
 class PyodideTextMeasurements(AbstractTextMeasurements):
     def measure_text(self, text, font_data):
         log.info('Called measure text')

website/packages/playground/package.json

@@ -20,6 +20,7 @@
         "comlink": "^4.4.2",
         "easy-peasy": "^6.0.5",
         "file-saver": "^2.0.5",
+        "liblouis": "^0.2.0",
         "pyodide": "^0.26.4",
         "react": "^18.3.1",
         "react-bootstrap-icons": "^1.11.5",

website/packages/playground/src/worker/compat-api.ts

@@ -2,9 +2,13 @@
  * This is the API used by PreFigure when running in the browser. It implements the necessary
  * functions for Prefigure's abstract classes.
  */
+
+//import { translateString } from "liblouis";
+
 export class PrefigBrowserApi {
     offscreenCanvas: OffscreenCanvas | null = null;
     ctx: OffscreenCanvasRenderingContext2D | null = null;
+
     measure_text(text: string, _font_data?: unknown) {
         if (!this.offscreenCanvas) {
             this.offscreenCanvas = new OffscreenCanvas(200, 200);
@@ -26,6 +30,20 @@ export class PrefigBrowserApi {
             tm.actualBoundingBoxDescent,
         ];
     }
+
+    translate_text(text: string, typeform: number[]): string {
+        //const tables = ["tables/braille-patterns.cti", "tables/en-us-g2.ctb"];
+        const tables = "tables/en-us-g2.ctb";
+        try {
+  //          const unicode_result = translateString(tables, text);
+            const unicode_result = '';
+            console.log("Translated string", unicode_result);
+            return unicode_result
+        } catch(error) {
+            console.log("Error translating text:", error);
+            return '';
+        }
+    }
 }
 
 export const prefigBrowserApi = new PrefigBrowserApi();