Bug 1815339 - Change the method for knowing when the engine process is ready; r=nordzilla

Differential Revision: https://phabricator.services.mozilla.com/D192474

Author: gregtatum

toolkit/components/translations/actors/TranslationsEngineChild.sys.mjs

@@ -27,6 +27,14 @@ export class TranslationsEngineChild extends JSWindowActorChild {
     this.#exportFunctions();
   }
 
+  handleEvent(event) {
+    switch (event.type) {
+      case "DOMContentLoaded":
+        this.sendAsyncMessage("TranslationsEngine:Ready");
+        break;
+    }
+  }
+
   // eslint-disable-next-line consistent-return
   async receiveMessage({ name, data }) {
     switch (name) {

toolkit/components/translations/actors/TranslationsEngineParent.sys.mjs

@@ -21,6 +21,14 @@ export class TranslationsEngineParent extends JSWindowActorParent {
 
   async receiveMessage({ name, data }) {
     switch (name) {
+      case "TranslationsEngine:Ready":
+        if (!lazy.TranslationsParent.resolveEngine) {
+          throw new Error(
+            "Unable to find the resolve function for when the translations engine is ready."
+          );
+        }
+        lazy.TranslationsParent.resolveEngine(this);
+        return undefined;
       case "TranslationsEngine:RequestEnginePayload": {
         const { fromLanguage, toLanguage } = data;
         const payloadPromise =

toolkit/components/translations/actors/TranslationsParent.sys.mjs

@@ -175,6 +175,13 @@ export class TranslationsParent extends JSWindowActorParent {
    */
   languageState;
 
+  /**
+   * Allows the TranslationsEngineParent to resolve an engine once it is ready.
+   *
+   * @type {null | () => TranslationsEngineParent}
+   */
+  resolveEngine = null;
+
   /**
    * The cached URI spec where the panel was first ever shown, as determined by the
    * browser.translations.panelShown pref.
@@ -425,6 +432,10 @@ export class TranslationsParent extends JSWindowActorParent {
     const chromeWindow = await hiddenFrame.get();
     const doc = chromeWindow.document;
 
+    const actorPromise = new Promise(resolve => {
+      this.resolveEngine = resolve;
+    });
+
     const browser = doc.createXULElement("browser");
     browser.setAttribute("remote", "true");
     browser.setAttribute("remoteType", "web");
@@ -436,42 +447,8 @@ export class TranslationsParent extends JSWindowActorParent {
     );
     doc.documentElement.appendChild(browser);
 
-    // Wait for the translations engine to be loaded.
-    await new Promise(resolve => {
-      const listener = {
-        QueryInterface: ChromeUtils.generateQI([
-          "nsIWebProgressListener",
-          "nsIWebProgressListener2",
-          "nsISupportsWeakReference",
-        ]),
-
-        /**
-         * @param {nsIWebProgress} _webProgress
-         * @param {nsIRequest} request
-         * @param {number} stateFlags
-         * @param {nsresult} _status
-         */
-        onStateChange(_webProgress, request, stateFlags, _status) {
-          if (!request) {
-            return;
-          }
-          if (
-            stateFlags & Ci.nsIWebProgressListener.STATE_STOP &&
-            stateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK
-          ) {
-            browser.removeProgressListener(listener);
-            resolve();
-          }
-        },
-      };
-      browser.addProgressListener(listener, Ci.nsIWebProgress.NOTIFY_STATE_ALL);
-    });
-
-    const actor =
-      browser.browsingContext.currentWindowGlobal.getActor(
-        "TranslationsEngine"
-      );
-
+    const actor = await actorPromise;
+    this.resolveEngine = null;
     return { hiddenFrame, browser, actor };
   }
 

toolkit/modules/ActorManagerParent.sys.mjs

@@ -552,6 +552,9 @@ let JSWINDOWACTORS = {
     },
     child: {
       esModuleURI: "resource://gre/actors/TranslationsEngineChild.sys.mjs",
+      events: {
+        DOMContentLoaded: { createActor: true },
+      },
     },
     includeChrome: true,
     matches: ["chrome://global/content/translations/translations-engine.html"],