Bug 1834014 - Add effects to always- and never-translate menuitems r=gregtatum

Adds functionality to the following menuitems:

always-translate language will immediately translate
the page if not already translated.

never-translate language will hide the translations
button and restore the page if translated.

never-translate site will hide the translations
button and restore the page if translated.

Depends on D177860

Differential Revision: https://phabricator.services.mozilla.com/D178512

browser/components/translations/content/translationsPanel.js

@@ -504,6 +504,28 @@ var TranslationsPanel = new (class {
     }).catch(error => this.console.error(error));
   }
 
+  /**
+   * Removes the translations button.
+   */
+  #hideTranslationsButton() {
+    const { button, buttonLocale, buttonCircleArrows } = this.elements;
+    button.hidden = true;
+    buttonLocale.hidden = true;
+    buttonCircleArrows.hidden = true;
+    button.removeAttribute("translationsactive");
+  }
+
+  /**
+   * Returns true if translations is currently active, otherwise false.
+   *
+   * @returns {boolean}
+   */
+  #isTranslationsActive() {
+    const { requestedTranslationPair } =
+      this.#getTranslationsActor().languageState;
+    return requestedTranslationPair !== null;
+  }
+
   /**
    * Handle the translation button being clicked on the default view.
    */
@@ -570,8 +592,20 @@ var TranslationsPanel = new (class {
    */
   async onAlwaysTranslateLanguage() {
     const docLangTag = await this.#getDocLangTag();
-    TranslationsParent.toggleAlwaysTranslateLanguagePref(docLangTag);
-    await this.#updateSettingsMenuLanguageCheckboxStates();
+    const toggledOn =
+      TranslationsParent.toggleAlwaysTranslateLanguagePref(docLangTag);
+    const translationsActive = this.#isTranslationsActive();
+    this.#updateSettingsMenuLanguageCheckboxStates();
+
+    if (toggledOn && !translationsActive) {
+      await this.onDefaultTranslate();
+    } else if (!toggledOn && translationsActive) {
+      await this.onRestore();
+    }
+
+    // If always-translate was activated while translations is active
+    // If always-translate was deactivated while translations is inactive
+    // There is no need to change the state of the page.
   }
 
   /**
@@ -582,7 +616,13 @@ var TranslationsPanel = new (class {
   async onNeverTranslateLanguage() {
     const docLangTag = await this.#getDocLangTag();
     TranslationsParent.toggleNeverTranslateLanguagePref(docLangTag);
-    await this.#updateSettingsMenuLanguageCheckboxStates();
+    this.#updateSettingsMenuLanguageCheckboxStates();
+
+    if (this.#isTranslationsActive()) {
+      await this.onRestore();
+    } else {
+      this.#hideTranslationsButton();
+    }
   }
 
   /**
@@ -592,7 +632,13 @@ var TranslationsPanel = new (class {
    */
   async onNeverTranslateSite() {
     await this.#getTranslationsActor().toggleNeverTranslateSitePermissions();
-    await this.#updateSettingsMenuSiteCheckboxStates();
+    this.#updateSettingsMenuSiteCheckboxStates();
+
+    if (this.#isTranslationsActive()) {
+      await this.onRestore();
+    } else {
+      this.#hideTranslationsButton();
+    }
   }
 
   /**
@@ -654,8 +700,7 @@ var TranslationsPanel = new (class {
             buttonCircleArrows.hidden = true;
           }
         } else {
-          button.removeAttribute("translationsactive");
-          button.hidden = true;
+          this.#hideTranslationsButton();
         }
 
         switch (error) {

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

@@ -1487,14 +1487,19 @@ export class TranslationsParent extends JSWindowActorParent {
    * to the pref list if it is not present, or removing it if it is present.
    *
    * @param {string} langTag - A BCP-47 language tag
+   * @returns {boolean} Whether the pref was toggled on for the langTag
    */
   static toggleAlwaysTranslateLanguagePref(langTag) {
     if (TranslationsParent.shouldAlwaysTranslateLanguage(langTag)) {
+      // The pref was toggled off for this langTag
       this.#removeLangTagFromPref(langTag, ALWAYS_TRANSLATE_LANGS_PREF);
-    } else {
-      this.#addLangTagToPref(langTag, ALWAYS_TRANSLATE_LANGS_PREF);
-      this.#removeLangTagFromPref(langTag, NEVER_TRANSLATE_LANGS_PREF);
+      return false;
     }
+
+    // The pref was toggled on for this langTag
+    this.#addLangTagToPref(langTag, ALWAYS_TRANSLATE_LANGS_PREF);
+    this.#removeLangTagFromPref(langTag, NEVER_TRANSLATE_LANGS_PREF);
+    return true;
   }
 
   /**
@@ -1505,11 +1510,14 @@ export class TranslationsParent extends JSWindowActorParent {
    */
   static toggleNeverTranslateLanguagePref(langTag) {
     if (TranslationsParent.shouldNeverTranslateLanguage(langTag)) {
+      // The pref was toggled off for this langTag
       this.#removeLangTagFromPref(langTag, NEVER_TRANSLATE_LANGS_PREF);
-    } else {
-      this.#addLangTagToPref(langTag, NEVER_TRANSLATE_LANGS_PREF);
-      this.#removeLangTagFromPref(langTag, ALWAYS_TRANSLATE_LANGS_PREF);
+      return;
     }
+
+    // The pref was toggled on for this langTag
+    this.#addLangTagToPref(langTag, NEVER_TRANSLATE_LANGS_PREF);
+    this.#removeLangTagFromPref(langTag, ALWAYS_TRANSLATE_LANGS_PREF);
   }
 
   /**