ChromeVox: Keep track of the last spoken locale.

This change further refines the locale announcement given when
switching between locales within the same language. We
announce the locale once when switching to more specific locales,
e.g. en -> en-us. We never announce the locale when switching to less
specific locales, e.g. en-us -> en. Finally, all subsequent switches
from en -> en-us will not be announced. The above logic only applies
when we stay within the same language. If the language changes e.g.
en -> pt, then the above state will reset.

This change also adds a test to confirm behavior. We also removed a
test since it can be merged into the new test.

same language.

Bug: 1098548
Change-Id: Ie7015f68bc6c6c747065d815697584f5fd642092
AX-Relnotes: Refine voice switching behavior when switching within the
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2466497
Commit-Queue: Akihiro Ota <akihiroota@chromium.org>
Reviewed-by: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816295}

chrome/browser/resources/chromeos/accessibility/chromevox/background/locale_output_helper.js

@@ -23,6 +23,8 @@ LocaleOutputHelper = class {
         chrome.i18n.getUILanguage().toLowerCase();
     /** @private {string} */
     this.currentLocale_ = LocaleOutputHelper.BROWSER_UI_LOCALE_ || '';
+    /** @private {string} */
+    this.lastSpokenLocale_ = this.currentLocale_;
     /**
      * Confidence threshold to meet before assigning sub-node language.
      * @const
@@ -64,6 +66,7 @@ LocaleOutputHelper = class {
     if (this.hasVoiceForLocale_(newLocale)) {
       this.setCurrentLocale_(newLocale);
       if (shouldAnnounce) {
+        this.lastSpokenLocale_ = newLocale;
         // Prepend the human-readable locale to |outputString|.
         const displayLanguage =
             chrome.accessibilityPrivate.getDisplayNameForLocale(
@@ -141,21 +144,20 @@ LocaleOutputHelper = class {
    * @private
    */
   shouldAnnounceLocale_(newLocale) {
-    // Note: currentLocale_ and newLocale are guaranteed to contain a language
-    // code. However, they might not contain a country code.
-    const [currentLanguage, currentCountry] = this.currentLocale_.split('-');
+    const [lastSpokenLanguage, lastSpokenCountry] =
+        this.lastSpokenLocale_.split('-');
     const [newLanguage, newCountry] = newLocale.split('-');
-    if (currentLanguage !== newLanguage) {
+    if (lastSpokenLanguage !== newLanguage) {
       return true;
     }
 
-    if (!currentCountry || !newCountry) {
-      // If one of the countries is blank, then we don't want to announce the
-      // locale. For example, we don't want to announce 'en' -> 'en-us'.
+    if (!newCountry) {
+      // If |newCountry| is undefined, then we don't want to announce the
+      // locale. For example, we don't want to announce 'en-us' -> 'en'.
       return false;
     }
 
-    return currentCountry !== newCountry;
+    return lastSpokenCountry !== newCountry;
   }
 
   // =============== Static Methods ==============

chrome/browser/resources/chromeos/accessibility/chromevox/background/locale_output_helper_test.js

@@ -578,42 +578,31 @@ TEST_F(
       });
     });
 
-TEST_F(
-    'ChromeVoxLocaleOutputHelperTest', 'DoNotAnnounceLocaleFirstCase',
-    function() {
-      const mockFeedback = this.createMockFeedback();
-      this.runWithLoadedTree(
-          `
+// Tests logic in shouldAnnounceLocale_(). We only announce the locale once when
+// transitioning to more specific locales, e.g. 'en' -> 'en-us'. Transitions to
+// less specific locales, e.g. 'en-us' -> 'en' should not be announced. Finally,
+// subsequent transitions to the same locale, e.g. 'en' -> 'en-us' should not be
+// announced.
+TEST_F('ChromeVoxLocaleOutputHelperTest', 'MaybeAnnounceLocale', function() {
+  const mockFeedback = this.createMockFeedback();
+  this.runWithLoadedTree(
+      `
   <p lang="en">Start</p>
-  <p lang="en-us">End</p>
+  <p lang="en-ca">Middle</p>
+  <p lang="en">Penultimate</p>
+  <p lang="en-ca">End</p>
   `,
-          function() {
-            localStorage['languageSwitching'] = 'true';
-            this.setAvailableVoices();
-            mockFeedback.call(doCmd('jumpToTop'))
-                .expectSpeechWithLocale('en', 'Start')
-                .call(doCmd('nextObject'))
-                .expectSpeechWithLocale('en-us', 'End')
-                .replay();
-          });
-    });
-
-TEST_F(
-    'ChromeVoxLocaleOutputHelperTest', 'DoNotAnnounceLocaleSecondCase',
-    function() {
-      const mockFeedback = this.createMockFeedback();
-      this.runWithLoadedTree(
-          `
-  <p lang="en-us">Start</p>
-  <p lang="en">End</p>
-  `,
-          function() {
-            localStorage['languageSwitching'] = 'true';
-            this.setAvailableVoices();
-            mockFeedback.call(doCmd('jumpToTop'))
-                .expectSpeechWithLocale('en-us', 'Start')
-                .call(doCmd('nextObject'))
-                .expectSpeechWithLocale('en', 'End')
-                .replay();
-          });
-    });
+      function() {
+        localStorage['languageSwitching'] = 'true';
+        this.setAvailableVoices();
+        mockFeedback.call(doCmd('jumpToTop'))
+            .expectSpeechWithLocale('en', 'Start')
+            .call(doCmd('nextObject'))
+            .expectSpeechWithLocale('en-ca', 'English (Canada): Middle')
+            .call(doCmd('nextObject'))
+            .expectSpeechWithLocale('en', 'Penultimate')
+            .call(doCmd('nextObject'))
+            .expectSpeechWithLocale('en-ca', 'End')
+            .replay();
+      });
+});