Add remaining regex patterns & fixes.

app/src/main/java/org/oppia/android/app/customview/SegmentedCircularProgressView.kt

@@ -8,10 +8,14 @@ import android.util.AttributeSet
 import android.util.TypedValue
 import android.view.View
 import androidx.core.content.ContextCompat
-import androidx.core.text.TextUtilsCompat
 import androidx.core.view.ViewCompat
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentManager
+import javax.inject.Inject
 import org.oppia.android.R
-import java.util.Locale
+import org.oppia.android.app.translation.AppLanguageResourceHandler
+import org.oppia.android.app.view.ViewComponentFactory
+import org.oppia.android.app.view.ViewComponentImpl
 
 private const val STROKE_DASH_GAP_IN_DEGREE = 12
 
@@ -22,10 +26,14 @@ private const val STROKE_DASH_GAP_IN_DEGREE = 12
  * Reference: // https://stackoverflow.com/a/39210676
  */
 class SegmentedCircularProgressView : View {
+  @Inject
+  lateinit var resourceHandler: AppLanguageResourceHandler
+
   private var sweepAngle = 0f
   private var strokeWidth = 0f
-  private val isRTL = TextUtilsCompat
-    .getLayoutDirectionFromLocale(Locale.getDefault()) == ViewCompat.LAYOUT_DIRECTION_RTL
+  private val isRtl by lazy {
+    resourceHandler.getLayoutDirection() == ViewCompat.LAYOUT_DIRECTION_RTL
+  }
 
   private lateinit var baseRect: RectF
   private lateinit var chapterFinishedArcPaint: Paint
@@ -81,8 +89,16 @@ class SegmentedCircularProgressView : View {
     }
   }
 
+  override fun onAttachedToWindow() {
+    super.onAttachedToWindow()
+
+    val viewComponentFactory = FragmentManager.findFragment<Fragment>(this) as ViewComponentFactory
+    val viewComponent = viewComponentFactory.createViewComponent(this) as ViewComponentImpl
+    viewComponent.inject(this)
+  }
+
   override fun onDraw(canvas: Canvas) {
-    if (isRTL)
+    if (isRtl)
       rotationY = 180f
     super.onDraw(canvas)
     if (!this::baseRect.isInitialized) {

app/src/main/java/org/oppia/android/app/help/faq/FAQListViewModel.kt

@@ -6,7 +6,6 @@ import org.oppia.android.app.help.faq.faqItemViewModel.FAQContentViewModel
 import org.oppia.android.app.help.faq.faqItemViewModel.FAQHeaderViewModel
 import org.oppia.android.app.help.faq.faqItemViewModel.FAQItemViewModel
 import org.oppia.android.app.viewmodel.ObservableViewModel
-import java.util.Locale
 import javax.inject.Inject
 import org.oppia.android.app.translation.AppLanguageResourceHandler
 

app/src/main/java/org/oppia/android/app/hintsandsolution/HintsAndSolutionDialogFragmentPresenter.kt

@@ -22,7 +22,6 @@ import org.oppia.android.util.gcsresource.DefaultResourceBucketName
 import org.oppia.android.util.parser.html.ExplorationHtmlParserEntityType
 import org.oppia.android.util.parser.html.HtmlParser
 import java.lang.IllegalStateException
-import java.util.Locale
 import javax.inject.Inject
 import org.oppia.android.app.model.WrittenTranslationContext
 import org.oppia.android.app.translation.AppLanguageResourceHandler

app/src/main/java/org/oppia/android/app/player/audio/LanguageDialogFragment.kt

@@ -5,7 +5,6 @@ import android.content.Context
 import android.os.Bundle
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.view.ContextThemeWrapper
-import androidx.fragment.app.DialogFragment
 import org.oppia.android.R
 import java.util.Locale
 import kotlin.collections.ArrayList
@@ -59,6 +58,7 @@ class LanguageDialogFragment : InjectableDialogFragment() {
       if (languageCode == "hi-en") {
         languageNameArrayList.add("Hinglish")
       } else {
+        // TODO(#3791): Remove this dependency.
         val locale = Locale(languageCode)
         val name = locale.getDisplayLanguage(locale)
         languageNameArrayList.add(name)

app/src/main/java/org/oppia/android/app/translation/AppLanguageResourceHandler.kt

@@ -49,6 +49,8 @@ class AppLanguageResourceHandler @Inject constructor(
   fun computeDateTimeString(timestampMillis: Long): String =
     getDisplayLocale().computeDateTimeString(timestampMillis)
 
+  fun getLayoutDirection(): Int = getDisplayLocale().getLayoutDirection()
+
   private fun getDisplayLocale(): OppiaLocale.DisplayLocale =
     appLanguageLocaleHandler.getDisplayLocale()
 }

app/src/main/java/org/oppia/android/app/view/ViewComponentImpl.kt

@@ -4,6 +4,7 @@ import android.view.View
 import dagger.BindsInstance
 import dagger.Subcomponent
 import org.oppia.android.app.customview.LessonThumbnailImageView
+import org.oppia.android.app.customview.SegmentedCircularProgressView
 import org.oppia.android.app.home.promotedlist.ComingSoonTopicsListView
 import org.oppia.android.app.home.promotedlist.PromotedStoryListView
 import org.oppia.android.app.player.state.DragDropSortInteractionView
@@ -30,4 +31,5 @@ interface ViewComponentImpl: ViewComponent {
   fun inject(imageRegionSelectionInteractionView: ImageRegionSelectionInteractionView)
   fun inject(lessonThumbnailImageView: LessonThumbnailImageView)
   fun inject(promotedStoryListView: PromotedStoryListView)
+  fun inject(segmentedCircularProgressView: SegmentedCircularProgressView)
 }

app/src/sharedTest/java/org/oppia/android/app/administratorcontrols/AppVersionActivityTest.kt

@@ -230,6 +230,8 @@ class AppVersionActivityTest {
     }
   }
 
+  // TODO(#3792): Remove this usage of Locale (probably by introducing a test utility in the locale
+  //  package to generate these strings).
   private fun getDateTime(dateTimeTimestamp: Long): String? {
     return oppiaDateTimeFormatter.formatDateFromDateString(
       OppiaDateTimeFormatter.DD_MMM_YYYY,

app/src/sharedTest/java/org/oppia/android/app/player/audio/AudioFragmentTest.kt

@@ -313,6 +313,7 @@ class AudioFragmentTest {
       testCoroutineDispatchers.runCurrent()
       onView(withId(R.id.audio_language_icon)).perform(click())
 
+      // TODO(#3791): Remove this dependency.
       val locale = Locale("es")
 
       testCoroutineDispatchers.runCurrent()

app/src/sharedTest/java/org/oppia/android/app/splash/SplashActivityTest.kt

@@ -108,6 +108,8 @@ class SplashActivityTest {
   @Inject
   lateinit var fakeMetaDataRetriever: FakeExpirationMetaDataRetriever
 
+  // TODO(#3792): Remove this usage of Locale (probably by introducing a test utility in the locale
+  //  package to generate these strings).
   private val expirationDateFormat by lazy { SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()) }
 
   @Before

domain/BUILD.bazel

@@ -154,6 +154,7 @@ TEST_DEPS = [
     "//third_party:robolectric_android-all",
     "//utility/src/main/java/org/oppia/android/util/caching/testing:caching_test_module",
     "//utility/src/main/java/org/oppia/android/util/extensions:context_extensions",
+    "//utility/src/main/java/org/oppia/android/util/locale:prod_module",
     "//utility/src/main/java/org/oppia/android/util/networking:debug_module",
     "//utility/src/main/java/org/oppia/android/util/networking:debug_util_module",
 ]

domain/src/main/java/org/oppia/android/domain/onboarding/AppStartupStateController.kt

@@ -1,19 +1,16 @@
 package org.oppia.android.domain.onboarding
 
+import javax.inject.Inject
+import javax.inject.Singleton
 import org.oppia.android.app.model.AppStartupState
 import org.oppia.android.app.model.AppStartupState.StartupMode
 import org.oppia.android.app.model.OnboardingState
 import org.oppia.android.data.persistence.PersistentCacheStore
 import org.oppia.android.domain.oppialogger.OppiaLogger
 import org.oppia.android.util.data.DataProvider
 import org.oppia.android.util.data.DataProviders.Companion.transform
-import java.text.ParseException
-import java.text.SimpleDateFormat
-import java.util.Date
-import java.util.Locale
-import javax.inject.Inject
-import javax.inject.Singleton
 import org.oppia.android.util.extensions.getStringFromBundle
+import org.oppia.android.util.locale.OppiaLocale
 
 private const val APP_STARTUP_STATE_DATA_PROVIDER_ID = "app_startup_state_data_provider_id"
 
@@ -22,10 +19,9 @@ private const val APP_STARTUP_STATE_DATA_PROVIDER_ID = "app_startup_state_data_p
 class AppStartupStateController @Inject constructor(
   cacheStoreFactory: PersistentCacheStore.Factory,
   private val oppiaLogger: OppiaLogger,
-  private val expirationMetaDataRetriever: ExpirationMetaDataRetriever
+  private val expirationMetaDataRetriever: ExpirationMetaDataRetriever,
+  private val machineLocale: OppiaLocale.MachineLocale
 ) {
-  private val expirationDateFormat by lazy { SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()) }
-
   private val onboardingFlowStore =
     cacheStoreFactory.create("on_boarding_flow", OnboardingState.getDefaultInstance())
 
@@ -88,18 +84,9 @@ class AppStartupStateController @Inject constructor(
       ) ?: true
     return if (isAppExpirationEnabled) {
       val expirationDateString = applicationMetadata?.getStringFromBundle("expiration_date")
-      val expirationDate = expirationDateString?.let { parseDate(it) }
+      val expirationDate = expirationDateString?.let { machineLocale.parseOppiaDate(it) }
       // Assume the app is in an expired state if something fails when comparing the date.
-      expirationDate?.before(Date()) ?: true
+      expirationDate?.isBeforeToday() ?: true
     } else false
   }
-
-  private fun parseDate(dateString: String): Date? {
-    return try {
-      expirationDateFormat.parse(dateString)
-    } catch (e: ParseException) {
-      oppiaLogger.e("DOMAIN", "Failed to parse date string: $dateString", e)
-      null
-    }
-  }
 }

domain/src/test/java/org/oppia/android/domain/onboarding/AppStartupStateControllerTest.kt

@@ -14,6 +14,13 @@ import dagger.BindsInstance
 import dagger.Component
 import dagger.Module
 import dagger.Provides
+import java.text.SimpleDateFormat
+import java.time.Duration
+import java.time.Instant
+import java.util.Date
+import java.util.Locale
+import javax.inject.Inject
+import javax.inject.Singleton
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -40,20 +47,15 @@ import org.oppia.android.util.data.AsyncResult
 import org.oppia.android.util.data.DataProviders.Companion.toLiveData
 import org.oppia.android.util.data.DataProvidersInjector
 import org.oppia.android.util.data.DataProvidersInjectorProvider
+import org.oppia.android.util.locale.MachineLocaleModule
 import org.oppia.android.util.logging.EnableConsoleLog
 import org.oppia.android.util.logging.EnableFileLog
 import org.oppia.android.util.logging.GlobalLogLevel
 import org.oppia.android.util.logging.LogLevel
 import org.oppia.android.util.networking.NetworkConnectionUtilDebugModule
+import org.oppia.android.util.system.OppiaClockModule
 import org.robolectric.Shadows.shadowOf
 import org.robolectric.annotation.Config
-import java.text.SimpleDateFormat
-import java.time.Duration
-import java.time.Instant
-import java.util.Date
-import java.util.Locale
-import javax.inject.Inject
-import javax.inject.Singleton
 
 /** Tests for [AppStartupStateController]. */
 @RunWith(AndroidJUnit4::class)
@@ -85,6 +87,8 @@ class AppStartupStateControllerTest {
   @Captor
   lateinit var appStartupStateCaptor: ArgumentCaptor<AsyncResult<AppStartupState>>
 
+  // TODO(#3792): Remove this usage of Locale (probably by introducing a test utility in the locale
+  //  package to generate these strings).
   private val expirationDateFormat by lazy { SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()) }
 
   @Test
@@ -431,6 +435,7 @@ class AppStartupStateControllerTest {
       LogStorageModule::class, RobolectricModule::class,
       TestModule::class, TestDispatcherModule::class, TestLogReportingModule::class,
       NetworkConnectionUtilDebugModule::class,
+      OppiaClockModule::class, MachineLocaleModule::class,
       ExpirationMetaDataRetrieverModule::class // Use real implementation to test closer to prod.
     ]
   )

scripts/assets/file_content_validation_checks.textproto

@@ -170,3 +170,47 @@ file_content_checks {
   prohibited_content_regex: "android:configChanges"
   failure_message: "Never explicitly handle configuration changes. Instead, use saved instance states for retaining state across rotations. For other types of configuration changes, follow up with the developer mailing list with how to proceed if you think this is a legitimate case."
 }
+file_content_checks {
+  file_path_regex: ".+?.kt"
+  prohibited_content_regex: "java\\.util\\.Calendar"
+  failure_message: "Don't use Calendar directly. Instead, use OppiaClock and/or OppiaLocale for calendar-specific operations."
+  exempted_file_name: "testing/src/main/java/org/oppia/android/testing/time/FakeOppiaClock.kt"
+  exempted_file_name: "testing/src/test/java/org/oppia/android/testing/time/FakeOppiaClockTest.kt"
+  exempted_file_name: "utility/src/main/java/org/oppia/android/util/locale/MachineLocaleImpl.kt"
+  exempted_file_name: "utility/src/main/java/org/oppia/android/util/system/OppiaClock.kt"
+}
+file_content_checks {
+  file_path_regex: ".+?.kt"
+  prohibited_content_regex: "java\\.util\\.Date"
+  failure_message: "Don't use Date directly. Instead, perform date-based operations using OppiaLocale."
+  exempted_file_name: "app/src/sharedTest/java/org/oppia/android/app/splash/SplashActivityTest.kt"
+  exempted_file_name: "domain/src/main/java/org/oppia/android/domain/locale/DisplayLocaleImpl.kt"
+  exempted_file_name: "domain/src/test/java/org/oppia/android/domain/onboarding/AppStartupStateControllerTest.kt"
+  exempted_file_name: "testing/src/main/java/org/oppia/android/testing/time/FakeOppiaClock.kt"
+  exempted_file_name: "utility/src/main/java/org/oppia/android/util/system/OppiaClock.kt"
+  exempted_file_name: "utility/src/main/java/org/oppia/android/util/locale/MachineLocaleImpl.kt"
+}
+file_content_checks {
+  file_path_regex: ".+?.kt"
+  prohibited_content_regex: "java\\.text"
+  failure_message: "Don't perform date/time formatting directly. Instead, use OppiaLocale."
+  exempted_file_name: "app/src/sharedTest/java/org/oppia/android/app/splash/SplashActivityTest.kt"
+  exempted_file_name: "domain/src/main/java/org/oppia/android/domain/locale/DisplayLocaleImpl.kt"
+  exempted_file_name: "domain/src/test/java/org/oppia/android/domain/onboarding/AppStartupStateControllerTest.kt"
+  exempted_file_name: "testing/src/main/java/org/oppia/android/testing/time/FakeOppiaClock.kt"
+  exempted_file_name: "utility/src/main/java/org/oppia/android/util/locale/MachineLocaleImpl.kt"
+}
+file_content_checks {
+  file_path_regex: ".+?.kt"
+  prohibited_content_regex: "java\\.util\\.Locale"
+  failure_message: "Don't use Locale directly. Instead, use LocaleController, or OppiaLocale & its subclasses."
+  exempted_file_name: "app/src/main/java/org/oppia/android/app/player/audio/LanguageDialogFragment.kt"
+  exempted_file_name: "app/src/sharedTest/java/org/oppia/android/app/administratorcontrols/AppVersionActivityTest.kt"
+  exempted_file_name: "app/src/sharedTest/java/org/oppia/android/app/player/audio/AudioFragmentTest.kt"
+  exempted_file_name: "app/src/sharedTest/java/org/oppia/android/app/splash/SplashActivityTest.kt"
+  exempted_file_patterns: "domain/src/main/java/org/oppia/android/domain/locale/.+?\\.kt"
+  exempted_file_name: "domain/src/test/java/org/oppia/android/domain/onboarding/AppStartupStateControllerTest.kt"
+  exempted_file_patterns: "scripts/.+?\\.kt"
+  exempted_file_patterns: "utility/src/main/java/org/oppia/android/util/locale/.+?\\.kt"
+  exempted_file_name: "utility/src/main/java/org/oppia/android/util/logging/firebase/FirebaseEventLogger.kt"
+}

scripts/src/java/org/oppia/android/scripts/ci/ComputeAffectedTests.kt

@@ -64,7 +64,7 @@ fun main(args: Array<String>) {
 
 // Needed since the codebase isn't yet using Kotlin 1.5, so this function isn't available.
 private fun String.toBooleanStrictOrNull(): Boolean? {
-  return when (toLowerCase(Locale.getDefault())) {
+  return when (toLowerCase(Locale.US)) {
     "false" -> false
     "true" -> true
     else -> null
@@ -110,7 +110,7 @@ class ComputeAffectedTests(
     println("Current branch: ${gitClient.currentBranch}")
     println("Most recent common commit: ${gitClient.branchMergeBase}")
 
-    val currentBranch = gitClient.currentBranch.toLowerCase(Locale.getDefault())
+    val currentBranch = gitClient.currentBranch.toLowerCase(Locale.US)
     val affectedTestTargets = if (computeAllTestsSetting || currentBranch == "develop") {
       computeAllTestTargets(bazelClient)
     } else computeAffectedTargetsForNonDevelopBranch(gitClient, bazelClient, rootDirectory)

utility/src/main/java/org/oppia/android/util/logging/BUILD.bazel

@@ -27,6 +27,7 @@ kt_android_library(
         ":log_level",
         "//third_party:javax_inject_javax_inject",
         "//third_party:org_jetbrains_kotlinx_kotlinx-coroutines-core",
+        "//utility/src/main/java/org/oppia/android/util/locale:oppia_locale",
         "//utility/src/main/java/org/oppia/android/util/threading:annotations",
     ],
 )

utility/src/main/java/org/oppia/android/util/logging/ConsoleLogger.kt

@@ -7,9 +7,9 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 import org.oppia.android.util.threading.BlockingDispatcher
 import java.io.File
-import java.util.Calendar
 import javax.inject.Inject
 import javax.inject.Singleton
+import org.oppia.android.util.locale.OppiaLocale
 
 /** Wrapper class for Android logcat and file logging. All logs in the app should use this class. */
 @Singleton
@@ -18,7 +18,8 @@ class ConsoleLogger @Inject constructor(
   @BlockingDispatcher private val blockingDispatcher: CoroutineDispatcher,
   @EnableConsoleLog private val enableConsoleLog: Boolean,
   @EnableFileLog private val enableFileLog: Boolean,
-  @GlobalLogLevel private val globalLogLevel: LogLevel
+  @GlobalLogLevel private val globalLogLevel: LogLevel,
+  private val machineLocale: OppiaLocale.MachineLocale
 ) {
   private val blockingScope = CoroutineScope(blockingDispatcher)
   private val logDirectory = File(context.filesDir, "oppia_app.log")
@@ -93,7 +94,9 @@ class ConsoleLogger @Inject constructor(
       Log.println(logLevel.logLevel, tag, fullLog)
     }
     if (enableFileLog) {
-      logToFileInBackground("${Calendar.getInstance().time}\t${logLevel.name}/$tag: $fullLog")
+      logToFileInBackground(
+        "${machineLocale.computeCurrentTimeString()}\t${logLevel.name}/$tag: $fullLog"
+      )
     }
   }
 

utility/src/main/java/org/oppia/android/util/logging/firebase/FirebaseEventLogger.kt

@@ -28,6 +28,7 @@ class FirebaseEventLogger(
   override fun logEvent(eventLog: EventLog) {
     bundle = eventBundleCreator.createEventBundle(eventLog)
     firebaseAnalytics.logEvent(eventLog.actionName.toString(), bundle)
+    // TODO(#3792): Remove this usage of Locale.
     firebaseAnalytics.setUserProperty(COUNTRY_USER_PROPERTY, Locale.getDefault().displayCountry)
     firebaseAnalytics.setUserProperty(
       NETWORK_USER_PROPERTY, connectivityManager.activeNetworkInfo.typeName