merge latest changes from upstream and resolve conflicts

app/src/main/java/org/oppia/android/app/administratorcontrols/appversion/AppVersionViewModel.kt

@@ -5,9 +5,9 @@ import androidx.lifecycle.ViewModel
 import org.oppia.android.R
 import org.oppia.android.app.fragment.FragmentScope
 import org.oppia.android.app.translation.AppLanguageResourceHandler
-import org.oppia.android.app.utility.getLastUpdateTime
-import org.oppia.android.app.utility.getVersionName
 import org.oppia.android.app.viewmodel.ObservableViewModel
+import org.oppia.android.util.extensions.getLastUpdateTime
+import org.oppia.android.util.extensions.getVersionName
 import javax.inject.Inject
 
 /** [ViewModel] for [AppVersionFragment]. */

app/src/main/java/org/oppia/android/app/notice/DeprecationNoticeActionListener.kt

@@ -1,9 +1,24 @@
 package org.oppia.android.app.notice
 
-import org.oppia.android.app.splash.DeprecationNoticeActionType
+import org.oppia.android.app.model.DeprecationNoticeType
 
 /** Listener for when an option on any deprecation dialog is clicked. */
 interface DeprecationNoticeActionListener {
   /** Called when a dialog button is clicked. */
-  fun onActionButtonClicked(noticeType: DeprecationNoticeActionType)
+  fun onActionButtonClicked(noticeActionResponse: DeprecationNoticeActionResponse)
+}
+
+/** Sealed data class for the response to a deprecation notice action. */
+sealed class DeprecationNoticeActionResponse {
+  /** Action for when the user presses the 'Close' button on a deprecation dialog. */
+  object Close : DeprecationNoticeActionResponse()
+
+  /** Action for when the user presses the 'Dismiss' button on a deprecation dialog. */
+  data class Dismiss(
+    val deprecationNoticeType: DeprecationNoticeType,
+    val deprecatedVersion: Int,
+  ) : DeprecationNoticeActionResponse()
+
+  /** Action for when the user presses the 'Update' button on a deprecation dialog. */
+  object Update : DeprecationNoticeActionResponse()
 }

app/src/main/java/org/oppia/android/app/notice/ForcedAppDeprecationNoticeDialogFragmentPresenter.kt

@@ -4,14 +4,13 @@ import android.app.Dialog
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
 import org.oppia.android.R
-import org.oppia.android.app.splash.DeprecationNoticeActionType
 import org.oppia.android.app.translation.AppLanguageResourceHandler
 import javax.inject.Inject
 
 /** Presenter class responsible for showing an app deprecation dialog to the user. */
 class ForcedAppDeprecationNoticeDialogFragmentPresenter @Inject constructor(
   private val activity: AppCompatActivity,
-  private val resourceHandler: AppLanguageResourceHandler
+  private val resourceHandler: AppLanguageResourceHandler,
 ) {
   private val deprecationNoticeActionListener by lazy {
     activity as DeprecationNoticeActionListener
@@ -31,12 +30,12 @@ class ForcedAppDeprecationNoticeDialogFragmentPresenter @Inject constructor(
       )
       .setPositiveButton(R.string.forced_app_update_dialog_update_button_text) { _, _ ->
         deprecationNoticeActionListener.onActionButtonClicked(
-          DeprecationNoticeActionType.UPDATE
+          DeprecationNoticeActionResponse.Update
         )
       }
       .setNegativeButton(R.string.forced_app_update_dialog_close_button_text) { _, _ ->
         deprecationNoticeActionListener.onActionButtonClicked(
-          DeprecationNoticeActionType.CLOSE
+          DeprecationNoticeActionResponse.Close
         )
       }
       .setCancelable(false)

app/src/main/java/org/oppia/android/app/notice/OptionalAppDeprecationNoticeDialogFragmentPresenter.kt

@@ -4,14 +4,18 @@ import android.app.Dialog
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
 import org.oppia.android.R
-import org.oppia.android.app.splash.DeprecationNoticeActionType
+import org.oppia.android.app.model.DeprecationNoticeType
 import org.oppia.android.app.translation.AppLanguageResourceHandler
+import org.oppia.android.util.platformparameter.OptionalAppUpdateVersionCode
+import org.oppia.android.util.platformparameter.PlatformParameterValue
 import javax.inject.Inject
 
 /** Presenter class responsible for showing an optional update dialog to the user. */
 class OptionalAppDeprecationNoticeDialogFragmentPresenter @Inject constructor(
   private val activity: AppCompatActivity,
-  private val resourceHandler: AppLanguageResourceHandler
+  private val resourceHandler: AppLanguageResourceHandler,
+  @OptionalAppUpdateVersionCode
+  private val optionalAppUpdateVersionCode: PlatformParameterValue<Int>,
 ) {
   private val deprecationNoticeActionListener by lazy {
     activity as DeprecationNoticeActionListener
@@ -31,12 +35,15 @@ class OptionalAppDeprecationNoticeDialogFragmentPresenter @Inject constructor(
       )
       .setPositiveButton(R.string.optional_app_update_dialog_update_button_text) { _, _ ->
         deprecationNoticeActionListener.onActionButtonClicked(
-          DeprecationNoticeActionType.UPDATE
+          DeprecationNoticeActionResponse.Update
         )
       }
       .setNegativeButton(R.string.optional_app_update_dialog_dismiss_button_text) { _, _ ->
         deprecationNoticeActionListener.onActionButtonClicked(
-          DeprecationNoticeActionType.DISMISS
+          DeprecationNoticeActionResponse.Dismiss(
+            deprecationNoticeType = DeprecationNoticeType.APP_DEPRECATION,
+            deprecatedVersion = optionalAppUpdateVersionCode.value
+          )
         )
       }
       .setCancelable(false)

app/src/main/java/org/oppia/android/app/notice/OsDeprecationNoticeDialogFragmentPresenter.kt

@@ -4,14 +4,18 @@ import android.app.Dialog
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
 import org.oppia.android.R
-import org.oppia.android.app.splash.DeprecationNoticeActionType
+import org.oppia.android.app.model.DeprecationNoticeType
 import org.oppia.android.app.translation.AppLanguageResourceHandler
+import org.oppia.android.util.platformparameter.LowestSupportedApiLevel
+import org.oppia.android.util.platformparameter.PlatformParameterValue
 import javax.inject.Inject
 
 /** Presenter class responsible for showing an OS deprecation dialog to the user. */
 class OsDeprecationNoticeDialogFragmentPresenter @Inject constructor(
   private val activity: AppCompatActivity,
-  private val resourceHandler: AppLanguageResourceHandler
+  private val resourceHandler: AppLanguageResourceHandler,
+  @LowestSupportedApiLevel
+  private val lowestSupportedApiLevel: PlatformParameterValue<Int>
 ) {
   private val deprecationNoticeActionListener by lazy {
     activity as DeprecationNoticeActionListener
@@ -31,7 +35,10 @@ class OsDeprecationNoticeDialogFragmentPresenter @Inject constructor(
       )
       .setNegativeButton(R.string.os_deprecation_dialog_dismiss_button_text) { _, _ ->
         deprecationNoticeActionListener.onActionButtonClicked(
-          DeprecationNoticeActionType.DISMISS
+          DeprecationNoticeActionResponse.Dismiss(
+            deprecationNoticeType = DeprecationNoticeType.OS_DEPRECATION,
+            deprecatedVersion = lowestSupportedApiLevel.value
+          )
         )
       }
       .setCancelable(false)

app/src/main/java/org/oppia/android/app/notice/testing/ForcedAppDeprecationNoticeDialogFragmentTestActivity.kt

@@ -2,8 +2,8 @@ package org.oppia.android.app.notice.testing
 
 import android.os.Bundle
 import org.oppia.android.app.notice.DeprecationNoticeActionListener
+import org.oppia.android.app.notice.DeprecationNoticeActionResponse
 import org.oppia.android.app.notice.ForcedAppDeprecationNoticeDialogFragment
-import org.oppia.android.app.splash.DeprecationNoticeActionType
 import org.oppia.android.app.testing.activity.TestActivity
 
 /** [TestActivity] for setting up a test environment for testing the beta notice dialog. */
@@ -24,7 +24,7 @@ class ForcedAppDeprecationNoticeDialogFragmentTestActivity :
       .showNow(supportFragmentManager, "forced_app_deprecation_dialog")
   }
 
-  override fun onActionButtonClicked(noticeType: DeprecationNoticeActionType) {
-    mockCallbackListener.onActionButtonClicked(noticeType)
+  override fun onActionButtonClicked(noticeActionResponse: DeprecationNoticeActionResponse) {
+    mockCallbackListener.onActionButtonClicked(noticeActionResponse)
   }
 }

app/src/main/java/org/oppia/android/app/notice/testing/OptionalAppDeprecationNoticeDialogFragmentTestActivity.kt

@@ -2,8 +2,8 @@ package org.oppia.android.app.notice.testing
 
 import android.os.Bundle
 import org.oppia.android.app.notice.DeprecationNoticeActionListener
+import org.oppia.android.app.notice.DeprecationNoticeActionResponse
 import org.oppia.android.app.notice.OptionalAppDeprecationNoticeDialogFragment
-import org.oppia.android.app.splash.DeprecationNoticeActionType
 import org.oppia.android.app.testing.activity.TestActivity
 
 /** [TestActivity] for setting up a test environment for testing the beta notice dialog. */
@@ -24,7 +24,7 @@ class OptionalAppDeprecationNoticeDialogFragmentTestActivity :
       .showNow(supportFragmentManager, "optional_app_deprecation_dialog")
   }
 
-  override fun onActionButtonClicked(noticeType: DeprecationNoticeActionType) {
-    mockCallbackListener.onActionButtonClicked(noticeType)
+  override fun onActionButtonClicked(noticeActionResponse: DeprecationNoticeActionResponse) {
+    mockCallbackListener.onActionButtonClicked(noticeActionResponse)
   }
 }

app/src/main/java/org/oppia/android/app/notice/testing/OsDeprecationNoticeDialogFragmentTestActivity.kt

@@ -2,8 +2,8 @@ package org.oppia.android.app.notice.testing
 
 import android.os.Bundle
 import org.oppia.android.app.notice.DeprecationNoticeActionListener
+import org.oppia.android.app.notice.DeprecationNoticeActionResponse
 import org.oppia.android.app.notice.OsDeprecationNoticeDialogFragment
-import org.oppia.android.app.splash.DeprecationNoticeActionType
 import org.oppia.android.app.testing.activity.TestActivity
 
 /** [TestActivity] for setting up a test environment for testing the beta notice dialog. */
@@ -24,7 +24,7 @@ class OsDeprecationNoticeDialogFragmentTestActivity :
       .showNow(supportFragmentManager, "os_deprecation_dialog")
   }
 
-  override fun onActionButtonClicked(noticeType: DeprecationNoticeActionType) {
-    mockCallbackListener.onActionButtonClicked(noticeType)
+  override fun onActionButtonClicked(noticeActionResponse: DeprecationNoticeActionResponse) {
+    mockCallbackListener.onActionButtonClicked(noticeActionResponse)
   }
 }

app/src/main/java/org/oppia/android/app/player/exploration/ExplorationActivityPresenter.kt

@@ -397,6 +397,7 @@ class ExplorationActivityPresenter @Inject constructor(
         activity.startActivity(
           TopicActivity.createTopicActivityIntent(context, profileId.internalId, topicId)
         )
+        activity.finish()
       }
     }
   }

app/src/main/java/org/oppia/android/app/player/state/itemviewmodel/ImageRegionSelectionInteractionViewModel.kt

@@ -1,5 +1,6 @@
 package org.oppia.android.app.player.state.itemviewmodel
 
+import androidx.annotation.StringRes
 import androidx.databinding.Observable
 import androidx.databinding.ObservableField
 import org.oppia.android.R
@@ -9,6 +10,7 @@ import org.oppia.android.app.model.Interaction
 import org.oppia.android.app.model.InteractionObject
 import org.oppia.android.app.model.UserAnswer
 import org.oppia.android.app.model.WrittenTranslationContext
+import org.oppia.android.app.player.state.answerhandling.AnswerErrorCategory
 import org.oppia.android.app.player.state.answerhandling.InteractionAnswerErrorOrAvailabilityCheckReceiver
 import org.oppia.android.app.player.state.answerhandling.InteractionAnswerHandler
 import org.oppia.android.app.player.state.answerhandling.InteractionAnswerReceiver
@@ -31,6 +33,9 @@ class ImageRegionSelectionInteractionViewModel private constructor(
 ) : StateItemViewModel(ViewType.IMAGE_REGION_SELECTION_INTERACTION),
   InteractionAnswerHandler,
   OnClickableAreaClickedListener {
+  private var pendingAnswerError: String? = null
+  var errorMessage = ObservableField<String>("")
+  private var isDefaultRegionClicked = false
   var answerText: CharSequence = ""
   val selectableRegions: List<ImageWithRegions.LabeledRegion> by lazy {
     val schemaObject = interaction.customizationArgsMap["imageAndRegions"]
@@ -49,25 +54,58 @@ class ImageRegionSelectionInteractionViewModel private constructor(
       object : Observable.OnPropertyChangedCallback() {
         override fun onPropertyChanged(sender: Observable, propertyId: Int) {
           errorOrAvailabilityCheckReceiver.onPendingAnswerErrorOrAvailabilityCheck(
-            pendingAnswerError = null,
-            inputAnswerAvailable = answerText.isNotEmpty()
+            pendingAnswerError = pendingAnswerError,
+            inputAnswerAvailable = true // Allow blank answer submission.
           )
         }
       }
     isAnswerAvailable.addOnPropertyChangedCallback(callback)
+    errorMessage.addOnPropertyChangedCallback(callback)
+
+    // Initializing with default values so that submit button is enabled by default.
+    errorOrAvailabilityCheckReceiver.onPendingAnswerErrorOrAvailabilityCheck(
+      pendingAnswerError = null,
+      inputAnswerAvailable = true
+    )
   }
 
   override fun onClickableAreaTouched(region: RegionClickedEvent) {
+
     when (region) {
       is DefaultRegionClickedEvent -> {
         answerText = ""
         isAnswerAvailable.set(false)
+        isDefaultRegionClicked = true
       }
       is NamedRegionClickedEvent -> {
         answerText = region.regionLabel
         isAnswerAvailable.set(true)
       }
     }
+    checkPendingAnswerError(AnswerErrorCategory.REAL_TIME)
+  }
+
+  /** It checks the pending error for the current image region input, and correspondingly updates the error string based on the specified error category. */
+  override fun checkPendingAnswerError(category: AnswerErrorCategory): String? {
+    when (category) {
+      AnswerErrorCategory.REAL_TIME -> {
+        pendingAnswerError = null
+      }
+
+      AnswerErrorCategory.SUBMIT_TIME -> {
+        if (answerText.isNotEmpty() || isDefaultRegionClicked) {
+          pendingAnswerError = null
+        } else {
+          pendingAnswerError =
+            ImageRegionParsingUiError.createFromParsingError(
+              getSubmitTimeError(answerText.toString())
+            ).getErrorMessageFromStringRes(resourceHandler)
+        }
+      }
+    }
+
+    errorMessage.set(pendingAnswerError)
+    return pendingAnswerError
   }
 
   override fun getPendingAnswer(): UserAnswer = UserAnswer.newBuilder().apply {
@@ -91,10 +129,60 @@ class ImageRegionSelectionInteractionViewModel private constructor(
       .build()
   }
 
+  /**
+   * Returns [ImageRegionParsingError.EMPTY_INPUT] if input is blank, or
+   * [TextParsingError.VALID] if input is not empty.
+   */
+  fun getSubmitTimeError(text: String): ImageRegionParsingError {
+    if (text.isNullOrBlank()) {
+      return ImageRegionParsingError.EMPTY_INPUT
+    }
+    return ImageRegionParsingError.VALID
+  }
+
+  /** Represents errors that can occur when parsing region name. */
+  enum class ImageRegionParsingError {
+
+    /** Indicates that the considered string is a valid. */
+    VALID,
+
+    /** Indicates that the input text was empty. */
+    EMPTY_INPUT
+  }
+
+  enum class ImageRegionParsingUiError(@StringRes private var error: Int?) {
+    /** Corresponds to [ImageRegionParsingError.VALID]. */
+    VALID(error = null),
+
+    /** Corresponds to [ImageRegionParsingError.EMPTY_INPUT]. */
+    EMPTY_INPUT(error = R.string.image_error_empty_input);
+
+    /**
+     * Returns the string corresponding to this error's string resources, or null if there is none.
+     */
+    fun getErrorMessageFromStringRes(resourceHandler: AppLanguageResourceHandler): String? =
+      error?.let(resourceHandler::getStringInLocale)
+
+    companion object {
+      /**
+       * Returns the [ImageRegionParsingUiError] corresponding to the specified [ImageRegionParsingError].
+       */
+      fun createFromParsingError(parsingError: ImageRegionParsingError): ImageRegionParsingUiError {
+        return when (parsingError) {
+
+          ImageRegionParsingError.VALID -> VALID
+
+          ImageRegionParsingError.EMPTY_INPUT -> EMPTY_INPUT
+        }
+      }
+    }
+  }
+
   /** Implementation of [StateItemViewModel.InteractionItemFactory] for this view model. */
   class FactoryImpl @Inject constructor(
     private val resourceHandler: AppLanguageResourceHandler
   ) : InteractionItemFactory {
+
     override fun create(
       entityId: String,
       hasConversationView: Boolean,