Fix oppia#5404: Migrate away from onBackPressed for remaining activit…

…ies (oppia#5526)

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## Explanation
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 Fixes oppia#5404 

This PR migrates deprecated `onBackPressed` usage to
`OnBackPressedDispatcher` callback in the following activities and
presenters.

- ProfileEditActivity
- ProfileEditActivityPresenter
- QuestionPlayerActivityPresenter
- WalkthroughFinalFragmentPresenter

## Essential Checklist
<!-- Please tick the relevant boxes by putting an "x" in them. -->
- [x] The PR title and explanation each start with "Fix #bugnum: " (If
this PR fixes part of an issue, prefix the title with "Fix part of
#bugnum: ...".)
- [x] Any changes to
[scripts/assets](https://github.com/oppia/oppia-android/tree/develop/scripts/assets)
files have their rationale included in the PR explanation.
- [x] The PR follows the [style
guide](https://github.com/oppia/oppia-android/wiki/Coding-style-guide).
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Studio
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#undo-unnecessary-changes)).
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is up-to-date with "develop".
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---------

Co-authored-by: Adhiambo Peres <[email protected]>
Co-authored-by: Mr. 17 <[email protected]>

app/src/main/java/org/oppia/android/app/settings/profile/ProfileEditActivity.kt

@@ -3,6 +3,7 @@ package org.oppia.android.app.settings.profile
 import android.content.Context
 import android.content.Intent
 import android.os.Bundle
+import androidx.activity.OnBackPressedCallback
 import org.oppia.android.app.activity.ActivityComponentImpl
 import org.oppia.android.app.activity.InjectableAutoLocalizedAppCompatActivity
 import org.oppia.android.app.model.ProfileEditActivityParams
@@ -43,17 +44,25 @@ class ProfileEditActivity : InjectableAutoLocalizedAppCompatActivity() {
     super.onCreate(savedInstanceState)
     (activityComponent as ActivityComponentImpl).inject(this)
     profileEditActivityPresenter.handleOnCreate()
+
+    onBackPressedDispatcher.addCallback(
+      this,
+      object : OnBackPressedCallback(/* enabled = */ true) {
+        override fun handleOnBackPressed() {
+          this@ProfileEditActivity.handleBackPress()
+        }
+      }
+    )
   }
 
-  override fun onBackPressed() {
+  private fun handleBackPress() {
     val args = intent.getProtoExtra(
       PROFILE_EDIT_ACTIVITY_PARAMS_KEY,
       ProfileEditActivityParams.getDefaultInstance()
     )
     val isMultipane = args?.isMultipane ?: false
     if (isMultipane) {
-      @Suppress("DEPRECATION") // TODO(#5404): Migrate to a back pressed dispatcher.
-      super.onBackPressed()
+      finish()
     } else {
       val intent = Intent(this, ProfileListActivity::class.java)
       intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)

app/src/main/java/org/oppia/android/app/settings/profile/ProfileEditActivityPresenter.kt

@@ -31,8 +31,7 @@ class ProfileEditActivityPresenter @Inject constructor(
 
     toolbar.setNavigationOnClickListener {
       if (isMultipane) {
-        @Suppress("DEPRECATION") // TODO(#5404): Migrate to a back pressed dispatcher.
-        activity.onBackPressed()
+        activity.onBackPressedDispatcher.onBackPressed()
       } else {
         val intent = Intent(activity, ProfileListActivity::class.java)
         intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)

app/src/main/java/org/oppia/android/app/topic/questionplayer/QuestionPlayerActivity.kt

@@ -3,6 +3,7 @@ package org.oppia.android.app.topic.questionplayer
 import android.content.Context
 import android.content.Intent
 import android.os.Bundle
+import androidx.activity.OnBackPressedCallback
 import org.oppia.android.app.activity.ActivityComponentImpl
 import org.oppia.android.app.activity.InjectableAutoLocalizedAppCompatActivity
 import org.oppia.android.app.hintsandsolution.HintsAndSolutionListener
@@ -56,11 +57,16 @@ class QuestionPlayerActivity :
     val profileId =
       intent.extractCurrentUserProfileId()
     questionPlayerActivityPresenter.handleOnCreate(profileId)
-  }
 
-  override fun onBackPressed() {
-    showStopExplorationDialogFragment()
-    questionPlayerActivityPresenter.setReadingTextSizeNormal()
+    onBackPressedDispatcher.addCallback(
+      this,
+      object : OnBackPressedCallback(/* enabled = */ true) {
+        override fun handleOnBackPressed() {
+          showStopExplorationDialogFragment()
+          questionPlayerActivityPresenter.setReadingTextSizeNormal()
+        }
+      }
+    )
   }
 
   override fun restartSession() = questionPlayerActivityPresenter.restartSession()

app/src/main/java/org/oppia/android/app/topic/questionplayer/QuestionPlayerActivityPresenter.kt

@@ -61,8 +61,7 @@ class QuestionPlayerActivityPresenter @Inject constructor(
     activity.setSupportActionBar(binding.questionPlayerToolbar)
 
     binding.questionPlayerToolbar.setNavigationOnClickListener {
-      @Suppress("DEPRECATION") // TODO(#5404): Migrate to a back pressed dispatcher.
-      activity.onBackPressed()
+      activity.onBackPressedDispatcher.onBackPressed()
     }
 
     retrieveReadingTextSize().observe(

app/src/main/java/org/oppia/android/app/walkthrough/WalkthroughActivity.kt

@@ -3,6 +3,7 @@ package org.oppia.android.app.walkthrough
 import android.content.Context
 import android.content.Intent
 import android.os.Bundle
+import androidx.activity.OnBackPressedCallback
 import org.oppia.android.app.activity.ActivityComponentImpl
 import org.oppia.android.app.activity.InjectableAutoLocalizedAppCompatActivity
 import org.oppia.android.app.model.ProfileId
@@ -22,6 +23,15 @@ class WalkthroughActivity :
     super.onCreate(savedInstanceState)
     (activityComponent as ActivityComponentImpl).inject(this)
     walkthroughActivityPresenter.handleOnCreate()
+
+    onBackPressedDispatcher.addCallback(
+      this,
+      object : OnBackPressedCallback(/* enabled = */ true) {
+        override fun handleOnBackPressed() {
+          walkthroughActivityPresenter.handleSystemBack()
+        }
+      }
+    )
   }
 
   override fun currentPage(walkthroughPage: Int) {
@@ -33,10 +43,6 @@ class WalkthroughActivity :
     walkthroughActivityPresenter.changePage(walkthroughPage)
   }
 
-  override fun onBackPressed() {
-    walkthroughActivityPresenter.handleSystemBack()
-  }
-
   companion object {
 
     fun createWalkthroughActivityIntent(context: Context, internalProfileId: Int): Intent {

app/src/main/java/org/oppia/android/app/walkthrough/end/WalkthroughFinalFragmentPresenter.kt

@@ -103,7 +103,6 @@ class WalkthroughFinalFragmentPresenter @Inject constructor(
   }
 
   override fun goBack() {
-    @Suppress("DEPRECATION") // TODO(#5404): Migrate to a back pressed dispatcher.
-    activity.onBackPressed()
+    activity.onBackPressedDispatcher.onBackPressed()
   }
 }