Fix Part of #4938: Introduce New App Language Selection Screen for on…

…boarding (#5373)

<!-- READ ME FIRST: Please fill in the explanation section below and
check off every point from the Essential Checklist! -->
## Explanation
Fixes Part of #4938: Introuduces new app language selection screen.

This PR introduces the layout files and the presenter for displaying the
language functionality, along with associated test cases.

I have modified the custom view `SurveyOnboardingBackgroundView` to make
it generic and reusable in the new layouts.

These changes include both darkmode support and alternate screen size
and orientation layouts, as per figma mocks.

## 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).
- [x] The PR does not contain any unnecessary code changes from Android
Studio
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#undo-unnecessary-changes)).
- [x] The PR is made from a branch that's **not** called "develop" and
is up-to-date with "develop".
- [x] The PR is **assigned** to the appropriate reviewers
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#clarification-regarding-assignees-and-reviewers-section)).

## For UI-specific PRs only
||||
|--- |---|---|
||Lightmode Portrait|Darkmode & Landscape|
|Mobile
**xxhdpi**|![Screenshot_1711564671](https://github.com/oppia/oppia-android/assets/59600948/7399cad6-709c-4aa0-a2e8-5c2aeceb36d7)|![Screenshot_1712156819](https://github.com/oppia/oppia-android/assets/59600948/b6cace78-28ed-452a-b5d2-c8ce1e0e2567)|
|Mobile
**mdpi**|![Screenshot_1712156777](https://github.com/oppia/oppia-android/assets/59600948/3ce79b76-f8d0-44e2-ac2f-329c2cc9f598)|![Screenshot_1712156762](https://github.com/oppia/oppia-android/assets/59600948/0c0cba3f-8d5c-4aa6-9fab-7b902de08a0e)|
|Tablet
**xxhdpi**|![Screenshot_1711554842](https://github.com/oppia/oppia-android/assets/59600948/58ac2b67-ecec-439e-91f4-dc1dde2f2918)|![Screenshot_1712151724](https://github.com/oppia/oppia-android/assets/59600948/c8eafa6a-8550-449b-a79d-76ec961c24bc)|
|Tablet
**hdpi**|![Screenshot_1711563235](https://github.com/oppia/oppia-android/assets/59600948/4e4ae865-1e8c-4f8f-879e-8a46fe795ab4)|![Screenshot_1712151535](https://github.com/oppia/oppia-android/assets/59600948/52d07d1a-5146-41ce-b4da-597e22c4a529)|

app/BUILD.bazel

@@ -408,9 +408,9 @@ VIEWS_WITH_RESOURCE_IMPORTS = [
     "src/main/java/org/oppia/android/app/customview/ChapterNotStartedContainerConstraintLayout.kt",
     "src/main/java/org/oppia/android/app/customview/ContinueButtonView.kt",
     "src/main/java/org/oppia/android/app/customview/LessonThumbnailImageView.kt",
+    "src/main/java/org/oppia/android/app/customview/OppiaCurveBackgroundView.kt",
     "src/main/java/org/oppia/android/app/customview/PromotedStoryCardView.kt",
     "src/main/java/org/oppia/android/app/customview/SegmentedCircularProgressView.kt",
-    "src/main/java/org/oppia/android/app/customview/SurveyOnboardingBackgroundView.kt",
     "src/main/java/org/oppia/android/app/customview/VerticalDashedLineView.kt",
     "src/main/java/org/oppia/android/app/survey/SurveyMultipleChoiceOptionView.kt",
     "src/main/java/org/oppia/android/app/survey/SurveyNpsItemOptionView.kt",
@@ -485,6 +485,7 @@ BINDING_ADAPTERS_WITH_RESOURCE_IMPORTS = [
 BINDING_ADAPTERS = [
     "src/main/java/org/oppia/android/app/databinding/AppCompatCheckBoxBindingAdapters.java",
     "src/main/java/org/oppia/android/app/databinding/CircularProgressIndicatorAdapters.java",
+    "src/main/java/org/oppia/android/app/databinding/ColorBindingAdapters.java",
     "src/main/java/org/oppia/android/app/databinding/ConstraintLayoutAdapters.java",
     "src/main/java/org/oppia/android/app/databinding/EditTextBindingAdapters.java",
     "src/main/java/org/oppia/android/app/databinding/GuidelineBindingAdapters.java",

app/src/main/AndroidManifest.xml

@@ -329,6 +329,9 @@
       android:label="@string/survey_activity_title"
       android:theme="@style/OppiaThemeWithoutActionBar"
       android:windowSoftInputMode="adjustNothing" />
+    <activity
+      android:name=".app.testing.ColorBindingAdaptersTestActivity"
+      android:theme="@style/OppiaThemeWithoutActionBar" />
 
     <provider
       android:name="androidx.work.impl.WorkManagerInitializer"

app/src/main/java/org/oppia/android/app/activity/ActivityComponentImpl.kt

@@ -59,6 +59,7 @@ import org.oppia.android.app.testing.AdministratorControlsFragmentTestActivity
 import org.oppia.android.app.testing.AppCompatCheckBoxBindingAdaptersTestActivity
 import org.oppia.android.app.testing.AudioFragmentTestActivity
 import org.oppia.android.app.testing.CircularProgressIndicatorAdaptersTestActivity
+import org.oppia.android.app.testing.ColorBindingAdaptersTestActivity
 import org.oppia.android.app.testing.ConceptCardFragmentTestActivity
 import org.oppia.android.app.testing.DragDropTestActivity
 import org.oppia.android.app.testing.DrawableBindingAdaptersTestActivity
@@ -216,4 +217,5 @@ interface ActivityComponentImpl :
   fun inject(viewEventLogsTestActivity: ViewEventLogsTestActivity)
   fun inject(walkthroughActivity: WalkthroughActivity)
   fun inject(surveyActivity: SurveyActivity)
+  fun inject(colorBindingAdaptersTestActivity: ColorBindingAdaptersTestActivity)
 }

app/src/main/java/org/oppia/android/app/customview/SurveyOnboardingBackgroundView.kt → app/src/main/java/org/oppia/android/app/customview/OppiaCurveBackgroundView.kt

@@ -1,50 +1,54 @@
 package org.oppia.android.app.customview
 
 import android.content.Context
+import android.content.res.Configuration
+import android.content.res.Resources
 import android.graphics.Canvas
 import android.graphics.Color
 import android.graphics.Paint
 import android.graphics.Path
 import android.util.AttributeSet
 import android.view.View
-import androidx.core.content.ContextCompat
 import androidx.core.view.ViewCompat
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentManager
-import org.oppia.android.R
 import org.oppia.android.app.translation.AppLanguageResourceHandler
 import org.oppia.android.app.view.ViewComponentFactory
 import org.oppia.android.app.view.ViewComponentImpl
 import javax.inject.Inject
 
 /**
- * CustomView to add a background to [SurveyWelcomeDialogFragment] and [SurveyOutroDialogFragment].
- * Without chaptersFinished and totalChapters values this custom-view cannot be created.
+ * CustomView to add a background to views that require a bezier curve background.
  *
  * Reference: // https://proandroiddev.com/how-i-drew-custom-shapes-in-bottom-bar-c4539d86afd7 and
  * // https://ciechanow.ski/drawing-bezier-curves/
  */
-class SurveyOnboardingBackgroundView : View {
-  @Inject
-  lateinit var resourceHandler: AppLanguageResourceHandler
+class OppiaCurveBackgroundView @JvmOverloads constructor(
+  context: Context,
+  attrs: AttributeSet? = null,
+  defStyleAttr: Int = 0
+) : View(context, attrs, defStyleAttr) {
+  /**
+   * Used to retrieve the layout direction that should be used to mirror the direction of the
+   * curve based on locale.
+   */
+  @Inject lateinit var resourceHandler: AppLanguageResourceHandler
 
   private val isRtl by lazy {
     resourceHandler.getLayoutDirection() == ViewCompat.LAYOUT_DIRECTION_RTL
   }
 
+  private val orientation = Resources.getSystem().configuration.orientation
+
+  private var customBackgroundColor = Color.WHITE // Default color.
+
   private lateinit var paint: Paint
   private lateinit var path: Path
   private var strokeWidth = 2f
 
-  constructor(context: Context) : super(context)
-  constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
-  constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(
-    context,
-    attrs,
-    defStyleAttr
-  )
-
-  init {
+  /** Sets the desired background color to the view and initializes the view. */
+  fun setCustomBackgroundColor(colorRes: Int) {
+    this.customBackgroundColor = colorRes
     setupCurvePaint()
   }
 
@@ -61,17 +65,37 @@ class SurveyOnboardingBackgroundView : View {
     val width = this.width.toFloat()
     val height = this.height.toFloat()
 
-    val controlPoint1X = width * 0.5f
-    val controlPoint1Y = 0f
-
-    val controlPoint2X = width * 0.5f
-    val controlPoint2Y = height * 0.2f
-
-    val controlPoint3X = width * 1f
-    val controlPoint3Y = height * 0.1f
+    val controlPoint1X: Float
+    val controlPoint1Y: Float
+
+    val controlPoint2X: Float
+    val controlPoint2Y: Float
+
+    val controlPoint3X: Float
+    val controlPoint3Y: Float
+
+    if (orientation == Configuration.ORIENTATION_PORTRAIT) {
+      controlPoint1X = width * 0.55f
+      controlPoint1Y = 0f
+      controlPoint2X = width * 0.52f
+      controlPoint2Y = height * 0.2f
+      controlPoint3X = width * 1f
+      controlPoint3Y = height * 0.1f
+    } else {
+      controlPoint1X = width * 0.40f
+      controlPoint1Y = 0f
+      controlPoint2X = width * 0.60f
+      controlPoint2Y = height * 0.40f
+      controlPoint3X = width * 1f
+      controlPoint3Y = height * 0.2f
+    }
 
     path.reset()
-    path.moveTo(0f, height * 0.1f)
+    if (orientation == Configuration.ORIENTATION_PORTRAIT) {
+      path.moveTo(0f, height * 0.10f)
+    } else {
+      path.moveTo(0f, height * 0.30f)
+    }
     path.cubicTo(
       controlPoint1X,
       controlPoint1Y,
@@ -90,12 +114,9 @@ class SurveyOnboardingBackgroundView : View {
     path = Path()
     paint = Paint(Paint.ANTI_ALIAS_FLAG)
     paint.apply {
-      style = Paint.Style.FILL_AND_STROKE
-      strokeWidth = this@SurveyOnboardingBackgroundView.strokeWidth
-      color = ContextCompat.getColor(
-        context,
-        R.color.component_color_survey_popup_background_color
-      )
+      style = Paint.Style.FILL
+      strokeWidth = this@OppiaCurveBackgroundView.strokeWidth
+      color = customBackgroundColor
     }
     setBackgroundColor(Color.TRANSPARENT)
   }

app/src/main/java/org/oppia/android/app/databinding/ColorBindingAdapters.java

@@ -0,0 +1,14 @@
+package org.oppia.android.app.databinding;
+
+import android.view.View;
+import androidx.databinding.BindingAdapter;
+
+/** Holds all custom binding adapters that set color values. */
+public final class ColorBindingAdapters {
+
+  /** Binding adapter for setting the `customBackgroundColor` for a [View]. */
+  @BindingAdapter("customBackgroundColor")
+  public static void setCustomBackgroundColor(View view, int color) {
+    view.setBackgroundColor(color);
+  }
+}

app/src/main/java/org/oppia/android/app/onboarding/OnboardingFragment.kt

@@ -7,13 +7,22 @@ import android.view.View
 import android.view.ViewGroup
 import org.oppia.android.app.fragment.FragmentComponentImpl
 import org.oppia.android.app.fragment.InjectableFragment
+import org.oppia.android.util.platformparameter.EnableOnboardingFlowV2
+import org.oppia.android.util.platformparameter.PlatformParameterValue
 import javax.inject.Inject
 
 /** Fragment that contains an onboarding flow of the app. */
 class OnboardingFragment : InjectableFragment() {
+  @Inject
+  lateinit var onboardingFragmentPresenterV1: OnboardingFragmentPresenterV1
+
   @Inject
   lateinit var onboardingFragmentPresenter: OnboardingFragmentPresenter
 
+  @Inject
+  @field:EnableOnboardingFlowV2
+  lateinit var enableOnboardingFlowV2: PlatformParameterValue<Boolean>
+
   override fun onAttach(context: Context) {
     super.onAttach(context)
     (fragmentComponent as FragmentComponentImpl).inject(this)
@@ -24,6 +33,10 @@ class OnboardingFragment : InjectableFragment() {
     container: ViewGroup?,
     savedInstanceState: Bundle?
   ): View? {
-    return onboardingFragmentPresenter.handleCreateView(inflater, container)
+    return if (enableOnboardingFlowV2.value) {
+      onboardingFragmentPresenter.handleCreateView(inflater, container)
+    } else {
+      onboardingFragmentPresenterV1.handleCreateView(inflater, container)
+    }
   }
 }